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Low-complexity iterative channel estimation with lattice reduction-based detection for multiple-input multiple-output systems

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IET COMMUNICATIONS 2014年第6期8卷 905-913页

作者： Bai, Lin Dou, Shengyue Li, Qiaoyu Xing, Weixi Choi, Jinho Beihang Univ Sch Elect & Informat Engn Beijing Peoples R China Swansea Univ Coll Engn Swansea W Glam Wales GIST Sch Informat & Commun Kwangju South Korea

Iterative channel estimation and detection (ICED) can provide a better performance as the channel estimation can be improved through iterations. For a multiple-input multiple-output channel, owing to a large size of the signal alphabet, ICED becomes less practical unless a low-complexity detector such as a lattice reduction-based detector is employed. However, since the lattice basis reduction has to be carried out for each iteration, the resulting complexity can be still high. In this study, a computationally efficient technique was proposed to perform the lattice basis reduction within ICED over both static and slowly time-varying block-fading channels, where orthogonal defect of basis, as well as error probability are considered to decide whether or not basis reduction is needed for each iteration.

关键词： channel estimation fading channels iterative methods MIMO communication iterative channel estimation lattice reduction-based detection multiple-input multiple-output systems multiple-input multiple-output channel low-complexity detector time-varying block-fading channels error probability

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Semi-deterministic channel model for MIMO systems Part-II: results

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IET MICROWAVES ANTENNAS & PROPAGATION 2010年第1期4卷 26-34页

作者： Emami-Forooshani, A. Noghanian, S. Univ British Columbia Dept Elect & Comp Engn Vancouver BC V5Z 1M9 Canada Univ N Dakota Dept Elect Engn Grand Forks ND 58201 USA

This article presents the results of applying 'Single Interaction ScatTEring Reflecting' (SISTER) model to different multiple-input multiple-output (MIMO) channels. The SISTER model is a semi-deterministic channel model which is described in details in Part-I of this article. MIMO performance is investigated for outdoor and indoor environments considering both line of sight (LOS) and non-line of sight (NLOS) cases. Different results are obtained by changing antenna array parameters such as spacing and number of elements and antenna half power beam width (HPBW), as well as environment parameters such as ground's and walls' conductivity, and number and distribution of scatterers. In addition, space and angle diversity methods are compared for most of the studied cases. As the results show for most scenarios, the MIMO performance may be further improved by using multi-beams (angle diversity) rather than multi-antenna elements (space diversity).

关键词： outdoor environments line of sight antenna array indoor environments wall conductivity nonline of sight diversity reception space diversity method SISTER model antenna half power beam width multiple-input multiple-output channel multiantenna elements single interaction scattering reflecting model antenna arrays Antenna arrays MIMO systems angle diversity method Radio links and equipment MIMO communication semideterministic channel model

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Experimental evaluation of unsupervised channel deconvolution for wireless multiple-transmitter/multiple-receiver systems

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ELECTRONICS LETTERS 2002年第20期38卷 1214-1216页

作者： Samardzija, D Papadias, C Valenzuela, R Bell Labs Lucent Technol Wireless Res Lab Holmdel NJ 07733 USA

An over-the-air demonstration of unsupervised (blind) multiple-input/multiple output (MIMO) channel deconvolution is presented. The results were obtained in an indoor multiple antenna (BLAST) context. A suitable unsupervised MIMO technique was used in order to avoid the effective reduction of spectral efficiency caused by the use of channel training. To the authors' knowledge, this may be the first reported experiment of successful over-the-air unsupervised MIMO deconvolution.

关键词： transmitting antennas unsupervised channel deconvolution MIMO systems over-the-air demonstration multiuser channels multiple-input multiple-output channel Bell-labs LAyered Space-Time architecture deconvolution radio transmitters multiuser kurtosis MIMO technique wireless multiple-transmitter/multiple-receiver systems Signal processing and detection radio receivers indoor multiple antenna BLAST Radio links and equipment receiving antennas

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Ergodic and outage capacity of interference temperature-limited cognitive radio multi-input multi-output channel

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IET COMMUNICATIONS 2011年第5期5卷 652-659页

作者： Kong, Asaduzzaman H. Y. Univ Ulsan Dept Elect Engn Ulsan South Korea

In this study, we consider a cognitive radio multi-input multi-output (CR-MIMO) system in which the cognitive radio (CR) users are allowed to access the spectrum of the licensed primary users, provided that interference power received at the primary receiver is less than a certain threshold. The authors investigate the effect of the MIMO diversity on such multi-constraint CR-MIMO systems. They consider peak interference power constraint at the primary receiver and peak transmit power constraint at the CR transmitter. In MIMO systems, the allowable transmit power is distributed over the transmit-antennas. The power allocation problem of such CR systems is studied under both sum power and interference constraints. The authors show that the equal power allocation does not improve the ergodic capacity but improves the outage capacity over the single-input single-output (SISO) system. Transmit antenna selection (TAS) which is a special case of power allocation is also investigated. The authors show that, under the peak interference and transmit power constraint, selecting a single transmit-antenna and allocating all the power to the selected best antenna achieves the same performance as the optimal power allocation (OPA). The authors evaluate ergodic capacity and outage capacity for both power allocation-and antenna selection-based schemes. The closed-form expressions of the outage probabilities are also derived. Results show that both OPA and TAS significantly improves the capacities over the SISO system.

