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multilevel coded CPFSK systems for AWGN and fading channels

IEEE TRANSACTIONS ON COMMUNICATIONS 2000年第5期48卷 764-773页

作者： Altunbas, I Aygölü, Ü Istanbul Tech Univ Fac Elect & Elect Engn TR-80626 Istanbul Turkey

In this paper, we introduce multilevel coded continuous-phase frequency-shift keying (CPFSK) systems for both additive white Gaussian noise and fading channels based on multilevel coding and multistage decoding techniques. These schemes are designed under the constraint M greater than or equal to 2P for M-ary CPFSK with modulation index J/P. In order to maintain the phase continuity property after multilevel coding, we use some specific set partitioning rules. We construct examples to show that the proposed systems outperform the corresponding conventional one-level schemes. For the fading case, we consider an ideal fading channel where adjacent fading symbols are assumed to be independent and a correlated fading channel where bit interleavers are needed at each coding level. The computer simulation results show that the proposed systems have bit-error performance and decoder complexity advantages over the corresponding reference codes taken from the literature. It is also shown that there is only a slight degradation on the bit error performance for correlated fading, compared to the ideal fading case.

关键词： continuous phase modulation fading channels multilevel coding

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Weighted adaptively grouped multilevel space time trellis codes

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INTERNATIONAL JOURNAL OF ELECTRONICS 2015年第5期102卷 886-896页

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

In existing grouped multilevel space-time trellis codes (GMLSTTCs), the groups of transmit antennas are predefined, and the transmit power is equally distributed across all transmit antennas. When the channel parameters are perfectly known at the transmitter, adaptive antenna grouping and beamforming scheme can achieve the better performance by optimum grouping of transmit antennas and properly weighting transmitted signals based on the available channel information. In this paper, we present a new code designed by combining GMLSTTCs, adaptive antenna grouping and beamforming using the channel state information at transmitter (CSIT), henceforth referred to as weighted adaptively grouped multilevel space time trellis codes (WAGMLSTTCs). The CSIT is used to adaptively group the transmitting antennas and provide a beamforming scheme by allocating the different powers to the transmit antennas. Simulation results show that WAGMLSTTCs provide improvement in error performance of 2.6dB over GMLSTTCs.

关键词： adaptive antenna grouping weighting multilevel coding space time trellis codes channel state information Rayleigh fading

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Coded modulation using superimposed binary codes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2004年第12期50卷 3331-3343页

作者： Ma, X Li, P City Univ Hong Kong Dept Elect Engn Kowloon 510275 Hong Kong Peoples R China Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510275 Peoples R China City Univ Hong Kong Dept Elect Engn Kowloon Hong Kong Peoples R China

In this correspondence, we investigate in a comprehensive fashion a one-layer coding/shaping scheme resembling a perfectly cooperated multiple-access system. At the transmitter, binary data are encoded by either single-level or multilevel codes. The coded bits are first randomly interleaved and then entered into a signal mapper. At each time, the signal mapper accepts as input multiple binary digits and delivers as output an amplitude signal, where the input are first independently mapped into 2-PAM signals (possibly having different amplitudes) and then superimposed to form the output. The receiver consists of an iterative decoding/demapping algorithm with an entropy-based stopping criterion. In the special cases when all the 2-PAM signals have equal amplitudes, based on an irregular trellis, we propose an optimal soft-input-soft-output (SISO) demapping algorithm with quadratic rather than exponential complexity. In the general cases, when multilevel codes are employed, we propose power-allocation strategies to facilitate the iterative decoding/dempaping algorithm. Using the unequal power-allocations and the Gaussian-approximation-based suboptimal demapping algorithm (with linear complexity), coded modulation with high bandwidth efficiency can be implemented.

关键词： Coded modulation sigma-mapping coding/shaping scheme iterative decoding/demapping algorithm iterative multistage decoding multilevel coding soft-input soft-output (SISO) demapping algorithm

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MONURBS:: A parallelized fast multipole multilevel code for analyzing complex bodies modeled by NURBS surfaces

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APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL 2008年第2期23卷 134-142页

作者： Gonzalez, I. Garcia, E. Saez de Adana, F. Catedra, M. F. Univ Alcala de Henares Dept Ciencias Computac Madrid 28871 Spain Univ Alcala de Henares Dept Automat Madrid 28871 Spain

This paper presents a Parallelized multilevel Fast Multipole (MLFMA) Moment Method (MoM) code for analyzing the scattering and radiation from electrically large complex bodies modeled by Non-Uniform Rational B-Spline Surfaces (NURBS). The bodies are represented by NURBS surfaces which are discretized without remeshing the original geometry. The basis and testing functions are defined and conformed to the exact representation of the geometry. This code has been parallelized using Message Passing Interface (MPI) and it has been successfully applied to the study of large bodies including complex and periodic multilayer structures where the real size and shape are very important.

