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Reliability improvement techniques for HomeRF system

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2003年第2期49卷 321-327页

作者： Cho, JH Song, HK Sejong Univ Dept Informat & Commun Engn Seoul South Korea

In this paper, we propose several techniques for the HomeRF system. A DC-offset compensation technique and a decision directed channel estimation technique are proposed. Because they use a TS field as reference information for initial training, the proposed techniques require no additional training sequence and only a little additional complexity. And finally, turbo coding technique and space-time block coding technique are considered as improved coding schemes. According to the results of our simulations, the performances of the proposed techniques are significantly improved in comparison with the conventional HomeRF system.

关键词： channel estimation DC-offset compensation space-time block coding turbo coding

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Optimization of satellite access lower layer for the transport of IP datagrams

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2004年第3期22卷 529-537页

作者： Leconte, K Morlet, C Alcatel Space 26 F-31037 Toulouse 1 France European Space Agcy ESTEC NL-2200 AG Noordwijk Netherlands

This paper presents a novel solution optimizing satellite access lower layers and system performances called variable size packets (VSPs) designed for the transport of Internet protocol (IP) datagrams or any packet type from the network layers characterized by a highly variable size. VSP objective is to maximize the, efficiency of layers 1 and 2 thrbugh a joint optimization of access and transport mechanisms mainly for satellite systems addressing residential or corporate terminals market through a multiple-access scheme. It, is particularly attractive for, the return link of next-generation satellite systems to be IP-based, as a possible evolution of the digital video broadcast-return channel via satellite (DVB-RCS) standard. The VSP solution relies on the definition of multiple encapsulation sizes, and is associated to a waveform and an access adapted to variable size packets' transport. It uses the traffic's variable size nature to increase encapsulation efficiency, coding, and spectral,efficiency performances, and system flexibility. It is well adapted to systems using an adaptive waveform leading to system capacity's increase and better performances. This paper describes the VSP principle, advantages and possible high-level system tradeoffs. It then focuses on one critical issue, the, coding, and presents a suitable coding scheme's choice with regards to performances and implementation complexity.

关键词： adaptive coding and modulation encapsulation encoding Internet protocol (IP) datagrams satellite communication turbo coding variable size packets

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Space-time turbo trellis codes for two, three, and four transmit antennas

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2004年第2期53卷 318-328页

作者： Hong, Y Yuan, JH Chen, Z Vucetic, B Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

New space-time turbo trellis codes (ST turbo TCs) with 4-phase-shift keying (PSK) and 8-PSK for two, three, and four transmit antennas in slow and fast fading channels are proposed in this paper. The component codes of the space-time turbo schemes are constructed by choosing the feedforward coefficients to maximize the minimum squared Euclidean distance and the feedback coefficients to minimize the iterative decoding threshold. The performance of the proposed ST turbo TCs with various memory orders, transmit antennas, and interleaver structures is evaluated by simulation. It is shown that the new codes achieve better performance than previously designed codes. The impact of antenna correlation and imperfect channel estimation on the code performance is also discussed.

关键词： diversity fading channels space-time (ST) coding trellis codes turbo coding

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Near-Capacity turbo Coded Soft-Decision Aided DAPSK/Star-QAM for Amplify-and-Forward Based Cooperative Communications

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IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第3期61卷 1080-1087页

作者： Liang, Dandan Ng, Soon Xin Hanzo, Lajos Univ Southampton Commun Signal Proc & Control Res Grp Southampton SO17 1BJ Hants England

Multilevel Differential Amplitude and Phase-Shift Keying (DAPSK) schemes do not require any channel estimation, which results in low complexity. In this treatise we derive the soft-output probability formulas required for a soft-decision based demodulation of high-order DAPSK, in order to facilitate iterative detection by exchanging extrinsic information with an outer turbo Code (TC). Furthermore, when the TC block size is increased, the system operates closer to the channel capacity. Compared to the identical-throughput TC assisted 64-ary Differential Phase-Shift Keying (64-DPSK) scheme, the 4-ring based TC assisted 64-ary DAPSK arrangement has a power-efficiency improvement of 2.3 dB at a bit error rate (BER) of 10(-5). Furthermore, when the TC block size is increased, the system operates closer to the channel capacity. More specifically, when using a TC block length of 400 modulated symbols, the 64 DAPSK (4, 16) scheme is 7.56 dB away from its capacity curve, while it had a reduced gap as low as 2.25 dB, when using a longer TC block length of 40 000 modulated symbols. Finally, as a novel application example, the soft-decision M-DAPSK scheme was incorporated into an Amplify-and-Forward (AF) based cooperative communication system, which attains another 4.5 dB SNR improvement for a TC block length of 40 000 modulated symbols.

关键词： Soft-decision iterative detection DAPSK turbo coding amplify-and-forward (AF) relaying protocol correlated Rayleigh fading channel near-capacity transceivers

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Full-rate complex orthogonal space-time block code for multiple antennas

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WIRELESS PERSONAL COMMUNICATIONS 2007年第1期40卷 81-89页

作者： Yu, Xiangbin Xu, Dazhuan Bi, Guangguo Nanjing Univ Aeronaut & Astronaut Informat & Commun Engn Postdoctoral Res Stn Nanjing 210016 Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China

In this paper, full-rate and complex orthogonal space-time block code (STBC) schemes for multiple antennas are proposed, and turbo code is employed as channel coding to improve the proposed STBC schemes performance further. Compared with full-diversity multiple antennas STBC schemes, the proposed schemes can implement full data rate, partial diversity and a smaller complexity. On the condition of the same system throughput and concatenation of turbo code, the proposed schemes have lower bit error rate (BER) than those low-rate and full-diversity code schemes.

