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MIMO-OFDM/OCDM low-complexity equalization under a doubly dispersive channel in wireless sensor networks

INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2020年第6期16卷

作者： Solyman, Ahmad A. A. Attar, Hani Khosravi, Mohammad R. Koyuncu, Baki Istanbul Gelisim Univ Dept Elect & Elect Engn Istanbul Turkey Zarqa Univ Dept Energy Engn POB 132222 Zarqa 13132 Jordan Shiraz Univ Technol Dept Elect & Elect Engn Shiraz Iran

In this article, three novel systems for wireless sensor networks based on Alamouti decoding were investigated and then compared, which are Alamouti space-time block coding multiple-input single-output/multiple-input multiple-output multicarrier modulation (MCM) system, extended orthogonal space-time block coding multiple-input single-output MCM system, and multiple-input multiple-output system. Moreover, the proposed work is applied over multiple-input multiple-output systems rather than the conventional single-antenna orthogonal chirp division multiplexing systems, based on the discrete fractional cosine transform orthogonal chirp division multiplexing system to mitigate the effect of frequency-selective and time-varying channels, using low-complexity equalizers, specifically by ignoring the intercarrier interference coming from faraway subcarriers and using the LSMR iteration algorithm to decrease the equalization complexity, mainly with long orthogonal chirp division multiplexing symbols, such as the TV symbols. The block diagrams for the proposed systems are provided to simplify the theoretical analysis by making it easier to follow. Simulation results confirm that the proposed multiple-input multiple-output and multiple-input single-output orthogonal chirp division multiplexing systems outperform the conventional multiple-input multiple-output and multiple-input single-output orthogonal frequency division multiplexing systems. Finally, the results show that orthogonal chirp division multiplexing exhibited a better channel energy behavior than classical orthogonal frequency division multiplexing, thus improving the system performance and allowing the system to decrease the equalization complexity.

关键词： Orthogonal chirp division multiplexing multiple-input multiple-output orthogonal frequency division multiplexing wireless sensor networks doubly dispersive channel intercarrier interference

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Transmit Designs for the MIMO Broadcast Channel With Statistical CSI

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第17期62卷 4451-4466页

作者： Wu, Yongpeng Jin, Shi Gao, Xiqi McKay, Matthew R. Xiao, Chengshan Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Jiangsu Peoples R China Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Kowloon Hong Kong Peoples R China Missouri Univ Sci & Technol Dept Elect & Comp Engn Rolla MO 65409 USA

We investigate the multiple-input multiple-output broadcast channel with statistical channel state information available at the transmitter. The so-called linear assignment operation is employed, and necessary conditions are derived for the optimal transmit design under general fading conditions. Based on this, we introduce an iterative algorithm to maximize the linear assignment weighted sum-rate by applying a gradient descent method. To reduce complexity, we derive an upper bound of the linear assignment achievable rate of each receiver, from which a simplified closed-form expression for a near-optimal linear assignment matrix is derived. This reveals an interesting construction analogous to that of dirty-paper coding. In light of this, a low-complexity transmission scheme is provided. Numerical examples illustrate the significant performance of the proposed low complexity scheme.

关键词： Broadcast channel multiple-input multiple-output statistical CSI

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Information-Theoretic Security of MIMO Networks Under κ-μ Shadowed Fading Channels

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2021年第7期70卷 6302-6318页

作者： Vega Sanchez, Jose David Moya Osorio, Diana Pamela Lopez-Martinez, F. Javier Paredes Paredes, Martha Cecilia Felipe Urquiza-Aguiar, Luis Escuela Politecn Nacl EPN Dept Elect Telecomunicac & Redes Informac Quito 170525 Ecuador Univ Oulu Ctr Wireless Communicat CWC Oulu 90014 Finland Univ Malaga Dept Ingn Comunicac Campus Excelencia Int Andalucia Technol Malaga 29071 Spain

