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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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Joint source-and-relay beamforming for multiple-input multiple-output systems with single-antenna distributed relays

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IET COMMUNICATIONS 2012年第1期6卷 62-68页

作者： Li, C. Wang, X. Yang, L. Zhu, W. -P. Southeast Univ Minist Educ Key Lab Underwater Acoust Signal Proc Nanjing 210096 Peoples R China Southeast Univ Sch Informat Sci & Engn Nanjing 210096 Peoples R China Nanjing Univ Dept Math Nanjing 210093 Peoples R China Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada

A joint source-and-relay beamforming scheme is proposed for multiple-input multiple-output ( MIMO) systems with distributed single-antenna relays. First, a lower-bound of the signal-to-noise ratio at the destination is derived as an objective function to formulate a constrained beamforming optimisation problem. The joint beamforming problem is then divided into two sub-optimisation problems corresponding to the source and the relay beamforming, respectively. The first sub-problem is shown to be a quadratic concave minimisation, and is tackled by developing an iterative algorithm with each iteration solving a linear problem. The second one corresponds to a Rayleigh-Ritz ratio problem which is then solved by the generalised singular-value decomposition in a closed form. Based on the solutions to the subproblems, a global iterative algorithm is designed to implement the joint source-and-relay beamforming. Simulation results show that the proposed method outperforms some existing relaying schemes in terms of the capacity and outage probability of the whole MIMO relay system.

关键词： multiple-input multiple-output systems suboptimisation problems Rayleigh-Ritz ratio problem minimisation signal-to-noise ratio joint source-and-relay beamforming scheme global iterative algorithm quadratic concave minimisation MIMO relay system linear problem Optimisation techniques probability single-antenna distributed relays generalised singular-value decomposition iterative methods concave programming constrained beamforming optimisation problem antenna arrays Antenna arrays array signal processing Interpolation and function approximation (numerical analysis) lower-bound Radio links and equipment outage probability MIMO communication Other topics in statistics

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Channel prediction for precoded spatial multiplexing multiple-input multiple-output systems in time-varying fading channels

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IET SIGNAL PROCESSING 2009年第6期3卷 459-466页

作者： Khrwat, A. S. Sharif, B. S. Tsimenidis, C. C. Boussakta, S. Newcastle Univ Sch Elect Elect & Comp Engn Newcastle Upon Tyne NE1 7RU Tyne & Wear England

Conventional precoded spatial multiplexing multiple-input multiple-output (MIMO) systems using limited feedback are mainly based on the notion of time invariant channels throughout transmission. Consequently, the precoding matrix can be found during the training symbols and used over the subsequent data symbols. In this study, the authors consider a more practical system where the channel varies from one block of symbols to another. In such a scenario, the precoding matrix designed at the receiver based on the previous training symbols becomes outdated, which results in significant system performance degradation. In order to avoid this problem and reduce performance degradation, the authors propose the use of a Kalman filter linear predictor at the receiver to provide the transmitter with the precoding matrix for the next block of symbols. The performance of this method is assessed using computer simulation, and the obtained results for the proposed channel prediction demonstrate improved bit error rate performance for time-varying Rayleigh fading channels.

关键词： precoding matrix Communication switching multiple-input multiple-output systems space division multiplexing Codes precoding channel prediction training symbols matrix algebra time-varying fading channels data symbols channel estimation time-varying channels precoded spatial multiplexing Algebra channel coding bit error rate performance Kalman filters prediction theory MIMO systems Rayleigh fading channels Radio links and equipment Communication channel equalisation and identification Kalman filter linear predictor Rayleigh channels MIMO communication

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MIMO system identification and uncertainty calibration with a limited amount of data using transfer learning

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INTERNATIONAL JOURNAL OF systems SCIENCE 2025年第3期56卷 598-617页

作者： Dehaghani, Mostafa Rahmani Sajadi, Pouyan Tang, Yifan Akhavan, J. Wang, G. Gary Simon Fraser Univ Sch Mechatron Syst Engn Burnaby BC Canada Stevens Inst Technol Dept Mech Engn Hoboken NJ USA

multiple-input multiple-output (MIMO) systems are fundamental in numerous advanced engineering applications, from aerospace to telecommunications, where precise system identification is critical for optimal performance. However, the identification of such systems often faces significant hurdles due to data scarcity, with existing approaches typically requiring substantial amounts of data for effective training. Addressing this challenge, this paper introduces a novel transfer learning framework designed specifically for MIMO system identification under conditions of limited data and inherent uncertainties. The proposed framework is applied to two case studies: the first in metal additive manufacturing, specifically the laser-blown powder-directed energy deposition as the source domain and the laser hot wire-directed energy deposition as the target domain, and the second involving a nonlinear case study of a continuous stirred-tank reactor (CSTR) with a temperature-dependent reaction. The results underscore the framework's effectiveness in capturing the dynamics of the target systems, including the ability to effectively model nonlinear dynamics. Comparative analyses highlight the benefits of employing dimensionless numbers in dynamic system modelling, offering reduced dimensionality, more physical meaning, and increased model accuracy. Overall, the proposed framework presents a promising approach to enhance system identification in MIMO systems with limited data and uncertainties, with potential applications across diverse domains.

