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Design and Analysis of Multi-Level Physical-Layer Network coding for Gaussian Two-Way Relay Channels

IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第6期62卷 1803-1817页

作者： Chen, Zhiyong Xia, Bin Hu, Zixia Liu, Hui Shanghai Jiao Tong Univ Dept Elect Engn IWCT Shanghai 200240 Peoples R China Qualcomm San Jose CA 95110 USA

In this paper, we propose a multi-level physical-layer network coding (MPLNC) scheme that optimizes the relay performance for both symmetric and asymmetric traffic in a Gaussian two-way relay channel. The proposed MPLNC scheme enables each source to employ multiple linear binary codes for encoding, one per modulation level, and the relay node to decode superimposed network codewords at each modulation level. We first derive the achievable rate for the transmission of arbitrary constellations and then prove that MPLNC with multistage decoding (MPLNCMSD) can achieve the achievable rate if binary code rates are properly chosen for both sources. Furthermore, the design criteria for the proposed MPLNC scheme is investigated, which includes the rate design rule and the labeling strategy. Moreover, we derive the error exponent and an upper bound of the overall error probability for MPLNC. Our analysis and simulation results show that MPLNCMSD has a significant performance advantage in comparison to the existing bit-interleaved coded modulation (BICM)-based PLNC scheme.

关键词： Two-way relay channels multilevel coding physical-layer network coding symmetric and asymmetric relaying error exponent

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How to combat long echoes in OFDM transmission schemes: Sub-channel equalization or more powerful channel coding

How to combat long echoes in OFDM transmission schemes: Sub-...

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IEEE Global Telecommunications Conference

作者： Viterbo, E Fazel, K INST COMMUN TECHNOL GERMAN AEROSP RES ESTABDLRD-82234 OBERPFAFFENHOFENGERMANY

ISBN: (纸本)0780325109

The OFDM technique with guard-time, which has been proposed for terrestrial digital image and digital audio broadcasting applications in Europe, is an interesting approach to combat the frequency selectivity of the channel. However, it is sensitive to the interference caused by echoes longer than the guard-time. The aim of this article is twofold. First, the effects of the guard interval on a real case multipath channel are analyzed for an OFDM transmission system. The system performance is analytically derived as a function of the guard interval. The sensitivity of the OFDM system to the interference caused by echoes exceeding the guard-time is analyzed. The degradation due to the interference can be restored by applying two different techniques: using more powerful channel coding or employing sub-channel equalization. For channel coding, a combination of multilevel coding with multiresolution modulation, which is proposed for a digital terrestrial TV broadcasting, is used. The sub-channel equalizer is based on the DFE, where its adaptation calls-upon the LMS-algorithm, using the reference symbols sent periodically. Simulation results show that using powerful channel coding, rather than equalization, can partly restore the degradation caused by a shorter guard-time.

关键词： Channel coding frequency selectivity subchannel Echoes Equalization channel equalization Orthogonal frequency division multiplexing television broadcasting multilevel coding Transmission systems Fighter

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coding schemes for physical layer network coding over a two-way relay channel

Coding schemes for physical layer network coding over a two-...

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作者： Hern, Brett Michael Texas A&M University

学位级别：Ph.D.

We consider a two-way relay channel in which two transmitters want to exchange information through a central relay. The relay observes a superposition of the transmitted signals from which a function of the transmitted messages is computed for broadcast. We consider the design of codebooks which permit the recovery of a function at the relay and derive information-theoretic bounds on the rates for reliable decoding at the relay. In the spirit of compute-and-forward, we present a multilevel coding scheme that permits reliable computation (or, decoding) of a class of functions at the relay. The function to be decoded is chosen at the relay depending on the channel realization. We define such a class of reliably computable functions for the proposed coding scheme and derive rates that are universally achievable over a set of channel gains when this class of functions is used at the relay. We develop our framework with general modulation formats in mind, but numerical results are presented for the case where each node transmits using 4-ary and 8-ary modulation schemes. Numerical results demonstrate that the flexibility afforded by our proposed scheme permits substantially higher rates than those achievable by always using a fixed function or considering only linear functions over higher order fields. Our numerical results indicate that it is favorable to allow the relay to attempt both compute-and-forward and decode-and-forward decoding. Indeed, either method considered separately is suboptimal for computation over general channels. However, we obtain a converse result when the transmitters are restricted to using identical binary linear codebooks generated uniformly at random. We show that it is impossible for this code ensemble to achieve any rate higher than the maximum of the rates achieved using compute-and-forward and decode-and-forward decoding. Finally, we turn our attention to the design of low density parity check (LDPC) ensembles which can practically achieve

