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Time Domain Channel Estimation for Time and Frequency Selective Millimeter Wave MIMO Hybrid Architectures: Sparse Bayesian Learning-Based Kalman Filter

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WIRELESS PERSONAL COMMUNICATIONS 2021年第3期117卷 2453-2473页

作者： Shoukath Ali, K. Sampath, P. Bannari Amman Inst Technol Dept ECE Sathyamangalam Tamil Nadu India

In this paper, a Sparse Bayesian Learning (SBL) based channel estimation technique for frequency selective millimeter wave (mmWave) channel in the time domain approach is developed. Further, SBL based Kalman filter (SBL-KF) for time and frequency selective mmWave multiple-input multiple-output (MIMO) hybrid architecture is presented. Hybrid precoders and combiners are designed to estimate the channel of mmWave MIMO systems. The hybrid precoding technique provides low power consumption and high achievable rate performance at mmWave frequencies. mmWave channels are sparse in nature, and the sparse recovery problem is estimated using the channel estimation technique. A simulation result of SBL-KF is improved by 4 dB and 10 dB of SNR compared to the conventional SBL and Orthogonal Matching Pursuit based scheme, respectively. The proposed SBL-KF scheme provides low estimation error at smaller training overheads M = 50 compared to the other existing work.

关键词： Orthogonal Matching Pursuit Millimeter wave Sparse Bayesian Learning multiple-input multiple-output

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Active vibration control development in ultra-precision machining

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JOURNAL OF VIBRATION AND CONTROL 2021年第7-8期27卷 790-801页

作者： Aggogeri, Francesco Merlo, Angelo Pellegrini, Nicola Univ Brescia Dept Mech & Ind Engn Via Branze 38 I-25123 Brescia Italy Ce SI Ctr Studi Ind Via Tintoretto Cologno Monzese Italy

This study presents a combined feedback-feedforward adaptive regulator applied to an active vibration control tool holder platform to contain the effect of machining vibrations. The proposed mechatronic solution can be integrated in a milling machine tool as an interface between the beam (Z-axis) and the tool holder. The aim is to counteract vibrations in the broadband frequency range (100 Hz-900 Hz), controlling the tool position in real time. The active vibration control system is based on the harmonic steady-state concept due to the sinusoidal representation of the disturbance signals. The study focuses on the regulator architecture and the main logics applied to satisfy the required performance. A full investigation is executed through simulations and experimental campaigns, proving the disturbance reduction. The active vibration control system is implemented on a 4-axis machine tool and validated using multitonal disturbances. The system is evaluated in compensating a set of undesired effects, such as vibrations generated by unbalanced tools or hard material cutting processes. The obtained results show a maximum reduction of the vibration amplitude by 43.7% at the critical frequency.

关键词： Vibration adaptive control harmonic steady state multiple-input multiple-output

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OFDM-Based Generalized Optical MIMO

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2021年第19期39卷 6063-6075页

作者： Chen, Chen Zhong, Xin Fu, Shu Jian, Xin Liu, Min Yang, Helin Alphones, Arokiaswami Fu, H. Y. Chongqing Univ Sch Microelect & Commun Engn Chongqing 400044 Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Tsinghua Univ Tsinghua Berkeley Shenzhen Inst TBSI Shenzhen 518055 Peoples R China

The combination of multiple-input multiple-output (MIMO) transmission and orthogonal frequency division multiplexing (OFDM) modulation has been shown to be an effective way to substantially enhance the capacity of bandlimited optical wireless communication (OWC) systems. In this paper, we propose four OFDM-based generalized optical MIMO (GO-MIMO) techniques for intensity-modulation and direct-detection OWC systems, including OFDM-based frequency-domain generalized spatial modulation (FD-GSM), frequency-domain generalized spatial multiplexing (FD-GSMP), time-domain generalized spatial modulation (TD-GSM) and time-domain generalized spatial multiplexing (TD-GSMP). For OFDM-based FD-GSM and FD-GSMP, spatial mapping is performed in the frequency domain, while it is carried out in the time domain for OFDM-based TD-GSM and TD-GSMP. To efficiently estimate both spatial and constellation symbols in each OFDM-based GO-MIMO technique, a corresponding maximum-likelihood (ML) detection algorithm is designed. Extensive simulations are conducted to evaluate and compare the performance of OFDM-based GO-MIMO techniques under various MIMO settings in a typical indoor environment. Simulation results demonstrate that there exists an optimal GO-MIMO technique to achieve a target spectral efficiency for a given receiver location, and the obtained optimal GO-MIMO technique is also related to the specific location of the receiver.

