Intersymbol interference caused by multipath in band limited frequency selective time dispersive channels distorts the transmitted signal, causing bit error at receiver. ISI is the major obstacle to high speed data transmission over wireless channels. Channel estimation is a technique used to combat the intersymbol interference. The objective of this paper is to improve channel estimation accuracy in MIMO-OFDM system by using modified variable step size leaky Least Mean Square (MVSSLLMS) algorithm proposed for MIMO OFDM System. So we are going to analyze Bit Error Rate for different signal to noise ratio, also compare the proposed scheme with standard LMS channel estimation method.
Phase locked loop is a technique usually used to perform indirect digital frequency synthesizer for
most RF transceivers. A fractional-N phase locked loop frequency synthesizer has been used in recent years
since it achieves fine resolution and large loop bandwidth . This paper presents the design and simulation of a
fractional-N phase locked loop frequency synthesizer using sigma-delta modulation for bluetooth standard
systems with a frequency range from 2402 to 2480MHz. Loop filter and Sigma-Delta modulator are the most
important factors in improving the performance of fractional-N phase locked loop. The digital Sigma-Delta
modulator provides a useful noise shaping for the phase noise introduced by the fractional division operation,
while the loop filter bandwidth limits the speed of switching time between the synthesized frequencies. A forth
order passive loop filter was implemented at bandwidth equal to 200 KHz, 50° phase margin, and a second
order single loop modulator with 4-level quantizer was used to control the frequency divider. Simulation results
showed that the system is stable, and there is no fractional spurs in the output spectrum of the fractional-N
phase locked loop.
EE402B Radio Systems and Personal Communication Networks notesHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Multi carrier equalization by restoration of redundanc y (merry) for adaptive...IJNSA Journal
This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. The
performance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposed
DST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstrated
and less complexity also involved by the simulation of the DST-DMT system.
Intersymbol interference caused by multipath in band limited frequency selective time dispersive channels distorts the transmitted signal, causing bit error at receiver. ISI is the major obstacle to high speed data transmission over wireless channels. Channel estimation is a technique used to combat the intersymbol interference. The objective of this paper is to improve channel estimation accuracy in MIMO-OFDM system by using modified variable step size leaky Least Mean Square (MVSSLLMS) algorithm proposed for MIMO OFDM System. So we are going to analyze Bit Error Rate for different signal to noise ratio, also compare the proposed scheme with standard LMS channel estimation method.
Phase locked loop is a technique usually used to perform indirect digital frequency synthesizer for
most RF transceivers. A fractional-N phase locked loop frequency synthesizer has been used in recent years
since it achieves fine resolution and large loop bandwidth . This paper presents the design and simulation of a
fractional-N phase locked loop frequency synthesizer using sigma-delta modulation for bluetooth standard
systems with a frequency range from 2402 to 2480MHz. Loop filter and Sigma-Delta modulator are the most
important factors in improving the performance of fractional-N phase locked loop. The digital Sigma-Delta
modulator provides a useful noise shaping for the phase noise introduced by the fractional division operation,
while the loop filter bandwidth limits the speed of switching time between the synthesized frequencies. A forth
order passive loop filter was implemented at bandwidth equal to 200 KHz, 50° phase margin, and a second
order single loop modulator with 4-level quantizer was used to control the frequency divider. Simulation results
showed that the system is stable, and there is no fractional spurs in the output spectrum of the fractional-N
phase locked loop.
EE402B Radio Systems and Personal Communication Networks notesHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Multi carrier equalization by restoration of redundanc y (merry) for adaptive...IJNSA Journal
This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. The
performance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposed
DST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstrated
and less complexity also involved by the simulation of the DST-DMT system.
Signal and image processing on satellite communication using MATLABEmbedded Plus Trichy
Basic Explanations about satellite imaging and signal processing with the help of MATLAB.
Contact us: 23,Nandhi koil Street, Near Nakoda Showroom,Theppakulam,Trichy
Mb.No:9360212155.
