This document summarizes a lecture on smart antennas. It introduces the concept of spatial division multiple access (SDMA) which allows multiple users in the same cell to use the same frequency channel by using antenna arrays and signal processing. It describes early SDMA approaches that assumed line-of-sight propagation and used beamforming. More advanced approaches are needed to handle multipath propagation using techniques like MIMO channel modeling and source separation.
This document summarizes a lecture on CDMA (Code Division Multiple Access). It discusses different multiple access techniques including FDMA, TDMA, FH-CDMA, TH-CDMA and DS-CDMA. It provides details on DS-CDMA transmission and reception, including how code orthogonality allows multiple users to access the channel simultaneously. Advanced reception techniques for asynchronous CDMA and dispersive channels are also mentioned. Real-world CDMA applications including IS-95, UMTS and wireless LANs are listed.
This document summarizes a lecture on multi-tone modulation techniques. It discusses ADSL and VDSL specifications including spectrum allocation and channel characteristics. It then covers topics like bit loading, peak-to-average power ratio problems, time-domain equalization using a TEQ to shorten the channel impulse response, and alternative frequency-domain equalization structures. The document provides examples and illustrations of these concepts.
This document summarizes a lecture on transmitter design for digital communication systems. It discusses:
1) The basic components of a transmitter including constellations for linear modulation such as PAM, PSK, and QAM, and transmit filters.
2) Preliminaries on passband versus baseband transmission and how a baseband equivalent model can be obtained using complex envelope signals.
3) Details on common constellation designs including distance metrics for PAM, PSK, and QAM in an AWGN channel.
4) Analysis of bit error rate performance for the transmission of a single symbol over an AWGN channel for different constellations. The document also discusses designing transmit pulses to eliminate
A robust doa–based smart antenna processor for gsm base stationsmarwaeng
This document summarizes a robust smart antenna processor for GSM base stations that uses direction-of-arrival (DOA) estimation. It estimates DOAs in the uplink using multiple algorithms, including unitary ESPRIT and Capon's beamformer. It then tracks DOAs separately for uplink and downlink to form antenna patterns that suppress interference. By adapting weights within each GSM frame, it provides up to a 35dB improvement in signal-to-noise-and-interference ratio and outperforms conventional beamformers that place sharp nulls.
This document summarizes a lecture on multi-tone modulation techniques for digital subscriber line (DSL) modems. It discusses how discrete multi-tone (DMT) modulation, also known as orthogonal frequency division multiplexing (OFDM), is used in asymmetric digital subscriber line (ADSL) standards to divide high-speed data streams into multiple low-speed streams carried on individual frequency tones. This allows for higher data rates over copper telephone lines by mitigating interference and attenuation across the frequency spectrum. The lecture provides an overview of DMT principles including modulation and demodulation using the inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT).
This document outlines a postacademic course on telecommunications transmission techniques taught by Marc Moonen at KU Leuven University. The course consists of 10 lectures covering basic digital communication principles as well as advanced topics like multicarrier modulation, CDMA, and MIMO transmission. It introduces concepts like modulation, channel coding, equalization, and multiple access. The document provides an overview of the course schedule, prerequisites, literature references and acknowledges prior work from which content has been adapted.
The document summarizes a lecture on equalization techniques for digital communications. It begins with the lecturer acknowledging feedback that previous lectures moved too quickly and were too technical. It then provides a high-level overview of equalization techniques, including:
- Zero-forcing equalization using linear filters and decision feedback equalizers
- MMSE equalization
- Fractionally spaced equalizers
It also summarizes the key concepts from previous lectures on digital transmission models and the optimal receiver structure involving a whitened matched filter front-end and maximum likelihood sequence estimation (MLSE). The goal of equalization techniques is to provide a lower complexity alternative to MLSE for the decision device while approaching similar performance with the use of channel coding
This document summarizes a lecture on optimal receiver design for digital communication systems. It discusses different types of optimal receivers, including minimum bit-error rate (BER), maximum a-posteriori probability (MAP), maximum likelihood (ML), and minimum distance (MD) receivers. It also examines the receiver structures for transmitting a single symbol and a sequence of symbols over a linear channel with additive white Gaussian noise (AWGN). For a single symbol, the optimal receiver is a matched filter frontend followed by sampling at the symbol rate and decision device. For a sequence, a matched filter frontend and maximum likelihood sequence estimation (MLSE) are used.
This document summarizes a lecture on CDMA (Code Division Multiple Access). It discusses different multiple access techniques including FDMA, TDMA, FH-CDMA, TH-CDMA and DS-CDMA. It provides details on DS-CDMA transmission and reception, including how code orthogonality allows multiple users to access the channel simultaneously. Advanced reception techniques for asynchronous CDMA and dispersive channels are also mentioned. Real-world CDMA applications including IS-95, UMTS and wireless LANs are listed.
This document summarizes a lecture on multi-tone modulation techniques. It discusses ADSL and VDSL specifications including spectrum allocation and channel characteristics. It then covers topics like bit loading, peak-to-average power ratio problems, time-domain equalization using a TEQ to shorten the channel impulse response, and alternative frequency-domain equalization structures. The document provides examples and illustrations of these concepts.
