A Joint Multiservice Transmission Scheme for RSMA-Aided Cell-Free mMIMO System

Abstract

In this letter, we propose a joint multi-service (MS) transmission scheme based on cell-free (CF) massive MIMO architecture. Based on the user-centric (UC) principle, we perform access point (AP) selection and form broadcast, multicast, and unicast messages at each AP according to the rate splitting multiple access (RSMA) technique, then we carry out the joint transmission of MS signals. In terms of system optimization, a novel three-step resource allocation algorithm is proposed to deal with the non-convex problem of achievable sum-rate maximization which downscales multidimensional variables to solve the one-dimensional problems of AP selection, intra-AP power ratio determination, and inter-AP power allocation in steps. We provide achievable sum-rate analyses backed by numerical results to show the superiority of the proposed scheme and optimization algorithm compared with the baselines.