Low Complexity Rate Splitting Approach in RIS-Aided Systems Based on Channel Statistics

TL;DR

This paper proposes a low-complexity rate splitting method for RIS-aided wireless systems that relies solely on statistical channel information, eliminating the need for frequent channel estimation and optimization.

Contribution

It introduces a quasi closed-form algorithm based on second-order channel statistics for RIS-aided systems, reducing design complexity and overhead.

Findings

Reduces system design complexity by avoiding real-time CSI estimation.

Provides a quasi closed-form solution based on channel statistics.

Enhances spectral and energy efficiency in RIS-aided systems.

Abstract

Rate splitting multiple access (RSMA) and reconfigurable intelligent surface (RIS) are two prospective technologies for improving the spectral and energy efficiency in future wireless communication systems. In this work, we investigate a rate splitting (RS) technique for an RIS-aided system in the presence of only statistical channel knowledge. We propose an algorithm with a quasi closed-form solution based only on the second-order channel statistics, which reduces the design complexity of the system as it does not require estimation of the channel state information (CSI) and optimisation of the precoding filters and phase shifts of the RIS in every channel coherence interval.