Fairness-Oriented Multiple RISs-Aided MmWave Transmission: Stochastic Optimization Approaches

12/11/2020
by   Gui Zhou, et al.
0

In millimeter wave (mmWave) systems, it is challenging to ensure the reliable connectivity of communications due to its sensitivity to the presence of blockages. In order to improve the robustness of the mmWave system under the presence of the random blockages, multiple reconfigurable intelligent surfaces (RISs) are deployed to enhance the spatial diversity gain, and robust beamforming is then designed based on a stochastic optimization for minimizing the maximum outage probability among multiple users to ensure the fairness. Under the stochastic optimization framework, we adopt the stochastic majorization–minimization (SMM) method and the stochastic successive convex approximation (SSCA) method to construct deterministic surrogate problems at each iteration for new channel realizations, and obtain the closed-form solutions of the precoding matrix at the base station (BS) and the passive beamforming vectors at the RISs. Both stochastic optimization methods have been proved to converge to the set of stationary points of the original stochastic problems. Finally, simulation results show that the proposed robust beamforming in the RIS-aided system can effectively compensate for the performance loss caused by the presence of the random blockages, especially at high blockage probability, compared with the benchmark solutions.

READ FULL TEXT
POST COMMENT

Comments

There are no comments yet.

Authors

page 5

page 6

page 10

page 15

page 19

page 20

page 23

page 32

01/25/2021

Joint Design of Hybrid Beamforming and Phase Shifts in RIS-Aided mmWave Communication Systems

This paper considers a reconfigurable intelligent surface (RIS)-aided mi...
05/15/2020

Outage Minimization for Intelligent Reflecting Surface Aided MISO Communication Systems via Stochastic Beamforming

Intelligent reflecting surface (IRS) has the potential to significantly ...
12/23/2020

Secure Wireless Communication in RIS-Aided MISO Systems with Hardware Impairments

In practice, residual transceiver hardware impairments inevitably lead t...
10/02/2020

Secrecy Rate Maximization in Multi-IRS Millimeter Wave Networks

In this paper, the problem of physical layer security enhancement in a m...
10/14/2019

Reliable mmWave Communication via Coordinated Multi-Point Connectivity

The fundamental challenge of mmWave frequency band is the sensitivity of...
11/29/2019

Hybrid Precoding Design for Reconfigurable Intelligent Surface aided mmWave Communication Systems

In this letter, we focus on the hybrid precoding (HP) design for the rec...
02/15/2020

Channel Estimation for RIS-Aided mmWave MIMO Channels

A reconfigurable intelligent surface (RIS) can shape the radio propagati...
This week in AI

Get the week's most popular data science and artificial intelligence research sent straight to your inbox every Saturday.