Mail:embeddedplusproject@gmail.com,
FB:www.facebook.com/embeddedplusproject
BER Performance of Antenna Array-Based Receiver using Multi-user Detection in...ijwmn
Antenna promises to provide significant increases in system capacity and performance in
wireless systems. In this paper, a simplified, near-optimum array receiver is proposed,
which is based on the angular gain of the spatial filter. This detection is then analyzed by
calculating the exact error probability.The proposed model confirms the benefits of adaptive
antennas in reducing the overall interference level (intercell/intracell) and to find an
accurate approximation of the error probability. We extend the method that has been
proposed for propagation over Nakagami-m fading channels, the model shows good
agreements with simulation results.
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
Performance of MMSE Denoise Signal Using LS-MMSE TechniqueIJMER
This paper presents performance of mmse denoises signal using consistent cycle spinning (ccs) and least square (LS) techniques. In the past decade, TV denoise technique is used to reduced the noisy signal. The main drawback is the low quality signal and high MMSE signal. Presently, we
proposed the CCS-MMSE and LS-MMSE technique .The CCS-MMSE technique consists of two steps. They are wavelet based denoise and consistent cycle spinning. The wavelet denoise is powerful decorrelating effect on many signal domains. The consistent cycle spinning is used to estimation the
MMSE in the signal domain. The LS-MMSE is better estimation of MMSE signal domain compare to
CCS-MMSE.The experimental result shows the average MMSE reduction using various techniques.
Blind Estimation of Carrier Frequency Offset in Multicarrier Communication Sy...IDES Editor
Orthogonal Frequency Division Multiplexing
(OFDM) systems are very sensitive to carrier frequency offset
(CFO), caused by either frequency differences between
transmitter and receiver local oscillators or by frequency
selective channels. The CFO disturbs the orthogonality among
subcarriers of OFDM system and results intercarrier
interference (ICI), which degrades the bit error rate (BER)
performance of the system. This paper presents a new blind
CFO estimation scheme for single-input single-output (SISO)
OFDM systems. The presented scheme is based on the
assumption that the channel frequency response changes
slowly in frequency domain. In this scheme an excellent tradeoff
between complexity and performance, as compared to
existing estimation schemes, is obtained. The improved
performance of the present scheme is confirmed through
extensive simulations.
A New Approach for Speech Enhancement Based On Eigenvalue Spectral SubtractionCSCJournals
In this paper, a phase space reconstruction-based method is proposed for speech enhancement. The method embeds the noisy signal into a high dimensional reconstructed phase space and uses Spectral Subtraction idea. The advantages of the proposed method are fast performance, high SNR and good MOS. In order to evaluate the proposed method, ten signals of TIMIT database mixed with the white additive Gaussian noise and then the method was implemented. The efficiency of the proposed method was evaluated by using qualitative and quantitative criteria.
Evaluation of channel estimation combined with ICI self-cancellation scheme i...ijcsse
Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme, which is used in several wireless systems for transferring data at high rate. The multi path fading channel and the frequency offset between the transmitted and received carrier frequencies introduce ICI (Inter Carrier Interference). ICI effects the OFDM symbols and degrades the system performance. This paper proposes a solution: combine channel estimation and ICI self-cancellation to combat against ICI in doubly selective fading channel. The simulation results show the effect of this solution
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Signal and image processing on satellite communication using MATLABEmbedded Plus Trichy
Basic Explanations about satellite imaging and signal processing with the help of MATLAB.
Contact us: 23,Nandhi koil Street, Near Nakoda Showroom,Theppakulam,Trichy
Mb.No:9360212155.
Mail:embeddedplusproject@gmail.com,
FB:www.facebook.com/embeddedplusproject
BER Performance of Antenna Array-Based Receiver using Multi-user Detection in...ijwmn
Antenna promises to provide significant increases in system capacity and performance in
wireless systems. In this paper, a simplified, near-optimum array receiver is proposed,
which is based on the angular gain of the spatial filter. This detection is then analyzed by
calculating the exact error probability.The proposed model confirms the benefits of adaptive
antennas in reducing the overall interference level (intercell/intracell) and to find an
accurate approximation of the error probability. We extend the method that has been
proposed for propagation over Nakagami-m fading channels, the model shows good
agreements with simulation results.
