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Matrix Power Control Algorithm for multi-input multi-output Random Vibration Test

Chinese Journal of Aeronautics 2011年第6期24卷 741-748页

作者： CUI Xuli CHEN Huaihai HE Xudong JIANG Shuangyan MOE Key Laboratory of Structure Mechanics and Control for Aircraft Institute of ~bration Engineering Research Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix （DELTM） may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm （PRMSCA） provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm （MPCA） is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA.

关键词： multi-input multi-output environmental testing vibration control random vibration auto-power spectrum cross-power spectrum

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Improving Wireless Physical Layer Security via Exploiting Co-Channel Interference

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IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 2016年第8期10卷 1433-1448页

作者： Li, Lingxiang Petropulu, Athina P. Chen, Zhi Fang, Jun Univ Elect Sci & Technol China Natl Key Lab Sci & Technol Commun Chengdu 611731 Peoples R China Rutgers State Univ Dept Elect & Comp Engn New Brunswick NJ 08854 USA

This paper considers a scenario in which a source-destination pair needs to establish a confidential connection against an external eavesdropper, aided by the interference generated by another source-destination pair that exchanges public messages. The goal is to compute the maximum achievable secrecy degrees of freedom (S.D.o.F) region of a MIMO two-user wiretap network. First, a cooperative secrecy transmission scheme is proposed, whose feasible set is shown to achieve all S.D.o.F. pairs on the S.D.o.F. region boundary. In this way, the determination of the S.D.o.F. region is reduced to a problem of maximizing the S.D.o.F. pair over the proposed transmission scheme. The maximum achievable S.D.o.F. region boundary points are obtained in closed form, and the construction of the precoding matrices achieving the maximum S.D.o.F. region boundary is provided. The proposed expressions are functions of the number of antennas at each terminal, and apply to any number of antennas, thus constituting an advancement over prior works that have considered only fixed antenna configurations.

关键词： Physical-layer security cooperative communications multi-input multi-output secrecy degrees of freedom (SDo.F)

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DOA and DOD Estimation Based on Double 1-D Root-MVDR Estimators for Bistatic MIMO Radars

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WIRELESS PERSONAL COMMUNICATIONS 2016年第3期86卷 1321-1332页

作者： Chen, Shiaw-Wu Meng, Chao-Li Chang, Ann-Chen Feng Chia Univ Dept Automat Control Engn Taichung 407 Taiwan Feng Chia Univ PhD Program Elect & Commun Engn Taichung 407 Taiwan Ling Tung Univ Dept Informat Technol Taichung 408 Taiwan

This paper deals with direction of arrival (DOA) and direction of departure (DOD) estimation of existing targets based on polynomial root finding estimators with minimum variance distortionless response (MVDR) criterion in bistatic multi-input multi-output radar systems. First, the presented estimator transforms the conventional two-dimensional searching approach into double one-dimensional polynomial root-MVDR approach for DOA and DOD estimation. Thus, the pairing operation can be obtained automatically. Second, to mitigate the influence of noise corruption and the estimate radial bias, we also presented a differential polynomial root-MVDR estimator to obtain more accuracy estimation performance. Finally, simulation results are provided to verify the efficiency of the proposed estimators.

关键词： Bistatic radar multi-input multi-output Direction of departure Direction of arrival Polynomial rooting Minimum variance distortionless response

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multi-Pair MIMO Two-Way Relaying: A Principal-Angle Perspective

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2016年第2期64卷 380-394页

作者： Xin, Haiyang Yuan, Xiaojun Liew, Soung-Chang Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China ShanghaiTech Univ Sch Informat Sci & Technol Shanghai 200031 Peoples R China