关键词： Electromagnetic compatibility and interference primary receiver CR transmitter licensed primary users single-input single-output system radio transmitters wireless channels diversity reception radiofrequency interference interference temperature-limited cognitive radio transmitting antennas CR-MIMO system optimal power allocation radio receivers multiple-input multiple-output channel Single antennas transmit antenna selection MIMO diversity Radio links and equipment radio spectrum management cognitive radio MIMO communication

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The Dirty MIMO multiple-Access channel

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IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第9期63卷 6031-6040页

作者： Khina, Anatoly Kochman, Yuval Erez, Uri Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel CALTECH Dept Elect Engn Pasadena CA 91125 USA Hebrew Univ Jerusalem Rachel & Selim Benin Sch Comp Sci & Engn IL-91904 Jerusalem Israel

In the scalar dirty multiple-access channel, in addition to Gaussian noise, two additive interference signals are present, each known non-causally to a single transmitter. It was shown by Philosof et al. that for strong interferences, an independent identically distributed ensemble of codes does not achieve the capacity region. Rather, a structured-codes approach was presented that was shown to be optimal in the limit of high signal-to-noise ratios, where the sum capacity is dictated by the minimal ("bottleneck") channel gain. In this paper, we consider the multiple-input multiple-output (MIMO) variant of this setting. In order to incorporate structured codes in this case, one can utilize matrix decompositions that transform the channel into effective parallel scalar dirty multiple-access channels. This approach, however, suffers from a "bottleneck" effect for each effective scalar channel and, therefore, the achievable rates strongly depend on the chosen decomposition. It is shown that a recently proposed decomposition, where the diagonals of the effective channel matrices are equal up to a scaling factor, is optimal at high signal-to-noise ratios, under an equal rank assumption. This approach is then extended to any number of transmitters. Finally, an application to physical-layer network coding for the MIMO two-way relay channel is presented.

关键词： multiple-access channel dirty-paper coding multiple-input multiple-output channel matrix decomposition physical-layer network coding two-way relay channel

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Joint Signal Alignment and Power Allocation for a Diagonalized AF MIMO Two-Way Relay channel

Joint Signal Alignment and Power Allocation for a Diagonaliz...

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54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Park, Heesun Chun, Joohwan Adve, Raviraj Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea Univ Toronto Dept Elect & Comp Engn Toronto ON Canada

ISBN: (纸本)9781424492688

This paper uses generalized singular value decomposition (GSVD) to reduce decoding complexity in an amplify-and-forward, multiple-input multiple-output, two-way relay channel (TWRC). The key is diagonalization of the effective channels at the source nodes;this formulation also simplifies the optimization problem of designing linear transceivers at each node to maximize the achievable sum rate (ASR). For the given diagonalized structure, we first align the entries of the diagonalized channels using a permutation followed by power allocation, provided in closed form. Simulation results demonstrate that the proposed GSVD-based relaying scheme, with the signal alignment and power allocation, significantly improves the ASR while retaining the diagonalized channel structure.

关键词： Complexity theory Decoding MIMO MIMO communication Peer to peer computing Relays Resource management Signal to noise ratio achievable sum rate amplify and forward amplify and forward communication decoding decoding complexity diagonalized AF MIMO two-way relay channel diagonalized channel structure generalized singular value decomposition joint signal alignment linear transceiver multiple-input multiple-output channel optimization problem permutation power allocation singular value decomposition source node wireless channels

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Super-orthogonal space-time-frequency trellis coded OFDM

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IET COMMUNICATIONS 2007年第3期1卷 317-324页

作者： Aksoy, K. Aygoelue, Ue. Tech Univ Istanbul Fac Elect & Elect Engn TR-34469 Istanbul Turkey

Super-orthogonal space-time trellis codes (SOSTTCs) given in the literature are full rate and provide full spatial diversity with high coding gain in narrowband quasistatic fading channels. The high number of parallel transitions in their trellis structure restricts their performance in wideband channels where the code performance suffers from multipath. Code design criteria are derived and a computer search based method is proposed to design full-rate optimised SOSTTCs exploiting full spatial and multipath diversity for multiple-input multiple-output orthogonal frequency division multiplexing systems. The proposed codes have codewords defined in space, time, and frequency. We evaluate the codeword error rates of the new 16, 32 and 64-state super-orthogonal space-time-frequency trellis codes for quadrature phase shift keying by computer simulation and show that they provide significant error performance improvement compared to their counterparts with equivalent delay length.

