scholarly journals Improvement of Fading Channel Modeling Performance for Wireless Channel

2018 ◽  
Vol 8 (3) ◽  
pp. 1451
Author(s):  
Inaam Abbas Heider
Keyword(s):  
Fading Channels ◽  
Fading Channel ◽  
Communication Channel ◽  
Channel Model ◽  
Signal To Noise Ratio ◽  
Channel Modeling ◽  
Wireless Channel ◽  
Rayleigh Channels ◽  
Geographical Position ◽  
Wireless Fading Channel

Fading channel modeling is generally defined as the variation of the attenuation of a signal with various variables. Time, geographical position, and radio frequency which is included. Fading is often modeled as a random process. Thus, a fading channel is a communication channel that experiences fading. In this paper, the proposed system presents a new design and simulate a wireless channel using Rayleigh channels. Rayleigh channels using two approaches (flat and frequency-selective fading channels) in order to calculate some path space loss efforts and analysis the performance of different wireless fading channel modeling. The results show that the bite error rate (BER) performance is dramatically improved in the value of signal to noise ratio (SNR) is equal to 45dB. Finally, the experimental results show that the proposed method enhances the performance of fading channel modeling by reducing the error of BER when the SNR is reduced also. Moreover, the more accurate model is Rayleigh model which can be considered for developing fading channel model.

On Capacity of 60GHz TH-PPM Systems in Frequency Selective Fading Channels

2012 ◽  
Vol 433-440 ◽  
pp. 5506-5511 ◽  
Author(s):  
Na Li ◽  
Hao Zhang ◽  
Jing Jing Wang ◽  
T. Aaron Gulliver
Keyword(s):  
Fading Channels ◽  
Fading Channel ◽  
Channel Model ◽  
Selective Fading ◽  
Pulse Modulation ◽  
Frequency Selective Fading ◽  
Single User ◽  
Frequency Selective ◽  
Performance Results ◽  
Channel Properties

Two pulse waveforms are designed and analyzed for 60GHz pulse modulation systems. An indoor frequency selective fading channel model is introduced for single user 60GHz TH-PPM systems. The capacity with this channel model of a 60GHz TH-PPM system based on the designed pulses is derived. Performance results are presented to illustrate the effects of the pulse waveforms and channel properties on the channel capacity.

scholarly journals Wireless Channel Models for Over-the-Sea Communication: A Comparative Study

2019 ◽  
Vol 9 (3) ◽  
pp. 443 ◽  
Author(s):  
Arafat Habib ◽  
Sangman Moh
Keyword(s):  
Wave Propagation ◽  
Comparative Study ◽  
Radio Wave ◽  
Marine Environment ◽  
Channel Model ◽  
Channel Modeling ◽  
Wireless Channel ◽  
Radio Wave Propagation ◽  
Channel Models ◽  
The Impact

Over the past few years, the modeling of wireless channels for radio wave propagation over the sea surface has drawn the attention of many researchers. Channel models are designed and implemented for different frequencies and communication scenarios. There are models that emphasize the influence of the height of the evaporation duct in the marine environment, as well as models that deal with different frequencies (2.5, 5, and 10 GHz, etc.) or the impact of various parameters, such as antenna height. Despite the increasing literature on channel modeling for the over-the-sea marine environment, there is no comprehensive study that focuses on key concepts that need to be considered when developing a new channel model, characteristics of channel models, and comparative analysis of existing works along with their possible improvements and future applications. In this paper, channel models are discussed in relation to their operational principles and key features, and they are compared with each other in terms of major characteristics and pros and cons. Some important insights on the design and implementation of a channel model, possible applications and improvements, and challenging issues and research directions are also discussed. The main goal of this paper is to present a comparative study of over-the-sea channel models for radio wave propagation, so that it can help engineers and researchers in this field to choose or design the appropriate channel models based on their applications, classification, features, advantages, and limitations.

Error Correction of Coding of Wireless Transmission Channel of Digital Images

2014 ◽  
Vol 536-537 ◽  
pp. 771-775
Author(s):  
Ming Kai Yue ◽  
Jia Hao Deng
Keyword(s):  
Error Correction ◽  
Channel Model ◽  
Simulation Analysis ◽  
Turbo Code ◽  
Signal To Noise Ratio ◽  
Wireless Channel ◽  
Wireless Transmission ◽  
Transmission Channel ◽  
Noise Interference ◽  
Wireless Channel Model

The wireless channel model, which was suitable with the complex environment of battlefield, was built by analyzing the digital image of wireless transmission channel, the transmission characteristics and the fading type. The error correction of coding for the compressed code stream of image was carried out specifically with Turbo code, and the Simulink simulation model was designed. The system simulation analysis was carried out for the performance parameters that affect the Turbo code and the BER performance of as-built wireless channel model. The results showed that the Turbo code is a kind of error correction one, which is anti-fading and strong interference among codes. It can not only reach higher peak signal to noise ratio, but also transmit more steadily and more reliably in the changeable channel environment under noise interference. Furthermore, the turbo can be applied for code correction and controlling.

