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hybrid precoding design for millimetre wave systems with the partially-connected structure

IET COMMUNICATIONS 2020年第4期14卷 561-567页

作者： Wang, Ye Zou, Weixia Beijing Univ Posts & Telecommun KeyLab Universal Wireless Commun Beijing Peoples R China

Millimetre wave (mmWave) communication is a promising technique for fifth generation networks. hybrid precoding is introduced to mmWave communication systems to provide a reasonable trade-off strategy between system performance and energy cost. The hybrid precoder with the partially-connected structure has relatively low hardware complexity and less energy consumption. In this study, the authors decompose the optimisation problem of analogue precoder into several subproblems, and introduce a heuristic method to find the solution. Then, they obtain the digital precoder according to the product of the channel matrix and analogue precoding matrix. Numerical simulations show that the proposed algorithm performs well in most cases. Considering the error of channel estimation or the finite resolution of phase shifters, the proposed algorithm is able to provide acceptable spectral efficiency as well.

关键词： optimisation channel estimation precoding millimetre wave communication 5G mobile communication matrix algebra millimetre wave systems partially-connected structure millimetre wave communication fifth generation networks mmWave communication systems system performance energy cost hybrid precoder low hardware complexity energy consumption digital precoder channel matrix analogue precoding matrix hybrid precoding design optimisation problem heuristic method numerical simulations channel estimation error phase shifters

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Deep Learning Based Low-Resolution hybrid Precoding Design for mmWave MISO Systems

Deep Learning Based Low-Resolution Hybrid Precoding Design f...

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IEEE Global Communications Conference (GLOBECOM) on Advanced Technology for 5G Plus

作者： Bo, Zhu Liu, Rang Guo, Yiqun Li, Ming Liu, Qian Dalian Univ Technol Sch Informat & Commun Engn Dalian 116024 Liaoning Peoples R China Dalian Univ Technol Sch Comp Sci & Technol Dalian 116024 Liaoning Peoples R China

ISBN: (纸本)9781728173078

Millimeter wave (mmWave) communication has been considered as a key enabling technology for next generation cellular systems. In order to combat severe path-loss of mmWave channel, hardware-efficient hybrid beamforming schemes are widely considered in mmWave massive multi-input multi-output (MIMO) systems. However, the high computational complexity for obtaining accurate channel estimation and designing hybrid beamformer is a major challenge, which hurdles the deployment of mmWave massive MIMO systems. In this paper, we consider a multi-user mmWave communication system with low-resolution phase shifters (PSs) and aim to design a novel deep learning based low-complexity and robust hybrid precoding design algorithm. A convolutional neural network (CNN) is utilized to predict/design analog precoders with roughly estimated channels using a small amount of pilot signals. Analog precoder can be efficiently predicted from the imperfect channel convolutional neural network (IC-CNN). Once the analog precoder is obtained, the digital precoder is designed by minimum mean square error method. Simulation results demonstrate that the proposed algorithm is efficient and can achieve satisfactory performance with a significant reduction in computing time.

关键词： Millimeter wave (mmWave) communications hybrid precoder deep learning imperfect channel state information low-resolution phase shifters

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ROD-based hybrid TH precoding and combining for mmWave large-scale MIMO systems

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DIGITAL SIGNAL PROCESSING 2019年 93卷 102-114页

作者： Bai, Xiaoyu Liu, Fulai Du, Ruiyan Kan, Xiaodong Xu, Yixin Zhang, Yanshuo Northeastern Univ Sch Comp Sci & Engn Shenyang 110819 Liaoning Peoples R China Northeastern Univ Qinhuangdao Inst Engn Optimizat & Smart Antenna Qinhuangdao 066004 Hebei Peoples R China

