1. The document discusses the development of base station antennas for mobile communications. It covers the history and trends, basic technologies, and major technical specifications for BS antenna design.
2. The impacts of antenna parameters like lobe, downtilt, and isolation on cell coverage and frequency reuse are addressed. Key antenna technologies include shaped beam, diversity, and suppression of passive intermodulation are presented.
3. The document serves as an overview of BS antennas for readers to understand their role in mobile telecommunications networks and the considerations in antenna design.
The document discusses various parameters used in LTE drive testing including:
- RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, and throughput which provide information on signal strength, quality, and performance. Phone-based drive testing allows monitoring of these parameters and correlation with data performance. MIMO and handovers between LTE and other technologies can also be evaluated. Key metrics include coverage, capacity, and end-user experience.
2.6 cellular concepts - frequency reusing, channel assignmentJAIGANESH SEKAR
- Cellular networks address the problem of limited spectrum availability by using frequency reuse, where nearby base stations are assigned different channels to avoid interference. Cells are arranged in a hexagonal pattern and the same set of channels are reused in cells sufficiently far from each other.
- There are two main channel assignment strategies - fixed assignment, where each cell has a predetermined set of channels, and dynamic assignment, where channels are allocated on demand by a central controller considering interference levels. Dynamic assignment helps improve spectrum utilization but requires more complex coordination.
- Frequency reuse allows the available spectrum to be reused as needed across multiple cells as long as interference is kept at acceptable levels, increasing network capacity.
Hata model + youngs model + okumara model summarizadKhalid Ali
The document discusses several radio propagation models used for predicting signal behavior in different environments:
1. The Hata model is based on the Okumura model and has separate models for urban, suburban, and open areas. The urban Hata model is most widely used for built up areas.
2. Mathematical formulations are provided for path loss prediction using the Hata model for various environments. Frequency range is 150-1500 MHz.
3. The Young model is based on data from New York City and models signal behavior in large cities with tall structures. Frequency range is 150 MHz to 3700 MHz.
4. The Okumura model was developed using data from Tokyo and serves as the basis for the
M-ary encoding allows for digital signals with multiple possible conditions or voltage levels through the use of multiple binary variables. The number of conditions possible is represented by M, while the number of bits needed to produce those conditions is given by the logarithmic relationship N = log2M. M-ary PSK and M-ary QAM are two common types of M-ary encoding. M-ary PSK varies the phase of a carrier signal, while M-ary QAM varies both the amplitude and phase, allowing for greater power efficiency but identical bandwidth efficiency as M-ary PSK. Both modulation schemes use a constellation diagram to represent the multiple symbol states.
This document discusses multiple-input multiple-output (MIMO) systems. It begins by outlining the motivations and aspirations for developing MIMO systems, including achieving high data rates near 1 gigabit/second while maintaining quality of service. It then provides an overview of MIMO system modeling and capacity studies. Key topics covered include diversity versus spatial multiplexing design criteria, example architectures, MIMO with orthogonal frequency-division multiplexing, and networking applications involving MAC protocols.
MicroStrip Antenna
Introduction .
Micro-Strip Antennas Types .
Micro-Strip Antennas Shapes .
Types of Substrates (Dielectric Media) .
Comparison of various types of flat profile printed antennas .
Advantages & DisAdvantages of MSAs .
Applications of MSAs .
Radiation patterns of MSAs .
How to Optimizing the Substrate Properties for Increased Bandwidth ?
Comparing the different feed techniques .
This document discusses different techniques for achieving diversity in wireless communications and combining received signals:
1. Selection diversity techniques select the strongest signal from multiple antennas, either based on received signal strength (RSSI) or bit error rate (BER). Combining diversity techniques combine all received signals.
2. Combining diversity techniques include maximal ratio combining (MRC), which weights signals by amplitude, and equal gain combining (EGC), which weights all signals equally after phase correction. MRC achieves better performance than EGC when signals are highly faded.
3. The document compares the advantages and disadvantages of different selection criteria and combining techniques. It also describes switched and feedback selection diversity approaches.
The document discusses various parameters used in LTE drive testing including:
- RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, and throughput which provide information on signal strength, quality, and performance. Phone-based drive testing allows monitoring of these parameters and correlation with data performance. MIMO and handovers between LTE and other technologies can also be evaluated. Key metrics include coverage, capacity, and end-user experience.
2.6 cellular concepts - frequency reusing, channel assignmentJAIGANESH SEKAR
- Cellular networks address the problem of limited spectrum availability by using frequency reuse, where nearby base stations are assigned different channels to avoid interference. Cells are arranged in a hexagonal pattern and the same set of channels are reused in cells sufficiently far from each other.
- There are two main channel assignment strategies - fixed assignment, where each cell has a predetermined set of channels, and dynamic assignment, where channels are allocated on demand by a central controller considering interference levels. Dynamic assignment helps improve spectrum utilization but requires more complex coordination.
- Frequency reuse allows the available spectrum to be reused as needed across multiple cells as long as interference is kept at acceptable levels, increasing network capacity.
Hata model + youngs model + okumara model summarizadKhalid Ali
The document discusses several radio propagation models used for predicting signal behavior in different environments:
1. The Hata model is based on the Okumura model and has separate models for urban, suburban, and open areas. The urban Hata model is most widely used for built up areas.
2. Mathematical formulations are provided for path loss prediction using the Hata model for various environments. Frequency range is 150-1500 MHz.
3. The Young model is based on data from New York City and models signal behavior in large cities with tall structures. Frequency range is 150 MHz to 3700 MHz.
4. The Okumura model was developed using data from Tokyo and serves as the basis for the
M-ary encoding allows for digital signals with multiple possible conditions or voltage levels through the use of multiple binary variables. The number of conditions possible is represented by M, while the number of bits needed to produce those conditions is given by the logarithmic relationship N = log2M. M-ary PSK and M-ary QAM are two common types of M-ary encoding. M-ary PSK varies the phase of a carrier signal, while M-ary QAM varies both the amplitude and phase, allowing for greater power efficiency but identical bandwidth efficiency as M-ary PSK. Both modulation schemes use a constellation diagram to represent the multiple symbol states.
This document discusses multiple-input multiple-output (MIMO) systems. It begins by outlining the motivations and aspirations for developing MIMO systems, including achieving high data rates near 1 gigabit/second while maintaining quality of service. It then provides an overview of MIMO system modeling and capacity studies. Key topics covered include diversity versus spatial multiplexing design criteria, example architectures, MIMO with orthogonal frequency-division multiplexing, and networking applications involving MAC protocols.
MicroStrip Antenna
Introduction .
Micro-Strip Antennas Types .
Micro-Strip Antennas Shapes .
Types of Substrates (Dielectric Media) .
Comparison of various types of flat profile printed antennas .
Advantages & DisAdvantages of MSAs .
Applications of MSAs .
Radiation patterns of MSAs .
How to Optimizing the Substrate Properties for Increased Bandwidth ?
Comparing the different feed techniques .
This document discusses different techniques for achieving diversity in wireless communications and combining received signals:
1. Selection diversity techniques select the strongest signal from multiple antennas, either based on received signal strength (RSSI) or bit error rate (BER). Combining diversity techniques combine all received signals.
2. Combining diversity techniques include maximal ratio combining (MRC), which weights signals by amplitude, and equal gain combining (EGC), which weights all signals equally after phase correction. MRC achieves better performance than EGC when signals are highly faded.
3. The document compares the advantages and disadvantages of different selection criteria and combining techniques. It also describes switched and feedback selection diversity approaches.
The document discusses different channel assignment strategies for wireless networks, including fixed channel assignment where each cell is predetermined channels and dynamic channel assignment where channels are allocated on request based on factors like channel occupancy. It also describes a partially overlapping channel (FPOC) assignment strategy that aims to increase capacity while minimizing interference through intelligent channel allocation between neighboring nodes.
Its exploring the technique for spatially successive interference cancellation and superposition of transmission for upcoming radio communication 5G technology.
This document discusses scattering matrices (S-parameters) which relate the incoming and outgoing wave amplitudes at the ports of a network. It provides definitions and formulations for S-parameters, including that an S-matrix is a square matrix that describes the scattering properties of passive, linear, and time-invariant microwave networks. Key advantages of S-parameters are that matched loads are used, eliminating termination effects, and power can be easily measured at high frequencies. Loss factors like return loss, insertion loss, transmission loss, and reflection loss are also defined in terms of S-parameters.
Mobile Communication Academic Assignment
For B.Tech Electronics and Communication Engineering 7th Semester
Index:
1. Introduction
2. Techniques
3. Schemes
4. History
5. Digital an Analog Beamforming
6. Difference between Digital and Analog Beamforming
7. Analog Beamforming Working
8. Digital Beamforming Working with receiver and transmitter
9. Digital Beamforming Challenges with receiver and transmitter
10. Solutions to the Challenges
11. For Speech Audio
Source: Wikipedia, Research Papers etc
Global system for mobile communication Introduction, GSM architecture, GSM interfaces, Signal processing in GSM,
Frame structure of GSM, Channels used in GSM
The document discusses digital communication systems and outlines topics that will be covered, including digital data communication, multiplexing techniques, digital modulation and demodulation, and performance comparisons of modulation schemes. The objectives are to provide an overview of communication systems and concepts, discuss digital transmission methods and modulation types, and enable students to design simple communication systems and discuss industry trends.
Orthogonal Frequency Division Multiplexing (OFDM)Gagan Randhawa
The document discusses Orthogonal Frequency Division Multiplexing (OFDM), including its principles, advantages, disadvantages and applications. OFDM divides the available spectrum into multiple orthogonal subcarriers, each modulated with a low data rate stream. This makes OFDM robust to multipath fading and intersymbol interference. While OFDM provides high data rates and spectral efficiency, it suffers from issues like high peak-to-average power ratio and sensitivity to frequency errors. OFDM is used in technologies like WiFi, WiMAX and digital audio/video broadcasting.
The document discusses parameters for planning and designing line-of-sight microwave communication links, including path loss calculations. It covers topics like survey requirements, link budget calculations, transmission concepts, tower heights, earth bulge, fresnel zones, frequency assignments and limitations of line-of-sight systems. Key aspects addressed include determining tower heights to clear obstructions along the signal path based on factors like frequency, distance, earth curvature and fresnel zone radius.
Optical networking technologies provide high-speed, high-bandwidth data transmission over long distances using fiber optic cables. Key technologies include passive optical networks (PON) for access networks, SONET/SDH for metro networks, and dense wavelength division multiplexing (DWDM) for long-haul transport networks. DWDM works by transmitting multiple optical signals simultaneously on different wavelengths over the same fiber, vastly increasing network capacity. Proper layer-2 encapsulation is required to transport layer-3 protocols like IP over DWDM.
A Practical Look At Lte Backhaul Capacity RequirementsWi-Fi 360
This document discusses the backhaul capacity requirements for LTE networks. It notes that average data consumption per user is over 10 GB per month in some markets. LTE sites require peak downlink capacities of 50-100 Mbps for 10 MHz networks and 100-200 Mbps for 20 MHz networks. Microwave backhaul can meet these needs through statistical multiplexing and bringing aggregation points closer to cell sites. Most major LTE operators in Europe rely on fiber backhaul where available but also utilize microwave, while North American operators use a mix of fiber and microwave backhaul.
MIMO uses multiple antennas at both the transmitter and receiver to improve wireless communication performance. It takes advantage of multipath propagation by using spatial diversity or spatial multiplexing. With spatial diversity, the same information is transmitted from different antennas to improve reliability and coverage. With spatial multiplexing, different data streams are transmitted from different antennas to increase data rates. MIMO can significantly increase capacity, quality, and spectral efficiency compared to single-input systems. It is used in technologies like 3G, 4G, and will be important for 5G networks.
This chapter provides an overview of fundamental antenna concepts and properties including polarization, radiation pattern, gain, bandwidth, and voltage standing wave ratio (VSWR). It then discusses microstrip patch antennas, including their structure and advantages. Finally, it introduces metamaterials and defected ground structures (DGS), which can be used to reduce antenna size by providing a negative refractive index substrate. The chapter establishes the background knowledge needed to understand the goals of developing a miniaturized antenna using metamaterial substrates with DGS.
This document provides information about designing a microwave link between two sites in Pakistan for a semester project. It includes:
1) Details of the two sites and student information.
2) An introduction explaining microwave radio relay technology and how it is used to transmit signals over long distances using line-of-sight paths.
3) Technical explanations of key concepts in microwave communication systems like frequency, wavelength, free space loss, antenna gain, and how they relate to designing an optimal microwave link.
The document provides an overview of MIMO (multiple-input multiple-output) systems in wireless communications. It discusses how MIMO can provide array gain, diversity gain, and multiplexing gain to improve spectral efficiency, coverage, and quality of service. It also describes how MIMO reduces co-channel interference. The document covers MIMO channel models and capacity results for different scenarios. It concludes by discussing how MIMO can be used to maximize diversity or throughput through different transmission techniques.
