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Temporal Correlation Enhanced Sparse Activity Detection in MIMO Enabled Grant-Free NOMA

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2022年第3期71卷 2887-2899页

作者： Wu, Liantao Wang, Zhibo Sun, Peng Yang, Yang ShanghaiTech Univ Sch Informat Sci & Technol Shanghai 201210 Peoples R China Zhejiang Univ Coll Comp Sci & Technol Hangzhou 310027 Peoples R China Chinese Univ Hong Kong Sch Sci & Engn Shenzhen 518172 Peoples R China Shenzhen Inst Artificial Intelligence & Robot Soc Shenzhen 518172 Peoples R China ShanghaiTech Univ Shanghai Inst Fog Comp Technol SHIFT Shanghai 201210 Peoples R China Peng Cheng Lab Res Ctr Network Commun Shenzhen 518000 Peoples R China Shenzhen SmartCity Technol Dev Grp Co Ltd Shenzhen 518046 Peoples R China

Exploiting the sparse user activity induced by sporadic transmission, compressed sensing (CS) has been widely applied in multiple-input multiple-output (MIMO) enabled non-orthogonal multiple access (NOMA) for efficient multiuser detection. However, most of the existing detection schemes in MIMO enabled NOMA systems focus mainly on the spatial structure in user activity induced by multiantenna reception, while the temporal correlation in user activity has rarely been incorporated for further performance improvement. To address this issue, we propose a novel Multiuser Detection framework in MIMO enabled NOMA (MDMN), which explicitly integrates the temporal correlation in user activity into the detection process to improve the user detection accuracy. Specifically, we first formulate multiuser detection with multiantenna reception in MDMN as a block CS problem, by exploiting the spatial correlation in user activity. Furthermore, through incorporating the temporal correlation in active user sets into block CS, an adaptive CS algorithm based on subspace pursuit is developed for MDMN, named spatial-temporal correlation enhanced adaptive subspace pursuit (STASP). In particular, STASP does not require any prior knowledge of the user sparsity, as the cross validation designed in STASP can properly terminate the algorithm. The superior performance of the proposed MDMN framework and the corresponding algorithms is corroborated by extensive simulation results.

关键词： Correlation Transmitting antennas Slot antennas Receiving antennas NOMA Multiuser detection MIMO communication multiple-input multiple-output grant-free non-orthogonal multiple access multiuser detection spatial-temporal correlation adaptive compressed sensing

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Spatial and Wavelength Division Joint multiplexing System Design for MIMO-OFDM Visible Light Communications

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IEEE ACCESS 2024年 12卷 109526-109543页

作者： Chen, Cheng Huang, Shenjie Tavakkolnia, Iman Safari, Majid Haas, Harald Univ Cambridge Dept Engn Elect Engn Div Cambridge CB3 0FA England Univ Edinburgh Inst Imaging Data & Commun IDCOM Sch Engn Edinburgh EH9 3FD Scotland

The low-pass characteristics of front-end elements including light-emitting diodes (LEDs) and photodiodes (PDs) limit the transmission data rate of visible light communication (VLC) and Light Fidelity (LiFi) systems. Using multiplexing transmission techniques, such as spatial multiplexing (SMX) and wavelength division multiplexing (WDM), is a solution to overcome bandwidth limitation. However, spatial correlation in optical wireless channels and optical filter bandpass shifts typically limit the achievable multiplexing gain in SMX and WDM systems, respectively. In this paper, we consider a multiple-input multiple output (MIMO) joint multiplexing VLC system that exploits available degrees-of-freedom (DoFs) across space, wavelength and frequency dimensions simultaneously. Instead of providing a new precoder/post-detector design, we investigate the considered joint multiplexing system from a system configuration perspective by tuning system parameters in both spatial and wavelength domains, such as LED positions and optical filter passband. We propose a novel spatial clustering with wavelength division (SCWD) strategy which enhances the MIMO channel condition. We propose to use a state-of-the-art black-box optimization tool: Bayesian adaptive direct search (BADS) to determine the desired system parameters, which can significantly improve the achievable rate. The extensive numerical results demonstrate the superiority of the proposed method over conventional SMX and WDM VLC systems.