This document summarizes a lecture on transmitter design for digital communication systems. It discusses:
1) The basic components of a transmitter including constellations for linear modulation such as PAM, PSK, and QAM, and transmit filters.
2) Preliminaries on passband versus baseband transmission and how a baseband equivalent model can be obtained using complex envelope signals.
3) Details on common constellation designs including distance metrics for PAM, PSK, and QAM in an AWGN channel.
4) Analysis of bit error rate performance for the transmission of a single symbol over an AWGN channel for different constellations. The document also discusses designing transmit pulses to eliminate
A robust doa–based smart antenna processor for gsm base stationsmarwaeng
This document summarizes a robust smart antenna processor for GSM base stations that uses direction-of-arrival (DOA) estimation. It estimates DOAs in the uplink using multiple algorithms, including unitary ESPRIT and Capon's beamformer. It then tracks DOAs separately for uplink and downlink to form antenna patterns that suppress interference. By adapting weights within each GSM frame, it provides up to a 35dB improvement in signal-to-noise-and-interference ratio and outperforms conventional beamformers that place sharp nulls.
This document summarizes a lecture on multi-tone modulation techniques for digital subscriber line (DSL) modems. It discusses how discrete multi-tone (DMT) modulation, also known as orthogonal frequency division multiplexing (OFDM), is used in asymmetric digital subscriber line (ADSL) standards to divide high-speed data streams into multiple low-speed streams carried on individual frequency tones. This allows for higher data rates over copper telephone lines by mitigating interference and attenuation across the frequency spectrum. The lecture provides an overview of DMT principles including modulation and demodulation using the inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT).
This document outlines a postacademic course on telecommunications transmission techniques taught by Marc Moonen at KU Leuven University. The course consists of 10 lectures covering basic digital communication principles as well as advanced topics like multicarrier modulation, CDMA, and MIMO transmission. It introduces concepts like modulation, channel coding, equalization, and multiple access. The document provides an overview of the course schedule, prerequisites, literature references and acknowledges prior work from which content has been adapted.
The document summarizes a lecture on equalization techniques for digital communications. It begins with the lecturer acknowledging feedback that previous lectures moved too quickly and were too technical. It then provides a high-level overview of equalization techniques, including:
- Zero-forcing equalization using linear filters and decision feedback equalizers
- MMSE equalization
- Fractionally spaced equalizers
It also summarizes the key concepts from previous lectures on digital transmission models and the optimal receiver structure involving a whitened matched filter front-end and maximum likelihood sequence estimation (MLSE). The goal of equalization techniques is to provide a lower complexity alternative to MLSE for the decision device while approaching similar performance with the use of channel coding
This document summarizes a lecture on optimal receiver design for digital communication systems. It discusses different types of optimal receivers, including minimum bit-error rate (BER), maximum a-posteriori probability (MAP), maximum likelihood (ML), and minimum distance (MD) receivers. It also examines the receiver structures for transmitting a single symbol and a sequence of symbols over a linear channel with additive white Gaussian noise (AWGN). For a single symbol, the optimal receiver is a matched filter frontend followed by sampling at the symbol rate and decision device. For a sequence, a matched filter frontend and maximum likelihood sequence estimation (MLSE) are used.
Channel Overlapping Between IMT-Advanced Users and Fixed Satellite ServiceEECJOURNAL
This document summarizes a research paper that proposes a new algorithm to mitigate interference between IMT-Advanced base stations and fixed satellite services. The algorithm aims to form nulls in the radiation pattern of base stations towards satellites by extracting null directions using MUSIC algorithm and controlling handover. It studies two mobile users moving around a satellite and simulates calculating the shortest separation distance after identifying critical points. Results show the algorithm can enable good coexistence and spectrum sharing between the different wireless services in the C-band frequency range.
This document summarizes a lecture on equalization techniques for digital communications.
1) The optimal receiver structure for transmission over a channel consists of a whitened matched filter frontend and a maximum likelihood sequence estimator (MLSE) such as the Viterbi algorithm. However, the MLSE has high complexity.
2) Equalization filters combined with a memoryless decision device can provide a lower complexity alternative to the MLSE. Linear equalizers like zero-forcing and minimum mean squared error (MMSE) are discussed, as well as decision feedback equalizers.
3) The lecture reviews transmission models and optimal receivers developed in previous lectures, and establishes an input-output model of the transmission system to serve as the basis
The document discusses the syllabus for the EC6801 Wireless Communication course. It covers 5 units: wireless channels, cellular architecture, digital signaling for fading channels, multipath mitigation techniques, and multiple antenna techniques. The key topics covered include path loss models, small scale fading parameters, multiple access techniques, diversity combining, equalization, MIMO systems and capacity in fading channels. The document also provides sample problems for the first two units.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The document analyzes the performance of vector antenna arrays compared to uniform linear arrays for code division multiple access (CDMA) signals in a multipath fading channel. It considers a closed loop power control system for a beamformer-RAKE receiver for a wireless CDMA system with multiple users. Both theoretical analysis and simulations show that vector antennas, which can detect six independent components of the electromagnetic field, can better exploit multipath diversity and significantly improve bit error rate performance over uniform linear arrays in frequency selective rich multipath channels. The vector antennas provide additional diversity to combat signal fading and improve interference suppression for multiple users.
