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Toward a Better Comprehension of Decode-and-Forward Buffer-Aided Relaying: Case Study of a Single Relay

IEEE COMMUNICATIONS LETTERS 2020年第5期24卷 1005-1009页

作者： Abou-Rjeily, Chadi Lebanese Amer Univ LAU Dept Elect & Comp Engn Byblos 961 Lebanon

This work considers the problem of decode-and-forward (DF) buffer-aided (BA) relaying with a single relay. For this scenario, a Markov chain analysis is tractable resulting in closed-form performance measures that can shed more light on the capabilities of the more general BA networks. In particular, a novel generic relaying scheme is proposed and this scheme encompasses many of the existing single relay schemes as special cases. The proposed scheme is controlled by a single parameter and the letter highlights on the impact of this parameter on the triad of diversity gain, coding gain and queuing delay that can be contemplated.

关键词： Relays Avalanche photodiodes Markov processes Diversity methods Delays Protocols Steady-state Relaying buffer dual-hop outage probability diversity order coding gain queuing delay asymptotic analysis

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Improving Generalized Spatial Modulation Using Translation Patterns

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IEEE COMMUNICATIONS LETTERS 2020年第12期24卷 2814-2818页

作者： Singla, Lakshit Natarajan, Lakshmi Prasad IIT Hyderabad Dept Elect Engn Hyderabad 502285 India

Generalized spatial modulation (GSM) is a spectral-efficient technique used in multiple-input multiple-output (MIMO) wireless communications when the number of radio frequency chains at the transmitter is less than the number of transmit antenna elements. We propose a family of signal constellations, as an improvement over GSM, which splits the information bits into three parts, and encodes the first part into a set of complex symbols, the second part into the choice of a subset of antennas activated for transmission (as in GSM), and the third into a translation pattern that offsets the symbols transmitted through the activated antennas. The nominal coding gain (the ratio of the squared minimum distance between transmit vectors to the transmit power) of our scheme is higher than that of GSM by at least 0.86 dB, and this improvement can be as much as 2.87 dB based on the system parameters. We show that the new scheme has advantages over other known signal constellations for GSM, in terms of error performance, nominal coding gain and design flexibility.

关键词： GSM Transmitting antennas Constellation diagram Encoding gain Quadrature amplitude modulation coding gain generalized spatial modulation (GSM) MIMO minimum distance

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An approximate statistical analysis of wireless channel over α - μ shadowed fading channel

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2021年第13期34卷 e4884-e4884页

作者： Upaddhyay, Vipin Kumar Soni, Sanjay K. Chauhan, Puspraj Singh MMMUT Dept Elect & Commun Engn Gorakhpur Uttar Pradesh India

In this work, we have comprehensively investigated the impact of non-linearity (alpha - mu) and shadowing (inverse gamma) collectively over the wireless channel. To this effect, an approximate closed-form probability density function (PDF) expression is derived over alpha - mu/inverse gamma fading channel by employing Gauss-Laguerre quadrature polynomial. The accuracy of the proposed approximate solution is validated through the Kullback-Leibler divergence test. Subsequently, the proposed solution is utilized in the development of various fundamental statistics like commutative distribution function (CDF), moment generating function (MGF) and nth moment. This contribution also includes the derivation of coding gain and diversity gain to study average symbol error probability (SEP) with MRC and EGC diversity. It is observed that diversity gain is independent of shadowing and as the channel condition improves, the coding gain decreases. Finally, the closed-form solutions of spectral efficiency under different adaptive transmission policies are also developed specifically, optimal power and rate adaptation (OPRA) and effective capacity along with simpler low- and high-power expressions. Monte-Carlo simulations are utilized to validate the proposed analytical and numerical results.

关键词： asymptotic solutions coding gain hypergeometric function link layer capacity symbol error probability

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Calculation and error bound of Min-approximated bitwise log-likelihood ratios of generalised M-ary PAM

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JOURNAL OF ENGINEERING-JOE 2020年第3期2020卷 104-106页

作者： Park, Sung-Joon Lee, Daniel C. Gangneung Wonju Natl Univ Dept Elect Engn Kangnung South Korea Simon Fraser Univ Sch Engn Sci Burnaby BC Canada

In modern digital communication systems, a high-order modulation and advanced channel coding are often jointly used to increase the spectral efficiency and coding gain. In this work, the authors investigate a computationally efficient method for evaluating the bitwise log-likelihood ratios of generalised M-ary pulse amplitude modulation (PAM) signals with the Min approximation. The proposed scheme is simple and can be applied to demodulate the M-ary PAM having an arbitrary symbol spacing and a bit stream mapping. The computational complexity and upper bounds of the approximation error are also provided for a better understanding of the proposed scheme.