关键词： Transfer learning dimensional analysis multiple-input multiple-output systems system identification metal additive manufacturing uncertainty calibration

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Magnetic Field Leakage Cancellation in multiple-input multiple-output Wireless Power Transfer systems

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IEEE MAGNETICS LETTERS 2022年 13卷 1页

作者： Kobuchi, Daisuke Matsuura, Kentaro Narusue, Yoshiaki Morikawa, Hiroyuki Univ Tokyo Grad Sch Engn Dept Elect Engn & Informat Syst Tokyo 1130033 Japan

This letter presents a method to cancel magnetic field leakage while maintaining high power transfer efficiency (PTE) in multiple-input multiple-output wireless power transfer systems. To achieve low leakage and high PTE, the problem of PTE maximization under the cancellation condition of the magnetic field leakage is solved, which is a maximization problem of affinely constrained Rayleigh quotients. Subsequently, the optimal amplitudes and phases of the input voltages at the transmitter array and the optimal load impedances at the receivers are shown. This method can further reduce the magnetic field leakage by up to 31 dB compared with the PTE maximization method, while having a PTE drop within 5.5%.

关键词： Magnetic fields Coils Receivers Transmitters MIMO communication Magnetic field measurement Load modeling Electromagnetics electromagnetic compatibility multiple-input multiple-output systems electromagnetic interference wireless power transfer magnetic field leakage

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Performance analysis of multiple-input multiple-output free-space optical systems with partially coherent Gaussian beams and finite-sized detectors

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OPTICAL ENGINEERING 2016年第11期55卷 111607-111607页

作者： Gokce, Muhsin Caner Baykal, Yahya Uysal, Murat Cankaya Univ Dept Elect & Commun Engn TR-06790 Ankara Turkey Cankaya Univ Dept Elect Elect Engn TR-06790 Ankara Turkey Ozyegin Univ Dept Elect Elect Engn Nisantepe Mevki Orman Sk 13 Alemdag Cekmekoy TR-34794 Istanbul Turkey

multiple-input multiple-output (MIMO) techniques are employed in free-space optical (FSO) links to mitigate the degrading effects of atmospheric turbulence. We consider a MIMO FSO system, which consists of a radial laser array with partially coherent Gaussian beams at the transmitter and a detector array with Gaussian apertures at the receiver. The average power and the power correlation function at the finite-sized receiver apertures are formulated by using the extended Huygens-Fresnel principle in weak atmospheric turbulence. This let us further quantify the performance metrics such as the power scintillation index, the aperture averaging factor, and the average bit error rate (BER) as functions of system parameters. The derived power scintillation equation correctly reduces to the existing coherent and partially coherent Gaussian beam scintillation indices in the limiting cases. Using the performance metrics, we analyze the effect of various practical system parameters on the performance of a MIMO FSO system. Practical system parameters include the transmitter and receiver ring radius, number of beamlets, number of finite-aperture receivers, source size, degree of source coherence, receiver aperture radius, link distance, and the structure constant of atmosphere. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： multiple-input multiple-output systems free-space optical communication optical wave propagation power scintillation aperture averaging bit error rate

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An efficient waveform diversity based on variational mode decomposition of coded beat-frequency shifted signals algorithm for multiple-input multiple-output millimetre-wave imaging

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IET RADAR SONAR AND NAVIGATION 2021年第10期15卷 1266-1280页

作者： Molaei, Amir Masoud Yurduseven, Okan Fusco, Vincent Queens Univ Belfast Inst Elect Commun & Informat Technol ECIT Northern Ireland Sci PkQueens Rd Belfast Antrim North Ireland

Waveforms used in multiple-input multiple-output (MIMO) systems must be considered in such a way that individual transceiver (T-R) pairs can be separated from the composite received signal. An algorithm called variational mode decomposition of coded beat-frequency shifted signals (VMD-CBFSS) is presented for waveform diversity. First, transmitters are divided into several groups. A small shift is applied to the carrier frequency of the transmitters of different groups. Also, signals within each group are encoded by assigning a binary phase in a time block. On the receiver side, by using a multiresolution analysis technique, the combined signal is decomposed into its main frequency components and then the composite signals of each group are decoded to retrieve each T-R pair. VMD-CBFSS provides an efficient solution in terms of overall transmitting time and sampling rate in addition to robustness against channel noise. Moreover, the algorithm is employed in a near-field MIMO millimetre-wave imaging system, and results are presented in the form of numerical simulations.