This document analyzes and compares the performance of different adaptive beamforming techniques for smart antennas. It describes switched beamforming, which uses fixed beams, and adaptive beamforming techniques that use algorithms like LMS, SMI, RLS, CGA, CMA, and LSCMA to form an adaptive beam. It simulates these algorithms using MATLAB for a uniform linear array and compares their ability to direct the main beam towards the desired user while nulling interference. The LMS, SMI, RLS, CMA and LSCMA algorithms are found to perform well at directing the beam to the desired user, with LMS having good interference rejection and RLS providing the fastest convergence but highest computational cost.
Comparitive analysis of bit error rates of multiple input multiple output tra...slinpublishers
The document compares the bit error rates of multiple input multiple output (MIMO) transmission schemes, including spatial multiplexing, space-time block codes (STBC), and space-time block coded spatial modulation (STBC-SM). It finds that STBC-SM provides better performance than STBC and vertical-Bell labs layered space-time (V-BLAST) spatial multiplexing. Specifically, simulations show STBC-SM has a lower bit error rate than the other schemes when using four transmit and four receive antennas. The document explains the techniques of V-BLAST, STBC, and STBC-SM in detail.
Error Rate Analysis of MIMO System Using V Blast Detection Technique in Fadin...IJERA Editor
Wireless communication system with multi- antenna arrays has been a field of intensive analysis on the last years. The appliance of multiple sending antennas and Receiving Antennas either side will considerably enhance the data rate and rate. The review of the performance limitations of MIMO system becomes vital since it will provide lot ideas in understanding and planning the important life MIMO systems. Vertical Bell Laboratories layered space Time (V-BLAST). The thought behind Multiple Input and Multiple Output system is that the signals on the transmitter antennas at one finish and also the receiver antennas at the opposite finish are correlative in such how that the performance (Bit Error Rate or BER) or the info rate (bits/sec) of the wireless communication system for every MIMO subscriber are improved. During this paper we tend to are proposing a technique that evaluates the performance of V-BLAST MIMO system in several thought of Rayleigh attenuation surroundings to urge higher performance of the system. In V- BLAST MIMO system a number of linear detection techniques will be used for interference cancellation. At this point we are using MMSE-IC for the same. Our expected system provide higher error rate performance with the used of matched filter at receiver aspect .The projected system compared within the presence of AWGN. Now matched filter applied on V- BLAST MIMO with MMSE-IC system in fading diversity surroundings.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The paper was prepared by communication student of wollega university It was ...ugushe
The document discusses Course Wavelength Division Multiplexing (CWDM) transmission systems. CWDM uses lasers operating at wavelengths spaced 20nm apart between 1271nm to 1611nm to transmit multiple signals over a single fiber. Key components of a CWDM system include optical multiplexer/demultiplexer cards, optical add/drop cards, Ethernet transport cards, and a node control processor. CWDM systems can transmit signals up to 75km and are commonly used in ring topologies for reliable transmission with features like optical add/drop and protection switching. Troubleshooting starts by checking the physical layer like fibers and transceivers, then external connections, and internal card configurations.
An analtical analysis of w cdma smart antennamarwaeng
The document analyzes the signal-to-interference-noise ratio (SINR) performance of two beamforming methods, complex conjugate (CC) and direction-of-arrival (DOA), used in Wideband Code Division Multiple Access (W-CDMA) smart antenna systems. It derives analytic SINR evaluation equations for both methods under different channel conditions. The results show that the CC and DOA methods provide the same mean SINR performance but the CC method is more robust to channel estimation errors. Simulation results are presented to verify the analytic performance and robustness analyses.
Iaetsd stbc-ofdm downlink baseband receiver for mobile wmanIaetsd Iaetsd
This document discusses a proposed space time block code-orthogonal frequency division multiplexing (STBC-OFDM) downlink baseband receiver for mobile wireless metropolitan area networks (WMANs). The proposed receiver applies STBC-OFDM techniques using two transmit antennas and one receive antenna to provide robust performance in outdoor mobile environments. It includes a simple and robust synchronizer and an accurate but affordable channel estimator to overcome challenges of multipath fading channels. Simulation results show the receiver can achieve a coded bit error rate of less than 10-6 for 16QAM modulation under vehicle speeds of 120 km/hr while supporting up to 27.32 Mb/s of uncoded data transmission. The receiver designed in a 90-nm CMOS
This document discusses multiple antenna techniques used in wireless communications. It describes MIMO systems and how they can provide spatial diversity and multiplexing to improve reliability and increase data rates. Spatial diversity techniques like receive and transmit diversity are covered, as well as spatial multiplexing approaches including open and closed loop methods. Beamforming and multi-user MIMO techniques for the uplink and downlink are also summarized. The document provides details on how these different multiple antenna techniques work to overcome challenges like fading and interference.