hybrid precoding is one of key techniques for millimeter wave (mmWave) large-scale multiple-input multiple-output (MIMO) systems. This paper considers a nonlinear hybrid precoding architecture which consists of a nonlinear unit, a reductive digital precoder and a constant modulus radio frequency (RF) precoder, and presents a novel hybrid Tomlinson-Harashima (TH) precoding and combining algorithm. Firstly, due to the intractability of the sum rates maximization problem for such a nonlinear hybrid precoding architecture, a tractable three-stage optimization problem is constructed through the lower bound of the sum rates, which allows the digital precoding matrix, the RF precoding matrix and the RF combining matrix to be optimized sequentially and independently. Then, in order to solve the three-stage optimization problem effectively, a novel row orthogonal decomposition (ROD) is defined. Based on the ROD, it is interesting that the necessary and sufficient condition of the optimal digital precoding matrix can be obtained, and a near-optimal RF precoding matrix can be derived. Finally, the optimization of the RF combining matrix is reformulated as a unimodular quadratic programming and solved by a generalized power method. Theoretical analyses and simulations indicate that the proposed ROD-based hybrid TH precoding and combining algorithm can offer a higher sum rates and a lower bit error rate with a comparable complexity in comparison to the previous works. (C) 2019 Elsevier Inc. All rights reserved.

关键词： Millimeter-wave hybrid precoder Tomlinson-Harashima precoding Nonlinear precoding MIMO

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hybrid precoding with phase shifter reduction for 5G massive antenna multi-user systems in millimetre wave

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IET COMMUNICATIONS 2019年第16期13卷 2429-2435页

作者： Zhao, Xiongwen Zhang, Yu Geng, Suiyan Du, Fei Fu, Zihao Zhou, Zhenyu North China Elect Power Univ Sch Elect & Elect Engn Beijing 102206 Peoples R China

In this study, the performances of commonly used precoding schemes are evaluated based on channel measurements carried out at 28GHz in a railway station for a massive antenna system configuration. And a hybrid precoding algorithm for a fifth generation (5G) multi-user antenna system is proposed and its performance is evaluated based on real measured channels. Specifically, An upper bound for achievable sum-rate of phased zero forcing (PZF) algorithm is derived and a precoding technique by reduction of phase shifters (PSs) named reduced-PZF (RPZF) is proposed, which can obviously reduce power consumption in hybrid precoding systems. In addition, the authors give the closed-form expression for achievable sum-rate when RPZF is used. There are no requirements in the authors' proposed scheme with complicated matrix decomposition and optimisation techniques. The simulation results show that it is possible to reduce 30 and 50% of the PSs by using the proposed hybrid precoder with better system performance in the line-of-sight (LoS) and non-LoS scenarios, respectively. In addition, the digital PSs with 3 bits low resolution can achieve the similar performance when using analogue ones.

关键词： precoding MIMO communication antenna arrays wireless channels multi-access systems phase shifters similar performance phase shifter reduction 5G massive antenna multiuser systems millimetre wave commonly used precoding schemes channel measurements 28 GHz railway station massive antenna system configuration hybrid precoding algorithm fifth generation multiuser antenna system measured channels achievable sum-rate phased zero forcing algorithm precoding technique phase shifters PSs reduced-PZF RPZF hybrid precoding systems authors complicated matrix decomposition optimisation techniques hybrid precoder system performance frequency 28 0 GHz word length 3 0 bit

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Low-Complexity Subspace-Based Multi-User hybrid Precoding

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IEEE COMMUNICATIONS LETTERS 2019年第2期23卷 222-225页

作者： Dutta, Biswajit Budhiraja, Rohit Koilpillai, Ravinder D. IIT Madras Dept Elect Engn Chennai 600036 India IIT Kanpur Dept Elect Engn Kanpur 208016 Uttar Pradesh India

We propose a novel multi-user hybrid precoder design that imitates the bit error rate (BER) performance of a given fully digital precoder by minimizing the Frobenious norm between them. We show that the proposed design equivalently minimizes the chordal distance between the column spaces of the phase-only RF precoder and the given fully digital precoder. The proposed design, in the large antenna regime, has the same BER as that of an existing optimal hybrid precoder design but with much reduced complexity. Furthermore, the proposed design is also shown to approach the BER of a given fully digital precoder.