This paper studies and analyzes a multi-pair MIMO two-way relay (TWR) system from a principal-angle perspective. In this system, users are grouped into pairs and two users in each pair exchange information through a common relay. The transmission scheme consists of two phases. In the uplink phase, the relay's receive signal space is divided into two subspaces for each pair: in one subspace, the signals of the two users are near-parallel, and physical-layer network coding (PNC) decoding is applied to retrieve network-coded messages;in the other subspace, the two user signals are near-orthogonal, and complete decoding (CD) is applied to retrieve individual user messages. In the downlink phase, the relay's transmit signal space is split into orthogonal subspaces for each pair, and in each subspace a common message is broadcasted to the two users. Our main contribution is to establish a critical link between the transmission scheme and the concept of principal angle in linear algebra. In particular, principal angle quantizes the degree of orthogonality between the user signals and helps determining how to partition the relay's receive signal space into PNC decoding subspace and CD decoding subspace. Building on that, we discuss the optimal design of user/relay precoders for both uplink and downlink phases to maximize the asymptotic sum-rate of the proposed scheme at high signal-to-noise ratio (SNR). The analysis and numerical results indicate that our scheme performs close to the cut-set outer bound and significantly outperforms the existing schemes in the literature.

关键词： multi-input multi-output physical-layer network coding principal angles/vectors two-way relay channel

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A 2 x 2 imaging MIMO system based on LED Visible Light Communications employing space balanced coding and integrated PIN array reception

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OPTICS COMMUNICATIONS 2016年 367卷 214-218页

作者： Li, Jiehui Xu, Yinfan Shi, Jianyang Wang, Yuanquan Ji, Xinming Ou, Haiyan Chi, Nan Fudan Univ Dept Commun Sci & Engn Key Lab Electromagnet Wave Informat Sci Shanghai 200433 Peoples R China Fudan Univ Dept Microelect State Key Lab ASIC & Syst Shanghai 200433 Peoples R China Tech Univ Denmark DTU Foton Orsteds Plads 343 DK-2800 Lyngby Denmark

In this paper, we proposed a 2 x 2 imaging multi-input multi-output (MIMO)-Visible Light Communication (VLC) system by employing Space Balanced Coding (SBC) based on two RGB LEDs and integrated PIN array reception. We experimentally demonstrated 1.4-Gbit/s VLC transmission at a distance of 2.5 m. The proposed imaging system not only overcomes the limitation of bandwidth existing in LEDs, but also can reject the second-order nonlinearity distortion. It turned out to be very promising to use integrated antennas in the VLC system in the future. (C) 2016 Published by Elsevier B.V.

关键词： Space balanced coding PIN array RGB LED OFDM multi-input multi-output

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Channel-Adapted Spatial Modulation for Massive MIMO Visible Light Communications

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IEEE PHOTONICS TECHNOLOGY LETTERS 2016年第23期28卷 2693-2696页

作者： Xu, Ke Yu, Hongyi Zhu, Yi-Jun Natl Digital Switching Syst Engn & Technol Res Ct Zhengzhou 450000 Peoples R China

Massive multi-input multi-output (MIMO) has great potential to improve transmission rate of visible light communication (VLC) systems. However, high inter-channel interference (ICI) is the main factor that seriously influences the transmission performance. In this letter, with the channel state information (CSI) known at the transmitters, a general criterion of balancing the spectral efficiency and the error performance is established by analyzing the special features of MIMO-VLC. Based on the criterion, a channel-adapted spatial modulation (CASM) for massive MIMO-VLC is proposed, so as to find the optimal combinations of active light-emitting diodes under the controlled ICI. Simulation results show that CASM achieves more bit-error-rate gains over optical multi-stream spatial modulation (OMS-SM) with the same spectral efficiency, or even considering 10% reduction in the spectral efficiency of CASM caused by updating the CSI. Moreover, the higher spectral efficiency, the more gains of CASM over OMS-SM.

关键词： Visible light communication multi-input multi-output spatial modulation channel-adapted

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Robust MIMO Precoding for Cognitive multiuser Relay Networks with Imperfect Channel State Information

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Transactions of Tianjin University 2016年第6期22卷 590-595页

作者：俎云霄揭昕政 School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper, a novel robust precoder with imperfect channel state information(CSI)is proposed for multi-input multi-output(MIMO)cognitive multiuser networks equipped with relays. In the proposed model, the secondary users(SUs)are allowed to share the spectrum with the primary users(PUs)when the interference temperature(IT)is below a specific threshold. The transmitting strategy of relays is amplify-and-forward(AF), and the CSI error is characterized in terms of spherical uncertainty region. A minmax problem for the transmit power of the relays is considered when the mean square error(MSE)of SUs and the IT of PU meet their corresponding thresholds, and it is transformed into a semi-definite programming(SDP)problem to search for the solution. Numerical simulations demonstrate the effectiveness of the proposed precoder.