This document provides an overview of GSM principles and network structure. It discusses key aspects of the GSM system including frequency reuse, multiple access techniques, network components, numbering plans and identifiers. The objectives are to understand the GSM system, its structure, protocols, channel combinations, radio techniques and the introduction of GPRS and EDGE. It contains detailed descriptions and illustrations of concepts such as cells, frequency division duplexing, time division multiple access, frequency planning and network interfaces.
This document summarizes key propagation models including Okumura, Hata, and COST231 models. It describes the models' parameters and equations. The Okumura model is empirical and based on extensive measurements in Japan. It accounts for factors like frequency, distance, and antenna heights. The Hata and COST231 models extend Okumura's validity to other frequencies and environments through curve-fitting. The document also explains how to extract data from the models' graphs using a web tool and simulate the models in MATLAB.
This document discusses carrier aggregation (CA) and the challenges it poses for LTE Advanced user equipment. It describes how CA works by aggregating multiple component carriers to provide bandwidths up to 100MHz. It also discusses the new requirements for cross isolation between transmit and receive bands of at least 50dB. Additionally, it covers various inter-band and intra-band challenges like higher peak-to-average power ratios, increased harmonic distortion, and intermodulation products. Finally, it presents different architectural options for implementing CA including separate antennas, switches, diplexers and multiplexers.
The document discusses beamforming antennas and their applications. It begins by outlining beamforming concepts and configurations like phased arrays and adaptive arrays. It then discusses applications of beamforming antennas in areas like radar, sonar, communications and imaging. Specific examples covered include phased array radar, neuronal spike sorting, and smart antenna systems for wireless networks. Vector antennas and their advantages over phased arrays are also summarized. Finally, the document discusses potential uses and challenges of beamforming antennas for wireless ad hoc networks.
This presentation gives an insight about various antennas that were in use in cell phones and are being used in today's smartphones. Images of various phone models showing antenna used are included to give pictorial view of internal antennas
This document discusses different types of antennas used in mobile devices. It begins by introducing antennas and their roles in transmitting and receiving electromagnetic waves. There are several key parameters discussed for antennas including bandwidth, gain, effective area, radiation pattern, impedance, efficiency, and polarization. The main types of antennas covered are isotropic antennas, which radiate equally in all directions; directional antennas, which radiate more effectively in one direction; and omnidirectional antennas, which radiate in all directions except the azimuth plane. The document focuses on different antenna types used specifically for mobiles, including roof mounted antennas, glass mounted antennas, high gain antennas, and various space diversity antennas oriented horizontally or vertically.
The document discusses different channel assignment strategies for wireless networks, including fixed channel assignment where each cell is predetermined channels and dynamic channel assignment where channels are allocated on request based on factors like channel occupancy. It also describes a partially overlapping channel (FPOC) assignment strategy that aims to increase capacity while minimizing interference through intelligent channel allocation between neighboring nodes.
Its exploring the technique for spatially successive interference cancellation and superposition of transmission for upcoming radio communication 5G technology.
This document discusses scattering matrices (S-parameters) which relate the incoming and outgoing wave amplitudes at the ports of a network. It provides definitions and formulations for S-parameters, including that an S-matrix is a square matrix that describes the scattering properties of passive, linear, and time-invariant microwave networks. Key advantages of S-parameters are that matched loads are used, eliminating termination effects, and power can be easily measured at high frequencies. Loss factors like return loss, insertion loss, transmission loss, and reflection loss are also defined in terms of S-parameters.
Mobile Communication Academic Assignment
For B.Tech Electronics and Communication Engineering 7th Semester
Index:
1. Introduction
2. Techniques
3. Schemes
4. History
5. Digital an Analog Beamforming
6. Difference between Digital and Analog Beamforming
7. Analog Beamforming Working
8. Digital Beamforming Working with receiver and transmitter
9. Digital Beamforming Challenges with receiver and transmitter
10. Solutions to the Challenges
11. For Speech Audio
Source: Wikipedia, Research Papers etc
Global system for mobile communication Introduction, GSM architecture, GSM interfaces, Signal processing in GSM,
Frame structure of GSM, Channels used in GSM
The document discusses digital communication systems and outlines topics that will be covered, including digital data communication, multiplexing techniques, digital modulation and demodulation, and performance comparisons of modulation schemes. The objectives are to provide an overview of communication systems and concepts, discuss digital transmission methods and modulation types, and enable students to design simple communication systems and discuss industry trends.
Orthogonal Frequency Division Multiplexing (OFDM)Gagan Randhawa
The document discusses Orthogonal Frequency Division Multiplexing (OFDM), including its principles, advantages, disadvantages and applications. OFDM divides the available spectrum into multiple orthogonal subcarriers, each modulated with a low data rate stream. This makes OFDM robust to multipath fading and intersymbol interference. While OFDM provides high data rates and spectral efficiency, it suffers from issues like high peak-to-average power ratio and sensitivity to frequency errors. OFDM is used in technologies like WiFi, WiMAX and digital audio/video broadcasting.
The document discusses parameters for planning and designing line-of-sight microwave communication links, including path loss calculations. It covers topics like survey requirements, link budget calculations, transmission concepts, tower heights, earth bulge, fresnel zones, frequency assignments and limitations of line-of-sight systems. Key aspects addressed include determining tower heights to clear obstructions along the signal path based on factors like frequency, distance, earth curvature and fresnel zone radius.
Optical networking technologies provide high-speed, high-bandwidth data transmission over long distances using fiber optic cables. Key technologies include passive optical networks (PON) for access networks, SONET/SDH for metro networks, and dense wavelength division multiplexing (DWDM) for long-haul transport networks. DWDM works by transmitting multiple optical signals simultaneously on different wavelengths over the same fiber, vastly increasing network capacity. Proper layer-2 encapsulation is required to transport layer-3 protocols like IP over DWDM.
A Practical Look At Lte Backhaul Capacity RequirementsWi-Fi 360
This document discusses the backhaul capacity requirements for LTE networks. It notes that average data consumption per user is over 10 GB per month in some markets. LTE sites require peak downlink capacities of 50-100 Mbps for 10 MHz networks and 100-200 Mbps for 20 MHz networks. Microwave backhaul can meet these needs through statistical multiplexing and bringing aggregation points closer to cell sites. Most major LTE operators in Europe rely on fiber backhaul where available but also utilize microwave, while North American operators use a mix of fiber and microwave backhaul.
MIMO uses multiple antennas at both the transmitter and receiver to improve wireless communication performance. It takes advantage of multipath propagation by using spatial diversity or spatial multiplexing. With spatial diversity, the same information is transmitted from different antennas to improve reliability and coverage. With spatial multiplexing, different data streams are transmitted from different antennas to increase data rates. MIMO can significantly increase capacity, quality, and spectral efficiency compared to single-input systems. It is used in technologies like 3G, 4G, and will be important for 5G networks.
This chapter provides an overview of fundamental antenna concepts and properties including polarization, radiation pattern, gain, bandwidth, and voltage standing wave ratio (VSWR). It then discusses microstrip patch antennas, including their structure and advantages. Finally, it introduces metamaterials and defected ground structures (DGS), which can be used to reduce antenna size by providing a negative refractive index substrate. The chapter establishes the background knowledge needed to understand the goals of developing a miniaturized antenna using metamaterial substrates with DGS.
This document provides information about designing a microwave link between two sites in Pakistan for a semester project. It includes:
1) Details of the two sites and student information.
2) An introduction explaining microwave radio relay technology and how it is used to transmit signals over long distances using line-of-sight paths.
3) Technical explanations of key concepts in microwave communication systems like frequency, wavelength, free space loss, antenna gain, and how they relate to designing an optimal microwave link.
The document provides an overview of MIMO (multiple-input multiple-output) systems in wireless communications. It discusses how MIMO can provide array gain, diversity gain, and multiplexing gain to improve spectral efficiency, coverage, and quality of service. It also describes how MIMO reduces co-channel interference. The document covers MIMO channel models and capacity results for different scenarios. It concludes by discussing how MIMO can be used to maximize diversity or throughput through different transmission techniques.
This document provides an overview of GSM principles and network structure. It discusses key aspects of the GSM system including frequency reuse, multiple access techniques, network components, numbering plans and identifiers. The objectives are to understand the GSM system, its structure, protocols, channel combinations, radio techniques and the introduction of GPRS and EDGE. It contains detailed descriptions and illustrations of concepts such as cells, frequency division duplexing, time division multiple access, frequency planning and network interfaces.
This document summarizes key propagation models including Okumura, Hata, and COST231 models. It describes the models' parameters and equations. The Okumura model is empirical and based on extensive measurements in Japan. It accounts for factors like frequency, distance, and antenna heights. The Hata and COST231 models extend Okumura's validity to other frequencies and environments through curve-fitting. The document also explains how to extract data from the models' graphs using a web tool and simulate the models in MATLAB.
This document discusses carrier aggregation (CA) and the challenges it poses for LTE Advanced user equipment. It describes how CA works by aggregating multiple component carriers to provide bandwidths up to 100MHz. It also discusses the new requirements for cross isolation between transmit and receive bands of at least 50dB. Additionally, it covers various inter-band and intra-band challenges like higher peak-to-average power ratios, increased harmonic distortion, and intermodulation products. Finally, it presents different architectural options for implementing CA including separate antennas, switches, diplexers and multiplexers.
The document discusses beamforming antennas and their applications. It begins by outlining beamforming concepts and configurations like phased arrays and adaptive arrays. It then discusses applications of beamforming antennas in areas like radar, sonar, communications and imaging. Specific examples covered include phased array radar, neuronal spike sorting, and smart antenna systems for wireless networks. Vector antennas and their advantages over phased arrays are also summarized. Finally, the document discusses potential uses and challenges of beamforming antennas for wireless ad hoc networks.
This presentation gives an insight about various antennas that were in use in cell phones and are being used in today's smartphones. Images of various phone models showing antenna used are included to give pictorial view of internal antennas
This document discusses different types of antennas used in mobile devices. It begins by introducing antennas and their roles in transmitting and receiving electromagnetic waves. There are several key parameters discussed for antennas including bandwidth, gain, effective area, radiation pattern, impedance, efficiency, and polarization. The main types of antennas covered are isotropic antennas, which radiate equally in all directions; directional antennas, which radiate more effectively in one direction; and omnidirectional antennas, which radiate in all directions except the azimuth plane. The document focuses on different antenna types used specifically for mobiles, including roof mounted antennas, glass mounted antennas, high gain antennas, and various space diversity antennas oriented horizontally or vertically.
An antenna is the most important device in a cell-phone in terms of wireless communication. If the antenna doesn't work very well, the signal strength drops drastically. For the design of cell-phone antennas, we can adopt a dipole, helical, PIFA (Planar Inverted F Antenna), or intennas.
This thesis focuses on mobile phones antenna design with brief description about the historical development, basic parameters and the types of antennas which are used in mobile phones. Mobile phones antenna design section consists of two proposed PIFA antennas. The first design concerns a single band antenna with resonant frequency at GPS frequency (1.575GHz). The first model is designed with main consideration that is to have the lower possible PIFA single band dimensions with reasonable return loss (S11) and the efficiencies. Second design concerns in a wideband PIFA antenna which cover the range from 1800MHz to 2600MHz. This range covers certain important bands: GSM (1800MHz & 1900MHz), UMTS (2100MHz), Bluetooth & Wi-Fi (2.4GHz) and LTE system (2.3GHz, 2.5GHz, and 2.6GHz). The wideband PIFA design is achieved by using slotted ground plane technique. The simulations for both models are performed in COMSOL Multiphysics.
The last two parts of the thesis present the problems of mobile phones antenna. Starting with Specific absorption rate (SAR) problem, efficiency of Mobile phones antenna, and hand-held environment.
The document presents a design for a multiband PIFA antenna for mobile devices. It begins with an introduction on antennas and the types used in mobile devices, including monopoles, helicals, microstrip antennas and PIFAs. It then discusses literature that proposed multiband PIFA designs using techniques like slots, strips and modified ground planes to increase bandwidth. The literature showed PIFAs can provide size reduction and bandwidth enhancement for multiple frequency bands. The document aims to design a PIFA antenna that supports even more bands through optimizations of the structure and ground plane.
Antenna Details for iPhone 5 and iPhone 4GWillie LU
Antenna performance in mobile phone is much more important than antenna design due to the very small size of antenna RF in a compact mobile phone device. Through near 20 years' research and development in RF, transceiver and antenna technology, Prof. Willie W. Lu carefully analyzed and evaluated each patent which Apple filed with USPTO on the antenna technology for iPhone and iPad, and pointed out that the major problem of iPhone antenna is the lack of optimal antenna optimization and calibration technology which result in the poor performance of its radio transmission between the iPhone and the basestation. Prof. Lu has writen a 500-pages report to address this technical issue based on the iPhone antenna patents Apple filed with USPTO. For more, please contact Prof. Lu at wwlu@ieee.org or visit http://4Gsummit.com to join our technical discussions.