关键词： Chordal distance hybrid precoder subspace

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Random SBT Precoding for Angle Estimation of mmWave Massive MIMO Systems Using Sparse Arrays Spacing

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IEEE ACCESS 2020年 8卷 163380-163393页

作者： Lin, Yuan-Pei Yang, Ting-Ming Natl Chiao Tung Univ Hsinchu 30010 Taiwan

In this article, we consider the estimation of angle of arrival (AoA) and angle of departure (AoD) for mmWave MIMO channels. For mmWave systems, there is typically a large number of antennas but limited radio frequency (RF) chains. The RF chain limitation indirectly restricts the effective number of antennas or the effective array size. In radar applications, it is known that a larger array size leads to more accurate AoA estimation or more resolvable paths. It is also known that with sparse arrays, which places antennas in a nonuniform sparse manner, an enlarged virtual array can be constructed when the sources are uncorrelated. We show that the idea of sparse arrays can also be used in mmWave systems to have augmented array sizes. The main difficulty in applying sparse arrays to mmWave MIMO channels lies in the fact the signals of different paths can be correlated in mmWave system, but uncorrelatedness is necessary for applying sparse array results. We show that the paths can be decorrelated by employing random precoders and combiners that are submatrices of banded Toeplitz matrices (SBT). When the precoder and combiner are SBT that are designed according to the antenna spacing of a sparse array, we can construct enlarged virtual transmit and receive arrays. With enlarged virtual arrays, accurate estimates can be obtained, as will be demonstrated by simulation examples.

关键词： Estimation Radio frequency Antenna arrays Training Channel estimation Covariance matrices Angle estimation hybrid precoder massive MIMO mmWave submatrix of a banded Toeplitz sparse arrays

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Multi-Robot Enhanced Intelligent Multi-User Millimeter-Wave MIMO Systems under Uncertain Environment

Multi-Robot Enhanced Intelligent Multi-User Millimeter-Wave ...

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International Conference on Computing, Networking and Communications (ICNC)

作者： Feng, Ming Xu, Hao Univ Nevada Dept Elect & Biomed Engn Reno NV 89557 USA

ISBN: (纸本)9781538692233

This paper investigates how to maximize the practical communication quality of multi-user millimeter-wave (mmWave) MIMO systems with uncertain environment through effectively using the mobility from multi-robots as dynamic relays and adopting machine learning techniques. mmWave MIMO has been considered as a promising wireless communication technology due to the high frequency usage efficiency from beamforming. However, the uncertain environment could seriously affect the effectiveness and practicality of beamforming since wireless channels may have a more complicated structure, and the coordination among multiple nodes could be more difficult. For instance, the uncertain distribution of mobile users could significantly affect the performance of wireless channels, and then significantly degrade practical communication quality. Therefore, this paper presents a novel Multi-Robot Enhanced Intelligent Multi-User Millimeter-Wave MIMO (MREI-MU-MIMO) system that adopt both dynamic codebook based beam training protocol and online reinforcement learning to supervise the mobility of multi-robot-relay as well as handle the serious effects form the uncertain environment. Firstly, a novel dynamic codebook development is presented that cannot only lower the complexity of existing beamforming codebooks and also handle the complicated channel structure under uncertainty during multi-user beam training. Then, a decentralized Deep Q-Network (DQN) reinforcement learning algorithm has been developed to intelligently manage multi-robot mobility and further effectively assign the optimal MIMO to handle the uncertainty from environment. The effectiveness of the proposed design has been demonstrated through real-time simulation and experiment.

关键词： Reinforcement learning DQN hybrid precoder Dynamic Codebook Millimeter-Wave MIMO

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Game Theoretic Based Intelligent Multi-User Millimeter-Wave MIMO Systems under Uncertain Environment and Unknown Interference

Game Theoretic Based Intelligent Multi-User Millimeter-Wave ...