关键词： Body METHOD OF MOMENTS multilayer structures Surfaces MULTIPOLES multilevel coding actual sizes Non Uniform Rational B-splines

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Multi-dimensional space-time multilevel codes

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2006年第11期5卷 3287-3295页

作者： Martin, Philippa A. Rankin, David M. Taylor, Desmond P. Univ Canterbury Dept Elect & Comp Engn Christchurch 8020 New Zealand

To date there has been little work done on multilevel codes for the space-time environment. In this paper we develop multi-dimensional space-time multilevel codes (ST-MLCs). Several construction methods are proposed, including a coset code approach. The proposed space-time multilevel encoders partition a 2N(t)-dimensional signalling space, which spans all N-t transmit antennas. The multi-dimensional partitioning can be-designed to reduce the complexity of detection/decoding. We develop a space-time multistage decoder for the proposed ST-MLCs. It allows the complexity of soft decision decoding to be significantly reduced compared to a single level approach. In addition, significant performance gains over a single level approach are obtained.

关键词： space-time coding multilevel coding coset coding multistage decoding LDPC codes

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multilevel space-time trellis coded cooperation with channel state information at transmitter

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2016年第18期29卷 2622-2631页

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

In this paper, the authors propose a system where a number of cooperating mobile nodes transmit information to a common destination node. Each cooperating node has a set of decoders to detect the information of other nodes and a set of encoders to further encode the decoded information as well as its own information using multilevel space-time trellis coding (MLSTTC) scheme. The coded information is mapped using multi-resolution modulation partitioning to M-ary quadrature amplitude modulation constellation. The mapped symbols are weighted based on the availale channel state information at transmitting nodes. The weighting of transmitting symbols provides beamforming resulting in receive signal-to-noise ratio gain. The weighted symbols are sent to destination node through two transmit antennas. If the information of other nodes has been correctly decoded at the cooperating node, then the destination node receives the information of each node as many times as there are number of transmitting nodes, thus achieving full diversity order. A multistage Viterbi decoder is used at the destination node to extract information of each mobile node. The results indicate that the performance of proposed cooperative MLSTTC system is superior to non-cooperative MLSTTC system. Copyright (C) 2016 John Wiley & Sons, Ltd.

关键词： multilevel coding space-time trellis code cooperative diversity channel state information Rayleigh fading channel

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multilevel-coded QAM with MIMO turbo-equalization in broadband single-carrier signaling

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2005年第3期54卷 954-966页

作者： Kansanen, K Schneider, C Matsumoto, T Thomä, R Univ Oulu Oulu 90014 Finland Tech Univ Ilmenau D-98684 Ilmenau Germany

A new scheme employing multilevel coded bit-interleaved transmission allowing for efficient turbo-equalization is proposed for multiple-input-multiple-output (MIMO) broadband single-carrier signaling. The proposed scheme is based on block-partitioned hierarchical constellations and offers robustness in data throughput efficiency against varying spatio-temporal characteristics of fading channels. The proposed scheme is compared to a standard bit-interleaved-coded-modulation (BICM) system in frequency-selective channels, and found to offer better overall throughput. It is also shown that level-wise retransmission control with the proposed multilevel single-carrier signaling scheme can offer further throughput improvement. Channel measurement-based simulations are used to evaluate performances of both schemes in real fields. Channel parameter analysis using a superresolution technique is performed to clarify the underlying reasons for the performance characteristics of the systems.

