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Multi-Target Localization of MIMO Radar with Widely Separated Antennas on Moving Platforms Based on Expectation Maximization Algorithm

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REMOTE SENSING 2022年第7期14卷 1670-1670页

作者： Lu, Jiaxin Liu, Feifeng Sun, Jingyi Miao, Yingjie Liu, Quanhua Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Minist Educ Key Lab Elect & Informat Technol Satellite Nav Beijing Inst Technol Beijing 100081 Peoples R China Xiaomi Commun Co Ltd Beijing 100085 Peoples R China

This paper focuses on multi-target parameter estimation of multiple-input multiple-output (MIMO) radar with widely separated antennas on moving platforms. Aiming at the superimposed signals caused by multi-targets, the well-known expectation maximization (EM) is used in this paper. Target's radar cross-section (RCS) spatial variations, different path losses and spatially-non-white noise appear because of the widely separated antennas. These variables are collectively referred to as signal-to-noise ratio (SNR) fluctuations. To estimate the echo delay/Doppler shift and SNR, the Q function of EM algorithm is extended. In addition, to reduce the computational complexity of EM algorithm, the gradient descent is used in M-step of EM algorithm. The modified EM algorithm is called generalized adaptive EM (GAEM) algorithm. Then, a weighted iterative least squares (WILS) algorithm is used to jointly estimate the target positions and velocities based on the results of GAEM algorithm. This paper also derives the Cramer-Rao bound (CRB) in such a non-ideal environment. Finally, extensive numerical simulations are carried out to validate the effectiveness of the proposed algorithm.

关键词： expectation maximization parameter estimation superimposed signals SNR fluctuations multiple-input multiple-output

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

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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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A Dual Circularly Polarized Patch Antenna With High Isolation for MIMO WLAN Applications

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IEEE ACCESS 2020年 8卷 117833-117840页

作者： Zhang, Enze Michel, Andrea Pino, Marcos Rodriguez Nepa, Paolo Qiu, Jinghui Harbin Inst Technol Dept Elect & Informat Engn Harbin 150001 Peoples R China Univ Pisa Dept Informat Engn I-56122 Pisa Italy Univ Oviedo Dept Elect Engn Gijon 33203 Spain

A dual circularly polarized (CP) stacked patch antenna for multiple-input multiple-output (MIMO) WLAN applications (2.4-2.485 GHz) is presented, which exploits a square ring slot feeding technique. The antenna occupies an overall area of 96 mm x 96 mm x 39 mm, when also including the metal reflector. The 7-dBic gain antenna prototype presents an axial ratio lower than 2.5 dB as well as a port isolation higher than 25 dB. An envelope correlation coefficient (ECC) lower than 0.02 is also achieved among the two ports, thanks to the polarization orthogonality. Moreover, the stacked patch has been duplicated and used in a two-antenna system for a 4 x 4 MIMO WLAN which fits an overall volume of 157 mm x 96 mm x 39 mm. Antenna performance in terms of S-Parameters, gain, axial ratio, ECC and channel capacity are compared and discussed, together with the effect of the inter-element distance.

关键词： Circular polarization dual-CP isolation patch antenna WLAN multiple-input multiple-output MIMO diversity square ring slot stacked patch

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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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Outage and ergodic sum-rate performance of cooperative MIMO-NOMA with imperfect CSI and SIC

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2020年第11期33卷 e4405-e4405页

作者： Aldababsa, Mahmoud Kucur, Oguz Gebze Tech Univ Elect Engn Dept TR-41400 Kocaeli Turkey

In this paper, we examine a half-duplex cooperative multiple-input multiple-output non-orthogonal multiple access system with imperfect channel state information (CSI) and successive interference cancelation. The base station (BS) and mobile users with multi-antenna communicate by the assistance of a CSI based or fixed gain amplify-and-forward (AF) relay with a single antenna. The diversity schemes, transmit antenna selection, and maximal ratio combining are applied at the BS and mobile users, respectively. We study the system performance in terms of outage probability (OP) and ergodic sum-rate. Accordingly, the exact OP expressions are first derived jointly for the CSI based and fixed gain AF relay cases in Nakagami-m fading channels. Next, the corresponding lower and upper bound expressions of the OP are obtained. The high signal-to-noise ratio analyses are also carried out to demonstrate the error floor value resulted in the practical case and achievable diversity order and array gain in the ideal case. Moreover, the lower and upper bounds of the ergodic sum-rate expressions are derived together for the CSI based and fixed gain AF relay cases. Finally, the Monte-Carlo simulations are used to verify the correctness of the analytical results.

