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Transceiver Optimization for Two-Hop AF MIMO Relay Systems With DFE Receiver and Direct Link

IEEE TRANSACTIONS ON COMMUNICATIONS 2022年第6期70卷 4134-4145页

作者： Su, Qiao Rong, Yue Army Engn Univ PLA Coll Commun Engn Nanjing 210007 Peoples R China Curtin Univ Sch Elect Engn Comp & Math Sci Bentley WA 6102 Australia

In this paper, we consider precoding and receiving matrices optimization for a two-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay system with a decision feedback equalizer (DFE) at the destination node in the presence of the direct source-destination link. By adopting the minimum mean-squared error (MMSE) criterion, we develop two new transceiver design algorithms for such a system. The first one employs an iterative procedure to design the source, relay, feed-forward, and feedback matrices. The second algorithm is a non-iterative suboptimal approach which decomposes the optimization problem into two tractable subproblems and obtains the source and relay precoding matrices by solving the two subproblems sequentially. Simulation results validate the better MSE and bit-error-rate (BER) performance of the proposed algorithms and show that the non-iterative suboptimal method has a negligible performance loss when the ratio of the source node transmission power to the relay node transmission power is small. In addition, the computational complexity analysis suggests that the second algorithm and one iteration of the first algorithm have the same order of complexity. As the first algorithm typically converges within a few iterations, both proposed algorithms exhibit a low complexity order.

关键词： Relays Receivers MIMO communication Transceivers Decision feedback equalizers Optimization matrix decomposition Amplify-and-forward MIMO relay precoding matrix decision feedback equalizer (DFE) direct link

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Secrecy precoding in MIMOME wireless communication system under partial CSI

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IET COMMUNICATIONS 2020年第13期14卷 2202-2209页

作者： Dong, Runze Wang, Buhong Cao, Kunrui Li, Xia Air Force Engn Univ Sch Informat & Nav Xian 710077 Peoples R China Natl Univ Def Technol Sch Informat & Commun Xian 710106 Peoples R China

In this study, a precoding scheme which is called singular value decomposition and null space (SVDNS) based scheme is proposed to enhance physical layer security of a multiple-input multiple-output multiantenna eavesdropper (MIMOME) system. Under the partial channel state information (CSI) of the eavesdropper, the precoding matrix for the information bearing signal is constructed firstly via SVDNS-based scheme to acquire a compromise between improving performance of the main channel and impairing that of the wiretap channel. Then the optimal power allocation over subchannels formed by precoding matrix is obtained through solving the secrecy rate maximise problem to further improve secrecy performance. After that, under the scenario that CSI of the wiretap channel is less knowable, precoding matrix for artificial noise (AN) is proposed via SVDNS-based scheme, and then the optimal power allocation between the information bearing signal and AN is obtained while optimal power allocation over subchannels is solved subsequently. Simulation results show that the SVDNS-based scheme with optimal power allocation achieves a higher secrecy rate than the existing schemes, and the SVDNS-based scheme with AN aiding could make up for the performance degradation of it without AN in the situation that CSI of the wiretap channel is more unknowable.

关键词： MIMO communication antenna arrays optimisation singular value decomposition precoding radio transmitters wireless channels telecommunication security secrecy precoding MIMOME wireless communication system partial CSI precoding scheme partial channel state information precoding matrix information bearing signal SVDNS-based scheme impairing wiretap channel optimal power allocation secrecy rate maximise problem secrecy performance singular value decomposition and null space based scheme multiple-input multiple-output multiantenna eavesdropper system

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1.7/2.6 GHz high-efficiency concurrent dual-band power amplifier with dual-band harmonic wave controlled transformer

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ELECTRONICS LETTERS 2014年第3期50卷 184-185页

作者： Chen, Peng He, Songbai Wang, Xianfei Dai, Zhijiang Univ Elect Sci & Technol China Sch Elect Engn Chengdu 611731 Peoples R China

A 1.7/2.6 GHz high-efficiency concurrent dual-band power amplifier (DBPA) with a dual-band harmonic wave controlled transformer is demonstrated. The proposed dual-band transformer, which transfers the fundamental and the second harmonic impedances of each frequency, is directly transmission line implemented with the help of an optimisation algorithm. The measurement results show that the proposed DBPA has performances of 70 and 64% power added efficiency with an 11 dB gain and a 41 dBm output power at 1.7 and 2.6 GHz, respectively. Its average drain efficiency is more than 42% and the adjacent channel leakage ratios are lower than -46 dBc at both frequencies with the digital predistortion adjustment for a 5 MHz WCDMA signal input.