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
Performance of MMSE Denoise Signal Using LS-MMSE TechniqueIJMER
This paper presents performance of mmse denoises signal using consistent cycle spinning (ccs) and least square (LS) techniques. In the past decade, TV denoise technique is used to reduced the noisy signal. The main drawback is the low quality signal and high MMSE signal. Presently, we
proposed the CCS-MMSE and LS-MMSE technique .The CCS-MMSE technique consists of two steps. They are wavelet based denoise and consistent cycle spinning. The wavelet denoise is powerful decorrelating effect on many signal domains. The consistent cycle spinning is used to estimation the
MMSE in the signal domain. The LS-MMSE is better estimation of MMSE signal domain compare to
CCS-MMSE.The experimental result shows the average MMSE reduction using various techniques.
Blind Estimation of Carrier Frequency Offset in Multicarrier Communication Sy...IDES Editor
Orthogonal Frequency Division Multiplexing
(OFDM) systems are very sensitive to carrier frequency offset
(CFO), caused by either frequency differences between
transmitter and receiver local oscillators or by frequency
selective channels. The CFO disturbs the orthogonality among
subcarriers of OFDM system and results intercarrier
interference (ICI), which degrades the bit error rate (BER)
performance of the system. This paper presents a new blind
CFO estimation scheme for single-input single-output (SISO)
OFDM systems. The presented scheme is based on the
assumption that the channel frequency response changes
slowly in frequency domain. In this scheme an excellent tradeoff
between complexity and performance, as compared to
existing estimation schemes, is obtained. The improved
performance of the present scheme is confirmed through
extensive simulations.
A New Approach for Speech Enhancement Based On Eigenvalue Spectral SubtractionCSCJournals
In this paper, a phase space reconstruction-based method is proposed for speech enhancement. The method embeds the noisy signal into a high dimensional reconstructed phase space and uses Spectral Subtraction idea. The advantages of the proposed method are fast performance, high SNR and good MOS. In order to evaluate the proposed method, ten signals of TIMIT database mixed with the white additive Gaussian noise and then the method was implemented. The efficiency of the proposed method was evaluated by using qualitative and quantitative criteria.
Evaluation of channel estimation combined with ICI self-cancellation scheme i...ijcsse
Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme, which is used in several wireless systems for transferring data at high rate. The multi path fading channel and the frequency offset between the transmitted and received carrier frequencies introduce ICI (Inter Carrier Interference). ICI effects the OFDM symbols and degrades the system performance. This paper proposes a solution: combine channel estimation and ICI self-cancellation to combat against ICI in doubly selective fading channel. The simulation results show the effect of this solution
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
For ease of analog or digital information transmission and reception, modulation is the foremost important technique. In the present project, we’ll discuss about different modulation scheme in digital mode done by operating a switch/ key by the digital data. As we know, by modifying basic three parameters of the carrier signal, three basic modulation schemes can be obtained; generation and detection of these three modulations are discussed and compared with respect to probability of error or bit error rate (BER).
During PMRExpo - the leading European exhibition in professional mobile radio communications that was held in Coloigne from 26 to 28 December 2017 - Alessandro Guido, Leonardo DMR Systems Design, participated in the Workshop Digital Mobile Radio Association DMR" discussing "How to build a DMR Simulcast Network".
Wireless Communication Networks and Systems 1st Edition Beard Solutions Manualpuriryrap
Full download : http://alibabadownload.com/product/wireless-communication-networks-and-systems-1st-edition-beard-solutions-manual/
Wireless Communication Networks and Systems 1st Edition Beard Solutions Manual
Compared to wireless deployment in areas with different environmentseIJECEIAES
In the mobile phone system, it is highly desirable to estimate the loss of the track not only to improve performance but also to achieve an accurate estimate of financial feasibility; the inaccurate estimate of track loss either leads to performance degradation or increased cost. Various models have been introduced to accurately estimate the path loss. One of these models is the Okomura / Hata model, which is recommended for estimating path loss in cellular systems that use micro cells. This system is suitable for use in a variety of environments. This study examines the comparison of path loss models for statistical analysis derived from experimental data collected in urban and suburban areas at frequencies of 150-1500 MHz’s The results of the measurements were used to develop path loss models in urban and suburban areas. The results showed that Pathloss increases in urban areas respectively.
