mmWave MIMO Systems Research Articles

Outage Probability of X-Duplex AF Relay-Aided mmWave MIMO Systems with Relay Selection in B5G and 6G

Outage Probability of X-Duplex AF Relay-Aided mmWave MIMO Systems with Relay Selection in B5G and 6G

Low-Complexity Mobile User Tracking in Quantized mmWave MIMO Systems

Low-Complexity Mobile User Tracking in Quantized mmWave MIMO Systems

Integrated Localization and Communication for IRS-Assisted Multi-User mmWave MIMO Systems

Integrated Localization and Communication for IRS-Assisted Multi-User mmWave MIMO Systems

Hybrid Precoding for Mitigating the Beam Squint in Wideband mmWave MIMO System

Hybrid Precoding for Mitigating the Beam Squint in Wideband mmWave MIMO System

Deep Learning Based Joint Hybrid Precoding and Combining Design for mmWave MIMO Systems

Deep Learning Based Joint Hybrid Precoding and Combining Design for mmWave MIMO Systems

Performance analysis of multiple RISs aided multi-user mmWave MIMO systems

Performance analysis of multiple RISs aided multi-user mmWave MIMO systems

Spectral efficiency of hybrid precoding and combining design for mm-Wave multi-user massive MIMO systems

Spectral efficiency of hybrid precoding and combining design for mm-Wave multi-user massive MIMO systems

RIS Selection and Design over Computable Channels in Massive MIMO mmWave Systems

RIS Selection and Design over Computable Channels in Massive MIMO mmWave Systems

Multi-RIS Aided Multi-User Mmwave MIMO System Modelled by Matérn Hard-Core Point Processes

Multi-RIS Aided Multi-User Mmwave MIMO System Modelled by Matérn Hard-Core Point Processes

Phase Modulated Hybrid Precoding Design for Multi-RIS Aided Cell-Free MmWave MIMO System

Phase Modulated Hybrid Precoding Design for Multi-RIS Aided Cell-Free MmWave MIMO System

Bitmask Dynamic Programming for User Scheduling in Multi-User MIMO mmWave Systems

Bitmask Dynamic Programming for User Scheduling in Multi-User MIMO mmWave Systems

DNN Based Hybrid Precoding Design for IRS-Aided mmWave MIMO Systems With Phase Modulation Array

DNN Based Hybrid Precoding Design for IRS-Aided mmWave MIMO Systems With Phase Modulation Array

Hybrid TH precoding with subarray connection for multi‐user mmWave MIMO systems

AbstractExisting linear algorithms based on subarray connection (SC) structures may cause noise enhancement and performance degradation. To solve this problem, this paper presents a nonlinear hybrid Tomlinson‐Harashima precoding (THP) algorithm based on SC structure, named as THP‐SC algorithm. In the proposed algorithm, the sum‐rate optimization problem can be transformed into two equivalent optimization subproblems including the transmitter optimization subproblem and the receiver optimization subproblem. These two subproblems are easy to solve. Furthermore, the analog precoding and combining matrices of the optimization subproblem are solved by a new improved successive interference cancelation (SIC) algorithm based on the singular value threshold shrinkage (SVS), which can effectively reduce the computational complexity while eliminating the interference. In the end, the digital precoding and combining matrices are obtained by TH method. Through the joint optimization of the transmitter and receiver matrices in the system, the optimal solution is obtained by alternate iteration of the matrices. In this paper, a more realistic line‐of‐sight (LOS) and non‐line‐of‐sight (NLOS) channel system is also considered. Simulations verify that the proposed algorithm can improve the spectral efficiency and energy efficiency to some extent with a comparable complexity compared to the previous works.

Fast Multibeam Training for mmWave MIMO Systems With Subconnected Hybrid Beamforming Architecture

In this article, we present novel multibeam training strategies for millimeter-wave communication systems with the subconnected hybrid architecture. To begin with, we propose an iterative selecting search (ISS) algorithm that can reduce the training complexity of multibeam training by a large margin, and its central concept is exploiting the prior information of scanned beam combinations to iteratively optimize the beam of each subarray in order to determine the possible optimal beam combination. Then, we apply the concept of the ISS algorithm to optimize the original beam set in line with channel sparsity, with the goal of effectively characterizing the large original beam set with a small beam subset, resulting in a much smaller search space for the optimized beam subset than for the original beam set. Furthermore, we adopt two linear search algorithms on our optimized beam subset to develop efficient multibeam training methods. As shown in the simulation results, the ISS scheme shines in terms of low training complexity but performs poorly in spectral efficiency. In comparison to individual linear search methods, beam-subset-optimization-based linear search schemes not only have a greater spectral efficiency, but also have a very low training complexity.