关键词： MIMO communication Optical transmitters Modulation Light emitting diodes GSM Optical modulation Frequency-domain analysis Optical wireless communication orthogonal frequency division multiplexing multiple-input multiple-output

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Spatial spectrum approach for pilot spoofing attack detection in MIMO systems

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ETRI JOURNAL 2021年第5期43卷 941-949页

作者： Ning, Lina Li, Bin Wang, Xiang Liu, Xiaoming Zhao, Chenglin Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing Peoples R China Beijing Jianyi Co Ltd Beijing Peoples R China

In this study, a spatial spectrum method is proposed to cope with the pilot spoofing attack (PSA) problem by exploiting the of uplink-downlink channel reciprocity in time-division-duplex multiple-input multiple-output systems. First, the spoofing attack in the uplink stage is detected by a threshold derived from the predefined false alarm based on the estimated spatial spectrum. When the PSA occurs, the transmitter (That is Alice) can detect either one or two spatial spectrum peaks. Then, the legitimate user (That is Bob) and Eve are recognized in the downlink stage via the channel reciprocity property based on the difference between the spatial spectra if PSA occurs. This way, the presence of Eve and the direction of arrival of Eve and Bob can be identified at the transmitter end. Because noise is suppressed by a spatial spectrum, the detection performance is reliable even for low signal-noise ratios and a short training length. Consequently, Bob can use beamforming to transmit secure information during the data transmission stage. Theoretical analysis and numerical simulations are performed to evaluate the performance of the proposed scheme compared with conventional methods.

关键词： multiple-input multiple-output physical layer security pilot spoofing attack spatial spectrum method time-division duplex

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Swish-Driven GoogleNet for Intelligent Analog Beam Selection in Terahertz Beamspace MIMO 95

Swish-Driven GoogleNet for Intelligent Analog Beam Selection...

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IEEE 95th Vehicular Technology Conference: (VTC-Spring)

作者： Hosein, Zarini Mohammad, Robat Mili Rasti, Mehdi Andreev, Sergey Nardelli, Pedro H. J. Amirkabir Univ Technol Dept Comp Engn Tehran Iran Sharif Univ Technol Elect Res Inst Tehran Iran Tampere Univ Tampere Finland Lappeenranta Lahti Univ Technol Lappeenranta Finland

ISBN: (数字)9781665482431

ISBN: (纸本)9781665482431

In this paper, we propose an intelligent analog beam selection strategy in a terahertz (THz) band beamspace multiple-input multiple-output (MIMO) system. First inspired by transfer learning, we fine-tune the pre-trained off-the-shelf GoogleNet classifier to learn analog beam selection as a multi-class mapping problem. Simulation results show 83% accuracy for the analog beam selection, which subsequently results in 12% spectral efficiency (SE) gain over the existing counterparts. For a more accurate classifier, we replace the conventional rectified linear unit (ReLU) activation function of the GoogleNet with the recently proposed Swish and retrain the fine-tuned GoogleNet to learn analog beam selection. It is numerically indicated that the fine-tuned Swish-driven GoogleNet achieves 86% accuracy, as well as 18% improvement in achievable SE, over the similar schemes. Eventually, a strong ensembled classifier is developed to learn analog beam selection by sequentially training multiple fine-tuned Swish-driven GoogleNet classifiers. According to the simulations, the strong ensembled model is 90% accurate and yields 27% gain in achievable SE in comparison with prior methods.

