A modified joint decoding scheme for RSMA-aided downlink

摘要

Rate splitting multiple access (RSMA) is envisioned as a promising next generation mobile communication.Numerous studies have demonstrated the superior performance of RSMA over conventional multiple access dueto its powerful interference management strategy and flexible multi-user management. However, a potentialissue of decoding at the receiver is ignored due to its unplanned power allocation to multi-user, which leads to asubstantial reduction in outage performance and additional energy consumption. To overcome the above issues,in this paper, a novel joint decoding design for the RSMA is investigated to improve the overall performance interms of outage probability and energy consumption. The focus of the investigation is to decode common andprivate messages at the receiver, providing the suboptimal power allocation to enhance decoding accuracyand reduce energy consumption. Unlike conventional RSMA decoding schemes, the common message andcorresponding private messages will be superposed as a new desired signal to be decoded, in order to avoid thedecoding signal power being smaller than the interference one by means of successive interference cancellation(SIC). Specifically, we investigate and analyze the outage performance by satisfying the rate constraints for ourproposed joint decoding scheme. Assuming Rayleigh fading channels, from the provided numerical results andsimulations, they are well matched in terms of outage probability to clarify the correctness of the theoreticalanalysis, as well as illustrate the superiorities of our proposed scheme compared with conventional RSMA. Theresearch results provide a theoretical basis for the development of future multi-user decoding.