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Experimental Verification of Signal Quality Difference Induced by Differential Modal Loss and Modal Crosstalk on Optical MIMO Transmission and its Compensation by Equipartition multiplexing

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2016年第3期34卷 918-927页

作者： Mori, Takayoshi Sakamoto, Taiji Wada, Masaki Yamamoto, Takashi Yamamoto, Fumihiko Nakajima, Kazuhide NTT Corp Access Network Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

We investigate experimentally the signal quality difference induced by differential modal loss and modal crosstalk (XT) in few-mode fiber during optical MIMO transmission. We measure the modal loss and modal XT properties of two LP mode fibers in the presence of tension and confirm that the coexistence of differential modal loss and modal XT leads to a signal quality imbalance even with MIMO digital processing. In addition, to compensate for the signal quality imbalance, we employ a novel equipartition multiplexing technique at the transmitter used in a mode-division-multiplexed transmission to equalize the mode-dependent impairment, and successfully achieve a two LP mode multiplexed transmission with a low signal quality difference.

关键词： Few-mode fibers multiple-input multiple-output

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Performance evaluation of applied Alamouti scheme on IEEE 802.15.4 network

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INTERNATIONAL JOURNAL OF SENSOR NETWORKS 2016年第1期22卷 58-66页

作者： Halim, Eddy Hartono Shin, Soo Young Kumoh Natl Inst Technol Dept IT Convergence Gumi 730701 Gyeongbuk South Korea Kumoh Natl Inst Technol Sch Elect Engn Gumi 730701 Gyeongbuk South Korea

This study evaluated the performance of IEEE 802.15.4 network in the case of applying Alamouti scheme using both 2 x 1 multiple-input single-output (MISO) and 2 x 2 multiple-input multiple-output (MIMO) antenna configurations. The modulation curves, i.e., bit error rate (BER) vs. signal-to-noise ratio (SNR) of the conventional IEEE 802.15.4, switching diversity, Alamouti scheme are obtained first. Using the modulation curves, performance of IEEE 802.15.4 network is investigated. Throughput, probability of successful transmission and energy efficiency are used as measures of performance. Simulations are performed to prove the effectiveness of applied Alamouti scheme in the viewpoint of IEEE 802.15.4 network.

关键词： Alamouti scheme IEEE 802.15.4 network MIMO multiple-input multiple-output throughput energy efficiency

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Joint Source-Relay Secure Precoding for MIMO Relay Networks With Direct Links

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IEEE TRANSACTIONS ON COMMUNICATIONS 2017年第7期65卷 2781-2793页

作者： Wang, Hui-Ming Huang, Ke-Wen Yang, Qian Han, Zhu Xi An Jiao Tong Univ Sch Elect & Informat Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Minist Educ Key Lab Intelligent Networks & Network Secur Xian 710049 Shaanxi Peoples R China Univ Houston Elect & Comp Engn Dept Houston TX 77004 USA

In this paper, we propose a joint source-relay precoding scheme to secure an amplify-and-forward multiple-input multiple-output wireless relay network in the existence of a multi-antenna eavesdropper. Different from existing works that only consider some specific signal design to simplify the problem, we take both the direct links from the source to the destination and to the eavesdropper into account, and investigate the general joint signal covariance matrices optimization problem to maximize the secrecy rate, which leads to a difficult non-convex optimization problem. To handle it, we propose a group alternating optimization algorithm to find a solution, which alternately optimizes the signal covariance matrix and the linear precoding matrix at the source and the relay, respectively. For optimizing the linear precoding matrix at the relay, the problem is still non-convex, and we propose a minorization-maximization (MM) method to handle it. The MM method transforms the original non-convex problem into a series of convex problems and guarantees the convergence of a local optimum. For optimizing the signal covariance matrix at the source, we reveal the convex-concave property of the problem, and find its global optimum using a barrier method combined with the Newton iteration. We also provide an initialization method to trigger the algorithm and analyze the convergence and complexity. The numerical results show the computational efficiency and the prominent performance of the proposed algorithm.