This paper investigates the impact of realistic propagation conditions on the achievable secrecy performance of multiple-input multiple-output systems in the presence of an eavesdropper (Eve). Specifically, we concentrate on the kappa-mu shadowed fading model because its physical underpinnings capture a wide range of propagation conditions, while, at the same time, it allows for a much better tractability than other state-of-the-art fading models. By considering transmit antenna selection and maximal ratio combining reception at the legitimate (Bob) and Eve's receiver sides, we study two relevant scenarios: 1) the transmitter knows Bob's channel state information (CSI) but not Eve's CSI, and 2) the transmitter is aware of the CSI of both Bob and Eve channels. For this purpose, we first obtain novel and tractable expressions for the statistics of the maximum of independent and identically distributed (i.i.d.) variates related to the legitimate channel. Based on these results, we derive novel closed-form expressions of the two aforementioned scenarios to assess the secrecy performance of the underlying system. Specifically, for cases: 1) the secrecy outage probability (SOP), the probability of strictly positive secrecy capacity (SPSC), and 2) the average secrecy capacity (ASC). Moreover, we develop analytical asymptotic expressions of the SOP and ASC in the high signal-to-noise ratio regime. In all instances, secrecy performance metrics are characterized in closed-form, without requiring the evaluation of Meijer-G or Fox-H functions. Some useful insights on how the different propagation conditions and the number of antennas impact the secrecy performance are also provided.

关键词： kappa-mu shadowed generalized fading channels maximal ratio combining multiple-input multiple-output physical layer security transmit antenna selection

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Low-Complexity Sorted QR Decomposition for MIMO Systems Based on Pairwise Column Symmetrization

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2014年第3期13卷 1388-1396页

作者： Kim, Tae-Hwan Korea Aerosp Univ Sch Elect Telecommun & Comp Engn Goyang Si 412791 Gyung Gi Do South Korea

QR decomposition (QRD) is a preprocessing technique for detecting symbols in multiple-input and multiple-output (MIMO) systems, but the computational complexity is prohibitively high when the systems incorporate a large number of antennas. This paper presents a low-complexity sorted QRD (SQRD) algorithm for MIMO systems. The proposed algorithm performs SQRD through orthogonalizations based on the modified Gram-Schmidt process, rearranging the column vectors of a real-valued MIMO channel matrix in such a way that the symmetry between the vectors is maintained. By using the symmetry, the computations required for orthogonalizing one of the two adjacent vectors can be eliminated effectively, which significantly reduces the computational complexity. Theoretical analyses show that the proposed algorithm reduces the computational complexity required for SQRD by 50% for any MIMO configurations, when compared to the conventional algorithm. In addition, the memory requirement to store resultant matrices is 50% of that in the conventional one.

关键词： multiple-input multiple-output QR decomposition sphere decoding symbol detection preprocessing Gram-Schmidt process

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Performance analysis of zero-forcing precoding with signal space diversity under antenna correlation

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PHYSICAL COMMUNICATION 2018年 30卷 115-121页

作者： Ozyurt, Serdar Ankara Yildirim Beyazit Univ Fac Engn & Nat Sci Ankara Turkey

We consider a multiantenna transmission system where the transmitter and receiver respectively have M and two antennas. Specifically, zero-forcing precoding is employed at the transmitter based on a possibly imperfect channel state information (CSI). The channel estimation is carried out at the transmitter using pilot signals sent from the receiver. Adopting a dual-stream transmission structure, the error performance of the system is enhanced by resorting to signal space diversity (SSD). The performance of the proposed system with binary phase shift keying modulation is studied under a slow flat Rayleigh fading scenario with uncorrelated transmit antennas and correlated receive antennas. We separately examine two cases: the perfect CSI and imperfect CSI at the transmitter. In the former scenario, we provide an exact closed-form expression on the bit error probability (BEP) of the proposed approach. A tight approximation on the BEP of the proposed scheme is presented for the latter scenario. The case with distinct channel estimation qualities for the two subchannels is also considered in the second scenario. The proper rotation angles for the BPSK signal constellation are analytically obtained such that the derived expressions on the BEP are minimized under both cases. We show that the inclusion of SSD into the original scheme yields a noteworthy improvement on the BEP performance with only an insignificant increase in complexity and no additional use of bandwidth/time slots. It is also shown that the proposed technique is more immune against the channel estimation errors as compared to the original method. (C) 2018 Elsevier B.V. All rights reserved.

