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Joint estimation and decoding of space-time trellis codes

EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2002年第3期2002卷 305-315页

作者： Zhang, JQ Djuric, PM SUNY Stony Brook Dept Elect & Comp Engn Stony Brook NY 11794 USA

We explore the possibility of using an emerging tool in statistical signal processing, sequential importance sampling (SIS), for joint estimation and decoding of space-time trellis codes (STTC). First, we provide background on SIS, and then we discuss its application to space-time trellis code (STTC) systems. It is shown through simulations that SIS is suitable for joint estimation and decoding of STTC with time-varying flat-fading channels when phase ambiguity is avoided. We used a design criterion for STTCs and temporally correlated channels that combats phase ambiguity without pilot signaling. We have shown by simulations that the design is valid.

关键词： space-time coding sequential importance sampling Kalman filtering phase ambiguity design criterion

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space-time turbo coded modulation: Design and applications

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EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2002年第3期2002卷 236-248页

作者： Tujkovic, D Juntti, M Latva-aho, M Univ Oulu Ctr Wireless Commun FIN-90014 Oulu Finland

A design method for recursive space-time trellis codes and parallel-concatenated space-time turbo coded modulation is proposed that can be applied to an arbitrary existing space-time trellis code. The method enables a large, systematic increase in coding gain while preserving the maximum transmit diversity gain and bandwidth efficiency property of the considered space-time trellis code. Applying the above method to Tarokh et al. space-time trellis codes, significant performance improvements can be obtained even with extremely short input information frames. The application of space-time turbo coded modulation to the space-frequency domain is also proposed in this paper. Exploiting the bandwidth efficient orthogonal frequency division modulation (OFDM), multiple transmit antennas and large frequency selectivity offered by typical low mobility indoor environments, the proposed space-frequency turbo coded modulation performs within 2.5 dB of the outage capacity for a variety of practical wideband multiple-input multiple-output (MIMO) radio channels.

关键词： space-time coding turbo coded modulation OFDM modulation

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MIMO waveform design for radar and communication integrated system in the presence of active interferences

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DIGITAL SIGNAL PROCESSING 2022年第0期129卷

作者： Wu, Wenhua Han, Guojun Cao, Yunhe Huang, Yongwei Guangdong Univ Technol Sch Informat Engn Guangzhou 510006 Peoples R China Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Peoples R China

In this paper, we propose a modified space-time coding scheme to design transmit waveform for the radar and communication integrated system in the presence of active interferences. Based on the shared co-located MIMO radar, the constraints of communication requirement, waveform orthogonality and active anti-interference are considered for the waveform design. To avoid the loss of information symbols for communication transmission and obtain sufficient anti-interference performance for radar detection, the transmit beam-pattern at each sub-pulse duration time is controlled to maintain the radiation powers unchanged towards communication direction and interference directions, which is distinct to the conventional transmit beamforming design. Furthermore, to tackle the coupling of the time-domain orthogonality and the space-domain beam-pattern, the constant envelope constraint of transmit waveform is relaxed to obtain the degree of freedom for space-time waveform design. Thus the peak-to-average power ratio (PAPR) reduction for transmit waveform is also discussed. Simulation results are finally presented to demonstrate the effectiveness of the proposed methods. (c) 2022 Elsevier Inc. All rights reserved.

关键词： MIMO waveform design Transmit beamforming space-time coding Anti-interference

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Simulace MIMO systémů

Simulace MIMO systémů

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作者： Kančo, Vít Brno University of Technology

MIMO systémy se používají zejména v aplikacích pro bezdrátové komunikace. Jejich principem je použití většího počtu antén jak pro vysílání, tak pro př&... 详细信息

MIMO systémy se používají zejména v aplikacích pro bezdrátové komunikace. Jejich principem je použití většího počtu antén jak pro vysílání, tak pro příjem signálu. Základem těchto systémů je použití časoprostorového kódování a to buď blokového nebo trellis časoprostorového kódu. V budoucnu se předpokládá obrovské rozšíření MIMO systémů v mnoha aplikacích.

