scholarly journals Performance Enhanced Coded OFDM with Almost Linear Inter leaver over Rayleigh Fading Channels

2021 ◽  
Author(s):  
chenggao han
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Rayleigh Fading Channels ◽  
Frequency Division ◽  
Industry Standards ◽  
Comprehensive Performance ◽  
Union Bound ◽  
Simulation Results ◽  
Coded Ofdm

This paper presents a comprehensive performance analysis of coded orthogonal frequency division multiplexing (COFDM) over the quasi-static multipath Rayleigh fading channels. We first analyze the pairwise error probability (PEP) of COFDM and then consider the union bound on bit error rate (BER) by introducing the notion of diversity guard (DG) and a novel interleaver class, named almost linear interleaver (ALI). A construction of ALI is also introduced with its parameter selection. Simulation results show that the COFDM with ALI outperforms that with random interleaver (RI) and the block interleaver (BI) adopted in the IEEE industry standards.<br><br>

scholarly journals Performance Enhanced Coded OFDM with Almost Linear Inter leaver over Rayleigh Fading Channels

2021 ◽  
Author(s):  
chenggao han
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Rayleigh Fading Channels ◽  
Frequency Division ◽  
Industry Standards ◽  
Comprehensive Performance ◽  
Union Bound ◽  
Simulation Results ◽  
Coded Ofdm

This paper presents a comprehensive performance analysis of coded orthogonal frequency division multiplexing (COFDM) over the quasi-static multipath Rayleigh fading channels. We first analyze the pairwise error probability (PEP) of COFDM and then consider the union bound on bit error rate (BER) by introducing the notion of diversity guard (DG) and a novel interleaver class, named almost linear interleaver (ALI). A construction of ALI is also introduced with its parameter selection. Simulation results show that the COFDM with ALI outperforms that with random interleaver (RI) and the block interleaver (BI) adopted in the IEEE industry standards.<br><br>

scholarly journals Software-Based Analysis of Multi User Orthogonal Frequency Division Multiplexing (OFDM)

2016 ◽  
Vol 3 (2) ◽  
pp. 1-6
Author(s):  
Widya Catur Kristanti Putri
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Code Rate ◽  
Rayleigh Fading Channels ◽  
Bandwidth Efficiency ◽  
Frequency Division ◽  
Frequency Allocation ◽  
Study Program ◽  
Bpsk Modulation

The application of OFDM technology is still not fully implemented in the Telecommunication Study Program at State Polytechnic of Malang. This is because the application of this technology is applied to hardware. However, this can be overcome by simulating the OFDM technology through software. From the application of the system into the program by entering the predetermined parameters, the BER value can be compared to the predetermined parameters. Bit error that appears in the application of the OFDM Multi user system for bit error in BPSK Modulation with AWGN and Rayleigh Fading channels appears bit error respectively with an average of 9 bits and 14 bits at 11 dB SNR. Whereas in the QPSK modulation with AWGN and Rayleigh Fading channels, each bit error appears with an average of 13 bits and 18 bits on the SNR of 14 dB. Furthermore, in the calculation of bandwidth efficiency in the frequency allocation of 20 MHz for BPSK modulation, three values ??of bandwidth efficiency are obtained, among others, 1 bps / Hz in theory for practical, namely the code rate ½ is 0.3 bps / Hz and the code rate ¾ is 0.45 bps / Hz. While the QPSK modulation also obtained three values ??of bandwidth efficiency, namely, 2 bps / Hz in theory for practical, namely the code rate ½ is 0.6 bps / Hz and the code rate ¾ is 0.9 bps / Hz.

scholarly journals Review of Channel Estimation for Candidate Waveforms of Next Generation Networks

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 956 ◽  
Author(s):  
Owoicho E. Ijiga ◽  
Olayinka O. Ogundile ◽  
Ayokunle D. Familua ◽  
Daniel J. J. Versfeld
Keyword(s):  
Fading Channels ◽  
Amplitude Modulation ◽  
Filter Bank ◽  
Rayleigh Fading ◽  
Perfect Reconstruction ◽  
Rayleigh Fading Channels ◽  
Next Generation Networks ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
5G Networks

