scholarly journals A New Design of Codebook for Hybrid Precoding in Millimeter-Wave Massive MIMO Systems

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 743
Author(s):  
Gang Liu ◽  
Honggui Deng ◽  
Kai Yang ◽  
Zaoxing Zhu ◽  
Jitai Liu ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Mimo Systems ◽  
Learning Algorithm ◽  
Matching Pursuit ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Iteration Algorithm ◽  
Codebook Design ◽  
Hybrid Precoding

The precoding scheme based on codebooks is used to save the same set of codebook in advance at the transmitter and the receiver, then, the receiver selects the most appropriate precoding matrix from codebooks according to different channel state information (CSI). Therefore, the design of codebook plays an important role in the performance of the whole scheme. The symmetry-based hybrid precoder and combiner is a highly energy efficient structure in the millimeter-wave massive multiple-input multiple-output (MIMO) system, but at the same time, it also has the problems of high bit error rate and low spectral efficiency. In order to improve the spectral efficiency, we formulate the codebook design as a joint optimization problem and propose an iteration algorithm to obtain the enhanced codebook by combining the compressive sampling matching pursuit (CoSaMP) algorithm with the dictionary learning algorithm. In order to prove the validity of the proposed algorithm, we simulate and analyze the change of the spectral efficiency of the algorithm with the signal-to-noise ratio (SNR) and the number of radio frequency (RF) chains of different precoding schemes. The simulation results demonstrate that the spectral efficiency of the algorithm is obviously outstanding compared with that of the OMP-based joint codebook algorithm and the hybrid precoding algorithm with quantization algorithm under low SNR and different numbers of RF chains. Particularly, when SNR is lower than 0 dB, the proposed algorithm performs very close to the optimal unconstrained precoding algorithm.

scholarly journals Design and Development of Novel Hybrid Precoder for Millimeter-Wave MIMO System

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
SRINIVAS K ◽  
T Srinivasulu
Keyword(s):  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Large Scale ◽  
Processing Time ◽  
Mimo Systems ◽  
Mimo System ◽  
Phase Shifters ◽  
Additional Element ◽  
Factorization Problem ◽  
Hybrid Beamforming

Power consumption and hardware cost reduction with the use of hybrid beamforming in large-scale millimeter wave MIMO systems. The large dimensional analog precoding integrates with the hybrid beamforming based on the phase shifters including digital precoding with lower dimensionality. The reduction of Euclidean distance between the hybrid precoder and fully digital is the major problem to overcome the minimization of resultant spectral efficiency. The issue formulates as a fully digital precoder’s matrix factorization problem based on the analog RF precoder matrix and the digital baseband precoder matrix. An additional element-wise unit modulus constraint is imposed by the phase shifters on the analog RF precoder matrix. The traditional methods have a problem of performance loss in spectral efficiency. In the processing time and iteration, high complexities result in optimization algorithms. In this paper, a novel low complexity algorithm proposes which maximizes the spectral efficiency and reduces the computational processing time. 

Adaptive MIMO Systems with High Spectral Efficiency

2009 ◽  
pp. 286-307 ◽  
Author(s):  
Zhendong Zhou ◽  
Branka Vucetic
Keyword(s):  
Spectral Efficiency ◽  
Adaptive System ◽  
Mimo Systems ◽  
Mimo System ◽  
Adaptive Modulation ◽  
Multiple Input Multiple Output ◽  
Adaptive Modulation And Coding ◽  
Multiple Input ◽  
High Spectral Efficiency ◽  
Input Multiple Output

This chapter introduces the adaptive modulation and coding (AMC) as a practical means of approaching the high spectral efficiency theoretically promised by multiple-input multiple-output (MIMO) systems. It investigates the AMC MIMO systems in a generic framework and gives a quantitative analysis of the multiplexing gain of these systems. The effects of imperfect channel state information (CSI) on the AMC MIMO systems are pointed out. In the context of imperfect CSI, a design of robust near-capacity AMC MIMO system is proposed and its good performance is verified by simulation results. The proposed adaptive system is compared with the non-adaptive MIMO system, which shows the adaptive system approaches the channel capacity closer.

scholarly journals GAMP-SBL-based channel estimation for millimeter-wave MIMO systems

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Jianfeng Shao ◽  
Xianpeng Wang ◽  
Xiang Lan ◽  
Zhiguang Han ◽  
Ting Su
Keyword(s):  
Channel Estimation ◽  
Millimeter Wave ◽  
Mimo Systems ◽  
Learning Algorithm ◽  
Mimo System ◽  
Estimation Algorithm ◽  
Mimo Channel ◽  
Estimation Methods ◽  
Estimation Accuracy ◽  
Signal Recovery