关键词： Terahertz (THz) band beamspace multiple-input multiple-output analog beam selection GoogleNet Swish ensembled classifier

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Performance-Complexity Trade-Off for Low-Complexity MIMO Detection: simplified BP vs. EP Receivers 95

Performance-Complexity Trade-Off for Low-Complexity MIMO Det...

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IEEE 95th Vehicular Technology Conference: (VTC-Spring)

作者： Mekhiche, Adam Cipriano, Antonio Maria Poulliat, Charly Thales INP Toulouse ENSEEIHT Gennevilliers France Thales Gennevilliers France INP Toulouse ENSEEIHT Toulouse France

ISBN: (数字)9781665482431

ISBN: (纸本)9781665482431

In this study, we intend to make an in-depth investigation of the performance-complexity trade-off of low complexity multiple-input multiple-output (MIMO) signal detection based on message passing algorithms. Several detection algorithms such as Belief Propagation (BP) and Expectation Propagation (EP) have been proposed to approximate symbol Maximum A Posteriori (MAP) for high dimensional signaling. We propose a thorough examination of those algorithms and some of their low-complexity versions, through a complexity/performance trade-off analysis to identify modes of operation depending on the number of antennas and constellation order. Finally, we propose a new simplified BP detection scheme, which combines the advantages of QR precoding and Interference Cancellation (IC).

关键词： multiple-input multiple-output Maximum A Posteriori Belief Propagation Expectation Propagation QR factorisation Parallel Interference Cancellation

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Double spatial media-based modulation with RF mirrors

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ANNALS OF TELECOMMUNICATIONS 2021年第11-12期76卷 813-825页

作者： Tsvaki, Ronald Pillay, Narushan Xu, Hongjun Univ KwaZulu Natal Sch Engn ZA-4041 Durban South Africa

Media-based modulation (MBM) is an attractive transmission technique that has been recently receiving increased research attention in the wireless communication domain. MBM employs the use of radio frequency mirrors to vastly improve the error performance and/or spectral efficiency of transmission schemes as compared to traditional source-based modulation techniques. Double spatial modulation (DSM) is a new multiple-input multiple-output transmission technique that aims to improve the spectral efficiency of conventional spatial modulation by increasing the number of active transmit antennas. In this study, DSM is extended to employ MBM, such as to improve error performance, and the scheme is termed double spatial media-based modulation (DSMBM). The theoretical average bit error probability of DSMBM is formulated and validated by Monte-Carlo simulation results. Lastly, coded channels are investigated. Typically, soft-output detection coupled with soft-input channel decoding yields a significant signal-to-noise ratio gain. Hence, the authors further propose soft-output maximum-likelihood detectors for the DSM and DSMBM systems.

关键词： Double spatial modulation (DSM) Media-based modulation (MBM) multiple-input multiple-output Radio frequency mirrors Soft-output maximum-likelihood detector Spatial modulation

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Automatic Space-Time Block Code Recognition Using Convolutional Neural Network With Multi-Delay Features Fusion

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IEEE ACCESS 2021年 9卷 79994-80005页

作者： Zhang, Yuyuan Yan, Wenjun Zhang, Limin Ma, Ling Naval Aviat Univ Dept Informat Fus Yantai 264001 Peoples R China Naval Aviat Univ Coll Coastal Def Yantai 264001 Peoples R China

Automatic signal recognition (ASR) is becoming increasingly important in spectrum identification and cognitive radio, but most existing space-time block code (STBC) recognition algorithms are traditional ones and do not account for the complementarities between different features. To overcome these deficiencies, a multi-delay features fusion scheme for ASR of STBC using a convolutional neural network (CNN) is proposed in this study. The proposed scheme tries to fuse different time-delay features of received STBC signals to obtain more discriminating features. The dilated convolution of different dilation rates is applied to realize automated multi-delay feature extraction. Then, two fusion methods, i.e., max-correlation (MC) fusion and multi-delay average (MDA) fusion, are proposed to combine the features of different time delays, and a residual block is applied to achieve better representation of signals. Finally, the simulation results demonstrate the superior performance of the proposed method. It is notable that the recognition accuracy can reach 97.4% with a signal-to-noise ratio (SNR) of -5 dB. In addition, the proposed multi-delay features fusion CNN (MDFCNN) scheme does not need a priori information, i.e., modulation type, channel coefficients, and noise power, which is well suited to non-collaborative communication.