关键词： MIMO systémy diverzita multiplexování kapacita kanálu časoprostorové kódování Rayleighův kanál AWGN šum MIMO systems diversity multiplexing capacity of channel space-time coding Rayleigh fading channel AWGN noise Text

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A Concatenated ML Decoder for ST/SFBC-OFDM Systems in Double Selective Fading Channels

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Journal of Shanghai Jiaotong university(Science) 2004年第4期9卷 15-20页

作者：李明齐张文军 Inst. of Image Comm. & Info. Processing Shanghai Jiaotong Univ. Shanghai 200030 China

This paper presented a concatenated maximum-likelihood (ML) decoder for space-time/space-frequency block coded orthogonal frequency diversion multiplexing (ST/SFBC-OFDM) systems in double selective fading channels. The proposed decoder first detects space-time or space-frequency codeword elements separately. Then, according to the coarsely estimated codeword elements, the ML decoding is performed in a smaller constellation element set to searching final codeword. It is proved that the proposed decoder has optimal performances if and only if subchannels are constant during a codeword interval. The simulation results show that the performances of proposed decoder is close to that of the optimal ML decoder in severe Doppler and delay spread channels. However, the complexity of proposed decoder is much lower than that of the optimal ML decoder.

关键词： wireless conmmunications OFDM space-time coding ML decoding

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Blind adaptive decorrelating RAKE (DRAKE) downlink receiver for space-time block coded multipath CDMA

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EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2002年第12期2002卷 1306-1313页

作者： Jayaweera, SK Poor, HV Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

A downlink receiver is proposed for space-time block coded CDMA systems operating in multipath channels. By combining the powerful RAKE receiver concept for a frequency selective channel with space-time decoding, it is shown that the performance of mobile receivers operating in the presence of channel fading can be improved significantly. The proposed receiver consists of a bank of decorrelating filters designed to suppress the multiple access interference embedded in the received signal before the space-time decoding. The new receiver performs the space-time decoding along each resolvable multipath component and then the outputs are diversity combined, to obtain the final decision statistic. The proposed receiver relies on a key constraint imposed on the output of each filter in the bank of decorrelating filters in order to maintain the space-time block code structure embedded in the signal The proposed receiver can easily be adapted blindly, requiring only the desired user's signature sequence, which is also attractive in the context of wireless mobile communications. Simulation results are provided to confirm the effectiveness of the proposed receiver in multipath CDMA systems.

关键词： multiuser detection space-time coding blind adaptive receivers code division multiple access

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On the construction of high-rate quasi-orthogonal STBC for MIMO QR demodulation

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2005年第7期E88D卷 1417-1429页

作者： Le, MT Pham, VS Mai, L Yoon, G Informat & Commun Univ Sch Engn Taejon 305714 South Korea

Orthogonal space-time block codes (STBCs) [1], [2] appear to be a very fascinating means of enhancing reception quality in quasistatic MIMO channels due to their full diversity, and especially their simple maximum-likelihood (ML) decoders. However, full-rate full-diversity orthogonal STBCs do not exist for more than two transmit antennas. Vertical layered space-time architecture (so-called the V-BLAST) [3] with a nulling- and cancelling-based detection algorithm, in contrast, has an ability of achieving high transmission rates at the cost of having very low diversity gain, an undesirable consequence caused by the interference nulling and cancelling processes. The uncoded V-BLAST system is able to reach its ML performance with the aid of the sphere decoder algorithm [4] at the expense of higher detection complexity. Undoubtedly, the tradeoff between transmission rates, diversity, and complexity is inherent in designing space-time codes. This paper investigates a method to increase the "nulling diversity gains" for a general high-rate space-time code and introduces a new design strategy for high-rate space-time codes detected based on interference nulling and cancelling processes, thanks to which high-rate quasi-orthogonal space-time codes for MIMO applications are proposed. We show that when n(T) transmit and n(R) = n(T) receive antennas are deployed, the first code offers a transmission rate of (n(T) - 1) with a minimum nulling diversity order of 3, whereas the second one offers a transmission rate of (n(T) - 2) with a minimum nulling diversity order of 5. Therefore, the proposed codes significantly outperform the V-BLAST as n(R) = n(T). Simulation results and discussions on the performance of the proposed codes are provided.