关键词： Physical layer security secrecy rate relay multiple-input multiple-output precoding

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A Novel Low-Complexity Precoding Algorithm for MIMO Cognitive Radio Systems

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WIRELESS PERSONAL COMMUNICATIONS 2017年第4期97卷 5077-5088页

作者： Wang, Kun Zhang, Baoyuan Wang, Xiyuan Dai, Linglong Coordinat Ctr China Natl Comp Network Emergency Response Tech Team Beijing Peoples R China China Film Arch Beijing Peoples R China Univ Sci & Technol Beijing Sch Comp & Commun Beijing Peoples R China Tsinghua Univ Dept Elect Engn Beijing Peoples R China

This paper proposes a novel efficient precoding algorithm to maximize the rate of the cognitive link, where a pair of multiple-input multiple-output cognitive radio users shares the spectrum allocated to multiple primary users as long as the interference power is acceptable. In our method, the precoding vectors are firstly obtained by solving an unconstrained convex problem which is formulated by using the penalty function idea and has a closed-form solution. Then, power is allocated to different precoding vectors to satisfy both the transmit-power constraint and interference-power constraints through interior method. Moreover, an effective set of the penalty weights is presented. Our method has much lower complexity than the optimal solution and similar complexity to other low-complexity methods. Simulation results show that our method significantly outperforms the existing low-complexity methods and has almost the same performance as the optimal solution.

关键词： Cognitive radio multiple-input multiple-output Precoding Penalty function Low complexity

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OSTBC transmission in MIMO AF relaying with M-FSK modulation

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2015年第1期2015卷 1页

作者： Nguyen, Ha X. Chai Dai Truyen Thai Tran, Nguyen N. Tan Tao Univ Sch Engn Duc Hoa Long An Vietnam Singapore Univ Technol & Design Singapore Singapore Vietnam Natl Univ Univ Sci Fac Elect & Telecommun Ho Chi Minh City Vietnam

This paper investigates orthogonal space-time block code (OSTBC) transmission for multiple-input multiple-output (MIMO) amplify-and-forward (AF) relaying networks composed of one source, K relays, and one destination and with M-ary frequency-shift keying (FSK) modulation. A non-coherent detection scheme is proposed and analyzed in a situation where the fading channels undergo temporal correlation. Specifically, by properly exploiting the implicit pilot-symbol-assist property of FSK transmission, the destination estimates the overall channels based on the linear minimum mean square error (LMMSE) estimation algorithm. It then utilizes the maximal ratio combining (MRC) to detect the transmitted information. An upper bound on the probability of errors is derived for a network with arbitrary numbers of transceiver antennas and relays. Based on the obtained bit error rate, the full achievable diversity order is verified. Simulation results are presented to show the validity of the analytical results.

关键词： Cooperative diversity Relay communications Frequency-shift-keying Fading channel Amplify-and-forward protocol multiple-input multiple-output Orthogonal space-time block codes

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Sum-Rate Maximization in the Multicell MIMO Broadcast Channel With Interference Coordination

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第6期62卷 1501-1513页

作者： Nguyen, Duy H. N. Tho Le-Ngoc McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0E9 Canada

This paper studies the precoding designs to maximize the weighted sum-rate (WSR) in a multicell multiple-input multiple-output (MIMO) broadcast channel (BC). We consider a multicell network under universal frequency reuse with multiple mobile stations (MS) per cell. With interference coordination (IC) between the multiple cells, the base-station (BS) at each cell only transmits information signals to the MSs within its cell using the dirty paper coding (DPC) technique, while coordinating the intercell interference (ICI) induced to other cells. The main focus of this work is to jointly optimize the encoding covariance matrices across the BSs in order to maximize the network-wideWSR. Since this optimization problem is shown to be nonconvex, obtaining its globally optimal solution is highly complicated. To address this problem, we consider two low-complexity solution approaches with distributed implementation to obtain at least locally optimal solutions. In the first approach, by applying a successive convex approximation technique, the original nonconvex problem is decomposed into a sequence of simpler problems, which can be solved optimally and separately at each BS. In the second approach, the WSR problem is solved via an equivalent problem of weighted sum mean squared error minimization. Both solution approaches will unfold the control signaling among the coordinated BSs to allow their distributed implementation. Simulation results confirm the convergence of the proposed algorithms, as well as their superior performances over schemes with linear precoding or no interference coordination among the BSs.