Third Generation Wireless Modeling in Urban EnvironmentEECJOURNAL
The global mobile communication is fast growing in industry. This paper recommends appropriate settings to evaluate the performance of wireless mobile system deploying third generation networks in an urban environment. To meet this aim, a case Study of Sulaimanyia city is considered for this study by establishing suitable radio channel models. The work presents a statistical channel model, where fixed and nomadic analysis services are considered in the simulated radio coverage scenario. The cartographic dataset had been collected, and Matlab Software was used for showing the analysis and simulation results. Statistical channel models are derived that combine standard parameters such as separation distance, operating frequency and terminal height with more advanced and innovative parameters such as distance dependent shadowing and LOS probability.
COMPARISON OF RADIO PROPAGATION MODELS FOR LONG TERM EVOLUTION (LTE) NETWORKijngnjournal
This paper concerns about the radio propagation models used for the upcoming 4th Generation (4G) of cellular networks known as Long Term Evolution (LTE). The radio wave propagation model or path loss model plays a very significant role in planning of any wireless communication systems. In this paper, a comparison is made between different proposed radio propagation models that would be used for LTE, like Stanford University Interim (SUI) model, Okumura model, Hata COST 231 model, COST Walfisch-Ikegami & Ericsson 9999 model. The comparison is made using different terrains e.g. urban, suburban and rural area.SUI model shows the lowest path lost in all the terrains while COST 231 Hata model illustrates highest path loss in urban area and COST Walfisch-Ikegami model has highest path loss for suburban and rural environments.
Similar to NetSim Technology Library- Propagation models (20)
NetSim VANET library (https://www.tetcos.com) supports the following protocols
IEEE 802.11p, IEEE 1609 WAVE
Layer 3 Routing – AODV, DSR, OLSR, ZRP
PHY Layer RF Propagation
o Pathloss
o Shadowing
o Fading
Source C Code
Automatic import of road network and vehicles from SUMO
Wide range of output metrics including Delay, Throughput, Error, Retransmission,
etc.
Interfacing between SUMO & NetSim via Traffic control interface (TraCI).
NetSim Technology Library - Software defined networksVishal Sharma
Software Defined Networking (SDN) module is featured from NetSim v11 onwards. This
module features an SDN controller which can be used to control packet forwarding of all Layer
3 devices in the Network.
NetSim Technology Library- Military radio-tdma-and-dtdmaVishal Sharma
NetSim Military Radio module features:
1. L3 - MANET Routing covering DSR, AODV, OLSR, ZRP
2. MAC – TDMA based on Link 16, and DTDMA with Slot planner
3. PHY
a. TDMA, DTDMA.
b. Freqyency Hopping
c. Bands: HF, VHF, UHF.
d. A wide range of propagation models covering pathloss, fading and shadowing
NetSim MANETs component can be interfaced with
Component 6 (IOT) module to run 802.15.4 in MAC/PHY
Component 9 (VANETs) module to run IEEE 1609 WAVE in MAC/PHY
Military Radio Add on to run TDMA/DTDMA in MAC/PHY
NetSim Long Term Evolution (LTE) Networks library includes LTE/LTE-A networks, LTE
Femto Cell, LTE D2D and LTE VANET. The LTE libraray allows you to connect, if required,
with Internetwork devices such as Routers, Switches etc running Ethernet, Wireless LAN, IP
Routing, TCP / UDP.
A legacy network is an old network which is rarely used today and not part of the TCP/IP
protocol suite. With the advent of TCP/IP as a common networking platform in the mid-1970s,
most legacy networks are no longer used.
Internet of Things (IoT) is an ecosystem of connected physical objects that are accessible
through the internet. It is the network of physical objects that can communicate, sense or
interact with their internal states or the external environment.
An internetwork is a collection of two or more computer networks (typically Local Area
Networks or LANs) which are interconnected to form a bigger network. All networks in an
Internetwork have a unique network address. Routers interconnect the networks
A network simulator mimics the behaviour of networks but cannot connect to real networks.
NetSim Emulator enables users to connect NetSim simulator to real hardware and interact
with live applications.
