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Multicarrier block-spread CDMA for broadband cellular downlink

EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2004年第10期2004卷 1568-1584页

作者： Petré, F Leus, G Moonen, M De Man, H IMEC B-3001 Louvain Belgium Delft Univ Technol NL-2628 CD Delft Netherlands Katholieke Univ Leuven ESAT Dept Elect Engn B-3001 Heverlee Belgium

Effective suppression of multiuser interference (MUI) and mitigation of frequency-selective fading effects within the complexity constraints of the mobile constitute major challenges for broadband cellular downlink transceiver design. Existing wideband direct-sequence (DS) code division multiple access (CDMA) transceivers suppress MUI statistically by restoring the orthogonality among users at the receiver. However, they call for receive diversity and multichannel equalization to improve the fading effects caused by deep channel fades. Relying on redundant block spreading and linear precoding, we design a so-called multicarrier block-spread- (MCBS-)CDMA transceiver that preserves the orthogonality among users and guarantees symbol detection, regardless of the underlying frequency-selective fading channels. These properties allow for deterministic MUI elimination through low-complexity block despreading and enable full diversity gains, irrespective of the system load. Different options to perform equalization and decoding, either jointly or separately, strike the trade-off between performance and complexity. To improve the performance over multi-input multi-output (MIMO) multipath fading channels, our MCBS-CDMA transceiver combines well with space-time block-coding (STBC) techniques, to exploit both multiantenna and multipath diversity gains, irrespective of the system load. Simulation results demonstrate the superior performance of MCBS-CDMA compared to competing alternatives.

关键词： multicarrier CDMA broadband cellular system frequency-selective fading channels equalization MlMO space-time block coding

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space time coding for Backscatter RFID

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第5期12卷 2272-2280页

作者： Boyer, Colby Roy, Sumit Univ Washington Dept Elect Engn Seattle WA 98195 USA

In this work, the use of space-time Codes in passive Radio Frequency IDentification (RFID) systems is explored;this is feasible whenever a tag possesses multiple antennas. Information is encoded across the multiple tag antennas and received by an RFID reader, also typically equipped with multiple antennas. The nature of passive RFID induces a unique fading channel known as the dyadic backscatter channel, which differs statistically compared to the canonical Rayleigh fading channel. We introduce a modified dyadic channel for RFID backscatter that adequately captures the space-time coding paradigm. We then propose known orthogonal space-time codes and derive an upper bound on the the pairwise error probability (PEP), leading to estimates of the (asymptotic) diversity order. Interestingly, the diversity order is shown to depend only on the number of tag antennas but not the number of receive antennas;the resultant performance trade-offs is discussed. Lastly, simulation of the symbol error rates for different channel configurations are conducted to validate the analysis.

关键词： Dyadic backscatter channel modulated backscatter MIMO space-time block coding RFID

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Frequency-Domain Equalization for Orthogonal and Quasi-Orthogonal STBCs over Frequency-Selective Wireless and Power-Line Channels

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WIRELESS PERSONAL COMMUNICATIONS 2013年第4期71卷 2445-2461页

作者： Sheikh-Hosseini, Mohsen Molavi-Kakhki, Mohammad Hodtani, Ghosheh Abed Ferdowsi Univ Mashhad Dept Elect Engn Program Commun Engn Mashhad Iran Ferdowsi Univ Mashhad Dept Elect Engn Mashhad Iran

In recent years, combination of single-carrier frequency-domain equalization (SC-FDE) and space-time block coding/code (STBC) techniques to exploit the advantages of both, has received a great attention. In this paper we propose new techniques for combining SC-FDE with orthogonal and Quasi-orthogonal STBCs applicable to any number of transmit antennas. For Quasi-orthogonal STBC we first propose a new structure for codes with four transmit antennas and then extend it to higher numbers. We convert Quasi-orthogonal system to two equivalent orthogonal subsystems and equalize and decode these subsystems based on our proposed procedure for orthogonal codes. Finally, we present our simulation results for different frequency-selective wireless and power-line channels and show that a significant SNR gain is achieved when SC-FDE is combined with diversity techniques.

关键词： Frequency-selective fading channels Power line communication space-time block coding Single-carrier frequency-domain equalization

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On the Performance of Cache-Free/Cache-Aided STBC-NOMA in Satellite-Terrestrial Networks

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IEEE WIRELESS COMMUNICATIONS LETTERS 2022年第12期11卷 2655-2659页

作者： Singh, Vibhum Solanki, Sourabh Eappen, Geoffrey Palisetty, Rakesh Vu, Thang X. Merlano-Duncan, Juan Carlos Chatzinotas, Symeon Ottersten, Bjorn Univ Luxembourg Interdisciplinary Ctr Secur Reliabil & Trust Luxembourg 1855 Luxembourg

Future wireless networks pose several challenges such as high spectral efficiency, wide coverage, massive connectivity, low receiver complexity, etc. To this end, this letter investigates an overlay-based cognitive hybrid satellite-terrestrial network (CHSTN) combining non-orthogonal multiple access (NOMA) and conventional Alamouti space-time block coding (STBC) techniques. Herein, a decode-and-forward based secondary terrestrial network cooperates with a primary satellite network for dynamic spectrum access. Further, for reliable content delivery and low latency requirements, wireless caching is employed, whereby the secondary network can store the most popular contents of the primary network. Considering the relevant heterogeneous fading channel models and the NOMA-based imperfect successive interference cancellation, we examine the performance of CHSTN for the cache-free (CF) STBC-NOMA and the cache-aided (CA) STBC-NOMA schemes. We assess the outage probability expressions for primary and secondary networks and further, highlight the corresponding achievable diversity orders. Indicatively, the proposed CF/CA STBC-NOMA schemes for CHSTN perform significantly better than the benchmark standalone NOMA and OMA schemes.