关键词： VMD-CBFSS variational techniques multiple-input multiple-output systems individual transceiver pairs main frequency components composite signals Signal processing and detection carrier frequency efficient waveform diversity multiple-input multiple-output millimetre-wave imaging millimetre wave communication combined signal composite received signal transmitters Mathematical analysis variational mode decomposition near-field MIMO millimetre-wave imaging system Radio links and equipment signal resolution coded beat-frequency shifted signals algorithm MIMO communication transceivers

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multiple-input multiple-output Gaussian channels:Optimal covariance for non-Gaussian inputs

Multiple-input multiple-output Gaussian channels:Optimal cov...

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IEEE Information Theory Workshop

作者： Rodrigues, Miguel R. D. Perez-Cruz, Fernando Verdu, Sergio Univ Porto Dept Comp Sci Inst Telecomunicacoes Oporto Portugal Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

ISBN: (纸本)9781424422692

We investigate the input covariance that maximizes the mutual information of deterministic multiple-input multiple-output (MIMO) Gaussian channels with arbitrary (not necessarily Gaussian) input distributions, by capitalizing on the relationship between the gradient of the mutual information and the minimum mean-squared error (MMSE) matrix. We show that the optimal input covariance satisfies a simple fixed-point equation involving key system quantities, including the MMSE matrix. We also specialize the form of the optimal input covariance to the asymptotic regimes of low and high snr. We demonstrate that in the low-snr regime the optimal covariance fully correlates the inputs to better combat noise. In contrast, in the high-snr regime the optimal covariance is diagonal with diagonal elements obeying the generalized mercury/waterfilling power allocation policy. Numerical results illustrate that covariance optimization may lead to significant gains with respect to conventional strategies based on channel diagonalization followed by mercury/waterfilling or waterfilling power allocation, particularly in the regimes of medium and high snr.

关键词： optimal input covariance multiple-input multiple-output systems mutual information MMSE Gaussian noise

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MIMO multichannel beamforming: SER and outage using new eigenvalue distributions of complex noncentral Wishart matrices

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IEEE TRANSACTIONS ON COMMUNICATIONS 2008年第3期56卷 424-434页

作者： Jin, Shi Mckay, Matthew R. Gao, Xiqi Collings, Iain B. SE Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Kowloon Hong Kong Peoples R China CSIRO ICT Ctr Wireless Technol Lab Brisbane Qld Australia

This paper analyzes MIMO systems with multi-channel beamforming in Ricean fading. Our results apply to a wide class of multichannel systems which transmit on the eigenmodes of the MIMO channel. We first present new closed-form expressions for the marginal ordered eigenvalue distributions of complex noncentral Wishart matrices. These are used to characterize the statistics of the signal to noise ratio (SNR) on each eigenmode. Based on this, we present exact symbol error rate (SER) expressions. We also derive closed-form expressions for the diversity order, array gain, and outage probability. We show that the global SER performance is dominated by the subchannel corresponding to the minimum channel singular value. We also show that, at low outage levels, the outage probability varies inversely with the Ricean K-factor for cases where transmission is only on the most dominant subchannel (i.e. a singlechannel beamfofming system). Numerical results are presented to validate the theoretical analysis.

关键词： multiple-input multiple-output systems Ricean fading Wishart matrices multichannel beamforming

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Generalised differential scheme for spatial modulation systems

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IET COMMUNICATIONS 2017年第13期11卷 2020-2026页

作者： Kadathlal, Kavish Xu, HongJun Pillay, Narushan Univ KwaZulu Natal Sch Engn Elect Elect & Comp Engn Durban 4041 South Africa

Spatial modulation (SM) is an efficient transmission scheme based on multiple-input multiple-output systems. SM, by nature, requires coherent detection to achieve optimal error performance. This requires that the receiver has full knowledge of the channel state information (CSI), however, determining the CSI results in an increase in the detection complexity at the receiver. Differential modulation systems are capable of performing detection without knowledge of the CSI at the receiver, however, they suffer a 3dB error performance penalty as compared to their coherent counterparts. In this study, the authors present a generalised differential scheme for SM (GD-SM) based on generalised differential modulation, which is capable of reducing the performance penalty incurred through optimal power allocation. Furthermore, they extend the architecture of GD-SM and optimal power allocation to conventional differential SM. The architecture of the proposed systems, advantageously permits the use of either M-ary quadrature amplitude modulation or M-ary phase shift keying constellations. Simulation and theoretical results demonstrate that GD-SM incurs only about 0.5dB performance loss as compared to coherent SM when the frame length is 400.

关键词： MIMO communication signal detection modulation generalised differential scheme spatial modulation systems transmission scheme multiple-input multiple-output systems coherent detection optimal error performance channel state information CSI detection complexity error performance penalty GD-SM generalised differential modulation optimal power allocation M-ary quadrature amplitude modulation M-ary phase shift keying constellation conventional differential SM

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