关键词： multiple-input multiple-output Zero-forcing precoding Signal space diversity Rayleigh fading Channel state information Antenna correlation Channel estimation errors

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Capacity of MIMO systems based on measured wireless channels

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2002年第3期20卷 561-569页

作者： Molisch, AF Steinbauer, M Toeltsch, M Bonek, E Thomä, RS AT&T Labs Res Wirless Commun Res Middletown NJ 07748 USA Vienna Univ Technol Inst Nachrichtentech & Hochfrequenztech A-1040 Vienna Austria FTW Res Ctr Telecommun A-1040 Vienna Austria Tech Univ Ilmenau D-98683 Ilmenau Germany

We measure the capacity of multiple-input multiple-output radio systems in microcellular environments. We use a new data evaluation method that allows to evaluate the cumulative distribution function of the capacity from a single measurement. This method is based on an extraction of the parameters of the multipath components and, thereafter, a synthetic variation of their phases. In the analyzed environments, we find capacities to be about 30% smaller than would be anticipated from an idealized model. In addition, the frequency selectivity of the channel makes the cdf of the capacity steeper and, thus, increases the outage capacity, compared with the frequency-flat case, but the influence on the mean capacity is small.

关键词： multipath channels multiple-input multiple-output radio propagation

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A minimum-of-maximum relative error support vector machine for simultaneous reverse prediction of concrete components

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COMPUTERS & STRUCTURES 2016年第Aug.期172卷 59-70页

作者： Gou Jin Fan Zong-Wen Wang Cheng Guo Wang-Ping Lai Xiong-Ming Chen Mei-Zhen Huaqiao Univ Coll Comp Sci & Technol Xiamen 361021 Peoples R China HuaQiao Univ Coll Mech & Automat Xiamen 361021 Peoples R China

The simultaneous reverse prediction of multiple concrete components is very difficult, but very important in practical engineering applications. Thus, this paper presents a variant support vector machine (SVM) that uses particle swarm optimization (PSO) to minimize the maximum relative error (RE) in a multiple-input multiple-output (MIMO) scenario. This PSO-RE-MIMO SVM uses a novel learning strategy whereby the maximum relative error is used as a constraint in the optimization problem. Experimental results demonstrate that the PSO-RE-MIMO-SVM performs well for reverse prediction of multiple concrete components compared with the least-squares SVM, back propagation neural network, and radial basis function neural network approaches. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Reverse prediction of multiple concrete components multiple-input multiple-output Minimum of maximum relative error Support vector machine (SVM) Particle swarm optimization (PSO)

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Capacity and SER Analysis of MIMO MRC Systems in an Interference-Limited Environment

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WIRELESS PERSONAL COMMUNICATIONS 2009年第2期50卷 133-142页

作者： Rui, Xianyi Soochow Univ Sch Elect & Informat Engn Suzhou 215021 Peoples R China

The effect of co-channel interference (CCI) is considered in multiple-input multiple-output (MIMO) systems employing maximal ratio combining (MRC) under independent and identically distributed Rayleigh fading. Closed-form capacity and symbol error rate expressions are presented to evaluate the performance without any numerical integrations or statistical simulations. The analytical results are compared with Monte Carlo simulations and the good agreement is obtained.

