A Novel Transceiver Architecture for Making Polar Codes Work Over Multipath Fading Channels as They Do Over Awgn Channels

A Novel Transceiver Architecture for Making Polar Codes Work Over Multipath Fading Channels as They Do Over Awgn Channels

Author: Jehad M. Hamamreh

Publisher: Wireless Innovations

Published: 2019-03-22

Total Pages: 26

ISBN-13: 9781091292277

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Polar codes, recently accepted for adoption in 5G standard due to their excellent performance at a very low complexity compared to other competitive schemes in the literature, are deemed to be a strong candidate for the Internet of Things (IoT) applications as well due to meeting their requirements. However, since polar codes construction is naturally channel-dependent, there has recently been an increasing interest in addressing the challenge of making polar codes work in realistic fading environments as they do in a binary symmetric channel (BSC). Recent studies on polar codes for fading channels have mainly focused on constructing new specific polar codes suitable to particular fading channels. This results in a non-universal code structure, leading to continuous changes in the code structure based on the channel, which is not desirable in practice. To address this problem, we develop and propose a novel transceiver architecture which enables using the polar coding design of a binary input additive white Gaussian noise (BI-AWGN) channel for multi-path fading channels without causing any changes in the structure of the encoder and decoder sides. This is made possible by eliminating the channel fading effect so that a net AWGN channel can be seen at the input of a simple successive cancellation decoder (SCD). The novelty of the proposed solution lies in using a channel-based orthonormal transformation with optimal power allocation at the transmitter and another transformation at the receiver to make the net, effective channel seen by the SCD very similar to an AWGN channel. The obtained results show that the proposed design makes the bit error rate (BER) performance of polar codes over a frequency selective fading channel the same as that over an AWGN channel. As an additional great advantage, the proposed design is found to be capable of providing confidentiality against eavesdropping receivers (i.e., unintended users) at the physical layer. Particularly, wireless physical layer security is delivered by the proposed scheme because of the fact that the transmitted data blocks are designed based on the channel of the legitimate receiver, which is naturally different from that of an eavesdropper, who is normally located several wavelengths away from the legitimate receiver and thus experiencing a different channel.==========================================================This short-length e-book is meant for students (master and Ph.D.), researchers, engineers, practitioners, and instructors who are interested in wireless communication and signal processing. You should have a fair understanding of digital communication systems, linear algebra, random variables, and channel coding to begin with.


Polar Codes for Rayleigh Fading Channels

Polar Codes for Rayleigh Fading Channels

Author: Oguzkan Akbel

Publisher:

Published: 2016

Total Pages: 88

ISBN-13:

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Polar codes are recently invented error control coding scheme by Erdal Arikan which are provably can achieve Shannon's Capacity for binary symmetric discrete memoryless channels. According to Shannon any coding scheme can achieve the capacity, but until now none of them did. Therefore, the general idea about the coding schemes was any coding scheme can achieve the capacity except the known ones. Erdal Arikan invented a new coding scheme by polarizing the channel and creating artificial ones which are completely noisy or reliable. Therefore, one can send the data from the reliable channels and the coding scheme will achieve the Shannon's Capacity. We show for additive white Gaussian noise, Rayleigh fading environment and fast fading OFDM channels, we can find almost completely reliable channels. Considering ununiversality of polar codes we use certain SNR levels for range of SNRs. Next, we show our results about the complexity of the algorithm. At the and we will introduce an end to end simulation of polar codes in Rayleigh multipath channel.