The advancement in wireless communication applications encourages the use of effective and efficient channel estimation (CE) techniques because of the varying behaviour of the Rayleigh fading channel. In most cases, the emphasis of most proposed CE schemes is to improve the CE performance and complexity for ensuring quality signal reception and improved system throughput. Candidate waveforms whose designs are based on filter bank multi-carrier (FBMC) modulation techniques such as filter bank orthogonal frequency division multiplexing based on offset quadrature amplitude modulation (OFDM-OQAM), universal filtered multicarrier (UFMC) and generalised frequency division multiplexing based on offset quadrature amplitude modulation (GFDM-OQAM) are no exception to the use of these proposed CE techniques in the literature. These schemes are considered as potential waveform candidates for the physical/media access control layer of the emerging fifth generation (5G) networks. Therefore, pinpoint CE techniques represent an important requirement for these waveforms to attain their full potentials. In this regard, this paper reviews the concept of CE as applicable to these waveforms as well as other waveform candidates under consideration in the emerging 5G networks. Since the design of the majority of the waveform candidates is filter based, a review of the general filter design considerations is presented in this paper. Secondly, we review general CE techniques for candidate waveforms of next generation networks and classify some of the studied CE techniques. In particular, we classify the CE schemes used in filter bank OFDM-OQAM and GFDM-OQAM based transceivers and present a performance comparison of some of these CE schemes. Besides, the paper reviews the performances of two linear CE schemes and three adaptive based CE schemes for two FBMC based waveform candidates assuming near perfect reconstruction (NPR) and non-perfect reconstruction (Non-PR) filter designs over slow and fast frequency selective Rayleigh fading channels. The results obtained are documented through computer simulations, where the performances of the studied CE schemes in terms of the normalised mean square error (NMSE) are analysed. Lastly, we summarise the findings of this work and suggest possible research directions in order to improve the potentials of the studied candidate waveforms over Rayleigh fading channels.

scholarly journals Equalization for Underwater Acoustic Coded OFDM Communication System Over Multipath Fading Via Simulation Platform

2019 ◽  
Vol 9 (2S3) ◽  
pp. 292-294
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Multipath Fading ◽  
Least Square ◽  
Adaptive Equalization ◽  
Frequency Division ◽  
Recursive Least Square ◽  
Error Performance ◽  
Multiple Paths ◽  
Coded Ofdm

In underwater shallow acoustic communication (UWSAC) channel, due to the reflections from bottom and surface, multiple paths propagated resulting Inter Symbol Interference (ISI). In this paper we present the bit error performance of convolution coded orthogonal frequency division multiplexing (CCOFDM) UWSAC system with the implementation of adaptive equalization to minimize the ISI over AWGN and Rayleigh fading based on Recursive least square (RLS) and Filtered Error Least Mean Squares (FELMS) Algorithms. From the simulation results it is observed that FELMS shown to improve BER as compared to an RLS with CCOFDM system..

scholarly journals Quasi-Orthogonal Time Division Multiplexing and Its Performances in Rayleigh Fading Channels

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Enchang Sun ◽  
Kechu Yi ◽  
Bin Tian ◽  
Dongying Zhang
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Carrier Frequency Offset ◽  
Satellite Communications ◽  
Rayleigh Fading Channels ◽  
Transmission Scheme ◽  
Time Division Multiplexing ◽  
Single Carrier ◽  
Time Division

This paper proposes an efficient transmission scheme, Quasi-Orthogonal Time Division Multiplexing (QOTDM), which employs the shift orthogonal property of the pulse function with raised-cosine spectral shape, and the signal waveforms are quasi-orthogonal in time domain. Comparing to orthogonal frequency division multiplexing (OFDM), QOTDM is less sensitive to carrier frequency offset and power amplifier nonlinearities while keeping a similar spectral efficiency with OFDM due to single-carrier characteristics. QOTDM is a suitable consideration for the downlink transmission such as in satellite communications. An upper bound of sample error probability (SER) is derived to evaluate the performance of QOTDM. Comparisons of QOTDM and OFDM in Rayleigh fading channels show that the proposed QOTDM system is better than that of OFDM system in terms of bit error rate (BER) in high Eb/No regions.

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