This document summarizes a lecture on adaptive equalization. It discusses how equalizers can be designed when the channel is unknown or time-varying using training sequences. Specifically, it describes how training sequences can be used to identify the channel model and design an optimal linear equalizer using a least squares approach. This results in an equation to compute the optimal equalizer coefficients directly from the received training sequence samples. Similar approaches are described for fractionally spaced and decision feedback equalizers.
This document discusses advanced wireless communication technologies and their evolution over time to meet increasing data rate demands. It covers:
1) How wireless spectrum has become crowded as usage has increased, challenging engineers to develop technologies to achieve higher data rates within limited spectrum.
2) The evolution of mobile communication standards from 1G analog to 2G digital systems like GSM, and then 3G technologies like UMTS that supported data rates up to 384kbps.
3) Emerging 4G technologies aimed to support rates over 20Mbps using techniques like MIMO, adaptive modulation, and OFDM to more efficiently use available spectrum.
This document discusses transmission systems in satellite communications. It begins by defining a transmission line as a device that transmits or guides energy from one point to another. It then discusses how transmission lines carry alternating current and are used to connect radio transmitters and receivers. The document goes on to describe the key components of fiber optic and wireless transmission systems, including transmitters, receivers, optical fiber cables, antennas, and amplifiers. It explains how each component functions and its role in transmitting signals across long distances.
This document provides information about the course EC351: Data Communication. It includes the following key points:
1. The course covers 5 modules that study various data communication techniques, including data encoding schemes, transmission media, error detection/correction, and networking protocols.
2. Assessment methods include assignments, seminars, tutorials, mini-projects, and a discussion forum.
3. The goal of the course is to provide students with an understanding of fundamental data communication concepts and how information is transmitted electronically over various channels.
This document provides information about the course EC351: Data Communication. It includes the following key points:
1. The course covers 5 modules that study various data communication techniques, including data encoding schemes, transmission media, error detection/correction, and networking protocols.
2. Assessment methods include assignments, seminars, tutorials, mini-projects, and a discussion forum.
3. The goal of the course is to provide students with an understanding of fundamental data communication concepts and how information is transmitted electronically over various channels.
This document contains a syllabus for a Communication Electronics course. The syllabus covers 6 units:
1) Amplitude Modulation
2) Angle Modulation
3) Pulse Modulation
4) Noise
5) AM and FM Receivers
6) Broadband Communication Links and Multiplexing
The syllabus provides an overview of the key topics that will be covered in each unit, including the concepts, mathematical analysis, generation methods, and applications of various modulation techniques. It also lists recommended textbooks and reference books for the course.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
This presentation is about Food Delivery Systems and how they are developed using the Software Development Life Cycle (SDLC) and other methods. It explains the steps involved in creating a food delivery app, from planning and designing to testing and launching. The slide also covers different tools and technologies used to make these systems work efficiently.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
Channel Overlapping Between IMT-Advanced Users and Fixed Satellite ServiceEECJOURNAL
This document summarizes a research paper that proposes a new algorithm to mitigate interference between IMT-Advanced base stations and fixed satellite services. The algorithm aims to form nulls in the radiation pattern of base stations towards satellites by extracting null directions using MUSIC algorithm and controlling handover. It studies two mobile users moving around a satellite and simulates calculating the shortest separation distance after identifying critical points. Results show the algorithm can enable good coexistence and spectrum sharing between the different wireless services in the C-band frequency range.
This document summarizes a lecture on equalization techniques for digital communications.
1) The optimal receiver structure for transmission over a channel consists of a whitened matched filter frontend and a maximum likelihood sequence estimator (MLSE) such as the Viterbi algorithm. However, the MLSE has high complexity.
2) Equalization filters combined with a memoryless decision device can provide a lower complexity alternative to the MLSE. Linear equalizers like zero-forcing and minimum mean squared error (MMSE) are discussed, as well as decision feedback equalizers.
3) The lecture reviews transmission models and optimal receivers developed in previous lectures, and establishes an input-output model of the transmission system to serve as the basis
The document discusses the syllabus for the EC6801 Wireless Communication course. It covers 5 units: wireless channels, cellular architecture, digital signaling for fading channels, multipath mitigation techniques, and multiple antenna techniques. The key topics covered include path loss models, small scale fading parameters, multiple access techniques, diversity combining, equalization, MIMO systems and capacity in fading channels. The document also provides sample problems for the first two units.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The document analyzes the performance of vector antenna arrays compared to uniform linear arrays for code division multiple access (CDMA) signals in a multipath fading channel. It considers a closed loop power control system for a beamformer-RAKE receiver for a wireless CDMA system with multiple users. Both theoretical analysis and simulations show that vector antennas, which can detect six independent components of the electromagnetic field, can better exploit multipath diversity and significantly improve bit error rate performance over uniform linear arrays in frequency selective rich multipath channels. The vector antennas provide additional diversity to combat signal fading and improve interference suppression for multiple users.