关键词： channel coding channel estimation iterative decoding matrix algebra OFDM modulation precoding vectors channel estimation symbol detection OFDM system data-nulling superimposed pilot scheme input data vector precoding matrix training pilot insertion frequency-division multiplexed pilot FDM pilot input data distortion mitigation simple iterative reconstruction scheme

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Spread Spectrum OFDM-IM With Efficient Precoded matrix and Low Complexity Detector

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IEEE ACCESS 2024年 12卷 192293-192300页

作者： Waheed, Ahmed Mohammady, Somayeh Technol Univ Dublin TUD Sch Elect & Elect Engn Dublin 7 Ireland

This paper introduces a novel scheme that employs efficient precoded matrices for index modulation orthogonal frequency division multiplexing namely (EP-OFDM-IM). This technique implements Discrete Fourier Transform (DFT) and Fast Walsh Hadamard Transform (FWHT) precoded matrices for spreading the subset of active M-ary data symbols and their indices to transmit additional information. This aims to enhance the system's transmit diversity (TD) by exploiting multipath and index diversities. Moreover, a low complex minimum means square error greedy detector (MMSE-GD) is proposed that can achieve optimal performance for perfect channel state information (CSI) and superior performance compared to maximum likelihood (ML) under imperfect CSI. The theoretical analysis based on pair-wise error probability is derived to estimate the bit error probability (BEP) of the proposed scheme for the performance analysis. Simulation results demonstrate that our proposed scheme EP-OFDM-IM significantly outperforms various existing competitive benchmark IM schemes. Specifically, at a spectral efficiency (SE) of 1.5 bps/Hz, and BEP of 10-3, our proposed scheme achieves addition of 15dB gain.

关键词： Discrete Fourier transforms OFDM Indexes Computational complexity Detectors Symbols precoding Modulation Vectors Diversity methods Index modulation precoding matrix maximum likelihood greedy detector MMSE Walsh-Hadamard fast Walsh-Hadamard transform discrete Fourier transform 5G 6G

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Symbol Detection Aided Algorithm for Interference Alignment of Maximum Signal to Interference and Noise Ratio 2018

Symbol Detection Aided Algorithm for Interference Alignment ...

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2nd International Conference on Telecommunications and Communication Engineering (ICTCE)

作者： Jia, Guoqing Wang, Xinqi Wang, Lu Niu, Jinxue Qinghai Nationalities Univ Xining Qinghai Peoples R China

ISBN: (纸本)9781450365857

In the KxK multiple-input and multiple-output ( MIMO) interference alignment ( IA) communication system, for the problem of the traditional maximum signal to noise ratio ( MAX-SINR) algorithm's poorly performed, a symbol detection aided maximum signal to interference and noise ratio ( SDA-MAX-SINR) algorithm for IA is proposed. The algorithm improves the system's performance of the traditional MAX-SINR algorithm. First, the traditional MAX-SINR algorithm for IA is used to obtain the received signal. Next, based on the maximum signal to interference and noise ratio(SINR) criterion, the receiver interference suppression matrix and the transmitter precoding matrix are calculated by using the received signal directly. The simulation result shows that compared with the traditional MAX-SINR algorithm, the SDA-MAX-SINR algorithm has decreases the mean square error ( MSE) and the bit error rate ( BER) of the system effectively, improved the dependability of MIMO system obviously.

关键词： Interference alignment Maximum signal to interference and noise ratio Symbol detection assistant precoding matrix interference suppression matrix

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A SVD-Based Optimum Algorithm Research for Macro-Femto Cell Interference Coordination 81

A SVD-Based Optimum Algorithm Research for Macro-Femto Cell ...