scholarly journals Network Coded Modulation for Two Way Relay Networks

2014 ◽  
Vol 41 (1) ◽  
pp. 9-14
Author(s):  
Abdulkareem Kadhim ◽  
Karrar Ali
Keyword(s):  
Wireless Networks ◽  
Fading Channels ◽  
Channel Model ◽  
Relay Node ◽  
Poor Performance ◽  
Wireless Channel ◽  
Coded Modulation ◽  
Cooperative Relaying ◽  
Coverage Area ◽  
Ber Performance

Modern wireless networks use cooperative relaying to expand its coverage area. Wireless relaying allows mobile terminals toparticipate in transmission even when these terminals are not being the initial source or final destination. This can be achieved in differentways ranging from simple conventional relaying to more sophisticated coding at terminal and relay nodes to improve transmissionperformance. The proposed work here studied such system by simulating different coding techniques to be used in two way relay networkcoding (TWRC). Some of these techniques were previously proposed to improve transmission performance in conventional datacommunication systems. BER performance of different arrangements of coding and relaying schemes are evaluated using computersimulation tests. Ideal AWGN channel model and standard wireless channel models for wireless networks are considered in the simulationtests. The results have been shown that coding schemes such as Trellis Coded Modulation (TCM) and Repeat Accumulate (RA) codes aremore suitable in two way relaying networks. Over AWGN, TCM-8PSK improves BER performance by at least 2 dB at high SNR fordifferent relaying arrangements. For fading channels, this advantage is slightly reduced. Regenerative repeating at relay node seems to be apromising arrangement. It seems that there is no sense in using RA codes over fading channels due to its poor performance and relativelylower speed caused by repetitions.

scholarly journals Variable Forgetting Factor LS Algorithm for Polynomial Channel Model

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Amit Kumar Kohli ◽  
Amrita Rai ◽  
Meher Krishna Patel
Keyword(s):  
Fading Channels ◽  
Fading Channel ◽  
Channel Model ◽  
Time Varying ◽  
Selective Fading ◽  
Forgetting Factor ◽  
Frequency Selective Fading ◽  
First Order ◽  
Variable Forgetting Factor ◽  
Frequency Selective Fading Channels

Variable forgetting factor (VFF) least squares (LS) algorithm for polynomial channel paradigm is presented for improved tracking performance under nonstationary environment. The main focus is on updating VFF when each time-varying fading channel is considered to be a first-order Markov process. In addition to efficient tracking under frequency-selective fading channels, the incorporation of proposed numeric variable forgetting factor (NVFF) in LS algorithm reduces the computational complexity.

Design and Implement of a Channel Model Based on TD-LTE

2014 ◽  
Vol 513-517 ◽  
pp. 2530-2533
Author(s):  
Hua Hua Wang ◽  
Ming Li ◽  
Lei Cheng Chen
Keyword(s):  
Relative Error ◽  
Doppler Effect ◽  
Fading Channel ◽  
Channel Model ◽  
Model Combining ◽  
Baseband Signal ◽  
Comparison And Analysis ◽  
Wireless Fading Channel ◽  
Set Up ◽  
Channel Simulator

This paper studies the characters of wireless fading channel based on TD-LTE, and it is critical of multipath effect and Doppler effect. So there design a math channel model combining these factors. And then set up link in Matlab to analyse the model. Through simulating we can optimize the model. After that it is implemented by FPGA of final determined math channel model. Using TD-LTE baseband signal as driven signal, this model is simulated and implemented in ModelSim platform. Through comparison and analysis the error between the channel impulse of the model and the result of Matlab link, we can obtain that the relative error is very little. So it can confirm reliability of this channel simulator.

Performance Analysis of Multi-Hop Multi-Branch Amplify-and-Forward Cooperative Communication Over Rician Fading Channels

2019 ◽  
Vol 29 (09) ◽  
pp. 2050148
Author(s):  
Hadi Fathollahi ◽  
Mohammad H. Madani
Keyword(s):  
Fading Channels ◽  
Cooperative Communication ◽  
Channel Model ◽  
Asymptotic Expression ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Maximal Ratio Combining ◽  
Rician Fading ◽  
Amplify And Forward ◽  
Rician Fading Channels

Performance of multi-hop multi-branch amplify and forward (AF) cooperative communication over Rician fading channels is presented in this paper by a novel analysis method. Rician distribution is used to analyze the system because this channel model is useful in aerospace wireless communication channels. We derive an asymptotic expression for the statistics of the received signal-to-noise ratio (SNR) in the system under study with well-known moment-generating function (MGF)-based approach with maximal ratio combining (MRC) scheme. Moreover, for comparative analysis in different branches and hops, outage probability and symbol error ratio are derived. Finally, numerical simulation results are provided to confirm the theoretical results. These results are presented to illustrate the considerable performance improvement achieved by the increasing number of branches and hops.

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