AbstractBased on the finite scattering characters of the millimeter-wave multiple-input multiple-output (MIMO) channel, the mmWave channel estimation problem can be considered as a sparse signal recovery problem. However, most traditional channel estimation methods depend on grid search, which may lead to considerable precision loss. To improve the channel estimation accuracy, we propose a high-precision two-stage millimeter-wave MIMO system channel estimation algorithm. Since the traditional expectation–maximization-based sparse Bayesian learning algorithm can be applied to handle this problem, it spends lots of time to calculate the E-step which needs to compute the inversion of a high-dimensional matrix. To avoid the high computation of matrix inversion, we combine damp generalized approximate message passing with the E-step in SBL. We then improve a refined algorithm to handle the dictionary matrix mismatching problem in sparse representation. Numerical simulations show that the estimation time of the proposed algorithm is greatly reduced compared with the traditional SBL algorithm and better estimation performance is obtained at the same time.

scholarly journals Joint Spectral Efficiency Optimization of Uplink and Downlink for Massive MIMO Enabled Wireless Energy Harvesting Systems

2020 ◽  
Author(s):  
Wenfeng Sun ◽  
Chen Liu ◽  
Mujun Qian ◽  
Yan Chen ◽  
Shu Xu
Keyword(s):  
Energy Harvesting ◽  
Spectral Efficiency ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Maximization Problem ◽  
Iteration Algorithm ◽  
Successive Approximation Method ◽  
Harvesting Systems ◽  
Wireless Energy Harvesting

Abstract This paper proposes a unified system model and uses a general wireless energy harvesting (EH) protocol in massive multiple-input multiple-output (MIMO) systems, in which the terminals have no fixed power supply and thus need to replenish energy via the received signals from the base station (BS). On the downlink, the BS delivers radio frequency (RF) signals to all terminals and each terminal coordinates the processes of EH and information decoding (ID) with wireless EH protocol. On the uplink, a fraction of the harvested energy is used for uplink pilot transmission and the remaining fraction is used for uplink data transmission. Closed-form lower bound expressions for each terminal are first obtained on the uplink and downlink, respectively. Based on these expressions, we then formulate the joint spectral efficiency (SE) of uplink and downlink maximization problem with some practical constraints. As the formulated optimization problem is non-linear and non-convex, it is hard to solve directly. To provide a solution, an iteration algorithm is proposed by utilizing one-dimensional search technique and successive approximation method based on geometric program (GP). Additionally, the convergence and complexity of the proposed algorithm are discussed as well. Finally, the feasibility of the proposed algorithm and analytical results are demonstrated by extensive computer simulations.

scholarly journals Dynamically Subarray-Connected Hybrid Precoding Scheme for Multiuser Millimeter-Wave Massive MIMO Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guangyan Liao ◽  
Feng Zhao
Keyword(s):  
Millimeter Wave ◽  
Massive Mimo ◽  
Mean Squared Error ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Hybrid Precoding ◽  
Minimum Mean Squared Error ◽  
Specific Subset ◽  
Input Multiple Output

Hybrid precoding is widely used in millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems. However, most prior work on hybrid precoding focused on the fully connected hybrid architectures and the subconnected but fixed architectures in which each radio frequency (RF) chain is connected to a specific subset of the antennas. The limited work shows that dynamic subarray architectures address the tradeoff between achievable spectral efficiency and energy efficiency of mmWave massive MIMO systems. Nevertheless, in the multiuser hybrid precoding systems, the existing dynamic subarray schemes ignore the fairness of users and the problem of user selection. In this paper, we propose a novel multiuser hybrid precoding scheme for dynamic subarray architectures. Firstly, we select a multiuser set among all users according to the analog effective channel information of the base station (BS) and then design the subset of the antennas to each RF by the fairness antenna-partitioning algorithm. Finally, the optimal analog precoding vector is designed according to each subarray, and the digital precoding is designed by the minimum mean-squared error (MMSE) criterion. The simulation results show that the performance advantages of the proposed multiuser hybrid precoding scheme for dynamic subarray architectures.

scholarly journals An Efficient Precoding Algorithm for mmWave Massive MIMO Systems

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1099 ◽  
Author(s):  
Imran Khan ◽  
Shagufta Henna ◽  
Nasreen Anjum ◽  
Aduwati Sali ◽  
Jonathan Rodrigues ◽  
...  
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Matching Pursuit ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Low Complexity ◽  
Global Optimum ◽  
Vital Role ◽  
Matrix Inversion ◽  
Inner Product

Symmetrical precoding and algorithms play a vital role in the field of wireless communications and cellular networks. This paper proposed a low-complexity hybrid precoding algorithm for mmWave massive multiple-input multiple-output (MIMO) systems. The traditional orthogonal matching pursuit (OMP) has a large complexity, as it requires matrix inversion and known candidate matrices. Therefore, we propose a bird swarm algorithm (BSA) based matrix-inversion bypass (MIB) OMP (BSAMIBOMP) algorithm which has the feature to quickly search the BSA global optimum value. It only directly finds the array response vector multiplied by the residual inner product, so it does not require the candidate’s matrices. Moreover, it deploys the Banachiewicz–Schur generalized inverse of the partitioned matrix to decompose the high-dimensional matrix into low-dimensional in order to avoid the need for a matrix inversion operation. The simulation results show that the proposed algorithm effectively improves the bit error rate (BER), spectral efficiency (SE), complexity, and energy efficiency of the mmWave massive MIMO system as compared with the existing OMP hybrid and SDRAltMin algorithm without any matrix inversion and known candidate matrix information requirement.

