Fairness-Aware Reliability Maximization of a Novel RSMA Framework for URLLC

Rate-Splitting Multiple Access (RSMA) has emerged as a promising technique to improve the connectivity of the next generation of wireless communications. However, the interference introduced by the non-orthogonal channel usage in the current RSMA framework still poses significant challenges for providing ultra-reliable and low-latency communications (URLLC) services. In this work, we propose a novel RSMA framework to improve interference management with the consideration of imperfect successive interference cancellation (SIC) performance. Leveraging this framework, we formulate a fairness-aware optimization problem to maximize the reliability among users by properly allocating the limited radio resources with finite blocklength codes. Then, we provide an approach with our analytical findings on the convexity property to efficiently solve the problem. Through numerical simulations, we demonstrate intuitive insights into the comparative advantages of RSMA, NOMA, and TDMA based on user channel gains, thereby providing a roadmap for future multi-access scheme selections.