关键词： channel state information ergodic sum-rate maximal ratio combining multiple-input multiple-output non-orthogonal multiple access outage probability successive interference cancellation transmit antenna selection

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Content Caching and Delivery in MIMO Fog-RANs With Wireless Fronthaul at Small Cache Size

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IEEE WIRELESS COMMUNICATIONS LETTERS 2020年第3期9卷 376-379页

作者： Cao, Youlong Tao, Meixia Xu, Fan Shanghai Jiao Tong Univ Dept Elect Engn Shanghai Inst Adv Commun & Data Sci Shanghai 200240 Peoples R China

This letter investigates the caching and delivery strategies in a multiple-input multiple-output (MIMO) fog radio access network (Fog-RAN). We focus on the small cache size scenario where the accumulated cache memories of all edge nodes (ENs) are not enough to cache the whole database. We propose a new file splitting and placement scheme tailored for the small cache size, which offers the freedom to adjust the duplication order of the cached contents to minimize the normalized delivery time (NDT). In the fronthaul delivery, we use multiple antennas to multiplex multiple messages while in the access delivery, transmitter cooperation induced by the duplicated contents among ENs is utilized to cancel interference. By jointly optimizing caching and delivery, we obtain an achievable minimum NDT. It is shown that the achievable NDT is within an additive gap of 1 to the theoretical optimum.

关键词： Wireless communication MIMO communication Databases Radio access networks Cache memory Antennas Measurement Caching multiple-input multiple-output fog radio access network normalized delivery time

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A Survey on Hybrid, 3D, Interference Mitigation and Secure Data Beamforming Techniques for 5G System

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WIRELESS PERSONAL COMMUNICATIONS 2020年第1期114卷 883-900页

作者： Yadav, Ranjeet Tripathi, Ashutosh Amity Univ Rajasthan Amity Sch Engn & Technol Dept ECE Jaipur Rajasthan India

By 2020 world will testimony new archaic Multi-antenna technologies like beamforming along with massive multiple-input multiple-output in 5G system. The cellular networks with 5th Generation (5G) are introduced with the determined aim of supporting a very heterogeneous service mixture, everyone with its individual detailed requirements. It largely leverages a very huge count of independently controllable antennas at the BS, and thereby attains greater enhancement regarding the energy and spectral efficiency. This paper elucidate about the Hybrid Beamforming techniques, 3D beamforming techniques, Interference mitigation between small and macro cell beamforming proficiency and secure data transmission pre-owned in beamforming technologies dispense a comprehensive analysis of all aspect of Beamforming technologies used in 5G systems.

关键词： multiple-input multiple-output 5G systems Beamforming Long term evolution Wireless communication

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Anti-Eavesdropping Scheme Based on Random Mapping for GSM-MBM Systems

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IEEE ACCESS 2020年 8卷 48416-48427页

作者： Gao, Zhenzhen Bai, Shaozhuang Liao, Xuewen Liu, Meiqin Xi An Jiao Tong Univ Sch Informat & Commun Engn Xian 710049 Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China Xi An Jiao Tong Univ Sch Elect Sci & Engn Xian 710049 Peoples R China

Media-based modulation (MBM) is a recently proposed modulation scheme which has the advantages of increased spectral efficiency and improved performance. In this paper, a physical layer security (PLS) scheme is proposed for the multiple-input multiple-output (MIMO) media-based modulation system using generalized spatial modulation (GSM) to resist the passive eavesdropping from a multiple-antenna eavesdropper. Secure mapping rules between the information bits and the transmit patterns are designed based on the abundant legitimate channel realizations of the MIMO MBM system. Due to the independent fading of the legitimate link and the eavesdropping link, the designed mapping rules are unavailable and appear random to the eavesdropper. Therefore, the correct detection of the information bits at the eavesdropper is prevented, which is validated through bit error rate (BER) analysis and simulations. The ergodic secrecy rate is analyzed and a tight closed-form approximation is derived. Simulation results show that the proposed secure GSM MBM scheme outperforms the existing secure MBM schemes without consuming jamming power or requiring eavesdropper & x2019;s channel state information.