This document analyzes and compares the performance of different adaptive beamforming techniques for smart antennas. It describes switched beamforming, which uses fixed beams, and adaptive beamforming techniques that use algorithms like LMS, SMI, RLS, CGA, CMA, and LSCMA to form an adaptive beam. It simulates these algorithms using MATLAB for a uniform linear array and compares their ability to direct the main beam towards the desired user while nulling interference. The LMS, SMI, RLS, CMA and LSCMA algorithms are found to perform well at directing the beam to the desired user, with LMS having good interference rejection and RLS providing the fastest convergence but highest computational cost.
Comparitive analysis of bit error rates of multiple input multiple output tra...slinpublishers
The document compares the bit error rates of multiple input multiple output (MIMO) transmission schemes, including spatial multiplexing, space-time block codes (STBC), and space-time block coded spatial modulation (STBC-SM). It finds that STBC-SM provides better performance than STBC and vertical-Bell labs layered space-time (V-BLAST) spatial multiplexing. Specifically, simulations show STBC-SM has a lower bit error rate than the other schemes when using four transmit and four receive antennas. The document explains the techniques of V-BLAST, STBC, and STBC-SM in detail.
Error Rate Analysis of MIMO System Using V Blast Detection Technique in Fadin...IJERA Editor
Wireless communication system with multi- antenna arrays has been a field of intensive analysis on the last years. The appliance of multiple sending antennas and Receiving Antennas either side will considerably enhance the data rate and rate. The review of the performance limitations of MIMO system becomes vital since it will provide lot ideas in understanding and planning the important life MIMO systems. Vertical Bell Laboratories layered space Time (V-BLAST). The thought behind Multiple Input and Multiple Output system is that the signals on the transmitter antennas at one finish and also the receiver antennas at the opposite finish are correlative in such how that the performance (Bit Error Rate or BER) or the info rate (bits/sec) of the wireless communication system for every MIMO subscriber are improved. During this paper we tend to are proposing a technique that evaluates the performance of V-BLAST MIMO system in several thought of Rayleigh attenuation surroundings to urge higher performance of the system. In V- BLAST MIMO system a number of linear detection techniques will be used for interference cancellation. At this point we are using MMSE-IC for the same. Our expected system provide higher error rate performance with the used of matched filter at receiver aspect .The projected system compared within the presence of AWGN. Now matched filter applied on V- BLAST MIMO with MMSE-IC system in fading diversity surroundings.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The paper was prepared by communication student of wollega university It was ...ugushe
The document discusses Course Wavelength Division Multiplexing (CWDM) transmission systems. CWDM uses lasers operating at wavelengths spaced 20nm apart between 1271nm to 1611nm to transmit multiple signals over a single fiber. Key components of a CWDM system include optical multiplexer/demultiplexer cards, optical add/drop cards, Ethernet transport cards, and a node control processor. CWDM systems can transmit signals up to 75km and are commonly used in ring topologies for reliable transmission with features like optical add/drop and protection switching. Troubleshooting starts by checking the physical layer like fibers and transceivers, then external connections, and internal card configurations.
An analtical analysis of w cdma smart antennamarwaeng
The document analyzes the signal-to-interference-noise ratio (SINR) performance of two beamforming methods, complex conjugate (CC) and direction-of-arrival (DOA), used in Wideband Code Division Multiple Access (W-CDMA) smart antenna systems. It derives analytic SINR evaluation equations for both methods under different channel conditions. The results show that the CC and DOA methods provide the same mean SINR performance but the CC method is more robust to channel estimation errors. Simulation results are presented to verify the analytic performance and robustness analyses.
Iaetsd stbc-ofdm downlink baseband receiver for mobile wmanIaetsd Iaetsd
This document discusses a proposed space time block code-orthogonal frequency division multiplexing (STBC-OFDM) downlink baseband receiver for mobile wireless metropolitan area networks (WMANs). The proposed receiver applies STBC-OFDM techniques using two transmit antennas and one receive antenna to provide robust performance in outdoor mobile environments. It includes a simple and robust synchronizer and an accurate but affordable channel estimator to overcome challenges of multipath fading channels. Simulation results show the receiver can achieve a coded bit error rate of less than 10-6 for 16QAM modulation under vehicle speeds of 120 km/hr while supporting up to 27.32 Mb/s of uncoded data transmission. The receiver designed in a 90-nm CMOS
This document discusses multiple antenna techniques used in wireless communications. It describes MIMO systems and how they can provide spatial diversity and multiplexing to improve reliability and increase data rates. Spatial diversity techniques like receive and transmit diversity are covered, as well as spatial multiplexing approaches including open and closed loop methods. Beamforming and multi-user MIMO techniques for the uplink and downlink are also summarized. The document provides details on how these different multiple antenna techniques work to overcome challenges like fading and interference.
This document summarizes a lecture on adaptive equalization. It discusses how equalizers can be designed when the channel is unknown or time-varying using training sequences. Specifically, it describes how training sequences can be used to identify the channel model and design an optimal linear equalizer using a least squares approach. This results in an equation to compute the optimal equalizer coefficients directly from the received training sequence samples. Similar approaches are described for fractionally spaced and decision feedback equalizers.