关键词： Broadcast channel convex optimization coordinated multipoint transmission/reception dirty-paper coding interference coordination MMSE multicell 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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Six-Mode Seven-Core Fiber for Repeated Dense Space-Division multiplexing Transmission

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2018年第5期36卷 1226-1232页

作者： Sakamoto, Taiji Saitoh, Kunimasa Saitoh, Shota Shibahara, Kohki Wada, Masaki Abe, Yoshiteru Urushibara, Azusa Takenaga, Katsuhiro Mizuno, Takayuki Matsui, Takashi Aikawa, Kazuhiko Miyamoto, Yutaka Nakajima, Kazuhide NTT Corp NTT Access Networks Serv Syst Labs Tsukuba Ibaraki 3050805 Japan Hokkaido Univ Grad Sch Informat Sci & Technol Sapporo Hokkaido 0600814 Japan Fujikura Ltd Chiba 2858550 Japan NTT Corp NTT Network Innovat Labs Yokosuka Kanagawa 2390847 Japan

We propose the optimum design of high spatial density few-mode multicore fiber (MCF) for repeated space-division multiplexed (SDM) transmission. Numerical analyses reveal that a hexagonally arranged six-mode seven-core structure is potentially better than the other possibility, the six-mode multicore structure, in terms of realizing high spatial density and low mode-dependent loss (MDL) characteristics at the splice point;its benefits will enable us to construct long-haul dense SDM transmission links. We fabricate a 171 mu m cladding six-mode seven-core fiber and successfully demonstrate low loss, differential mode delay (DMD), crosstalk, and splice-induced MDL characteristics while maintaining the relative core multiplicity factor of more than 50. Finally, we demonstrate repeated optical 12 x 12 MIMO transmission of more than 100 km using our six-mode MCF and erbium doped fiber amplifier (EDFA).

关键词： Mode dependent loss multi-core fiber multiple-input multiple-output

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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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Performances of Transmit Antenna Selection, Receive Antenna Selection, and Maximal-Ratio-Combining-Based Hybrid Techniques in the Presence of Feedback Errors

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2014年第4期63卷 1976-1982页

作者： Yilmaz, Ahmet Kucur, Oguz Turkish Sci & Technol Res Council TUBITAK Informat & Informat Secur Res Ctr BILGEM TR-41470 Gebze Turkey Gebze Inst Technol Dept Elect Engn TR-41400 Gebze Turkey

In this paper, performances of joint transmit and receive antenna selection (JTRAS), transmit antenna selection/maximal ratio combining (TAS/MRC), and transmit antenna selection/receive antenna selection (TAS/RAS) techniques are examined in a unified manner in the presence of feedback errors. Exact and closed-form outage probability, moments, moment-generating function, ergodic capacity, and symbol error probability (SEP) expressions are derived for flat Nakagami-m fading channels. In addition, to obtain diversity order and array gain of the investigated techniques in the presence of feedback errors, asymptotic outage probability and SEP expressions are also derived. Analytical results are validated by Monte Carlo simulations. Results show that the diversity order is significantly reduced in the presence of feedback errors, whereas all the systems provide full diversity order for a perfect feedback channel.

关键词： Diversity order feedback error joint transmit and receive antenna selection (JTRAS) maximal ratio combining (MRC) multiple-input multiple-output Nakagami-m fading receive antenna selection (RAS) transmit antenna selection (TAS)

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