Resource Allocation for RSMA-aided URLLC in NAFD Cell-Free mMIMO Systems

This paper investigates the application of rate-splitting multiple access (RSMA) within the framework of network-assisted full-duplex (NAFD) in cell-free massive multiple-input multiple-output (mMIMO) systems to achieve ultra-reliable and low-latency communication (URLLC). We derive the lower-bound expressions for both downlink and uplink ergodic data rates, which are pertinent to scenarios involving short-packet communication. In light of the challenges posed by imperfect channel state information (CSI) and pilot contamination, a graph-coloring based approach is implemented for the remote antenna unit (RAU) selection and pilot assignment. Subsequently, the focus shifts to the design of power allocation for full-duplex data transmission, which is formulated as an optimization problem with the objective of maximizing the sum of the lower bound of ergodic data rates (SER). To address the non-convex nature of this problem, a successive convex approximation (SCA) based algorithm is proposed. The article concludes with an extensive performance analysis that substantiates the effectiveness of the proposed framework and algorithm.