This document discusses advanced wireless communication technologies and their evolution over time to meet increasing data rate demands. It covers:
1) How wireless spectrum has become crowded as usage has increased, challenging engineers to develop technologies to achieve higher data rates within limited spectrum.
2) The evolution of mobile communication standards from 1G analog to 2G digital systems like GSM, and then 3G technologies like UMTS that supported data rates up to 384kbps.
3) Emerging 4G technologies aimed to support rates over 20Mbps using techniques like MIMO, adaptive modulation, and OFDM to more efficiently use available spectrum.
This document discusses transmission systems in satellite communications. It begins by defining a transmission line as a device that transmits or guides energy from one point to another. It then discusses how transmission lines carry alternating current and are used to connect radio transmitters and receivers. The document goes on to describe the key components of fiber optic and wireless transmission systems, including transmitters, receivers, optical fiber cables, antennas, and amplifiers. It explains how each component functions and its role in transmitting signals across long distances.
This document provides information about the course EC351: Data Communication. It includes the following key points:
1. The course covers 5 modules that study various data communication techniques, including data encoding schemes, transmission media, error detection/correction, and networking protocols.
2. Assessment methods include assignments, seminars, tutorials, mini-projects, and a discussion forum.
3. The goal of the course is to provide students with an understanding of fundamental data communication concepts and how information is transmitted electronically over various channels.
This document provides information about the course EC351: Data Communication. It includes the following key points:
1. The course covers 5 modules that study various data communication techniques, including data encoding schemes, transmission media, error detection/correction, and networking protocols.
2. Assessment methods include assignments, seminars, tutorials, mini-projects, and a discussion forum.
3. The goal of the course is to provide students with an understanding of fundamental data communication concepts and how information is transmitted electronically over various channels.
This document contains a syllabus for a Communication Electronics course. The syllabus covers 6 units:
1) Amplitude Modulation
2) Angle Modulation
3) Pulse Modulation
4) Noise
5) AM and FM Receivers
6) Broadband Communication Links and Multiplexing
The syllabus provides an overview of the key topics that will be covered in each unit, including the concepts, mathematical analysis, generation methods, and applications of various modulation techniques. It also lists recommended textbooks and reference books for the course.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
This presentation is about Food Delivery Systems and how they are developed using the Software Development Life Cycle (SDLC) and other methods. It explains the steps involved in creating a food delivery app, from planning and designing to testing and launching. The slide also covers different tools and technologies used to make these systems work efficiently.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
Instagram , Facebook etc. Now with high technology E-
Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Tools & Techniques for Commissioning and Maintaining PV Systems W-Animations ...Transcat
Join us for this solutions-based webinar on the tools and techniques for commissioning and maintaining PV Systems. In this session, we'll review the process of building and maintaining a solar array, starting with installation and commissioning, then reviewing operations and maintenance of the system. This course will review insulation resistance testing, I-V curve testing, earth-bond continuity, ground resistance testing, performance tests, visual inspections, ground and arc fault testing procedures, and power quality analysis.
Fluke Solar Application Specialist Will White is presenting on this engaging topic:
Will has worked in the renewable energy industry since 2005, first as an installer for a small east coast solar integrator before adding sales, design, and project management to his skillset. In 2022, Will joined Fluke as a solar application specialist, where he supports their renewable energy testing equipment like IV-curve tracers, electrical meters, and thermal imaging cameras. Experienced in wind power, solar thermal, energy storage, and all scales of PV, Will has primarily focused on residential and small commercial systems. He is passionate about implementing high-quality, code-compliant installation techniques.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
AI in customer support Use cases solutions development and implementation.pdfmahaffeycheryld
AI in customer support will integrate with emerging technologies such as augmented reality (AR) and virtual reality (VR) to enhance service delivery. AR-enabled smart glasses or VR environments will provide immersive support experiences, allowing customers to visualize solutions, receive step-by-step guidance, and interact with virtual support agents in real-time. These technologies will bridge the gap between physical and digital experiences, offering innovative ways to resolve issues, demonstrate products, and deliver personalized training and support.
https://www.leewayhertz.com/ai-in-customer-support/#How-does-AI-work-in-customer-support
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Open Channel Flow: fluid flow with a free surfaceIndrajeet sahu
Open Channel Flow: This topic focuses on fluid flow with a free surface, such as in rivers, canals, and drainage ditches. Key concepts include the classification of flow types (steady vs. unsteady, uniform vs. non-uniform), hydraulic radius, flow resistance, Manning's equation, critical flow conditions, and energy and momentum principles. It also covers flow measurement techniques, gradually varied flow analysis, and the design of open channels. Understanding these principles is vital for effective water resource management and engineering applications.