This document discusses several topics related to antenna design and performance:
1) It provides a brief history of major antenna discoveries from the 1920s to the 1970s, including Yagi-Uda antennas, horn antennas, arrays, parabolic reflectors, and patch antennas.
2) It explains how antennas work by describing how electric and magnetic fields propagate as waves.
3) Key factors that influence antenna performance are described, including frequency band, surrounding fields, size effects, efficiency, directivity, gain, impedance matching, and bandwidth.
Smart antenna arrays use digital signal processing to transmit and receive signals in an adaptive, spatially sensitive manner. They have applications in cellular networks, radar, satellite systems, and electronic warfare for counteracting jamming. Key benefits include higher capacity, coverage, bit rates, link quality and spectral efficiency. Smart antennas contain radiating elements, a combining network, and a control unit to maximize gain towards desired signals and minimize it for interferers. Two main types are switched beam antennas, which switch between predefined beams, and dynamically phased arrays, which continuously track signals using direction of arrival algorithms. Smart antennas allow for space division multiple access by separating multiple users on the same channel based on angle. They provide improved interference rejection compared to conventional or
This document describes different types of antennas used for transmitting and receiving electromagnetic waves. It discusses transmitter and receiver antennas. Specific antenna types covered include Yagi-Uda antennas, log-periodic antennas, helix antennas, parabolic antennas, loop antennas, and antenna arrays. Each antenna type has distinct characteristics that make it suitable for different frequency ranges and applications.
Microsoft Word Mobile Multi Media Applicationskkkseld
This document provides an overview of cellular communications and GSM technology. It discusses the evolution of mobile phone systems from early architectures to modern cellular networks. The key aspects covered include the cellular concept using frequency reuse, architecture of analog systems like AMPS, components of cellular networks, and digital access methods. A major section is devoted to GSM standards, including network architecture, operations, specifications and services. The document also introduces 3G mobile phones and their multimedia applications as well as future trends in this area. The overall aim is to understand the technologies behind GSM and 3G networks and their application in distributed multimedia environments.
The document summarizes the design of mobile phone antennas. It discusses designing a single band PIFA antenna for mobile phones as well as a wideband PIFA antenna to cover frequencies from 1800MHz to 2600MHz. It describes calculating the dimensions of PIFA antennas, simulating the antenna designs using COMSOL Multiphysics software, and analyzing the results to achieve impedance matching, gain, radiation patterns and bandwidth specifications. Problems with mobile phone antennas like efficiencies, size constraints, and mutual coupling are also outlined.
The document discusses tower technician responsibilities, including summarizing:
1) The roles of tower technicians include maintaining cellular tower equipment such as antennas, transmitters, and cables that allow cell phones to connect to networks.
2) Cellular towers use various antenna types and configurations depending on network needs, including directional antennas to focus signals in certain areas and MIMO antennas to increase data capacity.
3) Technicians must understand how cellular network equipment like the base transceiver station (BTS) and antennas function and be able to configure them properly to optimize network performance.
Small Size Planar Inverted-F Antenna for WiMAX ApplicationsIJEEE
This work presents a small size planner inverted-F antenna (PIFA), with a single feed which covers WiMAX (3.2-3.6 GHz) and (5-5.8 GHz) range. The proposed antenna has many advantages like compact size and wide operation bandwidth. The antenna portion of 20mm* 15mm and the overall dimension25mm *40mm can be easily applied in the USB dongle.
The first weather satellite was TIROS-1, created by a team at NASA in 1960 without a single inventor. Weather satellites use radiometers with detectors for infrared, microwave, and visible light to take images from orbit. They provide data on clouds, temperatures, storms, and other weather patterns up to every 12 hours. Infrared satellites in particular help fishermen and farmers by detecting tropical cyclones and calculating surface temperatures. All weather satellites have exterior imaging devices like radiometers and often use solar panels to generate power.
The document discusses antennas used in mobile phones. It describes how antennas work by transforming radio frequency signals into electromagnetic waves using principles of electromagnetism. It discusses the need for antennas in transmission and reception and their uses in devices like phones, WiFi, and radar. The key parameters of antennas that are described include input impedance, return loss, bandwidth, directivity, gain, radiation pattern, beamwidth, side lobes, nulls, and polarization. The document focuses on the types of antennas used in mobile phones, including external and internal antennas, and how antenna design has evolved with phones. It discusses specific absorption rate regulations for phones and provides an example data sheet on SAR values for different phone models. Potential health effects of
The weather satellite was invented by a group of scientists and engineers working for NASA, not a single person. On April 1, 2000, NOAA launched the first weather satellite, which was composed of GOES and POES satellites that provided full Earth coverage and processed collected data. Weather satellites use radiometers to scan the Earth and detect radiation to monitor weather, transmitting data to ground stations within a minute for meteorologists to track patterns and make forecasts. They can operate for 3 to 7 years in either geostationary or polar orbits.
Weather forecasting technology has advanced significantly in recent decades through the use of satellites, radar, weather models, and supercomputers. These tools allow meteorologists to observe storms, predict their movement and intensity, and issue warnings up to a week in advance. However, accurately predicting the weather still remains a complex challenge due to the highly variable and chaotic nature of the atmosphere.
How to improve customer experience with a self organizing networkComarch
Self-organizing networks can improve customer experience by automating network management tasks to reduce costs and optimize network performance. However, solely optimizing technical network parameters may not translate to better customer experience. The self-organizing network must be driven by customer-centric metrics and consider the holistic impact of optimization on both network resources and customer services. Gradual implementation of automation by leveraging existing OSS systems and controlling optimization with defined KPIs can help gain trust in the self-organizing capabilities over time.
This document defines and compares wireless local loop (WLL) networks to mobile systems. WLL uses wireless links to connect subscribers to local exchanges instead of copper cables, shortening construction periods and reducing costs. It is designed to serve subscribers at home or work with high voice quality and traffic support, unlike mobile systems meant for those on the move. The efficiency of WLL depends on factors like channel payload, signaling overhead, modulation, cell radius, and interference reduction techniques. Future technologies discussed include smart antennas, turbo codes, and multi-user detection to improve WLL network capacity.
The document discusses various topics related to GSM including:
- The GSM system architecture is divided into the mobile station, base station subsystem, and network subsystem. The base station subsystem consists of base transceiver stations and base station controllers. The network subsystem includes mobile switching centers, home location registers, visitor location registers, and authentication centers.
- Interfaces include the Um air interface, Abis interface between the BTS and BSC, and A interface between the BSS and MSC. Various protocols are used on each interface including those for physical transmission, data link layer, and network layer.
- The GSM air interface Um uses TDMA/FDMA, dividing the radio frequency spectrum into frames divided into
This document provides an overview of the Global System for Mobile Communications (GSM) standard. It describes the key components of the GSM system architecture, including the mobile station, base station subsystem (consisting of base transceiver stations and base station controllers), and network subsystem (consisting of mobile switching centers, home location registers, visitor location registers, and authentication centers). It also outlines the various interfaces that connect these components, such as the air interface Um, Abis interface, and A interface, as well as the protocols used on each interface.
Smart poles as a concept is not new but is getting extremely popular with Smart cities and Small cells. Penetration of smart phones and exponential growth of data consumption has pushed operators to deploy more sites to meet both coverage and capacity requirements. Interference and frequency re-use limitation stops operators to deploy more high-power macro sites and hence operators are moving towards low power solutions to cover hotspots.
This document provides an overview of GSM architecture and components:
1. It describes first and second generation cellular systems, noting the transition to digital with GSM.
2. It outlines the key components of GSM architecture - the mobile station (MS), base station subsystem (BSS) comprising BTS and BSC, and the network switching subsystem (NSS) comprising MSC, HLR, VLR and other registers.
3. It explains the roles of the main functional entities - the MS containing the SIM card, the BTS which provides radio access, the BSC which manages radio resources, and the MSC which acts as the call switch connecting to other networks.
This document provides guidelines for antenna system planning for GSM and UMTS radio networks. It summarizes key aspects of antenna selection, feeder length planning, tilt planning, diversity planning and installation. Rules are presented for choosing antenna types, using transmultiplexers, height planning, azimuth planning and ensuring compatibility for site sharing. Mounting guidelines are also covered for mast, tower, roof and wall installations. The document is intended as a reference for radio network engineers on the essential issues to consider for effective antenna system planning.
The document discusses competition in Spain's telecommunications sector. It begins by providing context on the evolution of telecommunications in Europe from monopolies to liberalization and the arrival of new technologies. It then examines Spain's telecommunications services supply across fixed line, mobile, fiber optic and emerging technologies. Next, it analyzes the competitive landscape among full service providers, multiservice operators, and specialized operators. It concludes by discussing industry trends and outlooks, including strategies by major operators like Telefonica.
Token Ring has proven to be a superior and robust technology for corporate networks since the 1980s. While networked applications have changed significantly, Token Ring has kept pace through only two changes to the underlying technology. In contrast, Ethernet has undergone many changes and forced users to repeatedly upgrade their networks. The document outlines how Token Ring addresses key issues of scalability, affordability, applications, and integration in a way that protects users' network investments into the future.
The document discusses radio network planning for 2G GSM networks. It covers topics such as coverage analysis, network structure analysis, traffic analysis, base station number decision, base station address planning, location area design, dual-band network design, indoor coverage design, tunnel coverage design, and repeater planning. The goal is to output documents on base station distribution, channel assignment, and cell data to guide the construction of a wireless mobile network based on analysis of coverage, capacity, and quality requirements.
UMTS is the 3G cellular technology standardized in Europe. It uses W-CDMA for its air interface and builds upon the existing GSM infrastructure, making it compatible with 2G networks. The basic UMTS network architecture consists of user equipment connecting to an access network, which connects to the core network and other networks. The access network uses Node B base stations and radio network controllers. The core network uses many of the same components as GSM like mobility management.
This document provides an overview of the GreenDroid mobile application processor prototype. GreenDroid targets the Android mobile software stack and aims to execute general mobile programs with 11 times less energy than current designs, through the use of 100+ automatically generated specialized cores called conservation cores (c-cores). C-cores are designed to reduce energy consumption by targeting specific Android hotspots. The GreenDroid architecture uses an array of tiles, each containing a CPU, cache, and 8-15 c-cores. C-cores handle frequently executed hotspot code while less common cold code runs on the CPU. This approach aims to maximize silicon utilization in the face of the growing dark silicon problem caused by the utilization wall effect from Moore's Law scaling
The document discusses the optical transport network (OTN) standard defined in ITU-T G.709. It describes the OTN layered structure, interfaces and rates, frame structure and overhead, and techniques for testing OTN elements. The OTN architecture allows more efficient transport of client signals using optical channels and standardized overhead to manage network functions like multiplexing and forward error correction.
The document is a master's thesis submitted by Edgar Ramos analyzing the media control interfaces and mobile media gateway for the IP Multimedia Subsystem (IMS). Specifically, it analyzes the Mp interface used to control the Multimedia Resource Function Processor (MRFP) and reviews various proposed media control protocols. It also describes the prototype developed to illustrate possible adaptations of the mobile media gateway to handle the Mp interface and setup IMS calls. The thesis contributes to understanding the transition from circuit-switched to packet-switched media using the mobile media gateway and a media server control model.
The report discusses the future role of terrestrial broadcasting. It finds that terrestrial broadcasting remains very important for delivering broadcast services due to its near-universal coverage, ability to provide fixed, portable, and mobile reception, and support from broadcasters and regulators. However, its role is changing as consumer expectations and technologies evolve. New distribution methods like broadband are complemented terrestrial broadcasting but not replace it. The report considers scenarios where terrestrial broadcasting could expand, reduce in scope, or phase out, and provides recommendations to ensure its long-term viability in fulfilling public service obligations.
This document provides an analysis of Texas Instruments in the cellular handset semiconductor industry. It begins with an introduction to Texas Instruments and an overview of the cellular handset semiconductor industry value chain. It then analyzes the industry structure using Porter's Five Forces model. The document finds that the industry has high barriers to entry, low supplier power, high buyer power, moderate to high rivalry, and low threat of substitutes. It also notes the industry has experienced healthy growth. The document evaluates Texas Instruments' position and strategy in the industry and analyzes competitors and emerging trends. It assesses TI's strengths, weaknesses and competitive advantages. Finally, it proposes emerging strategies for TI in the cellular handset semiconductor market and looks ahead to the company
Mobile WiMAX is a wireless broadband technology that uses OFDMA and MIMO to provide high-speed Internet access over long distances. It supports both TDD and FDD duplex modes and uses OFDM to divide the wireless signal into multiple sub-carriers. MIMO implements space-time coding to improve link robustness and reduce fade margin. Mobile WiMAX also features advanced security, mobility support with fast handovers, and dynamic allocation of uplink and downlink resources.