关键词： space-time block codes full rate multiple antennas turbo coding transmit diversity

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On the better protection of short-frame turbo codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2004年第9期52卷 1435-1439页

作者： Chi, ZP Wang, ZF Parhi, KK Marvell Semicond Inc Sunnyvale CA 94089 USA Oregon State Univ Dept Elect Engn Corvallis OR 97331 USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

Protecting short data frames by turbo coding is a challenging task because of the small interleaver size and the need for transmission efficiency. In this letter, turbo-decoding-metrics aided short cyclic redundancy check codes are applied to novel tailbiting encoded trellis codes with a twofold purpose: to stop the iterative decoding processes to achieve low-power design and to reduce fractional coding-rate loss. Significant coding gains can be achieved by actually increasing the transmission rate with a negligible increase in power consumption. Performance improvement is demonstrated over additive white Gaussian noise channels. The savings is up to 21.4% for the transmission throughput and 21.5% for the energy consumption of the turbo decoder when frame size 49 is used.

关键词： cyclic redundancy check (CRC) error detection low-power turbo decoder stopping criterion tailbiting trellis termination turbo coding

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Complexity reduced soft MIMO detetion using single tree search

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INTERNATIONAL JOURNAL OF SYSTEM ASSURANCE ENGINEERING AND MANAGEMENT 2020年第4期11卷 774-779页

作者： Ahmed, Saleem Bhatti, D. M. Saqib Kim, Sooyoung Dawood Univ Engn & Technol Comp Syst Engn Karachi Pakistan Chonbuk Natl Univ IT Convergence Res Ctr Div Elect Engn Jeonju South Korea

In MIMO systems, soft iterative detection and decoding can produce the near capacity performance. One of the promising detection techniques known as sphere decoder can play an important role in order to meet the requirements of achieving near optimal performance. The single tree search (STS) is based on the sphere decoding which can produce near optimal performance in iterative detection and decoding. The main hindering in STS method is that it is computationally complex. The complexity increases as we increase the iterations. In this paper, we propose to reduce complexity of the STS method by limiting the candidates of calculating soft information to those bits whose a priori information provided by turbo decoder is less reliable. Simulation results show that the proposed method can reduce the complexity with negligible performance degradation compared to the conventional full search and STS methods.

关键词： MIMO STS turbo coding

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Channel estimation and channel tracking for correlated block-fading channels in massive MIMO systems

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Digital Communications and Networks 2018年第2期4卷 138-147页

作者： Suresh Dahiya Arun Kumar Singh Department of Electrical Engineering Indian Institute of Technology Jodhpur Rajasthan 342011 India

This paper presents a channel estimation and tracking method for correlated block-fading channels in massive MIMO wireless cellular systems. In order to conserve resources, the proposed algorithm requires the uplink pilot signal only once, at the start of communication. By utilizing the temporal correlation between consecutive Resource Blocks （RBs） and the error correction capability of turbo codes, the channel matrix in subsequent RBs is estimated at the Base Station （BS） itself using the uplink data of current the RB and the estimated channel matrix of previous the RB. Compared to existing blind estimation methods, the proposed method places fewer limitations on the system settings such as the number of BS antennas, the number of users, and the number of coherent channel usage compared to existing blind estimation methods. Simulation results show that the proposed algorithm provides better performance for a moderate RB size, a high-order of QAM scheme, and a smaller ratio of the number of BS antennas and mobile terminals （N/K）. For a reasonably small N/K （order of 10）, the proposed scheme achieves a lower symbol error probability than the conventional pilot-based estimation approach.

关键词： Massive MIMO Channel estimation Resource block turbo coding Mobile terminal

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Systematic-bit-selection distributed turbo code with selective-relaying

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Journal of Beijing Institute of Technology 2014年第1期23卷 73-77页

作者：侯舒娟李凌云秦学方 School of Information and Electronics Beijing Institute of Technology

An improved distributed turbo coding(DTC)scheme,namely,systematic-bit-selection DTC,is proposed for a two-hop relay network implementing selective-relaying(SR).In the scheme,source broadcasts a punctured turbo code in order to increase the successful decoding rate of *** relay forwards systematic-bit to the destination in case of successful cyclic redundancy check(CRC).From the two versions of systematic-bit coming from relay and source respectively,the destination selects the one with higher signal-to-noise ratio(SNR)for turbo *** results show the improved bit error rate(BER)performance of our scheme.

关键词： distributed coding relay network turbo coding selective-relaying

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Distributed Video coding with Multiple Side Information Sets

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2010年第3期E93D卷 654-657页

作者： Park, Jung Ah Suh, Doug Young Park, Gwang-Hoon Kyung Hee Univ Coll Elect & Informat Media Lab Natl Res Lab Korea Yongin 449701 Kyunggi South Korea

This letter proposes a method to retrieve the original image X out of multiple sets of SI (Side Information) in distributed video coding (DVC). Using turbo decoding methods, the most reliable segments from the decoded Y-i's were selected for the composition of whose conditional entropy H(X vertical bar Y-infinity) became much lower than any individual conditional entropy H(X vertical bar Y-i). This proposal has improved the peak signal-to-noise ratio (PSNR) by 1.1 to 1.8 dB, compared to the conventional single SI-based approach.

关键词： DVC (Distributed Video coding) multiple side information turbo coding

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