Analysis of Optimum Precoding schemes in Millimeter Wave System

2020 ◽  
Vol 13 ◽  
Author(s):  
Divya Singh ◽  
Aasheesh Shukla
Keyword(s):  
Power Consumption ◽  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Phase Shifter ◽  
Phase Shifters ◽  
Achievable Rate ◽  
Wave System ◽  
Digital To Analog Converter ◽  
Hybrid Precoding ◽  
Analog Converter

Background : Millimeter wave technology is the emerging technology in wireless communication due to increased demand for data traffic and its numerous advantages however it suffers from severe attenuation. To mitigate this attenuation, phased antenna arrays are used for unidirectional power distribution. An initial access is needed to make a connection between the base station and users in millimeter wave system. The high complexity and cost can be mitigated by the use of hybrid precoding schemes. Hybrid precoding techniques are developed to reduce the complexity, power consumption and cost by using phase shifters in place of converters. The use of phase shifters also increases the spectral efficiency. Objective: Analysis of Optimum Precoding schemes in Millimeter Wave System. Method: In this paper, the suitability of existing hybrid precoding solutions are explored on the basis of the different algorithms and the architecture to increase the average achievable rate. Previous work done in hybrid precoding is also compared on the basis of the resolution of the phase shifter and digital to analog converter. Results: A comparison of the previous work is done on the basis of different parameters like the resolution of phase shifters, digital to analog converter, amount of power consumption and spectral efficiency. Table 2 shows the average achievable rate of different algorithms at SNR= 0 dB and 5 dB. Table 3 also compares the performance achieved by the hybrid precoder in the fully connected structure with two existing approaches, dynamic subarray structure with and without switch and sub connected or partially connected structure. Table 4 gives the comparative analysis of hybrid precoding with the different resolutions of the phase shifter and DAC. Conclusion: In this paper, some available literature is reviewed and summarized about hybrid precoding in millimeter wave communication. Current solutions of hybrid precoding are also reviewed and compared in terms of their efficiency, power consumption, and effectiveness. The limitations of the existing hybrid precoding algorithms are the selection of group and resolution of phase shifters. The mm wave massive MIMO is only feasible due to hybrid precoding.

Novel Convolutional Restricted Boltzmann Machine manifold learning inspired dynamic user clustering hybrid precoding for millimeter-wave massive multiple-input multiple-output systems

2021 ◽  
Vol 17 (11) ◽  
pp. 155014772110553
Author(s):  
Xiaoping Zhou ◽  
Haichao Liu ◽  
Bin Wang ◽  
Qian Zhang ◽  
Yang Wang
Keyword(s):  
Millimeter Wave ◽  
Manifold Learning ◽  
Multiple Input Multiple Output ◽  
Restricted Boltzmann Machine ◽  
Boltzmann Machine ◽  
Hybrid Precoding ◽  
User Clustering ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Low Dimensional

Millimeter-wave massive multiple-input multiple-output is a key technology in 5G communication system. In particular, the hybrid precoding method has the advantages of being power efficient and less expensive than the full-digital precoding method, so it has attracted more and more attention. The effectiveness of this method in simple systems has been well verified, but its performance is still unknown due to many problems in real communication such as interference from other users and base stations, and users are constantly on the move. In this article, we propose a dynamic user clustering hybrid precoding method in the high-dimensional millimeter-wave multiple-input multiple-output system, which uses low-dimensional manifolds to avoid complicated calculations when there are many antennas. We model each user set as a novel Convolutional Restricted Boltzmann Machine manifold, and the problem is transformed into cluster-oriented multi-manifold learning. The novel Convolutional Restricted Boltzmann Machine manifold learning seeks to learn embedded low-dimensional manifolds through manifold learning in the face of user mobility in clusters. Through proper user clustering, the hybrid precoding is investigated for the sum-rate maximization problem by manifold quasi-conjugate gradient methods. This algorithm avoids the traditional method of processing high-dimensional channel parameters, achieves a high signal-to-noise ratio, and reduces computational complexity. The simulation result table shows that this method can get almost the best summation rate and higher spectral efficiency compared with the traditional method.

Dynamically Connected Hybrid Precoding Scheme for Millimeter-Wave Massive MIMO Systems

2018 ◽  
Vol 22 (12) ◽  
pp. 2583-2586
Author(s):  
Xiaorong Jing ◽  
Lianghong Li ◽  
Hongqing Liu ◽  
Shaoqian Li
Keyword(s):  
Millimeter Wave ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Hybrid Precoding
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