关键词： Visible light communication optical wireless communication multiple-input multiple-output orthogonal frequency division multiplexing spatial multiplexing wavelength division multiplexing optical wireless communication multiple-input multiple-output orthogonal frequency division multiplexing spatial multiplexing wavelength division multiplexing

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Near optimal performance joint semi-blind channel estimation and data detection techniques for Alamouti coded single-carrier (SC) MIMO communication systems

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PHYSICAL COMMUNICATION 2013年 8卷 31-37页

作者： Bhalani, J. K. Chauhan, D. Kosta, Y. P. Trivedi, A. I. Charotar Univ Sci & Technol Dept Elect & Commun Engn Changa 388421 Gujarat India Marwari Grp Inst Rajkot Gujarat India MS Univ Fac Technol Dept Elect Engn Baroda Gujarat India

In this paper, two novel joint semi-blind channel estimation and data detection techniques are proposed and investigated for Alamouti coded single-carrier (SC) multiple-input multiple-output (MIMO) communication system using Rayleigh flat fading channel model. In the first novel semi-blind technique, blind channel estimation can be performed by using singular value decomposition (SVD) of received output autocorrelation matrix and training based channel estimation for orthogonal training symbols can be performed by using orthogonal pilot maximum likelihood (OPML) algorithm. Further using, that semi-blind channel estimate and received output, data detection is performed by using Maximum likelihood (ML) detection. Finally we derived new training symbols from error covariance matrix of estimated data and known orthogonal training symbols, which further applied to OPML algorithm for final channel estimate. In the second novel semi-blind technique, blind channel estimation can be performed by using matrix triangularization based on householder QR decomposition (H-QRD) of received output autocorrelation matrix instead of SVD decomposition. Other steps are same as the first novel technique to calculate data detection and final channel estimation. Simulation results are presented under 2-PSK, 4-PSK, 8-PSK and 16-QAM data modulation schemes using 2 transmitters and different combinations of receiver antennas to investigate the performances of novel techniques compare to conventional whitening rotation (WR) and rotation optimization maximum likelihood (ROML) based semi-blind channel estimation techniques. Result demonstrates that novel techniques outperform others by achieving near optimal performance. (C) 2013 Elsevier B.V. All rights reserved.

关键词： multiple-input multiple-output Orthogonal pilot maximum likelihood Rotation optimization maximum likelihood Householder QR decomposition Singular value decomposition Channel estimation

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Analyzing the Impact of Inter Cooperation Region Interference in Coordinated Multi-Point Uplink Networks

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第3期63卷 1006-1018页

作者： Banani, S. Alireza Adve, Raviraj S. Univ Toronto Dept Elect & Comp Engn Toronto ON M5S 3G4 Canada

We analyze the uplink of coordinated multi-point (CoMP) networks in which cooperation can be amongst N = 2 or N = 3 base stations (BSs). We consider a 2-D network of BSs on a regular hexagonal lattice wherein the cooperation tessellates the 2-D plane into cooperation regions (CRs);specifically, we analyze the impact of the interference between the CRs in the network. Our model accounts realistic propagation conditions, particularly including shadowing. We obtain accurate, closed-form, approximations for the user capacity coverage probability (CCP) and the ergodic capacity at each point within the CR. To provide a network-level analysis, we focus on the locations within each CR with the minimum CCP-"the worst-case point(s)". The worst-case CCP and/or ergodic capacity can be used in parametric studies for network design. Here, the analysis is applied to obtain the relationship between cell size and CCP and, thereby, the required density of BSs to achieve a chosen target capacity coverage. The analysis also allows for a comparison between different orders of BS cooperation, quantifying the reduced required BS density from higher orders of cooperation. Comprehensive simulations are used to illustrate the accuracy of our analysis, including the approximations used for analytic tractability.