关键词： automatic repeat-request bit-interleaved modulation multilevel coding multiple-input-multiple-output (MIMO) systems throughput efficiency turbo equalization

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Channel combining and splitting for cutoff rate improvement

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IEEE TRANSACTIONS ON INFORMATION THEORY 2006年第2期52卷 628-639页

作者： Arikan, E Bilkent Univ Dept Elect Elect Engn TR-06800 Ankara Turkey

The cutoff rate R-0 (W) of a discrete memoryless channel (DMC) W is often used as a figure of merit alongside the channel capacity C(W). If a channel W is split into two possibly correlated subchannels W-1, W-2, the capacity function always satisfies C(W-1) + C(W-2): <= C(W), while there are examples for which R-0 (W-1) + R-0 (W-2) > R-0 (W). The fact that cutoff rate can be '' created '' by channel splitting was noticed by Massey in his study of an optical modulation system. This paper gives a general framework for achieving similar gains in the cutoff rate of arbitrary DMCs by methods of channel combining and splitting. The emphasis is on simple schemes that can be implemented in practice. We give several examples that achieve significant gains in cutoff rate at little extra system complexity. Theoretically, as the complexity grows without bound, the proposed framework is capable of boosting the cutoff rate of a channel to arbitrarily close to its capacity in a sense made precise in the paper. Apart from Massey's work, the methods studied here have elements in common with Forney's concatenated coding idea, a method by Pinsker for cutoff rate improvement, and certain coded-modulation techniques, namely, Ungerboeck's set-partitioning idea and Imai-Hirakawa multilevel coding;these connections are discussed in the paper.

关键词： channel combining channel splitting coded modulation concatenated coding cutoff rate error exponent multilevel coding random-coding exponent reliability exponent set partitioning successive cancellation decoding

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multilevel Coded Modulation for the Full-Duplex Relay Channel

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2018年第6期17卷 3543-3555页

作者： Abotabl, Ahmed Attia Nosratinia, Aria Univ Texas Dallas Dept Elect Engn Richardson TX 75083 USA

We investigate coded modulation for full-duplex relay channels, proposing and analyzing a multilevel coding (MLC) framework with capacity approaching performance and practical features. Sufficient conditions are derived under which multilevel coding meets the known achievable rates for decode-and-forward relaying. The effect of a bit additive superposition and the linearity of multilevel code components on the performance of the system are studied. It is shown that linearity of the relay component codes imposes no penalty on rate, however, the linearity of the source-to-relay component codes may impose a performance penalty especially for small modulation constellations. We show that this rate loss occurs because a linearity constraint on codebooks at the source node introduces a new tension between optimality of rate allocation in multilevel coding layers and optimality of source/relay codebook correlations. Motivated by this insight, an alternative modulation labeling is proposed that minimizes the rate loss. The results are extended to multi-antenna relays. Slow fading and fast Rayleigh fading without channel state at the transmitter are also analyzed. The error exponent of the proposed scheme is studied. Finally, the frame-and bit-error rate performance of the proposed scheme is studied via simulations using point-to-point LDPC codes, showing that the proposed MLC relaying has excellent performance.

关键词： multilevel coding multistage decoding relay decode-forward full-duplex

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Throughput-Based Design for Polar-Coded Modulation

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IEEE TRANSACTIONS ON COMMUNICATIONS 2019年第3期67卷 1770-1782页

作者： Khoshnevis, Hossein Marsland, Ian Yanikomeroglu, Halim Carleton Univ Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada

Typically, forward error correction (FEC) codes are designed based on the minimization of the error rate for a given code rate. However, for applications that incorporate hybrid automatic repeat request (HARQ) protocol and adaptive modulation and coding, the throughput is a more important performance metric than the error rate. Polar codes, a new class of FEC codes with simple rate matching, can be optimized efficiently for maximization of the throughput. In this paper, we aim to design HARQ schemes using multilevel polar-coded modulation (MLPCM). Thus, we first develop a method to determine a set-partitioning-based bit-to-symbol mapping for high-order quadrature amplitude modulation (QAM) constellations. We simplify the log-likelihood ratio estimation of set-partitioned QAM constellations for a multistage decoder, and we introduce a set of algorithms to design throughput-maximizing MLPCM for the successive cancellation decoding (SCD). These codes are specifically useful for non-combining, chase-combining, and incremental redundancy HARQ protocols. Furthermore, since optimized codes for SCD are not optimal for SC list decoders (SCLDs), we propose a rate matching algorithm to find the best rate for SCLD while using the polar codes optimized for SCD. The resulting codes provide throughput close to the capacity with low decoding complexity when used with HARQ protocols.

关键词： Throughput-based polar code design HARQ chase-combining multilevel coding multistage decoding low complexity LLR estimation

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