关键词： Caching hybrid satellite-terrestrial networks non-orthogonal multiple access overlay cognitive radio space-time block coding

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Frequency Domain DFE for Single-Carrier STBC block Transmission

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IEEE COMMUNICATIONS LETTERS 2013年第6期17卷 1108-1111页

作者： Wang, Qiucai Yuan, Chaowei Zhang, Jinbo Hu, Ziwei Li, Yingxue Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100876 Peoples R China Changan Univ Sch Elect & Control Engn Xian 710064 Peoples R China

space-time block coding (STBC) is a novel transmit diversity technique that can substantially improve the reliability of wireless communication channel. In this letter, we investigate single-carrier STBC block transmission over frequency-selective fading channel. Based on the minimum mean square error (MMSE) criterion, by exploiting the reliability of tentative decision symbols, we propose a novel suboptimal, low complexity frequency domain decision feedback equalization (FD-DFE) scheme for SC STBC. Simulation results show that the proposed scheme provides better performance than the conventional scheme.

关键词： Single-carrier space-time block coding frequency domain decision feedback equalization frequency-selective fading channel

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Quadrature Spatial Modulation Aided Media-Based Modulation

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IEEE COMMUNICATIONS LETTERS 2022年第8期26卷 1928-1932页

作者： Li, Canlin Wang, Lei Nie, Gaoyang Xi An Jiao Tong Univ Sch Informat & Commun Engn Xian 710049 Peoples R China

In this work, we present the concept of quadrature spatial modulation aided media-based modulation (QSM-MBM), which combines QSM and MBM principles. The proposed two QSM-MBM schemes use dispersion matrices to generate QSM matrix and transmit it by designing two different channel state activation methods, which provides improved transmission rate, diversity gain as well as hardware simplicity. Simulations show that the proposed QSM-MBM schemes achieve remarkably better error performance than the existing MBM schemes.

关键词： Radio frequency Modulation Indexes Mirrors Diversity methods Receivers Encoding MIMO systems index modulation media-based modulation space-time block coding

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Equivalence of Optimum and Joint Processing Receivers for space-time block Coded Systems

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第1期8卷 51-54页

作者： Garg, Parul Mallik, Ranjan K. Netaji Subhas Inst Technol Div Elect & Commun Engn New Delhi 110078 India Indian Inst Technol Delhi Dept Elect Engn New Delhi 110016 India

A space-time block coded system in a correlated Rayleigh flat fading environment with transmit and receive correlation is considered. The channel state information (CSI) is estimated from a sequence of pilot code vectors which are known to the receiver and transmitted prior to data code transmission. Two receiver structures, namely the optimum receiver in which the estimated CSI is used in the maximum likelihood sense and the joint processing receiver that jointly processes the received data code and the received pilot code vectors, are presented an their equivalence is shown.

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A New Result on Turbo Coded QO-STBC Schemes

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IEEE COMMUNICATIONS LETTERS 2010年第3期14卷 199-201页

作者： Park, Unhee Kim, Youngmin Kim, Sooyoung Chonbuk Natl Univ Div Elect & Informat Engn Jeonju South Korea

In this letter, we present a new result on turbo coded quasi orthogonal space time block coding (QO-STBC) schemes. Proper utilization of soft decision information is one of the important factors affecting the performance of turbo codes. If a space time block coding (STBC) scheme is used with turbo codes, the output of the STBC decoder must be fed into a turbo code decoder as soft decision information. Therefore, the performance of turbo codes depends on how the STBC scheme generates soft decision information from its detection process. In this letter, we investigate the performance of turbo coded QO-STBC schemes, and present the optimum soft decision metrics.

关键词： space-time block coding QO-STBC soft decision turbo codes

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CM-Based channel estimators for space-time block-coded M-PSK and M-QAM systems

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IEEE COMMUNICATIONS LETTERS 2003年第7期7卷 311-313页

作者： Xu, CJ Le-Ngoc, T McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 2A7 Canada Nanjing Univ Posts & Telecommun Dept Telecommun Engn Nanjing 210003 Peoples R China

A constant modulus (CM)-based channel estimation scheme for space-time block-coded MPSK and M-QAM transmission systems is derived. Exploiting the orthogonal structure of the space-time block coded transmission model, the analytical solutions to minimize the CM cost function are given for 2(k) PSK (k > 2) and 2(2k)-QAM schemes, and used to derive the expressions for the CM-based channel estimators. Illustrative results on the performance are presented.

关键词： channel estimation constant modulus space-time block coding transmit diversity

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Investigation of peak-to-average power ratio in STBC-OFDM

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ELECTRONICS LETTERS 2003年第13期39卷 1010-1011页

作者： You, YH Jeon, WG Paik, JH Sejong Univ Sch Comp Engn Seoul South Korea Korea Elect Technol Inst DMB Project Off Kyungnam South Korea

The peak-to-average power ratio (PAR) performance in a space-time block coded (STBC) OFDM system using the selective mapping (SLM) approach is investigated. The investigated SLM-based STBC-OFDM system selects the transmitted sequence with the lowest average PAR over all transmit antennas, which retrieves the side information very accurately at the expense of only 0.5 dB degradation of the PAR performance, compared to the ordinary SLM approach.

关键词： space-time block coding orthogonal frequency division multiplexing selective mapping Communication switching Codes STBC-OFDM space-time codes OFDM modulation peak-to-average power ratio block codes

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