- The document defines handover procedures for circuit switched connections as the mobile moves between cells or radio networks. It covers intra-MSC, intra-3G_MSC, and inter-MSC handovers as well as SRNS relocation. The procedures ensure reliable transfer of signaling messages to maintain the connection to the mobile.
The document provides an overview of GSM systems, including:
- A review of first and second generation cellular networks and their focus on coverage over capacity.
- An overview of the key components of GSM architecture, including the mobile station, base station subsystem, and network switching system.
- Descriptions of the coverage and capacity challenges faced by early cellular networks as the subscriber base grew.
This document provides an overview of in-building wireless solutions, including Distributed Antenna Systems (DAS), Distributed Radio Systems (DRS), and Distributed Small Cells (DSC). It describes the basic architectures and components of passive DAS, active DAS, hybrid DAS, digital DAS, DRS, and DSC. The document also briefly introduces Anritsu's test solutions for evaluating in-building wireless performance.
Similar to Basic Principles and Design of The Antenna in Mobile Communications (20)
Basic Telecom concepts
Various Wireless Technologies
Cellular concepts & Principal of cellular Comm.
GSM Network Architecture
GSM channel Architecture
Call Flows in GSM
GSM Planning steps (Nominal Plan & RF surveys)
Alternative means of wireless communication
Walkie - Talkie
Pagers
Trunked private radios
Mobile Phone - the magic technology that enables everyone to communicate anywhere with anybody.
Till 1982 Cellular Systems were exclusively Analog Radio Technology.
Advanced Mobile Phone Service (AMPS)
U.S. standard on the 800 MHz Band
Total Access Communication System (TACS)
U.K. standard on 900 MHz band
Nordic Mobile Telephone System (NMT)
Scandinavian standard on the 450 & 900 MHz band
The GSM standard was developed by the Groupe SpecialMobile, which was an initiative of the Conference of European Post and Telecommunications (CEPT) administrations.
The responsibility for GSM standardization now resides with the
Special Mobile Group (SMG) under the European Telecommunication Standard Institute (ETSI).
Fully digital system utilizing the 900MHz frequency band.
TDMA over radiocarriers(200 kHz carrier spacing)
8 full rate or 16 half rate TDMA channels per carrier
User/terminal authentication for fraud control
Encryption of speech and data transmissions over the radio path
Full international roaming capability
Low speed data services (upto 9.6kb/s)
Compatibility with ISDN for supplementary services
Support of short message services(SMS)
GSM supports a range of basic and supplementary services, and these services are defined analogous to those for ISDN(i.e.,bearer services, teleservices, and supplementary services).
The most important service supported by GSM is Telephony.
Other services derived from telephony included in the GSM specification are emergency calling and voice messaging.
Bearer services supported in GSM include various asynchronous and synchronous data services for information transfer.
Teleservices based on these bearer services include group 3 fax and short message service(SMS)
The data capabilities of GSM have now been enhanced to include high speed circiut-switched data(HSCSD) and general packet radio service (GPRS).
Call offering services call forwarding
Call resrtiction services call barring
Call waiting service
Call hold service
Multi party service tele conferencing
Calling line presentation restriction services
Advice of charge service
Closed user group service
The GSM System comprises of Base Transceiver Station (BTS), Base Station Controllers (BSC), Mobile Switching Centers (MSC), and set of registers (databases) to assist in mobility management and security functions.
All signaling between the MSC and the various registers (databases) as well as between the MSCs takes place using the Signaling System 7(SS7) network, with the application level messages using the Mobile Application Protocol (MAP) designed specifically for GSM.
The MAP protocol utilizes the lower layer functions from the SS7 protocol stack.
This chapter provides an overview of basic wireless communication concepts such as frequency, bandwidth, channels, transmission rate and modulation methods. It describes Time Division Multiple Access (TDMA) used in digital cellular systems and discusses advantages of digital transmission over analog. Transmission problems like path loss, shadowing, multipath fading and solutions like channel coding, interleaving, antenna diversity and adaptive equalization are also covered. The chapter then explains the GSM transmission process from analog to digital conversion to burst formatting and modulation.
Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s
Half rate => Used for speech at 6.5 Kbits/s
or sending data at 4.8 Kbits/s
Enhanced Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s but
with almost Land line quality
FCCH = FREQUENCY CORRECTION CHANNEL
=> To tell the Mobile that this is the BCCH carrier
=> To able the Mobile to synchronize to the frequency
(Downlink only)
SCH = SYNCHRONISATION CHANNEL
=> Used for sending BSIC (Base station Identity Code)
=> Give TDMA frame number to the Mobile.
(Downlink only)
BCCH = BROADCAST CONTROL CHANNEL
=> Used for sending information to the mobile like
CGI (Cell Global identity), LAI (Location Area Identity),
BCCH carriers of the neighboring cells,
maximum output power allowed in the cell and other
broadcast messages like barred cell. (Downlink only)
PCH = PAGING CHANNEL
=> Used for paging the Mobile. (Downlink only)
Reason could be an incoming call or an incoming Short Message.
RACH = RANDOM ACCESS CHANNEL
=> Used for responding to the paging (terminating), Location updating
or to make call access (originating) by asking for a signaling channel.
(Uplink only)
AGCH = ACCESS GRANT CHANNEL
=> Used to allocate SDCCH to the mobile.
(Downlink only)
ell Allocation (CA) is the subset of the total frequency band that is available for one BTS. It can be viewed as the total transport resource available for traffic between the BTS and its attached MSs. One Radio Frequency CHannel (RFCH) of the CA is used to carry synchronization information and the Broadcast Control CHannel (BCCH). This can be any of the carriers in the cell and it is known as the BCCH carrier or the c
carrier. Strong efficiency and quality requirements have resulted in a
0
rather complex way of utilizing the frequency resource. This chapter describes the basic principles of how to use this resource from the physical resource itself to the information transport service offered by the BTS.
Carrier separation is 200 kHz, which provides: • 124 pairs of carriers in the GSM 900 band • 374 pairs of carriers in the GSM 1800 band • 299 pairs of carriers in the GSM 1900 band
Using Time Division Multiple Access (TDMA) each of these carriers is divided into eight Time Slots (TS). One TS on a TDMA frame is called a physical channel, i.e. on each duplex pair of carriers there are eight physical channels.
A variety of information is transmitted between the BTS and thMS. The information is grouped into different logical channelsEach logical channel is used for a specific purpose such as paging, call set-up and speech. For example, speech is sent on the logical channel Traffic CHannel (TCH). The logical channels are mapped onto the physical channels.
The information in this chapter does not include channels specific for GPRS (General Packet Radio Service). For basic information on GPRS see chapter 14 of this documentation.
Common core mechanics in Nokia UltraSite EDGE BTS Outdoor and Nokia UltraSite EDGE BTS Indoor
Common plug-in units
1940 x 770 x 750 mm (H x W x D)
Identical footprint to CityTalk BTS
Weight
Max weight (12 TRX) 340 kg
Heaviest single part 58 kg (core mechanics)
Heaviest plug-in unit 18 kg (RTC)
Acoustic noise (max): 68 dB(A)
Climatic conditions:
w/o heater -10°C ... +50°C
with optional heater -33°C ... +50°C
Ingress Protection Class: IP 55
Two level environmental protection:
BTS core and cabinet door provides EMC shielding
Outdoor kit provides additional weather proofing
The GENEX Assistant is excellent software tool for
Post-Processing 2G & 3G Drive Test Data.
With the GENEXAssistant, you can:
Have a panorama view of network performance
Locate network troubles
Improve network quality
Verify network planning and optimization
ANALYSIS OF LOGFILE
FOR POST PROCESSING OF LOGFILE IN
GENEX ASSISTANCE WE NEED TO
OPEN A NEW PROJECT
. Overview
2. Handover Causes & Priorities
3. Threshold Comparison Process
4. Target Cell Evaluation Process
5. Handover Algorithms
Power Budget (PBGT)
Level & Quality (RXLEV & RXQUAL)
Umbrella (& Combined Umbrella/PBGT)
MS Speed (FMMS & MS_SPEED_DETECTION)
6. Imperative Handovers
Distance
Rapid Field Drop (RFD) & Enhanced Rapid Field Drop (ERFD)
7. Handover Timers
Call continuity - to ensure a call can be maintained as a MS moves geographical location from the coverage area of one cell to another
Call quality - to ensure that if an MS moves into a poor quality/coverage area the call can be moved from the serving cell to a neighbouring cell (with better quality) without dropping the call
Traffic Reasons - to ensure that the traffic within the network is optimally
distributed between the different layers/bands of a network
If 2 or more handover (PC) criteria are satisfied simultaneously the following priority list
is used in determining which process is performed;
. Uplink and downlink Interference
2. Uplink quality
3. Downlink quality
4. Uplink level
5. Downlink level
6. Distance
7. Enhanced (RFD)
8. Rapid Field Drop (RFD)
9. Slow moving MS
10. Better cell i.e. Periodic check (Power Budget HO or Umbrella HO)
11. PC: Lower quality/level thresholds (UL/DL)
12. PC: Upper quality/level thresholds (UL/DL)
Introduction
Channel Configuration
Idle Mode Operation
Protocols
Radio resources
Measurements
Power Control
HO process
Intelligent Underlay Overlay
Handover Support for Coverage Enhanchements
The extended cell
Dynamic Hotspot
Dual band GSM/DCS Network Operation
Half Rate
HSCSD
Transmission management in BSS is a feature used in managing the Base Station Subsystem transmission system functions such as supervision, alarms, statistics
and settings. The network element mainly responsible for transmission management in BSS is the Base Station Controller (BSC).
Transmission management functionalities make it possible for the operators to manage the transmission equipment remotely from the BSC or from Nokia
NetAct integrated network management system, which simplifies network maintenance and operation. Supervision functions help minimise the time spent in maintenance, and statistics collection helps the operators analyse and optimise
the use of their transmission equipment. Moreover, new software can be downloaded in a way that does not interfere with the traffic.
Hardware and software requirements BSS transmission network elements
BSS transmission management functionalities Transmission parameters Transmission alarms
Transmission measurements
2.Hardware and software requirements
There are no specific hardware or software requirements for the transmission management functionalities. However, the type of the BTS poses certain
limitations.
The BTS type specific functionalities are listed in the table below.
More details about the functionalities can be found in BSS transmission management functionalities .
Polling list sending with priority is a functionality used in positioning. To ensure accurate positioning calculations, the LMU unit must supply Radio Interface Timing System (RIT) information to the network faster than the normal Q1 polling is able to do. Faster LMU polling is achieved by defining a Q1 polling
priority for each Q1 device, with the LMU having the highest priority. For more information see Location Services .
3.BSS transmission network elements
The base Station Subsystem (BSS) consists of at least one Base Station Controller (BSC) and its Base Transceiver Stations (BTS). The Transcoder Submultiplexer
(TCSM) is also part of the BSS although it is actually located in the MSC site. The three basic configurations (topologies) for transmission between the BSC and
the BTSs are: point-to-point connection
multidrop chain multidrop loop
In point-to-point configuration each BTS is connected directly to the BSC. In the multidrop chain, BTSs form a chain and the first BTS in the network is connected directly to the BSC. In the loop connection, the BTSs form a loop where the first and the last BTS in the loop are connected directly to the BSC via a crossconnecting node. The topology used depends on a number of factors such as the distance between the BSC and the BTS, the number of transceivers (TRXs) used at a particular BTS site and the signalling channel rate between the BSC and the\ BTS. Usually the topology used is a mixture of the three basic topologies. Formore information on the topologies, refer to Nokia BSS Transmission\Configuration .
This document discusses selecting the appropriate capacity for a Base Station Controller (BSC) in a mobile telecommunications network. It provides the following guidelines:
1. Allow a 20% margin for additional TRXs and space for future upgrading. Minimize handovers between BSCs.
2. Calculate required capacity based on offered traffic plus a 10% margin, not installed capacity.
3. Use Erlang B calculations to determine the number of channels needed to support the traffic load at a 0.1% blocking rate.
4. Divide the number of required channels by the number supported per Ater link or interface to determine the number of links needed between the BSC and core network.
– There are others : IS95 HDR, EDGE, etc.
» Direct Spread CDMA TDD
» Direct Spread CDMA FDD
» Multi-carrier CDMA FDD
Global 3G comprises of 3 modes :
– Marketed as Global 3G CDMA implying a single unified standard. In reality,
– Mostly dominated by Direct Sequence CDMA.
– Market is expected to be fragmented amongst several competing
IMT2000 guidelines defined by the ITU.
– Analog was 1G. GSM/IS95 were 2G. Next is 3G.
What is 3G ?
standards.
across the world.
Envisioned as a single Global standard allowing seamless roaming
Used interchangeably with IMT2000 although there are some specific
A loosely defined term referring to next generation wireless systems.