关键词： Coordinated multi-point capacity constraints coverage multiuser multiple-input multiple-output lognormal shadowing

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Outage probability analysis and adaptive combiner for multiuser multipolarized antenna systems

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TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES 2019年第1期27卷 67-+页

作者： Mohammed, Abdul Hai Muzammil Moinuddin, Muhammad Al-Saggaf, Ubaid Mohsin Hassan, Ahmad Kamal King Abdulaziz Univ Ctr Excellence Intelligent Engn Syst Jeddah Saudi Arabia King Abdulaziz Univ Dept Elect & Comp Engn Jeddah Saudi Arabia Ghulam Ishaq Khan Inst Engn Sci & Technol Fac Elect Engn Topi Pakistan

In this paper, we characterize the performance metrics of a multiuser multipolarized antenna system in a Rayleigh fading channel. We start by formulating a downlink system model that features a multiuser scenario in the presence of additive noise and a multipolarized antenna system;this is followed by evaluation of the outage probability in closed form. This is done by deriving the cumulative distribution function (CDF) of the signal-to-interference-plusnoise ratio using the approach of the ratio of indefinite quadratic forms. We thereby characterize the gradient of this CDF with respect to the combining vectors. Eventually, we obtain the optimum combining vectors by minimizing the outage probability via interior-point optimization technique. Simulation and theoretical results of our analysis are closely matched, which validates our analysis. Our findings suggest that the performance of the triple polarized antenna is better than that of the dual polarized antenna system for low signal-to-noise ratio (SNR) values in terms of outage probability;this situation, however, reverses for high SNR value.

关键词： multiple-input multiple-output wireless communications outage probability cross-polarization discrimination signal-to-interference-plus-noise ratio

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An MTL-Based Channel Model for Indoor Broadband MIMO Power Line Communications

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2016年第7期34卷 2045-2055页

作者： Corchado, Julio A. Cortes, Jose A. Canete, Francisco J. Diez, Luis Univ Malaga Dept Ingn Comunicac Escuela Tecn Super Ingn Telecomunicac E-29071 Malaga Spain

The recent release of indoor power line communication (PLC) standards with multiple-input multiple-output (MIMO) capabilities has led to the need for channel models that reflect the multiconductor nature of the grid. This paper proposes a model, based on the multiconductor transmission line theory, along with a random PLC channel generator operating in the frequency range from 1 to 100 MHz. Its distinctive features are the modeling of three key elements: the asymmetry in the layout caused by the derivations to the light switches, the impedance of the devices connected to the three wires of the grid, and the variable distance between the conductors in loose wiring deployments. The influence of these elements in the spatial correlation between the streams of the MIMO links is studied and compared with measurements.

关键词： Power line communications multiple-input multiple-output broadband spatial correlation multiconductor transmission line channel modeling

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Adaptive detection with conic rejection to suppress deceptive jamming for frequency diverse MIMO radar

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DIGITAL SIGNAL PROCESSING 2017年 69卷 32-40页

作者： Li, Shengyuan Zhang, Linrang Liu, Nan Zhang, Juan Zhao, Shanshan Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Shaanxi Peoples R China

With traditional radar systems, it is not easy to classify and suppress the intended false targets, especially in case of the mainlobe deceptive jamming. In this paper, the deceptive jamming suppression issue is formulated as a problem of detecting the presence of target signal while rejecting potential deceptive jamming under the multiple-input multiple-output (MIMO) radar with frequency diverse array (FDA) as the transmit array. The problem at hand is settled by resorting to the generalized likelihood ratio test (GLRT);at the design stage we define the sets where the false target and true target lie in. Since FDA-MIMO radar provides controllable degrees of freedom in both range and angle domains, the sets are range-angle related. This implies that both range and angle properties can be used to suppress the false targets. Based on the detector, a two-pulse scheme is proposed to guarantee high rejection probability of deceptive jamming. At the analysis stage, the performance of the detector is assessed in comparison with the conventional MIMO scenario and other detectors. The performance assessment shows that the proposed solutions are effective in the presence of electronic countermeasure (ECM) systems, especially when facing mainlobe deceptive jamming. (C) 2017 Elsevier Inc. All rights reserved.