关键词： Two-Way Relay Channel Physical Layer Network coding Information Theory Channel coding multilevel coding Thesis

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Signalling enhancement on multilevel turbo codes

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2008年第7期21卷 791-798页

作者： Bayat, Oguz Shafai, Bahram Salehi, Masoud Ucan, Osman N. Osman, Onur Beykent Univ Elect & Commun Engn Dept TR-34500 Istanbul Turkey Northeastern Univ Dept Elect & Comp Engn Boston MA 02115 USA Istanbul Univ Elect & Elect Dept TR-34850 Istanbul Turkey Istanbul Commerce Univ TR-34378 Istanbul Turkey

The design of multilevel turbo codes using M-PSK is optimized to achieve a low bit error rate (BER). Unequal error protection is employed via group set partitioning in multi-stage decoding to minimize the error propagation and BER. Simulation results are performed under Gaussian and Rayleigh fading channels to depict the superiority of the new scheme. Copyright (C) 2008 John Wiley & Sons, Ltd.

关键词： multilevel coding turbo codes signal set partitioning transmission systems

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Nulling and cancellation detector for MIMO channels and its application to multistage receiver for coded signals: Performance and optimization

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2006年第5期5卷 1207-1216页

作者： Choi, Jinho Univ New S Wales Sch Elect Engn & Telecomm Sydney NSW 2052 Australia

In this paper, we address some performance issues of multiple input multiple output (MIMO) channels with a nulling and cancellation (N/C) detector, which is based on the QR factorization. We find a theoretical bit error rate (BER). With this, an optimization for the bit energy allocation across multiple transmitter antennas has been considered with the proposed optimization criterion. In addition, the concept of multilevel coding has been adopted for optimizing the performance of a multistage receiver with the N/C detector when a channel code is employed. Through simulations, the performance has been compared for coded signals. Both the code rate and energy optimization across layers are shown to be effective means for improving the performance of MIMO systems when the multistage receiver is employed. In addition, it has been shown that the optimization of code rate for each layer is more effective means than that of bit energy.

关键词： space-time architecture nulling and cancellation detection MIMO channels performance analysis multilevel coding

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Adaptively Grouped multilevel Space-Time Trellis Codes

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WIRELESS PERSONAL COMMUNICATIONS 2014年第2期74卷 415-426页

作者： Jain, Dharmvir Sharma, Sanjay Thapar Univ Dept Elect & Commun Engn Patiala Punjab India

Grouped multilevel space-time trellis codes (GMLSTTCs) utilize multilevel coding (MLC), antenna grouping and space time trellis codes (STTCs) for simultaneously providing coding gain, diversity improvement and increased spectral efficiency. The performance of GMLSTTCs is limited due to predefining of the antenna groups. It has been shown that when perfect or partial channel state information is available at the transmitter, the performance and capacity of space-time coded system can be further improved. In this paper, we present a new code designed by combining MLC, STTCs, antenna grouping and channel state information at transmitter, henceforth referred to as adaptively grouped multilevel space time trellis codes (AGMLSTTCs). AGMLSTTCs use a single full-diversity STTC at initial some levels and multiple STTCs at some later levels. The single full diversity STTC at each initial level spans all transmit antennas and the STTC at each later level spans a group of transmit antennas. The channel state information at the transmitter is used to adaptively group the transmit antennas for the later levels. Instantaneous channel power gain is calculated between each transmit antenna and all the receive antennas. A subset of transmit antennas having maximum channel power gain is selected to form a group. The simulation results show that AGMLSTTCs enable to transmit more than one data symbol per time slot with improved error performance over GMLSTTCs with predefined transmit antenna grouping.