Cognitive Radio Network simulation is available from v7 of NetSim. Cognitive Radio Networks
allows you to connect, if required, with Ethernet, Wireless LAN, IP Routing, TCP / UDP and
allows users to log packet and event traces.
In NetSim, you can simulate and analyze the following cellular netwoks: (Global System for Mobile communication) GSM and Code-Division Multiple Access (CDMA)
Advanced Routing. Routing is the process of forwarding packets from one network to the destination address in another network. ... Each route is known as a routing entry
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
1. Ver 11.1 1
Propagation Models
Contents
1 Propagation models in NetSim ..............................................................................................2
1.1 Propagation Loss .......................................................................................................................2
2 Path loss...............................................................................................................................3
2.1 Path loss models........................................................................................................................3
2.1.1 Friis Free space propagation model.........................................................................3
2.1.2 Log distance .............................................................................................................4
2.1.3 Hata Urban...............................................................................................................4
2.1.4 Hata Suburban .........................................................................................................5
2.1.5 COST231 Hata Urban and COST231 Hata Suburban................................................5
2.1.6 Indoor office and Indoor factory..............................................................................6
2.1.7 Indoor home: ...........................................................................................................6
3 Shadowing models................................................................................................................7
3.1 Log normal shadowing ..............................................................................................................7
4 Fading models ......................................................................................................................7
4.1 Nakagami Fading.......................................................................................................................8
4.2 Rayleigh Fading .........................................................................................................................8
5 SINR Calculation ...................................................................................................................9
6 Bit Error Rate (BER) Calculation........................................................................................... 10
2. Ver 11.1 2
1 Propagation models in NetSim
Propagation models are used to model signal attenuation for all wireless links. These include
WLAN – 802.11, Legacy Networks, ZigBee / IOT / WSN – 802.15.4, LTE, Cognitive radio –
802.22 and VANET.
1.1 Propagation Loss
Three different and mutually independent propagation phenomena influence the power of
the received signal: path loss, shadowing and multipath fading.
The different models available in NetSim are
1. Path loss Models
Friis Free Space Propagation (Default option in GUI)
Log Distance
HATA Suburban
HATA Urban
COST 231 HATA Suburban
COST 231 HATA Urban
Indoor Office
Indoor Factory
Indoor Home
No Path Loss
2. Shadowing Models
None
Constant
Lognormal
3. Fading Models
None
Rayleigh
Nakagami
3. Ver 11.1 3
2 Path loss
Path loss is the reduction in power density of an electromagnetic wave as it propagates
through space. Path loss may be due to many effects, such as free reflection, aperture-
medium coupling loss, and absorption. The general formula by which path loss is calculated
is
RXpower = TXpower + GainTX + GainRX – PL1meter – 10 log Dn
Where n is the path loss exponent, whose value is normally in the range of 2 to 5. In NetSim,
the default value for path loss exponent is 2 and D is the distance between transmitter and
the receiver, usually measured in meters.
And PL1meter is the path loss at reference distance (here taken as 1m). This value varies
depending on the radio and is a user input available in the PHY layer of the radios. For
802.11b this value is 40dB
And the Gain represents the transmit and receive antenna gains
Example:
Calculating the received power at 2 due to node 1 transmission. The transmitter power of
node1 is 100mW (20dBm), frequency is 2412MHz
Rx_Power (dbm) = 20dBm + 0 + 0 – 40dB – 40dB = -60dBm
The default value for reference distance d0 and path loss at reference distance PL_d0 are
1. 802.11 a / b / g / n / ac / p
a. 2.4 GHz : Default d0 = 1m and PL_D0 = 40dB
b. 5 GHz: Default d0 = 1 m and PL_D0 = 47 dB
2. 802.15.4 - Default d0 = 8m and PL_D0 = 58.5 dB
3. In LTE the calculation is done for each carrier for uplink and download. Default d0 =
1m and PL_D0 = 32 dB
2.1 Path loss models
2.1.1 Friis Free space propagation model
The free space propagation model is used to predict received signal strength when the
transmitter and receiver have a clear, unobstructed line-of-sight path between them. Satellite
4. Ver 11.1 4
communication systems and microwave line-of-sight radio links typically undergo free space
propagation. As with most large scale radio wave propagation models, the free space model
predicts that received power decays as a function of T-R separation distance raised to some
power. The free space power received by a receiver antenna which is separated from a
radiating transmitter antenna by distance d, is given by the Friis free space equation
𝑃𝑟 = [𝑃𝑡] + [𝐺𝑡] + [𝐺𝑟] + 20𝑙𝑜𝑔10 [𝜆/ (4 ∗ 3.14 ∗ 𝑑𝑜)] + (10 ∗ 2 ∗ 𝑙𝑜𝑔10 (𝑑𝑜/𝑑))
where Pt is the transmitted power
Pr is the received power
Gt is the transmitter antenna gain
Gr is the receiver antenna gain
d is the T-R separation distance in meters
L is the system loss factor
λ is the wavelength in meters
2.1.2 Log distance
The average received power logarithmically decreases with distance, whether in outdoor or
indoor radio channels. The average large-scale path loss for an arbitrary T-R separation is
expressed as a function of distance by using path loss exponent n.