Kernels of Polar Codes and Their Applications to Wireless Channels, and Joint Source and Channel Coding Based on LDPC Codes

Kernels of Polar Codes and Their Applications to Wireless Channels, and Joint Source and Channel Coding Based on LDPC Codes

Author: Hsien-Ping Lin

Publisher:

Published: 2016

Total Pages:

ISBN-13: 9781369615203

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This dissertation contains three topics: Polar codes with optimal exponents based on linear and nonlinear binary kernels of sizes up to 16, a design of rate-compatible polar codes, and a new proposed structure of joint source and channel coding based on low-density-parity-check (LDPC) codes. Polar codes are proposed by Arıkan with construction based on a linear kernel of dimension 2 with polarizing properties. The performance of a polar code is characterized asymptotically in terms of the exponent of its kernel. In this dissertation, constructions of linear and nonlinear binary kernels of dimensions up to 16 are presented. The constructed kernels are proved to have maximum exponents except in the case of nonlinear kernels of dimension 12 where we show that there exists only one possible exponent greater than that of the presented construction. From the results, the minimum dimension where a linear kernel with exponent greater than 0.5, the exponent of the linear kernel proposed by Arıkan, is 15, while this minimum dimension is 14 for nonlinear kernels. We also found that there is a linear kernel with maximum exponent up to dimension 11. The kernels of dimensions 13, 14, 15 with maximum exponents, although nonlinear over GF(2), are shown to be Z4-linear or Z2Z4-linear. In addition to exploring the asymptotic behavior of polar codes, we propose a design of finite block length rate-compatible polar codes suitable for HARQ communications. The central feature of the proposed design is established on the puncturing order chosen with low complexity on a base code of short length, which is then extended to the desired length. With the designed puncturing order, a practical rate-matching system which can be adjusted to any desired rate through puncturing or repetition under polarization is suggested. The proposed rate-matching system combines a channel interleaver and a bit-mapping procedure to preserve the polarization of the rate-compatible polar code family under bit-interleaved coded modulation systems. Simulation results on AWGN and fast fading channels with different modulation orders in both Chase combining and incremental redundancy HARQ communications are listed. For the third topic, we investigate a joint source and channel LDPC coding scheme in which the source compression and the channel coding matrices are designed jointly as two submatrices of a sparse matrix H. The sparse matrix H is constructed algebraically with a structure free of cycles of length 4 and serves as the parity-check matrix for joint decoding of the channel output symbols and untransmitted source symbols. The integrated design of the source and channel coding matrices strengthens the information exchange between the source symbols and the channel output parity-check symbols, which provides a good waterfall error performance of the coded system and low error-foor.


Adaptive Digital Transceiver for Rayleigh Fading Channels

Adaptive Digital Transceiver for Rayleigh Fading Channels

Author: Jeffery R. Hughes

Publisher:

Published: 2003

Total Pages: 134

ISBN-13:

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This thesis presents an adaptive modulation scheme using a Walsh-code modulator. The Walsh-code modulator consists of a dynamic demultiplexer and predetermined sets of orthogonal Walsh-Hadamard codes. The demultiplexer can demultiplex the input bit stream into a maximum of thirty-two sub-streams. The Walsh- Hadamard codes are used to spread the spectrum of the demultiplexed sub-streams. The Walsh-code modulator produces a multi-level pulse amplitude modulated (PAM) signal by summing the spread sub-streams. The number of levels contained in the constellation of the PAM signal varies, based on the number of demultiplexed substreams. The error rate performance of different constellations produced by the Walsh-code modulator, differ when transmitted through a Rayleigh fading plus additive white Gaussian noise (AWGN) channel. As the level of fading experienced in the channel fluctuates, a desired level of error rate performance can be maintained by switching constellations, while trying to use the maximum number of sub-streams, or links, to transmit the data. Simulation results show the performance of several constellations when transmitted through an AWGN channel and a Rayleigh fading plus AWGN channel. Also, mapping of the PAM signal onto a quadrature amplitude modulation (QAM) constellation, in order to improve the performance of the system is discussed. It is found that for a Rayleigh fading plus AWGN channel, at a given error performance level, the amount of gain in signal-to-noise ratio (SNR), from the largest constellation to the smallest constellation, is 8dB for the symbol error rate (SER) and 14dB for the bit error rate (BER).