4
encompasses three optional modes of operation.”
Telecommunications Union (ITU) of a single CDMA third generation standard that
“Qualcomm and Ericsson ... jointly support approval by the International
Jun 1999 found compromise at the OHG.
“Qualcomm … is not prepared to grant licences according to the … ETSI IPR Policy.”
fair, reasonable and non-discriminatory basis in accordance with the ... ETSI IPR Policy.”
“Ericsson … is prepared to grant licences to these [W-CDMA & TD-CDMA] patents on
Dec 1998 saw a stand-off in standards.
WCDMA, WTDMA, OFDMA, Global CDMA 1 & 2.
Asia Pacific (ARIB & TTA):
WCDMA N/A, UWC-136, cdma2000, WIMS WCDMA, WP-CDMA.
North America(T1P1, TR45.3, TR45.5, TR46.1):
WCDMA, WTDMA,TDMA/CDMA, OFDMA, ODMA.
Europe (ETSI):
In
n
scrambling achieve?
scrambling achieve?
6
Secure link: a linear sequence of length 2
doesn’t
Benefits of wideband signals: multipath provides temporal diversity instead of ISI.
Spectral re-use factor of 1: all cells can use the same frequency spectrum.
does
What
What
Low cross-correlation (at any time offset).
High auto-correlation (at any time offset).
What are their important properties?
in to a low amplitude, wide bandwidth signal.
Converts a high amplitude, narrow bandwidth signal
How do they work?
Pseudo-random sequences: Gold codes, Kasami codes (M-sequences).
‘W’ of WCDMA.
W
This document provides an overview of MapInfo software and how to use its various functions. It discusses MapInfo basics like tables, workspaces and layers. It also covers how to register raster images, create vector maps, perform network analysis using drive test data, and output maps. The goal of the tutorial is to introduce common MapInfo operations and help users get familiar with the software for tasks like network planning and map maintenance.
Third generation mobile networks will provide significantly higher data rates and allow for convergence of various communication services. 3G networks will transition to an all-IP infrastructure and support multiple access technologies and standards to provide connectivity anywhere in the world. This will enable always-on high-speed access to multimedia applications and the internet from mobile devices.
Cdma2000 network problem analysis with mobile station 20030212-a-v1.0Tempus Telcosys
This document describes how to use a mobile station (MS) to locate network problems in CDMA2000 networks. It explains how to view debugging screens on different MSs to check indices like pilot strength, receive level, and transmit level, which can indicate issues with forward or reverse coverage. It also discusses using reverse frame error rate tests on the network side to evaluate connection quality and voice quality. The document provides guidance on interpreting these metrics and diagnosing potential problems based on the results, like interference issues affecting transmit levels or poor coverage in certain areas.
It is required that after the course study
you should:
Have a general concept about DT
Master Panorama DT operation
Master Panorama data analysis
Chapter 1 DT Introduction
Chapter 2 Panorama DT Introduction
Chapter 3 Panorama DT Data Analysis
Collect System Air interface data
Analyze Air interface data
Assist Export Analysis report
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
QCTest™ CDMA Air Interface Tester (CAIT™) 3.1 User’s GuideTempus Telcosys
QUALCOMM Proprietary
Export of this technology or software is regulated by the U.S. Government. Diversion contrary to Ulaw prohibited.
All data and information contained in or disclosed by this document are confidential and proprietinformation of QUALCOMM Incorporated, and all rights therein are expressly reserved. By acceptthis material, the recipient agrees that this material and the information contained therein are heldconfidence and in trust and will not be used, copied, reproduced in whole or in part, nor its contentsrevealed in any manner to others without the express written permission of QUALCOMM Incorporated.
Mobile communications is one of the communications fields that develop rapidly and energetically. The antenna builds the bridge between user terminals and base control devices. It is widely used in the mobile communications and the wireless access communication system. The rapid development of the antenna greatly promotes its technology innovation.
It is important to deeply grasp the knowledge of the antenna, which is useful to:
Install and maintain products.
Promote the network planning.
Chapter 1 Working Principle
Chapter 2 Classification
Chapter 3 Electrical Index
Chapter 4 Mechanical Index
When the conducting cable carries the alternating current, the electromagnetic wave radiation can be formed.
If two conducting cables are close, the directions of their current are opposite, and the electromotive force is counteracted. Thus the radiation becomes week.
If two conducting cables are open, the directions of their current are the same. Thus the radiation becomes strong.
When the length of the conducting cable is like the wavelength, the current on the cable will be enhanced. Thus the radiation becomes strong.
The straight conducting cable which can generate the strong radiation is called the dipole.
The pole whose two arms are of the same length (1/4 Wavelength) is called as dipole or half-wave-length dipole.
C cf radio propagation theory and propagation modelsTempus Telcosys
The radio propagation theory is an important lesson in the radio communication curriculum. This lesson answers the following questions:
How are radio waves transmitted from one antenna to the other antenna?
What features does the radio wave have during the propagation? Which factors affect the propagation distance?
What fruits are achieved by predecessors in the radio wave propagation theory? How to apply the theory to practice?
Chapter 1 Radio Propagation Theory
Chapter 2 Radio Propagation Environment
Chapter 3 Radio Propagation Models
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...EduSkills OECD
Andreas Schleicher, Director of Education and Skills at the OECD presents at the launch of PISA 2022 Volume III - Creative Minds, Creative Schools on 18 June 2024.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Basic Principles and Design of The Antenna in Mobile Communications
1. Document No. Product
Version
Confidentiality
V2.00
Wireless Network System Radio
Frequency Research Department
Huawei Technologies Co., Ltd.
Product Name: M900/1800 Total Pages: 37
Basic Principles and Design
Specifications of Antenna in Mobile
Communications
(Revised edition, for internal use only)
Prepared by Ai Ming Date 2001/09/08
Reviewed by Date yyyy/mm/dd
Reviewed by Date yyyy/mm/dd
Approved by Date yyyy/mm/dd
Tempus Telcosys(P) Ltd.
Time is Almighty.
www.TempusTelcosys.com
2. Revision Record
Date Revised
version
Description Author
1,999 1.00 Complete the first draft. Ai Ming
2000/11/9 1.00 Transfer the draft to the network planning
technical support team
Network planning technical
support team
2001/09/8 2.00 Revise the draft. Ai Ming
♦ Note:
1) The basic concepts of middle feed and bottom feeder of omni antenna are added; Sections 3.10 through
3.13 are added
2) Correct the errors in some figures. (2001-09-08)
www.TempusTelcosys.com
3. Table of Contents
1 Overview......................................................................................................................................... 5
1.1 Antennas............................................................................................................................... 5
1.2 Development Trends of BS Antenna .................................................................................... 7
1.3 Design Concepts of BS Antenna .......................................................................................... 8
2 Basic Technologies....................................................................................................................... 9
2.1 BTS Antenna......................................................................................................................... 9
2.2 System Requirements and Antenna Technologies ............................................................ 12
2.3 Types of Antennas.............................................................................................................. 15
2.4 Design of Shaped-beam Antenna....................................................................................... 19
2.4.1 Fan Beam Antenna .................................................................................................. 19
2.4.2 Vertical Shaped-beam Antenna ............................................................................... 24
2.4.3 Beam Tilt .................................................................................................................. 25
2.5 BS Diversity Antenna.......................................................................................................... 26
2.6 Passive Inter-modulation of Base Station Antenna ............................................................ 31
2.6.1 Relationship between PIM and Receiving-transmitting Frequency ......................... 31
2.6.2 PIM Generator and Suppression Technology.......................................................... 32
3 Major Index Requirement for BS Antenna Design................................................................... 33
3.1 VSWR of BS Antenna......................................................................................................... 33
3.2 Gain (dBi)............................................................................................................................ 33
3.3 Half Power Beam Width (HPBW) ....................................................................................... 34
3.4 Front-to-Back Ratio (F/B).................................................................................................... 35
3.5 Isolation between Ports ...................................................................................................... 35
3.6 Polarization ......................................................................................................................... 35
3.7 Power Capacity................................................................................................................... 35
3.8 Zero Stuffing ....................................................................................................................... 35
3.9 Upper Side Lobe Suppression............................................................................................ 36
3.10 Beam Downtilt................................................................................................................... 36
3.11 Two-band Dual Polarization Antenna ............................................................................... 36
3.12 Two-band Dual Polarization Duplex Antenna................................................................... 36
3.13 Grounding system............................................................................................................. 37
3.14 Antenna Input Connector.................................................................................................. 37
3.15 Passive Inter-Modulation (PIM) ........................................................................................ 37
3.16 Dimensions ....................................................................................................................... 38
3.17 Weight............................................................................................................................... 38
3.18 Wind Load......................................................................................................................... 38
3.19 Working Temperature....................................................................................................... 38
3.20 Humidity............................................................................................................................ 38
3.21 Lightning Protection .......................................................................................................... 38
3.22 3-Proof Capability ............................................................................................................. 38
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4. Basic Principles and Design Specifications of
Antenna in Mobile Communications
(Second Edition)
Key words: Mobile communications, antenna gain, design specifications
Abstract: Base station antenna is a bridge between user terminal and the Base
Station Controller (BSC). It is widely applied in the cellular mobile
telecommunications and ETS wireless telecommunication systems. This
document presents the history of antenna development, the basic antenna
technologies, and the major technical indices. Readers are expected to have an
overall understanding about the antenna of BSs in the mobile
telecommunications. The impacts of antenna lobe, antenna downtilt (mechanical
and electronic), isolation on the cell coverage and frequency reuse are also
mentioned in this document.
Abbreviation List:
Reference list
Name Author Document
No.
Release date Available place
or channel for
reference
Mobile Antenna System Manual Translated by Yang Kezhong and Jin
Shuhua
1997
Cellular Mobile Telecommunications ---
Design of BTS Antenna Feeder System
Xu Yubo 1998
Mobile Telecommunications Engineering Lu Errui, Shun Rushi, etc.
Microstrip Antenna Theory and
Engineering
Zhang Jun, Liu Kecheng, etc. 1998
Cellular Mobile Communication
Engineering Design
A. Marrola
Telecommunication Engineering Design
Manual ---- Mobile Telecommunications
Beijing Design Institute of Post and
Telecommunications Department
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5. 1 Overview
1.1 Antenna
With the rapid development of China’s economy, great changes have taken place in
the communications industry. Today, propelled by the technologies and the economic
benefits, communications industry has become one of the largest industries in China.
Major telecommunication organizations are restructured to accommodate to the rapid
development of this industry. Along with the advancement of communications industry
towards the information economy, communication is now become the key to the
sustainable development of various sectors of economy.
The development of the mobile telecommunication is even more remarkable.
Nowadays, people are no longer contented to process the information flow in fixed
places. Mobile telecommunications are in great demand when people are traveling or
on vacation. In China, the significant change of mobile telecommunications is evident.
Various types of mobile phones are everywhere bringing information about politics,
economy, culture, and life to people. The largest GSM network in China now provides
services for its over 20 million subscribers. The wireless access development is also
widely adopted to ensure the communications in rural and remote areas.
New technologies and new devices in mobile communications posed as great
challenges for antenna designers. For example, however small the terminal may be,
user would not accept the idea if the conventional antenna is attached to his portable
mobile terminal. Therefore, the antenna designers have to develop miniature or even
electronic antennas to keep up with the development of modern technologies.
In addition to small size, antenna designers have to seek more sophisticated
elements to equip the antenna with even more powerful functions such as the
diversity receiving capability, optional polarity features, and capacity to reduce the
multi-path fading. The focal point of antenna design is shifted from its physical
features (e.g. small-size, light-weight, etc.) to sophisticated electromagnetic structure,
so that antenna can play a significant role on the radio channel.
Antenna design will involve the propagation features, local environments, system
compositions and performance, Signal Noise Ratio (S/N), bandwidth features,
antenna's own mechanical structure, feasibility of production method, and the
convenience of installation. The type of the mobile communications also affects the
antenna design. The antennas used for the terrestrial system, offshore system, air
system, and satellite system differ a lot. In the cellular systems, the radiation pattern
should conform to segmentation pattern to avoid interference. In the urban areas,
diversity receiving function should be employed to offset the multipath fading.
Antennas of smaller size are required for the terminal mobile. In the design of
portable devices (e.g. the mobile phone), the antenna and Radio Frequency (RF)
front end circuit of transceiver should be integrated. Antenna unit and the equipment
should be treated as an antenna system.
In a word, the antenna should be designed as an organic party of the whole system
instead of an independent part. See Figure 1.
The design specifications described in this document only involve the base station
antenna (BS antenna) in wireless communication systems.