𝑃𝑟 = [𝑃𝑡] + [𝐺𝑡] + [𝐺𝑟] + 20𝑙𝑜𝑔10 [𝜆 / (4 ∗ 3.14 ∗ 𝑑𝑜)] + (10 ∗ 𝑛 ∗ 𝑙𝑜𝑔10 (𝑑𝑜/𝑑))
Where n = 2 - path loss exponent which indicates the rate at which the path loss increases
with distance,
d0 is the close in-reference distance which is determined from measurements close
to the transmitter
d is the T-R separation distance
2.1.3 Hata Urban
The hata model is an empirical formulation of the graphical path loss data provided by
Okumura. Hata presented the urban area propagation loss as a standard formula and
supplied correction equations for applications to other situations. The standard formula for
median path loss in urban areas is given by
𝑃𝑟 = [𝑃𝑡] − 𝐿50 (𝑑𝐵)
5. Ver 11.1 5
𝐿50(𝑑𝐵) = 69.55 + 26.16log(𝑓𝑐) – 13.82log(ℎ𝑡𝑒) – 𝑎(ℎ𝑟𝑒) + (44.9 – 6.55 log(ℎ𝑡𝑒))log(𝑑)
− − − − − − − − − − − −𝑒𝑞(1)
Where
L50 (dB) = 50th
percentile (median) value of path loss
fc = Frequency in MHz
hte = Transmitter antenna height ( Range 30m to 200m, default 30m)
hre = Receiver antenna height ( Range 1m to 10m, default 1m)
d = Separation distance in km. So if input is in meter, this should be divided by 1000
to convert to km
a (hre) = correction factor for effective mobile antenna height which is a function of
the size of coverage area.
𝑎 (ℎ𝑟𝑒) = 8.29 (𝑙𝑜𝑔 1.54 ℎ 𝑟𝑒 )2 – 1.1 𝑑𝑏 for fc < 300 MHz
𝑎 (ℎ𝑟𝑒) = 3.2 (𝑙𝑜𝑔 11.74 ℎ 𝑟𝑒 )2 – 4.97 𝑑𝑏 for fc >= 300 MHz
2.1.4 Hata Suburban
To obtain path loss in suburban area, the standard Hata formula in equation 1 is modified as
𝑃𝑟 = [𝑃𝑡] − 𝐿50 (𝑑𝐵)
𝐿50 (𝑑𝐵) = 𝐿50(𝑢𝑟𝑏𝑎𝑛)(𝑑𝐵) – 2[𝑙𝑜𝑔𝑓𝑐/28]^2– 5.4 − − − − − − − −𝑒𝑞(2)
2.1.5 COST231 Hata Urban and COST231 Hata Suburban
The European Co-operative for Scientific and Technical Research (EURO-COST formed
COST231 working committee to develop an extended version of the Hata model COST231
proposed the following formula to extend Hata’s model. The proposed model for path loss is
𝑃𝑟 = [𝑃𝑡] − 𝐿50 (𝑑𝐵)
𝐿50(𝑑𝐵) = 46.3 + 33.9log(𝑓𝑐) – 13.82log(ℎ𝑡𝑒) – 𝑎(ℎ𝑟𝑒) + (44.9 – 6.55 log(ℎ𝑡𝑒))log(𝑑) + 𝐶𝑀
Where CM =
3 dB for urban
0 dB for suburban
6. Ver 11.1 6
2.1.6 Indoor office and Indoor factory
Office buildings have large open areas which are constructed by using moveable office
partitions so that the space may be reconfigured easily and use metal reinforced concrete
between floors. Partitions that are formed as part of building structure are called hard
partitions and partitions that may be moved and which do not span to the ceiling are called
soft partitions. Partitions vary widely in their physical and electrical characteristics
𝑃𝑟 = [𝑃𝑡] + [𝐺𝑡] + [𝐺𝑟] + 20𝑙𝑜𝑔10 [𝜆/ (4 ∗ 3.14 ∗ 𝑑𝑜)] + (10 ∗ 𝑛 ∗ 𝑙𝑜𝑔10 (𝑑𝑜/𝑑))
