Phase shift optimization method for IRS-assisted downlink multi-user communication system

Abstract

The invention belongs to the technical field of mobile communication, and particularly relates to a phase shift optimization method for an IRS auxiliary downlink multi-user communication system, which comprises the following steps of: establishing an IRS auxiliary communication system model of a mobile user, and calculating the phase shift of the IRS auxiliary communication system model based on a relationship between a mean square error matrix of an optimal decoding matrix and channel capacity; constructing a channel capacity optimization model of the IRS auxiliary communication system by taking channel capacity maximization as a target; solving an optimal decoding matrix, an auxiliary matrix and a precoding matrix in the channel capacity optimization model, and constructing an IRS phase shift optimization model according to the channel capacity optimization model and a known matrix thereof; solving the IRS phase shift optimization model by adopting a Riemannian trust region method to obtain an optimal phase shift, and setting the optimal phase shift as a main diagonal element of an IRS phase shift matrix. According to the method, under the condition that throughput is not lost, complexity is greatly reduced, and the channel capacity obtained through the method is larger than that obtained through a traditional method under the same condition.

Description

technical field [0001] The invention belongs to the technical field of mobile communication, and in particular relates to a phase shift optimization method for an intelligent reflecting surface (Intelligent Reflecting Surfaces, IRS) to assist a downlink multi-user communication system. Background technique [0002] With the commercialization of the fifth generation (5G) wireless communication network, it means that the future wireless network will have higher spectral efficiency, faster transmission rate, and larger system capacity. In theory, its spectral efficiency can be 5 to 5 times higher than that of 4G. 15 times, and its peak transmission speed can reach 10Gbit / s. 5G key technologies such as massive antenna array (M-MIMO) and millimeter-wave (mm-Wave) communication have effectively contributed to the realization of this function. However, additional high hardware cost, huge power consumption or energy consumption, and siting of 5G base stations are the main obstacles...

AI Technical Summary

Problems solved by technology

Most of the existing IRS auxiliary communication system phase shift optimization algorithms use semi-definite relaxation technology (Semi-Definite Relaxation, SDR). Although this algorithm can...

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