关键词： space-time coding multiple-input multiple-output maximum likelihood detection diversity wireless communication multipath channels

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MIMO radar beampattern design by using Phased-Costas waveforms with PAR constraints employing a generalized ambiguity function

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DIGITAL SIGNAL PROCESSING 2023年第1期135卷

作者： Celik, Ozan Onur Tuncer, T. Engin Middle East Tech Univ Dept Elect & Elect Engn TR-06800 Ankara Turkiye

Multiple-input multiple-output (MIMO) radars have attracted interest due to some important advantages over Phased-array radars. The diversity that comes with multiple waveforms is used to maximize the power in the vicinity of targets and minimize the cross correlation of waveforms reflected from multiple targets for predefined angles. In this study, a novel approach is presented to overcome the limitations of current beamformer design techniques in terms of bandwidth, auto/cross (spatial) correlations, range-doppler resolutions, peak-to-average ratio (PAR) and mean squared error (MSE) for desired beamforming pattern. A generalized ambiguity function formulation is presented which employs all the beamformer design parameters in a mathematically tractable simple manner suitable for constrained optimization. We present Phased-Costas coded waveforms to generate desired beampatterns while minimizing range-doppler sidelobes and target cross-correlations with limited bandwidth. Beamformer design problem is casted as a constrained optimization which includes nonconvex PAR constraints. The resulting NP hard problem with nonconvex objective function is converted to a bi-convex form and the PAR constraints are converted as convex constraints. The final problem is efficiently solved by using Alternating Direction Method of Multipliers (ADMM) technique in polynomial time. The beamformer solution is shown to achieve PAR =1 with very little degradation compared to the unconstrained problem making the ultimate choice for MIMO beamforming applications. Several good features of the designed beamformer are shown through simulations and compared to the known methods.(c) 2023 Elsevier Inc. All rights reserved.

关键词： MIMO radar Transmit beampattern ADMM space-time coding Generalized ambiguity function Peak to average ratio (PAR)

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Diversity analysis of distributed space-time codes in relay networks with multiple transmit/receive antennas

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EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2008年第unknown期2008卷 254573-1-254573-17-0页

作者： Jing, Yindi Hassibi, Babak Univ Calif Irvine Dept Elect Engn & Comp Sci Irvine CA 92697 USA CALTECH Dept Elect Engn Pasadena CA 91125 USA

The idea of space-time coding devised for multiple-antenna systems is applied to the problem of communication over a wireless relay network, a strategy called distributed space-time coding, to achieve the cooperative diversity provided by antennas of the relay nodes. In this paper, we extend the idea of distributed space-time coding to wireless relay networks with multiple-antenna nodes and fading channels. We show that for a wireless relay network with M antennas at the transmit node, N antennas at the receive node, and a total of R antennas at all the relay nodes, provided that the coherence interval is long enough, the high SNR pairwise error probability (PEP) behaves as (1/P)(min{M, N}R) if M not equal N and (log(1/M) P/P)(MR) if M = N, where P is the total power consumed by the network. Therefore, for the case of M not equal N, distributed space-time coding achieves the maximal diversity. For the case of M = N, the penalty is a factor of log(1/M) P which, compared to P, becomes negligible when P is very high. Copyright (c) 2008.

关键词： space-time codes time coding Distribute Line of nodes Relay networks ANTENNA Trunk Node space-time coding wireless relay networks manganese ANTENNA SYSTEM

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space-time coded MC-CDMA: Blind channel estimation, identifiability, and receiver design

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EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2002年第12期2002卷 1314-1324页

作者： Sun, W Li, HB Villanova Univ Dept Elect & Comp Engn Villanova PA 19085 USA Stevens Inst Technol Dept Elect & Comp Engn Hoboken NJ 07030 USA

Integrating the strengths of multicarrier (MC) modulation and code division multiple access (CDMA), MC-CDMA systems are of great interest for future broadband transmissions. This paper considers the problem of channel identification and signal combining/detection schemes for MC-CDMA systems equipped with multiple transmit antennas and space-time (ST) coding. In particular, a subspace-based blind channel identification algorithm is presented Identifiability conditions are examined and specified which guarantee unique and perfect (up to a scalar) channel estimation when knowledge of the noise subspace is available. Several popular single-user based signal combining schemes, namely the maximum ratio combining (MRC) and the equal gain combining (EGC), which are often utilized in conventional single-transmit-antenna-based MC-CDMA systems, are extended to the current ST-coded MC-CDMA (STC-MC-CDMA) system to perform joint combining and decoding. In addition, a linear multiuser minimum mean square error (MMSE) detection scheme is also presented, which is shown to outperform the MRC and EGC at some increased computational complexity. Numerical examples are presented to evaluate and compare the proposed channel identification and signal detection/combining techniques.

关键词： MC-CDMA OFDM space-time coding blind channel identification identifiability multiuser detection

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