Where n =
2.1.7 Indoor home:
Houses typically use a wood frame partition with plaster board to form internal walls and
have wood or nonreinforced concrete between floors
𝑃𝑟 = [𝑃𝑡] + [𝐺𝑡] + [𝐺𝑟] + 20𝑙𝑜𝑔10 [𝜆/ (4 ∗ 3.14 ∗ 𝑑𝑜)] + (10 ∗ 𝑛 ∗ 𝑙𝑜𝑔10 (𝑑𝑜/𝑑))
Where n = 3
The default values of path loss exponent for all path loss models in NetSim are as shown
below:
Path loss model
Path loss exponent
(default)
Friis free space 2
Log distance 2
COST231 Urban -
COST231 Hata
Suburban
-
Hata Urban -
Hata Suburban -
Indoor Office 2.6
Indoor Factory 2.1
Indoor Home 3
2.6 for Indoor_office
2.1 for Indoor_factory
7. Ver 11.1 7
3 Shadowing models
3.1 Log normal shadowing
The mode in the Friis free space propagation equation does not consider the fact that the
surrounding environmental clutter may be vastly different at two different locations having
the same T-R separation. This leads to measured signals which are vastly different than the
average value predicted by the above equation. Measurements have shown that at any
value of d, the path loss PL (d) at a particular location is random and distributed log-normally
about the mean distance-dependent value i.e.
𝑃𝐿(𝑑)[𝑑𝐵] = 𝑃𝐿(𝑑) + 𝑋𝜎 = 𝑃𝐿(𝑑0) + 10𝑛𝑙𝑜𝑔(𝑑/𝑑0) + 𝑋𝜎
Where Xσ is a zero-mean Gaussian distributed random variable (in dB) with standard
deviation σ (in dB)
The log normal distribution describes random shadowing effects which occur over a large
number of measurement locations which have the same T-R separation, but have different
levels on the clutter propagation path. This phenomenon is referred to as log-normal
shadowing
The default values of standard deviation (dB) for all shadowing models in NetSim are as
shown below:
Shadowing Model Standard Deviation
Log Normal 5
Constant 5
4 Fading models
Fading is caused by interference between two or more versions of transmitted signal which
arrive at the receiver at slightly different times. These waves, called multipath waves,
combine at the receiver antenna to give a resultant signal which can vary widely in amplitude
and phase, depending on the distribution of the intensity and relative propagation time of the
waves and the bandwidth of the transmitted signal.
8. Ver 11.1 8
In built-up urban areas, fading occurs because the height of the mobile antennas are well
below the height of surrounding structures, so there is no single line-of-sight path to the base
station. The code for calculating fading power is present in
fn_NetSim_IEEE802_11_Phy_In() function in IEEE_802_11.c file inside IEEE802_11
project.