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Postacademic Course on
Telecommunications
Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven/ESAT-SISTA
Module-3 : Transmission
Lecture-10 (18/5/00)
Marc Moonen
Dept. E.E./ESAT, K.U.Leuven
marc.moonen@esat.kuleuven.ac.be
www.esat.kuleuven.ac.be/sista/~moonen/
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Lecture 10 : Smart Antennas -Overview
• Introduction:
Smart Antennas
SDMA (`driver application’)
• SDMA v1.0
Line-of-sight propagation & beamforming
DOA estimation and signal reconstruction
• SDMA v2.0
Multi-path propagation
MIMO channel modeling & source separation
• Related Topics
CDMA multi-user detection (see Lecture-9)
MIMO transmission (see Lecture-2)
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : Smart Antennas
• Antenna arrays (hardware) with (software) `beam-forming’
(`beam-steering’), or similar (in multi-path scenario, see
below).
• `Antenna diversity’
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : Smart Antennas
• Aim : increase signal-to-interference-and-noise ratio, hence
improved performance/increased capacity (e.g. in CDMA
systems)
• Antenna arrays mostly considered for base station
systems, not (often) for mobile terminals.
• Currently simple systems with switching between antenna
signals (=select best signal), fixed directional antennas for
sectorization (e.g. GSM), ...
• More advance systems considered for WLANs, for
W-CDMA, etc...
• Will consider SDMA as `driver application’
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
• `Conventional’ wireless communications
(`SISO’, TDMA/FDMA/CDMA)
• What we have in mind is ….
(MIMO transmission, SDMA)
transmitter
radio channel
x bits/sec/Hz/km2 receiver
transmitter receiver
transmitter
radio channel
2x bits/sec/Hz/km2
receiver
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
• Example : cellular mobile telephony (e.g. GSM)
• Basic network architecture :
-country covered by a grid of cells
-each cell has a base station
-base station connected to land telephone network and
communicates with mobiles via a radio interface
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
• Why cellular ?
Capacity increase by spectrum reuse
, pico-cells, etc.
• Capacity increase by multiplexing :
- GSM (900MHz) has 125 frequency channels/cell (FDMA)
8 time slots/channel (TDMA)
In practice, capacity per cell << 8*125 !
- Spatial multiplexing : allows different users in 1 cell to
use the same freq./time slot
- Tool = DSP algorithms for signal separation, equalization
4
1
d
P
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
• PS: in GSM neighboring cells cannot use same
frequency bands (intercell interference). Same
frequency band used in each 7th cell.
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
• SDMA (`spatial division multiple access’) allows different
users in the same cell to use the same frequency
channel/time slot/code, and thereby offers substantial
capacity increases when superimposed on a current
system!
• SDMA supports multiple directional connections on a
single conventional radio channel through the usage of
antenna arrays and advanced signal processing.
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Introduction : SDMA
PS: SDMA ~ `dynamic sectorization’
WARNING:
• Major practical impediment is computational complexity
(cfr. linear algebra-type operations at high sampling rates).
…Gflops requirement….
• Major challenge for VLSI/ASIC design
• First products probably in WLAN-type applications instead
of cellular/mobile
AIM:
• Illustrate (near) future system design concepts….
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Assumptions:
- sources are in the far-field
- line-of-sight (LOS) connections
- no multi-path effects
- homogeneous medium/ideal channel characteristics
- additive white Gaussian noise (AWGN)
- no inter-symbol interference
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Beamforming (`spatial filtering’):
PS: compare with regular temporal (FIR) filtering
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Data Model:
= *
antenna outputs sources
array gain
matrix
time samples for antenna-1
time samples for antenna-2
time samples for source-1
time samples for source-2
steering vector source-1
steering vector source-2
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Data Model:
`Steering vector’ a(theta)
= array response vector, contains gains and phase shifts
for a narrow-band wavefront impinging from direction-of-
arrival (DOA) theta (and for a certain carrier frequency)
The collection of `steering vectors’ for all possible angles
theta, is referred to as the `array manifold’
Knowledge of `array manifold’ is crucial is beamforming
approach
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Array manifold example:
Uniform Linear Array
where f = phase shift =
d
angle
)
)
sin(
.
.
.
2
.
exp(
c
d
f
j c
1
2
...
1
)
(
M
f
f
f
a
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Significance of array manifold:
-array manifold is a parametrization of the steering
vector as a function of the DOA
-if array manifold is known (by calibration or
physical modeling), `channel modeling’ is reduced
to DOA estimation. If the DOA for one particular
source is identified, its complete steering vector is
known.
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Problem Statement:
Given antenna outputs & array manifold,
compute :
-directions-of-arrival (DOA’s)
-source signals
= *
antenna outputs sources
array gain
matrix
?
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Solution (Part-1): DOA estimation
`low-resolution algorithms’ : Fourier-based (e.g. for ULA’s)
`high-resolution algorithms’ :
-MUSIC [Schmidt 1979]: search for DOA such that steering
vector optimally matches `column space’ of antenna output
matrix
-ESPRIT [Roy et al, 1987]: DOA’s identified as generalized
eigenvalues of a matrix `pencil’
= *
antenna outputs sources
array gain matrix
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Solution (Part-2):
Beamforming and signal reconstruction
Given steering vectors
of signal-of-interest and
interferers, compute
beamformer weights
such that interference
signals are eliminated
(`null steering’)
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Solution (Part-2):
Beamforming and signal reconstruction
compute weight vector w1, w2,…. such that….