关键词： fading channels orthogonal frequency division multiplexing system trellis coded OFDM narrowband quasistatic fading channels SOSTTC MIMO communication quadrature phase shift keying spatial diversity MIMO OFDM channel diversity reception multiple-input multiple-output channel super-orthogonal space-time-frequency trellis codes trellis coded modulation orthogonal codes codeword error rates channel coding parallel transitions multipath diversity space-time codes OFDM modulation computer search based method

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Space-time blind equalisation in impulsive noise

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IET SIGNAL PROCESSING 2009年第6期3卷 445-458页

作者： Li, S. Qiu, T. Sh. Zhang, Sh. F. Dalian Univ Technol Sch Elect & Informat Engn Dalian 116026 Peoples R China Dalian Univ Technol Coll Informat Engn Dalian 116024 Peoples R China

The presence of non-Gaussian impulsive noise in wireless system can degrade the performance of existing equalisers and signal detectors. The problem of blind source separation and equalisation for multiple-input/multiple-output (MIMO) channels under heavy-tailed impulsive noise environment is studied. A generalised multi-user constant modulus (CM) cost function is proposed by employing the fractional lower order CM property of the equaliser input signals as well as the fractional lower order cross-correlations between them. The associated adaptive blind equalisation algorithm based on a stochastic gradient descent method is defined as fractional lower order multi-user constant modulus algorithm (FMU_CMA), which is able to mitigate impulsive channel noise while recovering all input signals simultaneously. The steady-state mean-square error (MSE) performance of the FMU_CMA is studied in a noise-free environment;the approximate expression is derived based on the energy-preserving relation and the Taylor series expansion. Simulation studies are undertaken to support the analysis with CM and non-CM signal.

关键词： Electromagnetic compatibility and interference impulse noise energy-preserving relation signal detection signal detectors blind equalisers stochastic processes Other topics in statistics wireless channels MIMO channel wireless system Signal detection gradient methods fractional lower order cross-correlation stochastic gradient descent method steady-state mean-square error performance multiple-input multiple-output channel mean square error methods generalised multiuser constant modulus cost function impulsive channel noise mitigation space-time blind equalisation nonGaussian impulsive noise Interpolation and function approximation (numerical analysis) Radio links and equipment Communication channel equalisation and identification Taylor series expansion radio networks blind source separation MIMO communication interference suppression

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Definition of spatial multiplexing gain

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ELECTRONICS LETTERS 2005年第11期41卷 656-657页

作者： Wetzker, G Private address

A definition of spatial multiplexing gain is provided. The advantages of this definition are twofold. The spatial multiplexing gain of a multiple-input multiple-output channel can be calculated without approximations for a given channel and the spatial multiplexing gain is a measure of the signal-to-noise ratio improvement compared to a diversity system. Furthermore, this definition provides insight in the dependencies of the spatial multiplexing gain on the channel conditioning and the signal-to-noise ratio.

关键词： MIMO systems diversity reception multiplexing telecommunication channels channel conditioning diversity system multiple-input multiple-output channel signal-to-noiseratio improvement spatial multiplexing gain

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Partial-Response Maximum-Likelihood Joint Detection of Asynchronous Tracks

Partial-Response Maximum-Likelihood Joint Detection of Async...

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IEEE International Conference on Communications (ICC)

作者： Sadeghian, Elnaz Banan Barry, John R. Stevens Inst Technol Dept Elect & Comp Engn Hoboken NJ 07030 USA Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA

ISBN: (纸本)9781728171227

The industry standard for single-track detection in magnetic recording is partial-response equalization followed by a trellis-based sequence detector. We extend for the first time the partial-response paradigm to the case of multitrack detection when the multiple tracks being jointly detected were written asynchronously, with different bit phases and bit rates. We propose a multiple-input multiple-output (MIMO) partial-response equalizer that equalizes the unsynchronized samples of the multiple readback waveforms to a time-varying MIMO target, thereby enabling a trellis-based sequence detector that is based on the resulted time-varying target to account for the asynchrony. We evaluate the proposed equalization strategy on a two-dimensional magnetic-recording channel, and find that the proposed receiver outperforms a conventional receiver that detects one track at a time, and that it closely matches the performance of a fictitious system in which the tracks are perfectly synchronous.

关键词： Intertrack interference timing recovery multiple-input multiple-output channel two-dimensional magnetic recording (TDMR)

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