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6. 小型化强度 Miniaturized strength 区域距离 Distance between
regions
衰落多路径 Fading multipath 机械结构 Mechanical structure
电气指标 Electrical index 分集技术 Diversity technology
人机界面 Man-machine interface 环境 Environment
传播 Propagation 衰落 Fading
干扰 Interference 人为故障 Man-induced failure
天线 Antenna 系统 System
频率复用 Frequency reuse 多信道连接 Multi-channel connection
能力 Capability 类型 Type
陆地 Terrestrial 海事 Marine
航空 Navigation 卫星 Satellite
个人化 Customization
Figure 1 Integration of antenna and other systems
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7. 1.2 Development Trends of BS Antenna
BS antenna is the bridge between user terminal and the Base Station Controller
(BSC). It is widely applied in the cellular mobile telecommunications and ETS
wireless telecommunication systems.
The advancement of telecommunication technologies will definitely bring about the
radical change of antenna. For the mobile communication system in1970s, the omni
antennas or angle reflector antennas sufficed because the number of subscribers was
not large. A few carriers and BSs can sufficiently cover a city and satisfy the demands
of mobile telecommunications in a city.
However, mobile terminals are in great demand with the development of economy.
Old BSs can no longer meet the demands. Moreover, new types of antennas are
required as a result of the development of digital cellular technologies, so as to
improve the multipath fading, area planning and frequency reuse of the multi-channel
networks. The flat type antenna was widely adopted in the GSM digital cellular
system due to its features of low section, light structure, easy installation and
outstanding electronic performance.
From the mid1980s to the late 1990s, the unipolar antenna was used. As three
antennas were needed for one sector (see Figure 2), and a cell was usually divided
into three sectors, altogether nine antennas were needed for one cell. The large
number of antennas brought great difficulties to the construction and installation of the
base station. Under such a circumstance, the duplex polarization antenna
technologies came into being. See Figure 3.
单极化天线 Unipolar antenna 主接收 Main receiving
发射 Transmitting 分集接收 Diversity receiving
Figure 2 Configuration of unipolar antenna in one sector
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8. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
双极化天线 Bipolar antenna 主接收 Main receiving
发射 Transmitting 分集接收 Diversity receiving
双工装置 Duplex device
Figure 3 Two configurations of bipolar antenna in one sector
With channels and new BSs added, the cellular network should be adjusted and
optimized, which demands new types of BS antennas such as adaptive antennas and
intelligent antennas (The design specifications of these types will not be covered in
this document).
1.3 Design Concepts of BS Antenna
As the number of mobile communication users is increasing, the frequency allocated
to the mobile communication has been gradually raised from 30MHz to 50MHz,
150MHz, 250MHz, 450MHz, 800MHz and 1800MHz. The design of antennas has
also been changed accordingly.
The design of antennas primarily relies on some mathematical methods and
Computer Aided Design (CAD). The up-to-date method is Finite Difference of Time
Domain (FDTD), which allows the radiation structure to be of any shape and to be
made up of multiple layers of different materials. The BS antennas are usually divided
into directional antennas and omni antennas.
The BS antennas used in High Frequency (HF) and Very High Frequency (VHF) and
the omni antennas used for Ultra High Frequency (UHF) are of the line-shaped type,
which are usually analyzed and designed by the moments method. The directional
antennas used for UHF are normally the linear element antenna or paster-driven flat
type antenna.
These types of antennas can be analyzed and designed by using the element method
and Geometry Theory of Diffraction (GTD hybrid method). In fact, the latter type of
antennas can be simulated by the HFSS software of HP and Ansoft. HFSS can be
used to easily obtain the electrical specifications of this type of antennas, and then
the best design can be worked out.
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9. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
The BS antenna is a kind of open field-effect radiator, which involves sophisticated
field analysis and numerical analysis. However, pure and time-consuming theoretical
analysis is not desired as antenna is intended for practical use. Designers should
accumulate experience and take the advantage of simulation software to work out the
antenna design efficiently.
As previously mentioned, the design of antenna should take the system compatibility
into consideration. System design and antenna design are closely related. A
component (functional module) may be a high performance one when viewed
independently. However, it may not be the best choice from a system point of view.
Take the printed paster antenna for example. It is less efficient than the common
dipolar antenna. But due to its small cross section and the advantage of printing
technology, it has helped turn a lot of new systems into reality. Its advantages are
evident in the application of mobile telecommunication terminal, micro cellular, radar,
and navigation equipment. Hence, antenna designer should especially take the
following factors into consideration:
Regional structure: Determine the signal coverage area and the antenna
direction.
BS antenna: the antenna height, structure, installation, down tilt requirement of
beams.
Noise level: the thermal noise and ambient noise.
Interference: the interference level, features, and co-channel interference and
neighbor channel interference.
Signal requirement: the best working frequency, bandwidth, cross interference,
and frequency reuse.
Cost of research, development, and processing.
Reliability: the technical maintenance required, installation, and installation
charges.
Vulnerability: Rust and corrosion if the antenna is installed outdoors.
User requirements
There are also some other factors that need to be considered.
The key point is designers should turn these factors into specific requirements of
hardware design and then design the antenna according to these requirements.
2 Basic Technologies
2.1 BTS Antenna
BS is widely used in the GSM digital cellular communication system, ETS wireless
access system and other terrestrial communication fields. For different fields, different
types of antennas are used, and the design specifications also differ.
In the mobile communications, the BS serves the Mobile Station (MS). Generally
speaking, it is fixed, though it also can be semi-fixed or vehicle-mounted. The
semi-fixed BS refers to the BS whose location often changes, but communication
service is not required when it is moving.
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10. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
The vehicle-mounted BS is usually used in the vehicle dispatching center, which
requires communication in mobile state. The document describes only the antennas
of the fixed BSs.
Figure 4 shows the major considerations in BS antenna design. Though the antenna
design belongs to electrical design in the narrow sense, it involves with many other
fields. The most important is hardware technological conditions worked out according
to requirements of the system design.
基站天线设计 BS antenna design 电气设计 Electrical design
机械设计 Mechanical design 于无线链路有
关的设计事项
Design related to radio
link
单元和天线件设
计
Unit and antenna
component design
区域特点 Regional feature
要求的 D/U Required D/U 有无分集 Diversity requirement
频率范围 Frequency range 单元 Unit
方向图的合成 Pattern synthesis 馈电电路 Feeder cabling
无源交调 Passive
inter-modulation
风载荷设计 Wind load design
地震负载设计 Earthquake design 天线罩设计 Antenna mask design
结构件设计 Structure design 包装设计 Package design
Figure 4 Key issues in BS antenna design
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11. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
To determine the hardware technical specifications, the electrical and mechanical
performance should be compared, and tradeoff between performance and cost is
necessary. In some cases, performance and cost are put in the first place, followed by
the mechanical design of electricity. Figure 5 shows the procedures of antenna
design.
基站天线设计方
法
BS antenna design 无线电链路预
估
Radio link estimation
设备结构接口 Equipment interface 硬件分析 Hardware analysis
成本预估 Cost estimation 分析数据 Analysis data
测量数据 Measurement data 各种算法 Algorithms
CAD 技术 CAM
系统要求 System requirement 频率/带宽 Frequency/bandwidth
信道/容量 Channel/capacity 业务范围 Service range
D/U 值 D/U value 成本 Cost
指标要求 Index requirement
增益 Gain 方向图 Pattern
极化特征 Polarization feature 机械性能 Mechanical feature
尺寸/总量 Dimension/weight
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12. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
设计输出 Design output
结构布局 Structure layout 天线效率 Antenna efficiency
馈线网络 Feeder network 材料要求 Material requirement
电气参数 Electrical parameters 机械参数 Mechanical
parameters
成本组成 Cost composition
Figure 5 BS antenna design procedures
In practice, it is of great importance to consider how to install the antenna after the
antenna is assembled. It is because it may be much more expensive to install a BS
antenna than to produce one. Therefore, not only production cost but also an antenna
structure that allows easy installation should be taken into consideration.
2.2 System Requirements and Antenna Technologies
In the mobile communication system, the antenna helps establish the wireless
transmission connections between the wireless telephones. To ensure the
communication between the BS and the MSs within the service area, the energy of
the radio waves should radiate as evenly as possible, and the gain of the antenna
should be as high as possible.
As the width of the service area is definite, the gain cannot be raised by narrowing the
horizontal beam width. However, the vertical linear array antenna can raise the
antenna gain effectively. In the cellular system, the gain of the BS antenna is usually
between 7 dBd and 15 dBd.
Multi-channel communication is commonly used to increase the communication
capacity and improve frequency reuse ratio. This requires a wide band system with
functions of combiner and divider. At present, the frequency band of the BS devices in
China GSM cellular system is 890--960MHz. 890--915MHz is used for receiving
signals, and 935-960MHz for sending signals. The antenna relative band width is
required to be greater than 8%, and intra-band VSWR less than 1.5. When the
antenna is receiving and sending signals, passive inter-modulation will result, which in
turn increases cross interference.
With the rapid increase of the subscriber base, insufficiency of communication
channels has become a problem for urban communications. To solve this problem,
application of frequency reuse technology is strongly demanded. Though the cellular
system can reuse frequency, the effectiveness of this technology relies on the
radiation pattern of the BS antenna. The major-beam tilt and bean shaping
technologies can improve the reuse of frequency effectively.
Non-stadia transmission is one of the most common features in the mobile
communications, especially in the modern cities. The numerous high buildings in the
city constitute a complicated radio transmission environment for the mobile
subscribers and result in fading of radio transmission. The receiving electrical level is
thus affected and in some cases may fluctuate for more than 30 dB.
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13. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
If the system design should be based on the lowest receiving level, the equipment
could be rather expensive. The diversity receiving technology can overcome the
fading effectively. Though application of this technology needs more devices, it is the
most cost-effective solution from the system point of view and is at the moment the
most commonly-used technology to overcome fading.
Figure 6 shows the relationship between the system requirements and the antenna
technologies.
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14. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
系统要求 System requirements 高电平均匀照射业务区 Even radiation of high
level in the service
area
抑制业务区以外的辐射
(频率复用技术)
Suppression of
radiation outside the
service area
(frequency reuse
technology)
多信道宽频带 Multi-channel and
wide frequency band
稳定的接受电平 Steady receiving level 降低延迟扩展 Reduction of delayed
expansion
体积小,重量轻,抗风 Compact, light, and
wind-proof
天线技术 Antenna technology
主波束倾斜,赋形波束
综合
Integration of beam
downtilt and
shaped-beam
technologies
宽带天线单元,宽带匹
配网络
Broadband antenna
unit and broadband
matching network
分集接收 Diversity receiving 机械设计 Mechanical design
Figure 6 System requirement and antenna technology
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15. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
2.3 Types of Antennas
The structure or type of the BS antenna is determined by the size and landform of the
service area, and the number of cells and channels.
If the service area is within the limited range of angles on the horizontal plane, the
plat type antenna is often used. The half power beam angles of horizontal plane
include 33°, 60°, 90°, 120°, 180°, etc.
If the service area should be covered in all directions horizontally, the omni antenna is
often used, which can only tilted vertically. In the early cellular system, the length of
the antenna was determined by the gain required, and even excitation was usually
adopted for the array antennas to achieve a higher gain.
Figure 7 is the diagram of the typical structure of the omni antenna.
(a) Middle-feed mode (b) Bottom feed mode
Figure 7 Omni antenna
For the middle-feed antenna (see note 1), if the beam downtilt technology is not
applied, the maximum directivity in the direction of 0° without any tilting or declining in
the whole working frequency band.
As to the bottom-feed antenna (see note 2), however, the monotone phase variation
of every unit will cause the maximum beam directivity to change with the frequency,
which affects the network coverage seriously. When the cells should be re-divided to
achieve the effective reuse of frequency, the value of D/U is a consideration more
important than antenna gain in BS antenna design. At present, the electrical or
mechanical major-beam downtilt technology is commonly applied to the BS antenna
design in cellular mobile communications system.
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16. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
Experiments show that beam downtilt can reduce the co-channel interference by
about 10dB, as shown in Figure 8. The network optimization experts have fully
realized that the beam downtilt technology is the basic technology to increase
frequency reuse because it can form appropriate array antenna radiation pattern to
compress the side lobes beside the major beam, thus reducing the frequency reuse
distance. Figure 9 shows how the BS antennas can be classified by functions and by
features.
是理想的自由方向图假
设条件下的
Ideal pattern 计算方向图 Computed pattern
接收信号强度 Strength of received signal 倾角=3oC Downtilt=3oC
高基站距离 Distance between high
BTSs
Figure 8 Influence of beam downtilt to the frequency reuse
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17. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
天线 Antenna 低旁瓣 Lower side lobe
D/U 值增加,上旁瓣被
抑制
The D/U can be
increased to suppress
the upper side lobe.