= *
antenna outputs sources
array gain
matrix
* *
w1
w2
:
w1
w2
:
1
0
:
0
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Solution (Part-2):
- Compute weight vector w1, w2,…. that cancels all
interferers, and retains the signal of interest (cfr. supra)
- This is `zero-forcing’ solution. With additive noise, a
minimum-mean-squared-error solution is preferred.
- Other : Generalized sidelobe canceller, minimum variance
distortionless response beamforming, Griffiths-Jim
beamforming : adaptive beamformers, based on
knowledge of steering vector of (only) the signal-of-
interest, and where noise environment (incl. interferers)
may be time-varying.
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v1.0: Beamforming Approach
• Beamforming approach deficiencies :
- not always line-of-sight (LOS) connection
- multi-path effects
long/short term fading (e.g. wavelength=30cm @ 900MHz)
- inter-symbol-interference
(e.g. symbol ~ 1km @ 270kbits/sec)
• Conclusion:
- array manifold concept no longer useful
- need more sophisticated data models/algorithms
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v2.0: Channel Modeling Approach
• Instead of this…..
• we have this…..
• now what??
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v2.0: Channel Modeling Approach
• SDMA with multi-path corresponds to multi-user (multiple-
input/multiple output) channel equalization problem :
a) identify channel model
b) reconstruct channel inputs from outputs+model
single-user (e.g. GSM) multi-user (SDMA)
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v2.0: Channel Modeling Approach
• Step-1 is a channel modeling, i.e. identify...
• Training sequence based versus `blind algorithms’
(see Lecture 5-6)
L
-
user
signal
:
2
-
user
signal
1
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user
signal
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v2.0: Channel Modeling Approach
• Step-2 is equalizer design, i.e. identify…
• Zero-forcing (ISI=MUI=0) versus MMSE (see Lecture 5-6)
• This is combined equalization & source separation
L
-
user
signal
:
2
-
user
signal
1
-
user
signal
*
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
SDMA v2.0: Channel Modeling Approach
• Step-1 & -2 may be combined : direct (training sequence
based) equalizer design (see Lecture-5/6). Only training
sequence for user-of-interest needed (not for other users).
• Recursive vs batch processing (Lecture-5/6)
• `Oversampling’ (i.e. having more outputs (antennas) than
inputs (users)) is crucial for the existence of zero-forcing
solutions (for FIR channels).
• Connections with fractionally spaced equalization theory
and filter bank theory.
• Active area of research (blind algorithms based on 2nd
order statistics, finite alphabet properties, etc.).
• Commercial use: probably first WLAN, etc...
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Related Topics
CDMA multi-user detection algorithms (Lecture-9)
MUD algorithms are conceptually similar :
-Spreading viewed as a (transmit) filtering operation
and part of the `channel’.
-Nyquist-rate sampling at the receiver is symbol-
rate oversampling, which is equivalent to spatial
oversampling (multiple antennas).
-etc...
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Related Topics
MIMO Transmission (Lecture-2)
- Point-to-point transmission, where both transmitter
and sender have antenna array
- additional flexibility for sender (beamforming, …)
- with M antennas at both ends, allows for M-fold
channel capacity increase with the same transmit
power budget (!)
- example : V-BLAST
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Conclusions
• Smart Antennas
- Advantages : improved signal-to-interference-and-noise
ratio, increased capacity (CDMA).
- Considered for W-CDMA, ...
• SDMA v1.0
- Beamforming approach
- Conceptually simple, but not applicable in multi-path
environment
• SDMA v2.0
- Multi-path/MIMO channel modeling approach
- Powerful but complex
• Related Topics
- CDMA multi-user detection, MIMO transmission
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Assignment 5.1
`Brain Teaser’ :
• In Lecture-2, we have considered MIMO-transmission from
a channel capacity point of view. Look at the conclusions
again. One of the conclusions was that `one has to be
lucky with the channel characteristic’.
• Think of a similar channel capacity analysis for SDMA.
Does one again have to be `lucky with the channel’ ?
• What would be a most advantageous channel, in terms of
channel capacity ? What would be the obtained channel
capacity ? Is it `what we had in mind’ (cfr slide-5) ?
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Module-3 Transmission Marc Moonen
Lecture-10 Smart Antennas K.U.Leuven-ESAT/SISTA
Assignment 5.2
`Brain Teaser’:
• In Lecture 7-8 we have considered multi-tone
transmission, where a (high-rate) bit stream is split up into
(low-rate) parallel bit streams, which are then used to QAM
modulate different carriers.
• Now consider these low-rate streams as being different
users, accessing the same transmission channel. The
carrier modulation may be viewed/compared with a
spreading operation a la DS-CDMA.
• Based on this, compare DMT with CDMA and MIMO, both
from a capacity and a receiver structure point of view.
Look for similarities and differences.
• In a similar fashion, compare DMT with MIMO transmission