The default values of Fading parameters in NetSim are as shown below:
Fading Model Parameter Value
Rayleigh Fading Figure 5
Nakagami
Fading Figure 5
Shape parameter 1
Omega 2
4.1 Nakagami Fading
The Nakagami distribution is related to the gamma distribution. In particular, given a random
variable
𝑌 ~ 𝛾(𝐾, Ө)
it is possible to obtain a random variable
𝑋 ~ 𝑁𝑎𝑘𝑎𝑔𝑎𝑚𝑖 (𝑚, 𝛺)
by setting k = m, Ө= Ω/m and taking the square root of Y
𝑋 = 𝑆𝑞𝑟𝑡 (𝑌)
4.2 Rayleigh Fading
In mobile radio channels, the Rayleigh distribution is commonly used to describe the
statistical time varying nature of the received envelope of a flat fading signal, or the envelope
of an individual multipath component. It is well known that the envelope of the sum of two
quadrature Gaussian noise signals obeys a Rayleigh distribution. The Rayleigh distribution
has a probability density function (pdf) is given by
𝑃(𝑟) =
𝑟
𝜎2
𝑒𝑥𝑝(−
𝑟2
2𝜎2
) 0 <= 𝑟 <= ∞
𝑃(𝑟) = 0 𝑟 < 0
Where σ = rms value of the received voltage signal before envelope detection
9. Ver 11.1 9
σ^2 = time-average power of the received signal before envelope detection
The probability that the envelope of the received signal does not exceed a specified value R
is given y corresponding cumulative distribution function (CDF) is given by
𝑃(𝑅) = Pr(𝑟 ≤ 𝑅) = ∫ 𝑝(𝑟)𝑑𝑟
𝑅
0
= 1 − 𝑒𝑥𝑝(−
𝑅2
2𝜎2
)
The mean value rmean of the Rayleigh distribution is given by
𝑟𝑚𝑒𝑎𝑛 = 𝐸[𝑅] = ∫ 𝑟𝑝(𝑟)𝑑𝑟 = 𝜎√
𝜋
2
∞
0
= 1.2533𝜎
And the variance of the Rayleigh distribution is given by σr
2
which represents the ac power in
the signal envelope
𝜎𝑟2
= 𝐸[𝑟2]– 𝐸2
[𝑟] = ∫ 𝑟2
𝑝(𝑟)𝑑𝑟 −
𝜎2
𝜋
2
∞
0
= 𝜎2
(2 −
𝜋
2
)
5 SINR Calculation
Analogous to the SNR used often in wired communications systems, the SINR is defined as
the power of a certain signal of interest divided by the sum of the interference power (from all
the other interfering signals) and the power of some background noise.
The interference power is the difference between the total power received by the receiver
and the power received from one particular transmitter.
The background thermal noise in dBm at room temperature is given by:
P (in dBm) = −174 + 10 × 𝑙𝑜𝑔10(𝛥𝑓)
Where Δf is the Bandwidth in Hertz. For 802.15.4, Δf = 2 MHz. For 802.11a, b, g, Δf = 20
MHz, and for 802.11n, Δf = 20 MHz or 40 MHz.
P (in mW) = 10(
𝑃 (𝑖𝑛𝑑𝐵𝑚)
10
)
Therefore, SINR in dBm is calculated as:
SINR (in dBm) = 𝑙𝑜𝑔10 (
𝑅𝑒𝑐𝑒𝑖𝑣𝑒𝑑 𝑝𝑜𝑤𝑒𝑟 (𝑖𝑛 𝑚𝑊)
𝐼𝑛𝑡𝑒𝑟𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑁𝑜𝑖𝑠𝑒 (𝑖𝑛 𝑚𝑊) + 𝑇ℎ𝑒𝑟𝑚𝑎𝑙 𝑁𝑜𝑖𝑠𝑒 (𝑖𝑛 𝑚𝑊)
)
10. Ver 11.1 10
6 Bit Error Rate (BER) Calculation
The bit error rate (BER) is the number of bit errors divided by the total number of transferred
bits during a studied time interval. The BER calculation is calculated using as SNR – BER
tables for different modulation schemes. These codes for these tables are not available for
user modification. In the case of LTE an SNR-BER table is looked up for each MCS.
Note: Floating numbers may lose precision when converting from dbm to mw or vice (Ref:
https://msdn.microsoft.com/en-us/library/c151dt3s.aspx). Hence
If the received power (in mw) is less than 0.0001 then it’s assumed to be zero.
If the received power (in mw) is 0 then dbm value for same is -10000.0 not -inf
While adding two powers, decimal points after fifth digit is ignored. Ex
2.0000005+3.0000012 = 5.0