关键词： computational complexity channel coding digital communication pulse amplitude modulation channel coding spectral efficiency coding gain computationally efficient method ary PAM signals Min approximation computational complexity upper bounds approximation error Min-approximated bitwise log-likelihood ratios modern digital communication systems high-order modulation

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Research on a TCM-based Transmission Approach for EM-MWD by Combining Phase Modulation and Convolutional coding

Research on a TCM-based Transmission Approach for EM-MWD by ...

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IEEE International Instrumentation and Measurement Technology Conference (I2MTC)

作者： Zhang, Cheng Dong, Haobin Ge, Jian Liu, Huan Wang, Jiahao Luo, Wang Yuan, Zhiwen Zhu, Jun Zhang, Haiyang China Univ Geosci Sch Automat Wuhan 430074 Hubei Peoples R China Hubei Key Lab Adv Control & Intelligent Automat Wuhan 430074 Hubei Peoples R China Sci & Technol Near Surface Detect Lab Wuxi 214035 Jiangsu Peoples R China China Univ Geosci Sch Mech Engn & Elect Informat Wuhan 430074 Hubei Peoples R China

ISBN: (纸本)9781538634608

In practical applications of electromagnetic measurement while drilling (EM-MWD) in the underground coal mine, the signal-to-noise ratio (SNR) of the receiver cannot always meet the requirements of reliable communication conditions due to the earth-attenuation, interfering signal from a well site, etc. Traditional digital communication systems use independent design coding and modulation techniques to improve system performance. The coding is mainly achieved by introducing redundant bits and the improvement of error performance is at the expense of information rate. Aimed to solve this problem, we use a coding technique based on trellis coded modulation (TCM) to maximize the minimum distance between modulated output sequences and achieve significant coding gain. Simulation and experiments show that the system can improve the anti noise performance of the system by obtaining a coding gain without reducing the transmission rate. Compared to the uncoded quadrature phase shift keying (QPSK), TCM can achieve a coding gain of at least 3 dB under the same transmitting rate. At that time, as the number of TCM system states or trace back depth increases, the coding gain is further enhanced. The TCM code modulation method can be used in an EM-MWD system to improve the system performance.

关键词： EM-MWD Convolutional coding coding gain Trellis coded modulation

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A Practical Method for BEP Estimation of Convolutional coding in Impulse Noise Environments

A Practical Method for BEP Estimation of Convolutional Codin...

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IEEE Military Communications Conference (MILCOM)

作者： Eliardsson, Patrik Axell, Erik Komulainen, Arwid Wiklundh, Kia Tengstrand, Sara Orn Swedish Def Res Agcy Stockholm Sweden Qamcom Res & Technol Linkoping Sweden Scania CV AB Sodertalje Sweden

ISBN: (纸本)9781728142807

Forward error correction is a means to achieve robust communications. Knowing the performance of the error correcting code under operating circumstances is crucial in making a robust and cost-efficient design choice. Performance of error correcting codes are usually attained under the assumption of additive white Gaussian noise (AWGN). Such performance estimates can be orders of magnitude from the truth in impulse noise environments, that are common in military, automotive and industrial environments with lots of emitters and electronic equipment co-located closely together. A method previously proposed to model the impact of impulse noise, without the use of error correcting coding, is the impulsiveness correction factor (ICF), which can easily he measured. The main contribution of this work is to propose a practical method, using the ICE, to approximate the communication performance in impulse noise channels for a system using convolutional coding. Performance is evaluated in terms of bit error probability (BEP) at a given signalto-noise ratio (SNR), or analogously the required SNR to achieve a given BEP. The proposed method is practically useful for a wide range of interference types, and is derived numerically since the problem is analytically intractable. The proposed method uses the ICF of the uncoded system, code performance estimates for AWGN, and knowledge of the code parameters.

关键词： Impulse noise coding gain

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Rateless transmission of polar codes with information unequal error protection

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IET COMMUNICATIONS 2019年第12期13卷 1721-1727页

作者： Liang, Hao Liu, Aijun Zhang, Ying Xian Cheng, Feng Yi Army Engn Univ PLA Coll Commun Engn Nanjing 210007 Jiangsu Peoples R China

In this study, a rateless transmission scheme with information unequal error protection (UEP) is proposed by using polar codes. The proposed scheme is suitable for transmissions in time-varying channels, as well as pursues UEP goal of information with different reliability requirements. Firstly, the authors design rateless transmission for an unknown channel via extending polarisation matrix and importance-based puncturing. In particular, an algorithm ensuring full coding gain for UEP performance is proposed on the basis of rateless transmission. Moreover, in consideration of combining flexible successive cancellation list (SCL) decoding with UEP, they further present a size-adapted SCL decoding scheme with reduced complexity. Numerical simulation shows that their proposed rateless scheme based on polar codes could achieve good UEP performance with low complexity in unknown channels.