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International Conference on Computing, Networking and Communications (ICNC)

作者： Feng, Ming Xu, Hao Univ Nevada Dept Elect & Biomed Engn Reno NV 89557 USA

ISBN: (纸本)9781538692233

This paper investigates the intelligent development problem for of multi-user millimeter-wave (mmWave) MIMO systems under uncertain environment and unknown interference. To effectively increase the real-time performance of millimeter-wave (mmWave) MIMO system, a series of advanced communication techniques have been proposed recently, such as hybrid precoding and MIMO relay, which integrated analog and digital schemes to reduce the hardware complexity of the conventional fully-digital beamforming and further maximizing the capacity of the MIMO channel through introducing relays and formulating multi-hop system. However, in practice harsh conditions such as uncertainty environment like rain, wind, snow, users' movement, and the unknown interference, would seriously affect the effectiveness and practicality of those emerging communication techniques. This paper proposes a Game Theoretic Based Intelligent Multi-User Millimeter-Wave MIMO (GT-MU-MIMO) system that includes a novel dynamic codebook based beam training protocol and an online reinforcement learning algorithm supervising the mobility of multi-robot-relay as well as handling the serious effects from the uncertain environment and unknown ***, a novel dynamic codebook development has been introduced to lower the complexity during multi-user beam training. Then, a decentralized game theoretic deep reinforcement learning based intelligent algorithm has been developed. It will not only optimize GT-MII-MIMO beam training efficiency and managing mobility of multi-robot-relay online, and also effectively handle uncertainty while user moving and avoiding the signal interference from unknown radio jamming attack, etc. The effectiveness of proposed design has been demonstrated through computer aided simulation.

关键词： Reinforcement learning Deep Q Network hybrid precoder Dynamic Codebook Millimeter-Wave MIMO

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hybrid Precoding for mmWave Massive MIMO Systems With Partially Connected Structure

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IEEE ACCESS 2017年 5卷 15142-15151页

作者： Li, Nanxi Wei, Zaixue Yang, Hongwen Zhang, Xin Yang, Dacheng Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing 100876 Peoples R China

hybrid precoding is widely studied in millimetre-wave (mmWave) massive MIMO systems due to low cost as well as low power consumption. In general, there are two kinds of hybrid precoding structures: one is fully connected structure (FCS), where each radio frequency (RF) chain is connected to all antennas, and the other is partially connected structure (PCS), where each RF chain is connected to a sub-array. In this paper, we investigate the optimal hybrid precoder design problem for mmWave massive MIMO systems based on PCS, since this kind of structure is more practical for antenna deployment. We first focus on the optimization of analog precoder (AP) and propose two AP design schemes for high signal-to-noise ratio (SNR) condition and low SNR condition, respectively. For each of the schemes, the original optimization problem is reformulated to single-stream optimal transmitter beamforming problem with per-antenna power constraint, which has an optimal solution. Then, the optimal digital precoder is obtained by water-filling algorithm after AP is determined. Moreover, upper bounds of the achievable data rate for the proposed schemes with closed-form expression are derived.

关键词： Massive MIMO mmWave hybrid precoder partially connected structure

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Secure Massive MIMO Systems With Limited RF Chains

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2017年第6期66卷 5456-5461页

作者： Zhu, Jun Xu, Wei Wang, Ning Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada Southeast Univ Natl Mobile Commun Lab Nanjing 210096 Jiangsu Peoples R China Zhengzhou Univ Dept Elect Engn Zhengzhou 450001 Henan Peoples R China

In future practical deployments of massive multi-input multioutput (MIMO) systems, the number of radio-frequency (RF) chains at the base stations (BSs) may be much smaller than the number of BS antennas to reduce the overall expenditure. In this correspondence, we propose a novel design framework for joint data and artificial noise (AN) precoding in a multiuser massive MIMO system with limited number of RF chains, which improves the wireless security performance. With imperfect channel state information (CSI), we analytically derive an achievable lower bound on the ergodic secrecy rate of any mobile terminal (MT) for both analog and hybrid precoding schemes. The closed-form lower bound is used to determine optimal power splitting between data and AN that maximizes the secrecy rate through simple 1-D search. Analytical and numerical results together reveal that the proposed hybrid precoder, although suffering from reduced secrecy rate compared with the theoretical full-dimensional precoder, is free of the high computational complexity of large-scale matrix inversion and null-space calculations and largely reduces the hardware cost.

关键词： Artificial noise hybrid precoder imperfect channel-state information (CSI) limited radio-frequency (RF) chains massive multiple-input multiple-output (MIMO) physical layer security

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