关键词： Frequency diverse array multiple-input multiple-output Deceptive jamming Generalized likelihood ratio test

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Low-complexity MAP channel estimation for mobile MIMO-OFDM systems

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2008年第3期7卷 774-780页

作者： Gao, Jie Liu, Huaping Oregon State Univ Sch Elect Engn & Comp Sci Corvallis OR 97331 USA

This paper presents a reduced-complexity maximum a posteriori probability (MAP) channel estimator with iterative data detection for orthogonal frequency division multiplexing (OFDM) systems over mobile multiple-input multiple-output channels. The optimal MAP estimator needs to invert an N N-T x N N-T data-dependent matrix each in OFDM symbol interval, where N is the number of subcarriers and N-T is the number of transmit antennas. We derive an expectation maximization (EM) algorithm with low-rank approximation to avoid inverting large-size matrices, and thus drastically reduce the receiver complexity. In the iterative process, channel parameters are initially obtained by a least square (LS) estimator for temporary symbol decisions. Then, inter-carrier interference (ICI) due to fast fading is approximated and canceled. Finally, the temporary symbol decisions and the ICI-canceled received signals are processed by the EM-based MAP estimator to refine the channel state information for improved detection. The proposed scheme achieves about 2 dB gain over the LS scheme in channels with medium to high normalized Doppler shifts.

关键词： multiple-input multiple-output orthogonal frequency division multiplexing fast fading inter-carrier interference maximum a posteriori probability estimation low-rank approximation

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Robust Blind Separation for MIMO Systems against Channel Mismatch Using Second-Order Cone Programming

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China Communications 2017年第6期14卷 168-178页

作者： Zhongqiang Luo Chengjie Li Lidong Zhu School of Automation & Information Engineering Sichuan University of Science and Engineering National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China

To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple-output(MIMO) *** channel mismatch problem can be described as a channel with bounded fluctuant errors due to channel distortion or channel estimation *** problem of blind signal separation/extraction with channel mismatch is formulated as a cost function of blind source separation(BSS) subject to the second-order cone constraint,which can be called as second-order cone programing optimization *** the resulting cost function is solved by approximate negentropy maximization using quasi-Newton iterative methods for blind separation/extraction source *** analysis demonstrates that the proposed algorithm has low computational complexity and improved performance *** results verify that the capacity gain and bit error rate(BER) performance of the proposed blind separation method is superior to those of the existing methods in MIMO systems with channel mismatch problem.

关键词： multiple-input multiple-output channel mismatch second-order cone programming blind source separation independent component analysis

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Dual feed MIMO cylindrical dielectric resonator antenna with high isolation

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2017年第7期59卷 1686-1692页

作者： Das, Gourab Sharma, Anand Gangwar, Ravi Kumar IFF ISM Dhanbad Dept Elect Engn Jharkhand 826004 India

A cylindrical dielectric resonator antenna (CDRA) for multiple-input multiple-output (MIMO) applications is examined in this article. Proposed MIMO radiator achieves high isolation by generating orthogonal modes in CDRA with the help of dual feeding techniques, that is, aperture coupling (port-1) and coplanar waveguide (port-2) techniques. The fractional bandwidth for both port-1 and port-2 is 11.5% (4.9-5.5 GHz). The isolation in operating band between port-1 and port-2 exceed more than 32dB. For validating the optimized simulated results, the archetype of proposed MIMO antenna is fabricated and tested. The diversity performance of proposed structure is also examined and experimentally verified. The proposed radiator is found appropriate for 5.2 GHz WLAN application.

关键词： multiple-input multiple-output dielectric resonator antenna envelope correlation coefficient diversity gain channel capacity loss

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