波束倾斜 Beam downtilt
零点填充 Zero stuffing 高电平 High level
业务区 Service area 干扰区 Interference area
Figure 9 Impact of side lobe on frequency reuse
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18. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
基站天线 BS antenna 分集天线 Diversity antenna
单个天线 Single antenna 阵天线 Array antenna
单元天线 Unit antenna 水平面赋形波束 Shaped beam on
horizontal plane
垂直面赋形波束 Shaped-beam on
vertical plane
空间分集 Space diversity
极化分集 Polarization diversity 水平面波束控制 Beam control on
horizontal plane
多波束 Multi-beam 均匀激励 Uniform excitement
倾斜波束 E/M Beam downtilt E/M 旁瓣控制 Side lobe control
零点填充 Zero stuffing 振子,微带贴片,寄生
微带贴片
Oscillator,
micro-paster, parasitic
micro-paster
微带,缝隙,角反射器
天线
Micro-strip, slot,
corner-reflector
antenna
Figure 10 Classification of BS antenna
Note 1: Middle feeder refers to the case that the feeder point of the coaxial array omni
antenna is at the middle element. In this case, no matter how the frequency changes,
the phase change of the upper and lower elements is symmetrical, i.e., the maximum
gain of antenna is at 0°
(non-downtilt design technology).
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19. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
Note 2: Bottom feed refers to the case that the feed point of the coaxial array omni
antenna is at the bottom of each element
(Bottom feed is different from the case that the power input point is at the bottom,
because the power input point of the middle-feed antenna is also at the bottom. The
difference between the middle-feed antenna and the bottom-feed antenna lies in the
actual location of the feed point). In the case of bottom feed, the phase change from
the lower to the upper elements is not symmetrical, i.e. the maximum directivity is
related with the frequency.
2.4 Design of Shaped-beam Antenna
The shaped-beam technology can increase the space frequency reuse rate. In the
cellular system, the BS antenna is required to radiate the lowest possible level to
another cell using the same frequency, but the highest possible level to the
poorly-cover area within the service area. The shaped-beam antenna falls into two
types. One is horizontal shaped-beam radiation pattern, referred to as fan beam in
engineering; another is vertical shaped-beam radiation patter, or cosecant beam.
In fact, the major-beam downtilt is not the shaped-beam technology in real sense,
though they are used for similar purpose. This document only covers the design of
shaped-beam antenna in the cellular system. For implementation of beam synthesis
and numerical technique, please refer to the related documents.
2.4.1 Fan Beam Antenna
In the metropolitan cellular system, the horizontal beam of BS antenna is not
omni-directional. The fan beam can effectively cover the service area and improve the
reuse of frequency. The typical fan beam antenna is the corner-reflector antenna. It
can adjust the beam width by controlling the angle of the reflector. Figure 11 shows
the basic geometry of the corner-reflector antenna.
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20. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
偶极子 Dipole 馈电路 Feeder circuit
几何机构 Geometric
structure
H面方向图 Pattern on
horizontal plane
Figure 11 Corner-reflector antenna
In the early cellular system, this type of antenna was commonly used to get the fan
beam. However, it is now seldom used due to its defects such as less compact feeder
network, large cross section, and complicated structure. Hence, this document will
detail other types of fan beam antennas instead. These antennas are now commonly
applied to the modern cellular system. See Figure 12-a, 12-b, and 12-c.
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21. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
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22. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
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23. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
Figure 12 HFSS simulation instance
These units are called plat antenna units due to their thin cross section. When
assembled with the appropriate antenna cover, it looks like a flat board. The formulas
used for the design of these antenna units are rather complex and the hybrid method
of MM and GTD is often resorted to. However, these methods are not suitable for an
application engineer.
To solve this problem, two American companies, Ansoft and HP, released the High
Frequency Simulation Software (HFSS) so that the answer to the electromagnetic
field problem can be found out with basic antenna principles and experience about
antenna on mind. Through the simulation of HFSS, flat antenna can change the
values of width (W) and height (H) and thus can control the half-power beam width on
the horizontal plane.
The half-wave dipole HFSS result can be controlled within the range of 55°-120° (It
can be realized in terms of structure.). To obtain a beam width between 30° and 55°,
two excitation sources should be placed in a certain interval on the horizontal
direction of the flat.
Figure 13 is the HFSS simulation result of GSM 900MHz unipolar flat unit. Designers
should be noted that the effect of antenna cover on the radiation performance should
be taken into consideration.
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24. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
2.4.2 Vertical Shaped-beam Antenna
ixed to a certain height covers a limited area on
gnal level is equal in each spot of the service
As Figure 14 shows, the antenna f
horizontal plane so that the receiving si
area. To obtain shaped-beam on the vertical plane, multiple flat antennas are required
to form an array on the vertical plane. Meanwhile, appropriate amplitude and phase
feeding are required for each unit. The amplitude and phase control technology of
feeding network is very important for the beam shaping on vertical plane. The more
units there are, the more ideal shaped-beam can be obtained.
天线 Antenna 水平面 Horizontal plane
低旁瓣区 e lobeLower sid 方向图 Pattern
业务区半径 e nce areaRadius of servic
area
干扰区 Interfere
Figure 13 Shaped beam with low interference (vertical plane)
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25. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
Figure 14 Pattern of antenna array with four antennas (horizontal)
Figure 15 Pattern of antenna array with four antennas (vertical)
HFSS can be firstly used to obtain the fan beam required. Its vertical pattern is
Fv( ).
Take the four-unit array for example. The amplitudes and phases of the units
numbered from 1 to 4 are represented by A1, A2, A3, A4, ф1, ф2, ф3, and ф4
respectively. The following equation can be obtained:
f( ) = Ee−jkr
r {A1e−jk( 3
2 dxCOS( )+ 1)
+ A2e−jk( 1
2 dxCOS( )+ 2)
+A3e−jk(− 1
2 dxCOS( )+ 3)
+ A4e−jk(− 3
2 dxCOS( )+ 4)
} Fv( )
Change A1, A2, A3, A4, ф1, ф2, ф3, and ф4. With the help of computer, optimization
can be done and the vertical shaped beam as shown in Figure 16 can be obtained.
The figure clearly shows the first side lobe of the symmetrical radiation pattern is
much higher.
After the shaping, the upper side lobe is obviously suppressed and is improved by 7
dB as compared with the symmetrical radiation pattern. The zero point of the lower
side lobe is stuffed and the radiation level in the service area is improved.
2.4.3 Beam Tilt
The beam tilt technology aims to tilt the major beam so that the level of the radiation
towards the frequency reuse area can be reduced. In this case, although the level of
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26. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
the carrier on the boarder of the area is reduced, the interference level declines much
more than the carrier level does. It is an advantage in the system design and is
adopted worldwide by most of the cellular systems.
Figure 16
Figure (17-a) Maximum ratio combining of different correlation coefficients between
channels
The beam tilt can also be realized through electric design. That is, the downtilt of
beam can be achieved by adjusting the excitation coefficients, amplitude and phase.
A set of antenna equipped with both electric downtilt and mechanic downtilt can be
useful especially during the network optimization when the fixed electric downtilt is far
from enough.
2.5 BS Diversity Antenna
BS diversity antenna has been widely applied in the cellular systems. It can reduce
the fading when the two antennas are two wave lengths away from each other on
horizontal plane. Although receiving diversity needs two or more ports, it can
effectively reduce the fading. As a result, the BTS power is reduced and the
transmission quality is improved.
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27. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
In the mobile telecommunication, the signal received will be affected seriously in
urban area with a lot of high buildings or forest with a lot trees. The fast fading is
caused by the reflection of fixed and mobile objects. Deep fading exists in a certain
part of the wave length.
In a densely-populated area, the signals received by MS at any moment contain a lot
of plane electromagnetic waves that are transmitted in parallel. The amplitudes,
phases, and angles of these electromagnetic waves are random ones. Statistically,
the amplitude and phase of one electromagnetic wave can be regarded as
independent of other electromagnetic wave. All the signal components are
synthesized into one complex standing wave, whose signal strength varies with the
change of each component.
There could be a fading of 20-30dB in a distance of several vehicles and the
existence of large amount of propagation path results in the multi-path symptom. This
kind of fading is not only found in the MS receive signal, but also BTS receive signal.
However, the multi-path fast fading disappears in the place which is ten wave lengths
away. That is, the diversity receiving can improve the communication reliability
without increasing the transmitter power or channel bandwidth.
The diversity receiving is based on one basic concept: when two or more samplings
are made for a random process, these samplings are fading independently. The
probability that all the samples are less than a fixed value is much lower than the
probability that one sample is less than this value. Hence, the comprehensive
sampling can help improve the performance of transceiver and the effect is much
better than the single sampling.
The function of synthesis is to correct the phase and delay of signals after the
multi-path transmission, add up the input signal level vectors, and add the noise at
random. So the signal-to-noise ratio after synthesis of channels is generally greater
than that of the single receiving channel. As the chance of simultaneous fading of
incoherent signals is slim, the system can be more reliable. Figure (17-b) shows how
the correlation coefficient changes with the height of the antenna and the distance.
The structure of BS diversity antenna comes into three types: space diversity, pattern
diversity, and polarity diversity. Space diversity is the most common one.
Relationship between space diversity antenna and related coefficients
To explain this relationship, one parameter is introduced, where =
hbe
d ,hbe is
the effective height of the BS diversity receiving antenna and d is the distance
between the BS diversity receiving antennas.
Figure 17-b displays the curve that illustrates the relationship between coherent of
incidence angle ( ) and .
In the urban area, as there are a lot of scatterers along the propagation path between
MS and BS, the coherent is much smaller than that in the suburb. The greater the
coherent is, the higher diversity gain will be. When the coherent is greater than 0.7,
the improvement of diversity gain is not so obvious than the case when is less than
0.7.
Figure 17-a shows that when the signal level is -10dB, the probability that the
amplitude is lower than -10dB is 1.3% ( =0.7) or 0.52% ( =0.2). That is, when the
coherent drops from 0.7 to 0.2 and the probability is improved by 0.8% only. When
both the feasibility and cost are taken into consideration in practice, it is most
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28. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
appropriate to have less than 0.7. In this way, the BSs in urban area will have a
better diversity gain.
Figure 17-b also shows that when the receive signal reaches , the coherent is
affected substantially. When is equal to 0°, the coherent is the smallest and the
diversity gain is the greatest. When is equal to 90°, the coherent is the greatest,
while the diversity gain is the smallest. As the MS may move in any direction, i.e.,
could be any value within the range of 0°~90°, and the antenna will not be designed
based on the best ( =0°) case or worst case ( =90°), it is recommended to adopt the
mean value 45° for and the distance between two receive antennas is determined
by =45° and =0.7.
equaling to 45° and equaling to 0.7,With can be computed, i.e. 9. Table 1
shows the effective heights and inter-antenna spaces of the diversity antenna.
Table 2-1 Effective heights and inter-antenna spaces of the diversity antenna.( =45°, =0.7)
Effective height of
diversity antenna
(m)
20 50 70 80 90 100
Space between
antennas (m)
≥3.0 5.6 6.7 7.8 8.9 10 11.1
The following result can be obtained from the above data:
d = 0.11hbe [M]
The diversity gain is affected by the following factors: inter-antenna space, diversity
combination technology, diversity tuple, and communication probability. When the
duplex space diversity and maximum ratio combination are used, the relationship
between diversity gain and coherent can be illustrated by Figure 17-a.
For example, if the probability that the amplitude is larger than the horizontal ordinate
is 90% and =0.7, the signal level is -4.6dB and the signal level of a single Rayleigh
channel is -9.5dB. Thus, the gain of duplex space diversity is 4.9dB. The diversity
gain corresponding to other probability can be obtained in the same way.
When the antenna is placed horizontally as shown in Figure 17-c, its isolation is
determined by the antenna radiation pattern, the space, and gain.
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29. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
辐射方向图 Radiation pattern 90o
方向 90o
Figure 17 Horizontal placement of antenna
Generally, the fading introduced by Voltage Standing Wave Ratio (VSWR) is not
included. If the gain of the transmit antenna on the maximum radio direction is Gat
(dBi), the level of the side lobe at the direction of 90°is SLt, the gain of the receive
antenna on the maximum radio direction is Gar(dBi), the level of the side lobe at the
direction of 90° is SLr (dBp, against the major beam. The value is negative), the
horizontal spacing is Dh, the inter-antenna isolation can be given by:
Adis = -22 - 20log (Dh/l) + (Gat + Gar) + (SLt + SLr) (dB) [negative]
If the antenna is omni antenna, SLr=SLt=0 (dB) and l in the equation is the working
wave length. (regarded as far field). Generally the SL of 65° fan beam antenna is
about -18dBp, that of 90° fan beam antenna is about -9dBp, and that of 120° fan
beam antenna is about -7dBp. The actual value can be determined according to the
antenna pattern.
Example 1: 65° fan antenna, Gat=Gar=15dBi, SLt=SLr=-18dBp,
f=915MHz,l=0.328m
Adis=-30 dB (This index must be met in GSM system.)