关键词： decoding time-varying channels telecommunication network reliability matrix algebra polar codes information unequal error protection rateless transmission scheme time-varying channels polarisation matrix importance-based puncturing coding gain size-adapted SCL decoding scheme reliability requirements UEP performance flexible successive cancellation list decoding

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Four-dimensional trellis-coded modulation using sphere packing non-cubic constellations

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OPTIK 2019年 186卷 84-92页

作者： Zhang, Ye Hu, Guijun Yang, Xueying Sun, Yadong Jilin Univ Coll Commun Engn Changchun 130012 Jilin Peoples R China Beijing Univ Posts & Telecommun Coll Int Beijing 100876 Peoples R China

In the paper, we introduce the 8-state trellis-coded modulation (TCM) scheme using sphere packing four-dimensional (4D) non-cubic constellations on the basis of a novel set-partitioning (SP) method. Sphere packing four-dimensional formats have a higher asymptotic power efficiency (APE) because the spatial arrangement of constellation points is more dense. The scheme can f-urther alleviate the contradiction between spectral efficiency (SE) and APE in 4D modulation format. The SP process of 4D non-cubic constellations is completed in the condition that the minimum Euclidean distance between the constellation points and the number of nearest neighbors are adequately considered. We compared these 4D TCM formats to their corresponding 4D formats (i.e., dicyclic4_16, b4_32, b4_64, SP-QAM4_128 and 256-D-4) in the 800 km standard single-mode fiber (SSMF) transmission system. Through measurements of bit error rate (BEA) performance, at the BER = 1 x 10(-3), the coding gains are 5.7 dB, 3.8 dB, 3.6 dB, 3.9 dB and 4.1 dB respectively.

关键词： coding gain Four-dimensional modulation Set-partitioning Trellis-coded modulation

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Performance evaluation of underlay cognitive hybrid satellite-terrestrial relay networks with relay selection scheme

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IET COMMUNICATIONS 2019年第16期13卷 2550-2557页

作者： Lai, Ping Bai, Hang Huang, Yunlai Chen, Zhuang Liu, Tianjian Unit 32382 Wuhan Hubei Peoples R China

The applicability of cognitive radio (CR) techniques into satellite communications has received considerable attention in recent years. This study considers the integration of relay transmission into CR-based satellite terrestrial network, which offers the advantages of not only increasing the overall spectral efficiency by spectrum sharing but also extending the wireless coverage through the deployment of relays. Specifically, the authors derive the exact closed-form expression of the outage probability (OP) for the cognitive network, which provide an efficient means to evaluate the impact of key parameters on the system performance. Furthermore, the asymptotic OP expression at high signal-to-noise ratio is presented, which reveals the achievable diversity order and coding gain of the considered network. Finally, numerical results are carried out to validate the theoretical results, and shows that although a higher transmit power or weaker shadowing severity of the satellite interference link has a severe detrimental impact on the outage performance of the cognitive network by reducing the coding gain, the achievable diversity order only depends on the fading severities and the number of relays of the cognitive network.

关键词： relay networks (telecommunication) radiofrequency interference cognitive radio diversity reception probability telecommunication network reliability encoding satellite links performance evaluation underlay cognitive hybrid satellite-terrestrial relay networks relay selection scheme cognitive radio satellite communications relay transmission CR-based satellite terrestrial network spectral efficiency closed-form expression cognitive network system performance asymptotic OP expression high signal-to-noise ratio achievable diversity order coding gain satellite interference link outage performance

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Throughput enhancing concatenated codes

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IET COMMUNICATIONS 2019年第9期13卷 1278-1286页

作者： Rezaei, Elahe Fonseka, John P. Bo, Yu Univ Texas Dallas Dept Elect & Comp Engn Richardson TX 75083 USA

Traditionally, concatenation of codes is used to increase the coding gain at the expense of the code rate and the throughput. In contrast, throughput enhancing concatenated codes (TECCs) are constructed here aiming to increase the throughput. In a TECC, the coded sequence of a code C transmitted through the channel is altered according to the coded bits of a second coded sequence of an implicit code C'. In this study, TECCs select one bit in every segment of n coded bits of C based on n(s) <= log(2) n coded bits of C', and flip that selected coded bit of C before transmission. Even though the coded bits of C' are not transmitted explicitly over the channel, the information of coded bits of C' is transferred to the destination through the altered bits which can be recovered by exploiting the extrinsic information of explicitly coded bits. Using iterative decoding between codes C and C', the receiver can decode the coded bits of both the explicit code C and the implicit code C' jointly. TECCs that can increase the throughput of C by 25-37.5% without sacrificing the performance of C are reported, however, at the expense of increased complexity.

关键词： concatenated codes iterative decoding coding gain code rate explicitly coded bits implicit code throughput enhancing concatenated codes second coded sequence extrinsic information iterative decoding

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