Intelligent reflecting surface assisted multi-user MIMO uplink energy efficiency spectral efficiency joint optimization method

Abstract

The invention provides a multi-user MIMO uplink energy efficiency spectral efficiency joint optimization method assisted by an intelligent reflecting surface. In the method, a user sending signal is received by a base station after being reflected by an IRS, and a reflection unit of the IRS can change the phase of an incident signal. According to the method, part of channel state information is utilized, two different conditions that IRS reflection coefficients can be continuously valued and discretely valued are considered at the same time, and the IRS reflection coefficients can be continuously valued and discretely valued through an alternate optimization method, a deterministic equivalence principle, a secondary penalty method, an MM method, an accelerated projection gradient descent method and the like. And the precoding matrix of each user and the weighted sum of the reflection coefficient maximization energy efficiency and the spectral efficiency of the IRS are jointly designed.And when the channel state information changes, the central controller dynamically implements energy efficiency spectral efficiency joint optimization multi-user MIMO uplink transmission power distribution and IRS reflection coefficient adjustment. The method is low in implementation complexity, can effectively improve the energy efficiency and spectral efficiency of multi-user MIMO uplink communication, and achieves the balance between the energy efficiency and spectral efficiency.

Description

Technical field [0001] The present invention belongs to the field of communication, and more particularly to a multi-user MIMO uplink energy efficiency combined optimization method for intelligent reflective surface assisting with partial channel state information. Background technique [0002] Intelligent Reflecting Surface (IRS) is a programmable surface consisting of a passive passive reflecting unit, by controlling the shape, size and direction of the reflective element, each of the reflecting units can independently change the incident signal. Phase or amplitude. [0003] In the IRS assisted wireless communication system, an IRS is added between the transmitting end and the receiving end, and the signal is transmitted by the transmitting end to the receiving end. Each component of the IRS independently changes the incident signal, so that the wireless propagation environment can be intelligently reconfigured to significantly improve the performance of the wireless communicat...

AI Technical Summary

Problems solved by technology

Traditional wireless transmission method design is usually based on instantaneous channel state information, but in scenarios such as high mobility, it is difficult to obtain instantaneous channel state information, so the present invention provides an IRS-assisted multi-user MIMO uplink based on partial channel state information transmission method

For the optimization problem of maximizing the weighted sum of energy efficiency and spectral efficiency, since the objective function is non-convex and the constraints of the IRS reflection coefficient are also non-convex, it is usually difficult to solve

In addition, the objective function needs to be expected. When the number of IRS reflection units is large, the computational complexity is very high

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