The following result can be obtained as per previous formula: Dh=1.25 l=0.41m
Example 2: Omni antenna, Gat=Gar=11dBi,SLt=SLr=0dBp, f=915MHz, l=0.328m
Adis=-30 dB (This index must be met in GSM system.)
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30. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
The following result can be obtained as per previous formula: Dh=31.6 l=10.4m
When the antenna is placed vertically, the isolation between two antenna is
approximately:
Adis=-28-40log(Dv/l)
垂直面内辐射方向图 Radiation pattern on
vertical plane
90o
方向 90o
Figure 18 Vertical placement of antenna
Figure 18 shows the pattern space antenna for a whole cell. It is composed of four
sets of antennas, forming an angle of 90° with one another. They are used to achieve
the 180° fan bean in the omni pattern and are placed separately. The internal
between two omni antennas is 0. Thus, the difference of antenna receive power is
caused by the difference of pattern.
When the distance between the 180° fan beam antennas is 6 wave lengths, the test
shows that the correlation coefficient is less than 0.2.
Polarity diversity antenna emerges along with the rapid development of cellular
system. It integrates two orthogonal (0°/90° or +45°/-45°) polarity antennas and thus
compactness is its most remarkable feature. However, the polarization feature of
incidence angle is more likely to be vertical polarization and the average receive
power of the port of 0°/90° dual polarization antenna differs a lot. Hence, the
improvement of Signal Noise Ratio (S/N) is less obvious than other diversity
measures do. But with the +45°/-45° dual-polarization antenna, the diversity gain
equivalent to the one of space diversity antenna can be obtained.
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31. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
2.6 Passive Inter-modulation of Base Station Antenna
Passive inter-modulation (PIM) is one of the major factors that generate co-channel
interference. When the antenna works in duplex mode, PIM should be considered. In
most of the cases, the PIM on transmit channel is caused by the non-linear feature of
the metal heterojunction that is found between the antenna radiation unit and the
feeder.
The co-channel interference is thus generated on the receiving branch. To enable
the concurrent transmitting and receiving, the inter-modulation power should be lower
than a standard value during the design and processing of antenna. For GSM cellular
system, this standard value is around -103 dBm.
2.6.1 Relationship between PIM and Receiving-transmitting Frequency
Suppose the frequencies of two transmit carriers are respectively Fi and Fj, the (m +
n)th
modulation is:
mFi nfjF1M=
Where, m and n are positive odd numbers and is the frequency of the
interference wave on the receiving band. The probability of the interference wave is
decided by the space between transmit power and receive power and the value of (m
+ n).
F 1M
For example, the transmit frequency of GSM 900 MHz cellular system in China falls
within the range from 935MHz to 960MHz and the receive frequency from 890 to
915MHz. The space between transmit power and receive power is 20MHz. Thus, the
PIM is of 3-order. If no effective suppression measures are taken, serious interference
will result. See Figure 19.
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32. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
TX 产生 3 阶交调对 RX
的干扰
TX generates 3-order
inter-modulation that
interferes RX.
TX 产生 5 阶交调对 RX
的干扰
TX generates 5-order
inter-modulation that
interferes RX.
TX 产生 7 阶交调对 RX
的干扰
TX generates 7-order
inter-modulation that
interferes RX.
Figure 19 High-order inter-modulation and interference
The relationship between the order of PIM and the power generated can be
approximately illustrated by the formula: (m + n) × 10 dB. If the frequency space
between transmit wave and receive wave is small, 5-order or 3-order PIM will
generate interference and the level will be higher than the 7-order PIM by 20 or 40dB.
2.6.2 PIM Generator and Suppression Technology
Power generated by PIM is determined by the metal type and the structure of the
connector. PIM is mainly generated on the antenna radiator, co-axial connector,
welded joint and the contact surface that is likely to get rusted and corroded. By now,
there is no definite answer to the relationship between PIM and the structure of the
contact point.
With the rapid increase of mobile communication demand, a large number of BS
antennas are in demand, especially the duplex antenna which is more cost-effective.
The duplex antenna will be widely applied. Therefore, antenna designers should
attach more and more importance to the development of PIM suppression technology.
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33. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
Table 2-2 Table 2 Basic PIM suppression methods
PIM generator Suppression method:
Radiator Use printed antenna to replace the oscillator unit
Connector Increase the contact area and use silver plate
Welded joint Reduce the number of welded joints and add solder to the
welded joint
Rust and corrosive surface Coat the surface to prevent the oxidation
Feeding network Try to use strip line or micro-strip line to replace the cable
3 Major Index Requirement for BS Antenna Design
3.1 VSWR of BS Antenna
For the BS antenna of mobile communication cellular system, the maximum value of
VSWR should be less than or equal to 1.5:1. And this requirement should be met at
the specified working frequency band and temperature range. If the input impedance
of the antenna is ZA, the nominal characteristic impedance is , the reflection
factor can be given by:
Z0
|Г| =
|ZA−Z0|
|ZA+Z0|
,VSWR =
1+|Г|
1−|Г|
Where is equal to 50 . The matching feature of the port can also be
represented by the return loss:
Z0
R.L.(dB) = 20 |Г|logloglog .
When VSWR is 1.5:1, the computed R.L. should be -13.98dB.
3.2 Gain (dBi)
The directivity characteristic of antenna can be depicted by the pattern. But generally
the value is used to show the concentration degree of the electromagnetic energy
radiated by antenna, i.e. directivity factor D. D is defined by the following formula:
D =
Sd
S0
|P
∑d
=P
∑0
When the thermal loss of the antenna is considered, the antenna efficiency A
should be introduced. It is defined as follows:
A =
P
PA
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34. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
P PAWhere, is the radiation power of antenna and is the input power of
antenna.
When the radiation performances of the two antennas are compared, if their input
powers remain unchanged, the antenna gain can be given by:
G = A×D
G = 10 (
(suppose the efficiency of unipole antenna is 100%).
As generally the gain is given in decibel (dB), the gain can also be given by
logloglog A×D) dBi (as compared with Isotropic antenna).
If the half-wave dipole is used as the reference antenna, the unit of gain is dBd and 0
dBd equals to 2.15 dBi (see Figure 20). Other units will not be used for the BS
antenna. Please note that the BS antenna gain refers to the gain of the working
frequency band unless otherwise specified.
实际天线 Actual antenna 半波偶极子天线 Half-wave dipole
antenna
各向同性天线 Various like
antennas
Figure 20 Relationship between dBi, dBd, ERP, and EIRP
3.3 Half Power Beam Width (HPBW)
As the BS antenna is generally erected vertically to the ground, the HPBWs of vertical
plane and horizontal plane are often used to describe the HPBW of BS antenna. The
range of HPBW should be given for the working frequency band, e.g. 65°±6°.For a
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35. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
directional antenna, the included angle between the two half-power points relative to
the maximum radiant point is the half-power beam width.
3.4 Front-to-Back Ratio (F/B)
Front-to-Back Ratio (F/B) is an important factor measuring the suppression ability of
the antenna backward beam. It is the level difference between the maximum beam
and the side lobe within the range of 180°± 30° starting from 0o
. It is a positive value
in dB. F/B is associated with the antenna gain and the type of antenna and ranges
from 18 to 45 dB.
The specific index requirement is determined by the network planning and
optimization. At present, the F/B ratio of Huawei 900/1800 MHz directional antenna is
20-25dB.
3.5 Isolation between Ports
There are various types of multi-port antennas, such as dual polarization antenna,
two-band dual polarization antenna, two-band dual polarization duplex antenna.
When they work in duplex mode, the isolation between ports should be greater than
30dB.
3.6 Polarization
Polarization refers to the orientation of electric filed vector radiated by the antenna on
the space. The linear polarization antenna is often adopted for the BS.
With the ground as the reference plane, if the electric field vector is vertical to the
ground, it is called Vertical Polarization (VP).
If the electric field vector is parallel to the ground, it is called Horizontal Polarization
(HP). The dual polarization antenna often adopts the +45° and -45° cross dual-line
polarization.
3.7 Power Capacity
Power capacity here refers to the average power capacity. Antenna is composed of
matching device, balancing device, phase-shifting device, and other coupling device.
The power it can bear is limited. Based on the actual maximum input power of BS
antenna (Single carrier power is 20W.), if one antenna port can receive maximum 6
carriers, the antenna input power should be 120W. Thus the power capacity per
antenna port should be greater than 200W when the temperature is 65°
C.
3.8 Zero Stuffing
When shaped-beam design is adopted in the vertical surface of base station
antennas, the first zero point of the lower side lobe need to be stuffed without any
obvious depth, so as to make the radiant level more even within the service area.
Usually, if the zero depth is greater than -26dB in relation to major beam, this means
the antenna has zero stuffing.
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36. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
1)
2)
3)
3.9 Upper Side Lobe Suppression
To enhance the frequency reuse efficiency and reduce the co-channel interference to
adjacent cells in a microcell cellular system, the base station antenna beam can be
shaped based on some principles.
That is, those side lobes that aim at the interference area should be lowered as much
as possible, and the D/U value (ratio of strengths of desired and undesired signals)
should be increased, and the level of the upper side lobe should be less than -18dB.
There is no such a requirement for macrocell base station antennas
3.10 Beam Downtilt
Antenna downtilt needs to be adjusted to meet the coverage requirement or network
optimization requirement. However, if the downtilt is adjusted mechanically, when the
downtilt is adjusted by an angle of more than 8°, the horizontal beam width of base
station antenna will loss its shape, which affects the sector coverage. At present,
there are following types of beam downtilts:
Fixed beam electronic downtilt. By adjusting the amplitude and phase of radiator,
the antenna major beam can deviate from the normal direction of the antenna
array element for a certain angle, e.g. 3°, 6°, or 9°. When used together with
mechanical downtilt, electronic downtilt allows an adjustable range of antenna
downtilt angle of 18-20°.
Manual-adjustable beam electronic downtilt. The adjustable phase-shifter can be
adopted for the BS antenna, so that the direction of the main bean can be
adjusted continuously within the range of 0-10° (not including the mechanical
adjustment).The major suppliers of this type of antenna include
HUBER-SUNNER and ALLEN DB.
Remote-control beam electronic plunge angle. This type of base station antenna
is equipped with micro servo system. The phase shifter can be controlled by the
precision electric engine so as to remotely control the program. However, the
addition of active control circuit degrades the reliability of antenna and
complicates the lightening-proof problem. DELTEC (New Zealand) is one of the
major suppliers of this type of antenna.
3.11 Two-band Dual Polarization Antenna
It is a new type of antenna that integrates the antennas of two bands, e.g., GSM/DCS,
GSM/WCDMA and DCS/WCDMA. See figure 21.
3.12 Two-band Dual Polarization Duplex Antenna
To reduce the feeders, duplexer (in fact it is a filter combiner) is used to combine the
two powers with the same polarization but different frequency into one. See Figure
21.
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37. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
双频双极化天线 Two-band dual
polarization antenna
双频双工双极化天线 Two-band dual
polarization duplex
antenna
GSM 天线单元 GSM antenna unit DCS 天线单元 DCS antenna unit
滤波合路器 Filtering combiner
Figure 21 Multi-port antenna
3.13 Grounding system
BS antenna is normally installed on a high position. To prevent the lightning strike, the
DC resistance between inner and outer conductors of antenna port should be
designed as 0.
3.14 Antenna Input Connector
To reduce the passive inter-modulation and ensure the RF connection, the input
connector of antenna adopts 7/16DIN-Female. Before the antenna is used, the
connector should be properly capped to avoid the oxidation and the intrusion of
impurities.
3.15 Passive Inter-Modulation (PIM)
To reduce the noise resulting from the non-linearity of antenna, the PIM of antenna
should be less than -103dBm (2x10W).
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38. Basic Principles and Design Specifications of Antenna in Mobile Communications 001
3.16 Dimensions
To facilitate the storage, transportation, installation, and ensure the security, so far as
the electrical indices are satisfied, the size of antenna should be as small as possible.
3.17 Weight
To facilitate the storage, transportation, installation, and ensure the security, so far as
the electrical indices are satisfied, the antenna should be as light as possible.
3.18 Wind Load
As BS antennas are usually installed on high buildings and towers, it is required that
an antenna should work normally when the wind speed is 36m/s, and remain
undamaged when it is 55m/s, especially in coastal areas where the wind is usually
strong.
3.19 Working Temperature
A BS antenna should work normally when the environmental temperatures is between
-40°C and +65°C.
3.20 Humidity
A BS antenna should work normally when the environmental relative humidity is
between 0 and 98%.
3.21 Lightning Protection
Direct DC grounding is required for all the radio frequency input ports of a BS
antenna.
3.22 3-Proof Capability
A base station antenna should have a 3-proof capability, namely, humidity-proof, salt
fog-proof and mould-proof. A base station omni-antenna should allow upside-down
installation, and should satisfy the 3-proof requirement as well.
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