关键词： multilevel coding Space time trellis code Channel state information Rayleigh fading channel Adaptive antenna grouping

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Performance Analysis of Adaptively Grouped multilevel Space-Time Trellis Coded Systems using Different Component Codes

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WIRELESS PERSONAL COMMUNICATIONS 2015年第1期82卷 341-352页

作者： Jain, Dharmvir Sharma, Sanjay Thapar Univ Dept Elect & Commun Engn Patiala 147004 Punjab India

Adaptively grouped multilevel space-time trellis codes (AGMLSTTCs) utilize multilevel coding (MLC), space time trellis codes (STTCs) and adaptive transmit antenna grouping for simultaneously providing coding gain, diversity improvement and increased spectral efficiency. AGMLSTTCs use Chen, Yuan, and Vucetic (CYV) STTCs as component codes in MLC. In this paper, we present performance comparison of AGMLSTTCs generated using different component STTCs. We use Tarokh, Seshadri, and Calderbank (TSC), Baro, Bauch and Hansmann (BBH) and CYV codes as component STTCs. The simulation results show that AGMLSTTCs with CYV as component STTCs outperforms in comparison with the AGMLSTTCs with TSC and BBH as component STTCs.

关键词： multilevel coding Space time trellis code Channel state information Rayleigh fading channel Adaptive antenna grouping

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A Novel Cooperative Communication System Based on multilevel Convolutional Codes

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WIRELESS PERSONAL COMMUNICATIONS 2017年第4期95卷 3539-3556页

作者： Aneja, Sakshi Sharma, Sanjay Thapar Univ Dept Elect & Commun Engn Patiala Punjab India

The authors propose a system where single antenna mobile users share antennas to transmit their information cooperatively to the common base station. Each mobile user overhears the coded information transmitted by other users, detects it and further encodes it along with its own information. The encoding is done using multilevel coding scheme with convolutional codes as component codes. The proposed system considers the self-information of user u at level u to reduce complexity while decoding. The coded symbols are mapped to M-ary quadrature amplitude modulation constellation using multi-resolution modulation partitioning. This enables the component codes to be designed for lower order constellation. Each cooperative user transmits multilevel coded symbols to the common base station, thus creating transmit diversity. The base station receives noisy superposition of independent Rayleigh faded signals transmitted by cooperative users and pass it through a multistage decoder. The multistage decoder employs maximum likelihood based Viterbi decoder at each stage to detect the information of each user. The Viterbi decoder applies max-log approximation to reduce the branch metric complexity. The proposed cooperative multilevel coding system outperforms non-cooperative multilevel coding system and is less complex than the existing cooperative multilevel coding system.

关键词： Cooperative diversity multilevel coding Convolutional code Diversity methods Channel coding Rayleigh fading channel

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Noncoherent Block-Coded TAPSK and 16QAM Using Linear Component Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第9期58卷 2493-2498页

作者： Wei, Ruey-Yi Lin, Tzu-Shiang Gu, Shi-Shan Natl Cent Univ Dept Commun Engn Jhongli Taiwan

In this paper, we derive minimum noncoherent distances of block-coded TAPSK (twisted amplitude and phase shift keying) and 16QAM (quadrature-amplitude modulation), both using linear component codes. According to the derived distances, noncoherent block-coded TAPSK (NBC-TAPSK) and noncoherent block-coded 16QAM (NBC-16QAM) are proposed. If the block length is very small, NBC-16TAPSK performs best among all noncoherent schemes and NBC-16QAM performs worse due to its small minimum noncoherent distance. However, if the block is not short, NBC-16QAM has the best error performance because the codewords with small noncoherent distances are rare.

关键词： Noncoherent detection block-coded modulation multilevel coding

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On multilevel coded MPSK for the Rayleigh fading channel

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 1999年第3期48卷 840-846页

作者： Wei, RY Lin, MC Natl Taiwan Univ Dept Elect Engn Taipei 106 Taiwan

This paper presents a new upperbound on the pair,vise error probability of MPSK sequences for the Rayleigh fading channel when channel state information (CSI) is unavailable, This bound is derived by adding weight factors in computing symbol metrics. Simulation results show that the weight factors which optimize the upperbound likely optimize the error rate as well, multilevel coded MPSK schemes for the Rayleigh fading channel are also devised. Results show that the added weight factors improve the error performances of these schemes in the case that CSI is unavailable.

关键词： coded modulation fading channel multilevel coding

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