关键词： cognitive radio multi-input multi-output imperfect channel state information semi-definite programming robust precoding

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output Regulation for a Nonlinear Helicopter model with input Saturation by CNF Control

Output Regulation for a Nonlinear Helicopter model with Inpu...

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2016 IEEE Advanced Information Management,Communicates,Electronic and Automation Control Conference(IMCEC 2016)

作者： Ping Zhao Yuan Jiang Jiaming Zhu College of Information Engineering Nanchang Hangkong University Key Laboratory of Nondestructive Testing (Nanchang Hangkong University) Ministry of Education

ISBN: (纸本)9781509001668

This paper introduces the composite nonlinear feedback(CNF) control method to solve the output regulation problems of helicopter model with input *** solve the output regulation problem,an observer and an output feedback CNF control law are *** CNF control law includes a linear control law and a nonlinear control law.A linear state equation of helicopter model and a reference signal is *** solve the regulator equation,design a feedback gain and an observer gain through the experiment many *** order to study the performance of the controller,we have designed two controllers with or without external disturbances,*** the simulation results shown that the CNF controller works well,and it prove CNF control method can improve the transient performance obviously.

关键词： composite nonlinear feedback CE150 helicopter model output regulation problem multi-input multi-output

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Design and Experimental Demonstration of A Real-Time 95kbps Optical Camera Communication System 10

Design and Experimental Demonstration of A Real-Time 95kbps ...

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10th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP)

作者： Tian, Peng Huang, Wei Xu, Zhengyuan Univ Sci & Technol China Chinese Acad Sci Key Lab Wireless Opt Commun Hefei Peoples R China Tsinghua Univ Shenzhen Grad Sch Shenzhen Peoples R China

ISBN: (纸本)9781509025268

A real-time optical camera communication (OCC) system was designed and implemented. The system jointly utilizes 4 intensity levels for each color and 3 colors of each RGB LED of a 16x16 LED array, resulting in a 64-ary color-intensity modulation (CIM) carrying on 6-bit coded information in each symbol. The LED array is refreshed at 82.5 Hz, and a FPGA controlled commercial CMOS image sensor from a mobile phone operates at a frame rate of 330 fps whose outputs are fed into a PC for real-time signal demodulation. Excluding 60 boarder LEDs and 4 spatial synchronization LEDs, the remaining 192 data-carrying LEDs are able to transmit data at an effective rate of about 95 kbps. Bit error rate below 10-3 over a communication distance up to 1.2 m is achieved without any external optical lens.

关键词： Optical camera communication color intensity modulation multi-input multi-output

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Performance of Two-Way AF MIMO Relay Networks with Single and multiple Antenna Selection Schemes 27

Performance of Two-Way AF MIMO Relay Networks with Single an...

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27th IEEE Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)

作者： Fidan, Efendi Kucur, Oguz TUBITAK UME Time Frequency & Wavelength Lab TR-41470 Gebze Turkey Gebze Tech Univ Elect Engn TR-41400 Gebze Turkey

ISBN: (纸本)9781509032549

The performance of amplify-and-forward (AF) multi-input multi-output (MIMO) two way relaying networks (TWRNs) with multiple antenna selection scheme at the sources, while having single antenna selection at the relay node is investigated to maximize the effective signal-to-noise ratio (SNR) over flat Rayleigh fading channel. Both exact and asymptotic expressions for the sum outage probability are derived and verified through Monte Carlo simulation results. The diversity order of selection scheme is proven to be minimum of the number of antennas of the source with larger antennas and the product of the number of relay antennas with the number of antennas of the source having fewer antennas. It is shown that fewer antennas at the sources can be selected to reduce the complexity without a significant loss in performance with respect to full antenna usage, i.e., with respect to beamforming. Primary factors which affect optimum relay location are also determined.

关键词： Generalized Antenna Selection Generalized Selection Combining Transmit Antenna Selection Receive Antenna Selection Two Way Relaying Networks multi-input multi-output Rayleigh Fading Amplify-and-Forward

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