Application-Specific Rate-Splitting Multiple Access: Ultrareliable Low-Latency Communication in Cell-Free Massive Multiple-Input, Multiple-Output Networks

Rate-splitting multiple access (RSMA) emerges as a promising beyond 5G (B5G) network technology for ultrareliable low-latency communication (URLLC). It splits messages into private and common streams, and the common stream can be decoded by multiple receivers, allowing flexible signal interference management. Current RSMA schemes rely either on fixed preassigned or arbitrarily assigned transmission rates. However, this results in underutilization of network resources, reducing network efficiency. To address this limitation, we propose an application-specific RSMA, a feedback-based technique for URLLC in cell-free (CF) massive multiple-input, multiple-output (mMIMO) networks. The access points (APs) classify messages into traffic safety and nonsafety messages, based on the Third-Generation Partnership Project (3GPP) standard, to assign optimal transmission rates. Furthermore, the technique eliminates the need for a message combiner module, reducing the scheme’s complexity. A comparative analysis demonstrates promising improvements in the packet delivery ratio (PDR), minimized latency, and reduced computation complexity, which validates RSMA’s applicability in B5G for URLLC in CF mMIMO networks.