关键词： multiple-input multiple-output Maximal ratio combining Co-channel interference Channel capacity Symbol error rate

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Deep Learning Based Nonlinear Signal Detection in Millimeter-Wave Communications

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IEEE ACCESS 2020年 8卷 158883-158892页

作者： Liu, Hongfu Yang, Xu Chen, Peijun Sun, Mengwei Li, Bin Zhao, Chenglin Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing 100876 Peoples R China State Radio Monitoring Ctr Beijing 100037 Peoples R China Univ Edinburgh Sch Engn Edinburgh EH9 3FG Midlothian Scotland

For millimeter-wave (mm-Wave) communications, signal detection in the presence of the power amplifier (PA) nonlinearity and unknown multipath channel has remained one challenging task in single-input single-output (SISO) communication system. Besides, the PA nonlinearity in multiple-input multiple-output (MIMO) communication system also has severe effects upon the signal detection in *** this paper, firstly, we suggest a deep-learning (DL) framework, i.e. integrating feedforward neural network (FNN) and recurrent neural network (RNN), to combat both the nonlinear distortion and linear inter-symbol-interference (ISI) from a global point of view, thereby accomplishing nonlinear equalization and signal detection at the receiver-end in SISO communication *** the powerful mapping and learning capability of DL, our new method is able to detect symbols via the received signals corrupted by both nonlinear distortion and linear ISI, avoiding both the explicit nonlinear pre-distorter in transmitter and the channel state information (CSI) ***, our DL-based framework can also successfully cope with the joint nonlinear distortion and space-time decoding problem in MIMO communication system, without explicitly pre-calibrating nonlinear distortion and estimating *** experiments demonstrate our DL-based detector is more effective in alleviating the performance degradation both from the coupled nonlinear distortion and linear ISI in SISO communication system, and the coupled nonlinear distortion and linear space-time decoding in MIMO communication *** with the state-of-the-art methods, e.g. pre-distorter and post-equalizer, our DL-based scheme effectively improves the detection performance.

关键词： Nonlinear distortion MIMO communication Signal detection Detectors SISO communication Transmitters Decoding mm-Wave communications PA nonlinearity multipath propagation multiple-input multiple-output signal detection deep learning

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OFDM-based time-domain optical MIMO with general-numbered LED configurations

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OPTICAL AND QUANTUM ELECTRONICS 2023年第12期55卷 1-17页

作者： Al-Moliki, Yahya M. Alresheedi, Mohammed T. Abas, Ahmad Fauzi Mahdi, Mohd A. Khoon, Ng Eng King Saud Univ Dept Elect Engn Riyadh 11421 Saudi Arabia Univ Putra Malaysia Fac Engn Wireless & Photon Networks Res Ctr Serdang 43400 Selangor Malaysia Univ Cambridge Dept Engn Cambridge CB3 0FA England

For optical wireless communication systems with restricted bandwidth, combining multiple-input multiple-output (MIMO) transmission with orthogonal frequency division multiplexing (OFDM) modulation was found to be a highly effective method of boosting system capacity. This paper presents and analyzes two optical OFDM-based MIMO schemes for visible light communications, namely OFDM-based time domain general spatial modulation (TD-GSM) and OFDM-based time domain general spatial multiplexing (TD-GSMP), which utilize general-numbered MIMO configurations of light-emitting diodes (LEDs). These schemes exhibit reduced complexity and provide enhanced spectral efficiency (SE) in comparison to conventional frequency-domain (FD) GSM and GSMP schemes, achieved by transmitting twice the spatial information. Previous research in this area typically employed an even number of LEDs for spatial-based MIMO transmission, represented as 2(la), where l(a) is the number of spatial bits. However, to enhance SE, this paper introduces schemes that can accommodate a general number of LEDs without the constraint of an even-numbered LED configuration. In indoor environments, several LEDs are already used for illumination purposes, so incorporating additional LEDs for communication does not introduce complexity to the system. To detect both spatial and radiated information, a maximum-likelihood estimation algorithm is proposed. Simulation results demonstrate that, depending on the user's position, selecting the optimal MIMO configuration is crucial for achieving desired bit error rate (BER) performance and SE requirements. Moreover, as the total number of LEDs increases relative to the active number of LEDs, the modulation order required to transmit signals decreases in order to support a specified SE, resulting in improved BER performance. When all LEDs are active during communication, TD-GSMP outperforms TD-GSM in terms of BER performance. The results also show the superiority of TD schemes ov

关键词： Orthogonal frequency division multiplexing multiple-input multiple-output Visible light communications

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