Smart Cities Performability, Cognition, & Security

Smart Cities Performability, Cognition, & Security

Author: Fadi Al-Turjman

Publisher: Springer

Published: 2019-05-21

Total Pages: 248

ISBN-13: 3030147185

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This book provides knowledge into the intelligence and security areas of smart-city paradigms. It focuses on connected computing devices, mechanical and digital machines, objects, and/or people that are provided with unique identifiers. The authors discuss the ability to transmit data over a wireless network without requiring human-to-human or human-to-computer interaction via secure/intelligent methods. The authors also provide a strong foundation for researchers to advance further in the assessment domain of these topics in the IoT era. The aim of this book is hence to focus on both the design and implementation aspects of the intelligence and security approaches in smart city applications that are enabled and supported by the IoT paradigms. Presents research related to cognitive computing and secured telecommunication paradigms; Discusses development of intelligent outdoor monitoring systems via wireless sensing technologies; With contributions from researchers, scientists, engineers and practitioners in telecommunication and smart cities.


Channel Coding Techniques for Wireless Communications

Channel Coding Techniques for Wireless Communications

Author: K. Deergha Rao

Publisher: Springer Nature

Published: 2019-11-22

Total Pages: 484

ISBN-13: 9811505616

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This book discusses the latest channel coding techniques, MIMO systems, and 5G channel coding evolution. It provides a comprehensive overview of channel coding, covering modern techniques such as turbo codes, low-density parity-check (LDPC) codes, space–time coding, polar codes, LT codes, and Raptor codes as well as the traditional codes such as cyclic codes, BCH, RS codes, and convolutional codes. It also explores MIMO communications, which is an effective method for high-speed or high-reliability wireless communications. It also examines the evolution of 5G channel coding techniques. Each of the 13 chapters features numerous illustrative examples for easy understanding of the coding techniques, and MATLAB-based programs are integrated in the text to enhance readers’ grasp of the underlying theories. Further, PC-based MATLAB m-files for illustrative examples are included for students and researchers involved in advanced and current concepts of coding theory.


Fundamentals of Wireless Communication

Fundamentals of Wireless Communication

Author: David Tse

Publisher: Cambridge University Press

Published: 2005-05-26

Total Pages: 598

ISBN-13: 9780521845274

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This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.


LDPC-coded Modulation for Transmission Over AWGN and Flat Rayleigh Fading Channels

LDPC-coded Modulation for Transmission Over AWGN and Flat Rayleigh Fading Channels

Author: Rui Yang

Publisher:

Published: 2010

Total Pages: 0

ISBN-13:

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La modulation codée est une technique de transmission efficace en largeur de bande qui intègre le codage de canal et la modulation en une seule entité et ce, afin d'améliorer les performances tout en conservant la même efficacité spectrale comparé à la modulation non codée. Les codes de parité à faible densité (low-density parity-check codes, LDPC) sont les codes correcteurs d'erreurs les plus puissants et approchent la limite de Shannon, tout en ayant une complexité de décodage relativement faible. L'idée de combiner les codes LDPC et la modulation efficace en largeur de bande a donc été considérée par de nombreux chercheurs. Dans ce mémoire, nous étudions une méthode de modulation codée à la fois puissante et efficace en largeur de bande, ayant d'excellentes performances de taux d'erreur binaire et une complexité d'implantation faible. Ceci est réalisé en utilisant un encodeur rapide, un décoder de faible complexité et aucun entrelaceur. Les performances du système proposé pour des transmissions sur un canal additif gaussien blanc et un canal à évanouissements plats de Rayleigh sont évaluées au moyen de simulations. Les résultats numériques montrent que la méthode de modulation codée utilisant la modulation d'amplitude en quadrature à M niveaux (M-QAM) peut atteindre d'excellentes performances pour toute une gamme d'efficacité spectrale. Une autre contribution de ce mémoire est une méthode simple pour réaliser une modulation codée adaptative avec les codes LDPC pour la transmission sur des canaux à évanouissements plats et lents de Rayleigh. Dans cette méthode, six combinaisons de paires encodeur modulateur sont employées pour une adaptation trame par trame. L'efficacité spectrale moyenne varie entre 0.5 et 5 bits/s/Hz lors de la transmission. Les résultats de simulation montrent que la modulation codée adaptative avec les codes LDPC offre une meilleure efficacité spectrale tout en maintenant une performance d'erreur acceptable.