关键词： Convolution Delay effects Simulation Radio transmitters Feature extraction Encoding Robustness Automatic signal recognition multiple-input multiple-output space-time block code convolutional neural network features fusion

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Multi-User Angle-Domain MIMO-NOMA System for mmWave Communications

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IEEE ACCESS 2021年 9卷 129443-129459页

作者： Khaled, Israa Langlais, Charlotte El Falou, Ammar Elhassan, Bachar A. Jezequel, Michel UMR CNRS 6285 Lab STICC IMT Atlantique F-29238 Brest France Lebanese Univ Fac Engn Tripoli 1300 Libya Gustave Eiffel Univ EISEE Paris ESYCOM F-93160 Noisy Le Grand France

Thanks to the high directionality of millimeter-wave (mmWave) channels, angle-domain beamforming is an appealing technique for multi-user multiple-input multiple-output (MU-MIMO) in terms of sum-throughput performance and limited feedback. By utilizing only the angular information of users at the transmitter, we propose an angle-domain non-orthogonal multiple access (NOMA) scheme to enhance the sum-throughput of the mmWave MU-MIMO system, especially in congested cells. We first derive a set of angular-based performance metrics, such as the inter-user spatial interference, the user channel quality, and the sum-throughput, by exploiting the specific features of the mmWave propagation. Then, a multi-user clustering algorithm is developed based on the spatial interference metric, and a new user ordering strategy is proposed using the angular-based channel quality metric. Additionally, we design a power allocation method that maximizes the angular-based sum-throughput. Extensive numerical results show that the proposed scheme significantly improves the performance of the mmWave MU-MIMO system by achieving up to 39% increase in the spectral efficiency when the number of users is closed to the number of antennas. Moreover, we find that the proposed user ordering strategy outperforms other limited feedback strategies, and the angular-based power allocation allows for efficient successive interference cancellation.

关键词： NOMA Resource management Measurement Silicon carbide MIMO communication Array signal processing Clustering algorithms Millimeter-wave networks multiple-input multiple-output beamforming non-orthogonal multiple access

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Composite Fading Model for Aerial MIMO FSO Links in the Presence of Atmospheric Turbulence and Pointing Errors

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IEEE WIRELESS COMMUNICATIONS LETTERS 2021年第6期10卷 1295-1299页

作者： Khallaf, Haitham S. Kato, Kazutoshi Mohamed, Ehab Mahmoud Sait, Sadiq M. Yanikomeroglu, Halim Uysal, Murat Egyptian Atom Energy Author Nucl Res Ctr Inshas 13759 Egypt Kyushu Univ Grad Sch Informat Sci & Elect Engn Fukuoka 8190395 Japan Prince Sattam Bin Abdulaziz Univ Coll Engn Wadi Aldwaser 11991 Saudi Arabia Aswan Univ Fac Engn Elect Engn Dept Aswan 81542 Egypt King Fahd Univ Petr & Minerals Comp Engn Dept Dhahran 31261 Saudi Arabia Carleton Univ Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada Ozyegin Univ Dept Elect & Elect Engn TR-34794 Istanbul Turkey

In this letter, we introduce accurate approximation expressions for composite fading channel model and outage probability of multiple-input multiple-output (MIMO) free space optical (FSO) link between two unmanned aerial vehicles (UAVs) in hovering state. In our derivations, we consider the effects of weather attenuation, random fluctuations in UAVs' positions and orientations, and atmospheric turbulence. Our proposed model is unified with respect to turbulence effect, which means it is valid for different atmospheric turbulence models. We show the accuracy of the proposed model through comparisons with Monte Carlo simulations under different channel conditions.

关键词： Atmospheric turbulence free space optical communications multiple-input multiple-output pointing errors unmanned aerial vehicles

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