Cooperative hybrid beamforming design in Multi‐UAV MmWave MIMO systems

AbstractDue to the limitation of mobility and cost, it is inappropriate to utilize ground base station (GBS) to provide service in emergency scenarios or harsh environments. Unmanned aerial vehicle (UAV) is considered as a feasible way to solve the problem. Millimetre wave communication and UAV can be used together to offer wireless communications flexibly and rapidly for target area. However, fuselage jittering and energy supply would affect the quality and reliability of UAV communication seriously. To overcome the weakness of UAV, the authors prefer to use multiple UAVs to provide wireless communication service simultaneously. This paper investigates the design of hybrid beamforming in the scenarios including multiple UAVs and one end user. Cooperation strategy and alternating optimization method are applied in this design. The distributed UAV base stations are regarded as an entirety and the reference beamforming scheme obtained. Then, the beamforming problem for each UAV is formulated. Moreover, residual error minimization (REM) algorithm is proposed to find the solution of hybrid beamformers at UAV side. Finally, the beamformer of the receiver is optimized with the assist of effective channel, which includes the gain of both channel and beamformers of the transmitters. Simulation results show that the proposed algorithm can achieve near‐optimal spectral efficiency in different scenarios.

Hardware-Impaired RIS-Assisted mmWave Hybrid Systems: Beamforming Design and Performance Analysis

Reconfigurable intelligent surface (RIS) has been envisioned as an innovative technology to assist millimeter wave (mmWave) communications. Thanks to both advantages of low hardware cost and low power consumption, the hybrid transceiver structure also becomes an integral component of mmWave systems. However, due to practical limitations of hardware components, the RIS-assisted mmWave communications usually suffer unavoidable hardware impairments (HWIs). In this paper, we aim to minimize the (sum) MSE and maximize the average rate of the hardware-impaired RIS-assisted point-to-point mmWave MIMO system, respectively, by jointly optimizing the hybrid transceiver and RIS reflection coefficients under the realistic discrete phase shift constraints. We firstly consider the single-antenna user case and propose efficient alternating optimization (AO) algorithms to solve the two intractable problems. A binary-oriented exact penalty (BEP) method is developed for the involved discrete optimization, which is able to strike a good trade-off between performance and complexity. Moreover, we analyze the optimality of AO algorithms under the cascaded line-of-sight (LoS) channel condition, and reveal both the MSE floor effect and average rate saturation effect in the high-SNR regime. The above studies are then extended to the general multi-antenna user case, where a low-complexity two-phase scheme with the aim of creating the favorable RIS-cascaded channel in the first phase and enhancing system performance in the second phase is proposed. This two-phase scheme is also demonstrated to attain the optimal performance in the LoS scenario. Numerical results validate our theoretical analysis and illustrate superior performance of the proposed algorithms over various benchmark schemes.

Hybrid Precoder Design Based on mm-Wave MIMO System with GMD Method

Hybrid Precoder Design Based on mm-Wave MIMO System with GMD Method

Energy efficient degree of freedom aided multi beam transmit antenna precoding for mmWave MIMO system

Millimeter-wave communication system provides the feasible solution for the bandwidth limitation present in the sub 6-GHz system. This millimeter-wave communication system requires large antenna array for transmission and needs better RF chain utilization methods. Often single beam transmission over multiple antennas are deployed for RF chain reduction and inter user interference reduction. Multi beam Multi RF transmission system despite capable of providing maximum capacity is affected by power leakage and hence experiences poor energy efficiency. A Multi Beam Transmit Antenna Precoding for Multi beam Multi RF mmWave MIMO system based on analog power splitter arrangement was proposed instead of existing large digital switching network to reduce complexity. In this Multi Beam Transmit Antenna Precoder setup four new precoding algorithms based on alamouti, hadamard, toeplitz and zero correlation sequence were proposed. Sum rate and energy efficiency of the proposed methods were derived theoretically, simulated and compared with existing methods. Computational complexity and degree of freedom were also analyzed for the proposed methods.

Compressive Sensing-Based Beam Alignment Schemes for Time-Varying Millimeter-Wave Channels

This paper considers the implementation of compressive sensing (CS) approaches for beam alignment (BA) in multiuser millimeter wave (mmWave) MIMO systems. We particularly consider wideband time-varying channels in the practical low SNR regime. We examine two different time scales for beam-switching in the BA training phase at both the base station (BS) and the user equipment (UE). We also compare different time scales for running the CS algorithm at the UE, with their corresponding overhead and complexity. We propose an overarching trial-based protocol that re- initializes the BA process at particular times. We also propose a new approach to designing the CS sensing matrix (SM), based on a deterministic construction. Rows of our proposed SM are Kronecker product decomposable, making it ideal for the BA problem. We show that when block-based beam switching is employed in combination with running the CS algorithm Every Epoch (CS-EE), our proposed SM gives superior performance compared to the other approaches. Moreover, our proposed overarching trial-based protocol enhances the performance even further. We also show that running the CS algorithm Every Block (CS-EB) outperforms CS-EE at the cost of higher complexity and overhead.

Exploiting Fine-Grained Channel/Hardware Features for PHY-Layer Authentication in MmWave MIMO Systems

Exploiting Fine-Grained Channel/Hardware Features for PHY-Layer Authentication in MmWave MIMO Systems