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81st IEEE Vehicular Technology Conference (VTC Spring)

作者： Yan, Kaiyue Yang, Yan Dang, Shuping Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety Beijing 100044 Peoples R China Univ Oxford Dept Engn Sci Oxford OX1 3PJ England

ISBN: (纸本)9781479980888

The intra-tier interference in heterogeneous networks becomes more serious when the number of macro-femto cells dramatically increases. Based on the singular value decomposition (SVD) algorithm, this paper proposes an optimized interference alignment (IA) algorithm to improve the macrofemto cell downlink rate. To achieve the largest degrees of freedom (DOF), we adopt the precoding matrix as a powerful tool to mitigate the effect of inter-channel interference (ICI). In comparison with the conventional interference coordination methods, the SVD algorithm is capable of adjusting the coefficients of the precoding matrix with lower complexity. Furthermore, zero-forcing algorithm is also used to combat ICI in this proposed IA algorithm. The numerical results show that ICI can be suppressed effectively and the system performance in terms of throughput and signal-to-interference-plus-noise ratio (SINR) can be improved considerably.

关键词： Heterogeneous network macro-femto cell interference alignment singular value decomposition precoding matrix

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Stochastic precoding for MISO Interference Channels with Channel Mean Feedback

Stochastic Precoding for MISO Interference Channels with Cha...

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54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Ding, Minhua Zhang, Q. T. City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

ISBN: (纸本)9781424492688

Two linear precoding strategies are investigated for multiple-input single-out (MISO) interference channels with channel mean feedback at transmitters. The interference at each receiver is treated as additive noise. The challenge here is that previous analysis with perfect channel state information (CSI) at transmitters does not apply. Based on stochastic ordering, the altruistic non-equilibrium stochastic zero forcing strategy is first proposed, generalizing traditional zero forcing which requires perfect CSI. Interestingly, the precoding matrices here are all rank-one as in traditional zero forcing. The competitive use of the common channel is also formulated as a strategic game. Different from the perfect CSI case, with channel mean feedback, infinitely many Nash equilibria exist in general, which are not necessarily rank-one. Comparisons of the above two precoding strategies reveal no overall dominance of one over the other, thereby establishing stochastic zero forcing as an appealing alternative to the prevailing Nash equilibrium strategies.

关键词： Interference channels Laplace equations MISO interference channels Nash equilibrium Receivers Transmitters Vectors additive noise altruistic nonequilibrium stochastic zero forcing strategy channel mean feedback channel state information game theory infinitely many Nash equilibria linear precoding strategy multiple-input single-out interference channel precoding precoding matrix radio receivers radio transmitters radiofrequency interference receiver stochastic ordering stochastic precoding stochastic processes strategic game transmitter wireless channels

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Amplify-and-forward secondary spectrum access in multicarrier cognitive radio systems 3

Amplify-and-forward secondary spectrum access in multicarrie...

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IEEE International Workshop on Measurements and Networking (M&N)

作者： Darsena, Donatella Gelli, Giacinto Verde, Francesco Univ Parthenope Dipartimento Ingn Naples Italy Univ Federico II Dipartimento Ingn Elettr & Tecnol Informaz Naples Italy

ISBN: (纸本)9781479918607

Innovative spectrum sharing policies, possibly leveraged by cognitive radio (CR) technologies, are expected to play a significant role in forthcoming 5G systems, employing multicarrier techniques for modulation and multiple-access. In this paper, we propose an opportunistic amplify-and-forward relaying scheme for a multicarrier CR network, where a secondary user (SU) is allowed to share communication resources with a primary user (PU) transmitting with orthogonal frequency-division multiplexing (OFDM) technology. Instead of minimizing the interference to the PU, the SU transmitter relays the received PU signal on the different OFDM subcarriers by using a precoding matrix depending on the symbols that must be delivered to the SU receiver. The information-theoretic capacity of the proposed protocol is assessed, showing that, under mild conditions, the SU can gain a significant data-rate performance, while not degrading (but even improving) the PU performance.