关键词： Modulation Radio frequency MIMO communication Transmitting antennas Eavesdropping Bit error rate Mirrors Physical layer security media-based modulation generalized spatial modulation multiple-input multiple-output

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Impacts of Imperfect Channel State Information, Transceiver Hardware, and Self-Interference Cancellation on the Performance of Full-Duplex MIMO Relay System

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SENSORS 2020年第6期20卷 1671-1671页

作者： Ba Cao Nguyen Nguyen Nhu Thang Xuan Nam Tran Le The Dung Telecommun Univ Nha Trang 650000 Vietnam Le Quy Don Tech Univ Hanoi 100000 Vietnam Ton Duc Thang Univ Inst Computat Sci Div Computat Phys Ho Chi Minh City 700000 Vietnam Ton Duc Thang Univ Fac Elect & Elect Engn Ho Chi Minh City 700000 Vietnam

Imperfect channel state information (I-CSI) and imperfect transceiver hardware often happen in wireless communication systems due to the time-varying and random characteristics of both wireless channels and hardware components. The impacts of I-CSI and hardware impairments (HI) reduce not only the system performance but also the self-interference cancellation (SIC) capability of full-duplex (FD) devices. To investigate the system performance in realistic scenarios, in this paper, we consider the performance of an FD multiple-input multiple-output (MIMO) relay system under the effects of I-CSI, imperfect SIC (I-SIC), and imperfect transceiver hardware. We mathematically derive the exact closed-form expressions of the outage probability (OP) and ergodic capacity of the considered HI-FD-MIMO relay system over Rayleigh fading channels with the existence of I-CSI, I-SIC, and HI. Numerical results indicate that the performance in terms of OP and capacity reaches saturation faster, especially when the channel estimation error, the residual self-interference (RSI), and HI levels are remarkable. Therefore, various solutions for effectively reducing the channel estimation error, RSI, and HI levels in the HI-FD-MIMO relay system should be carried out to improve the system performance. All derived mathematical expressions are verified through Monte-Carlo simulations.

关键词： hardware impairments full-duplex multiple-input multiple-output channel state information outage probability ergodic capacity

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NOMA With Zero-Forcing V-BLAST

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IEEE COMMUNICATIONS LETTERS 2020年第9期24卷 2070-2074页

作者： Ozyurt, Serdar Simon, Eric Pierre Farah, Joumana Ankara Yildirim Beyazit Univ Dept Elect & Elect Engn TR-06010 Ankara Turkey Univ Lille F-59650 Villeneuve Dascq France IEMN Lab F-59650 Villeneuve Dascq France Lebanese Univ Fac Engn Dept Elect & Elect Beirut 1000 Lebanon

In this study, power-domain non-orthogonal multiple access (NOMA) is combined with zero-forcing (ZF) vertical Bell Labs layered space-time (V-BLAST) technique. Motivated by the fact that the successive interference cancellation (SIC) is a pivotal element in either technique, we thoroughly investigate the impact of SIC on inter-user and inter-layer interference. A two-user downlink scenario is investigated where a multi-antenna base station with no instantaneous channel state information simultaneously communicates with two users each with multiple antennas. The average sum rate of the considered system is analytically derived in an exact form. Correspondingly, the power allocation value on each substream is optimized such that the average sum rate is maximized. We show that when the classical power-domain NOMA idea is incorporated into the ZF V-BLAST algorithm, the far user cannot completely cancel inter-layer interference. Nonetheless, the proposed approach turns out to yield an average sum rate performance near to that of a higher-complexity method based on maximum likelihood detection.

关键词： NOMA Silicon carbide Interference Resource management Antennas Downlink Channel state information multiple-input multiple-output non-orthogonal multiple access zero-forcing V-BLAST average sum rate

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