关键词： 5G mobile communication OFDM modulation amplify and forward communication cognitive radio frequency division multiple access matrix algebra network coding precoding protocols radio receivers radio spectrum management radio transmitters relay networks (telecommunication) 5G system OFDM multiple access OFDM subcarrier amplify-and-forward secondary spectrum access communication resources share innovative spectrum sharing policy multicarrier cognitive radio system opportunistic amplify-and-forward relaying scheme orthogonal frequency-division multiplexing technology precoding matrix primary user protocol information-theoretic capacity secondary user receiver secondary user transmitter relay Correlation Discrete Fourier transforms Frequency-domain analysis OFDM Receivers Training Orthogonal frequency division multiplexing Frequency division multiaccess Cognitive radio Radio spectrum management discrete Fourier transform Frequency-domain analysis prediction coding radio receivers matrix algebra RADIO TRANSMITTERS Receivers Network coding protocols Functional training Plutonium

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Interference Alignment in Multi-Carrier Interference Networks

Interference Alignment in Multi-Carrier Interference Network...

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IEEE International Symposium on Information Theory (ISIT)

作者： Shi, Changxin Berry, Randall A. Honig, Michael L. Northwestern Univ Dept Elect Engn & Comp Sci Evanston IL 60208 USA

ISBN: (纸本)9781457705953

We consider an interference network with multicarrier transmission over M parallel sub-channels. There are K transmitter-receiver pairs, each transmitter transmits a single data stream with a rank-one precoding matrix, and the receivers are assumed to be linear. We show that a necessary condition for zero interference (alignment across sub-channels) is K <= 2M-2. In contrast, for a Multi-Input Multi-Output (MIMO) interference network with M x M spatial channels (full channel matrices) the corresponding condition is known to be K <= 2M-1. We also characterize the sum rate at high Signal-to-Noise Ratios (SNR) by bounding the SNR offset (x-intercept) of the asymptote of the sum rate vs SNR curve. For a randomly chosen aligned solution as M increases, this offset shifts to the right as log M. In contrast, the SNR offset for a MIMO interference network does not increase with M. An approximation for the performance of sampling the best out of L aligned solutions is also presented. Numerical results show the analytical asymptotes accurately predict the sum rate curves at moderate to high SNRs.

关键词： Equations Interference MIMO MIMO MIMO communication Random variables Receivers SNR Signal to noise ratio Transmitters channel coding data stream interference alignment interference suppression matrix algebra multicarrier interference networks multiple input multiple output parallel sub-channels precoding precoding matrix radio networks radio receivers radio transmitters receiver signal-to-noise ratio spatial channels transmitter wireless channels

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Channel Prediction for Limited Feedback Precoded MIMO-OFDM Systems

Channel Prediction for Limited Feedback Precoded MIMO-OFDM S...

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9th IEEE International Symposium on Signal Processing and Information Technology

作者： Khrwat, A. S. Sharif, B. S. Tsimenidis, C. C. Boussakta, S. Al-Dweik, A. J. Newcastle Univ Sch Elect Elect & Comp Engn Merz Court NE1 7RU Tyne & Wear England Khalifa Univ Dept Commun Engn Sharjah U Arab Emirates

ISBN: (纸本)9781424459490

In this paper;the performance of limited feedback precoded spatial multiplexing multiple-input multiple-output orthogonal frequency division multiplexing (MIMO OFDM) systems is investigated in time varying fading channels. Most studies into limited feedback precoded (MIMO OFDM) systems are based on the notion of time invariant channels throughout transmission. Therefore, the precoding matrix for each subcarrier can be designed at the receiver in terms of the current channel state, fed back to the transmitter;and used for the subsequent block of data symbols. However, in time varying channels, the feedback information becomes outdated, which results in significant system performance degradation. To mitigate this system performance degradation caused by outdated information due to a delay in the feedback channel, this paper considers a more practical system, where the channel varies from one block of symbols to another A method is proposed based on modelling the channel as an autoregressive (AR) model and using a Kalman filter linear predictor at the receiver to predict the channels states, required to design the precoding matrices for the next OFDM symbol carriers whose indexes are fed back to the transmitter The performance of this method is investigated using computer simulation, and the results obtained for the proposed channel prediction demonstrate improved bit error rate performance for time-varying Rayleigh fading channels, even in systems with high mobility

关键词： Channel prediction Limited feedback Kalman filter MIMO OFDM precoding matrix

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