On the Ergodic Rate of CR-Aided Multi-User Uplink RSMA and NOMA

Sixth-generation (6G) wireless networks require a range of technologies and possible designs to meet high through-put, huge connectivity, and different quality of service (QoS) needs due to the rapid growth of wireless devices. In this study, we created a three-user uplink cognitive radio system with two secondary users (SU1 and SU2), one close to the base station and the other farther away. We examined the ergodic rate performance of two decoding order protocols: CR-Fix-DO, which is based on Rate-Splitting Multiple Access (RSMA), and CR-Flex-DO, which is based on Non-Orthogonal Multiple Access (NOMA). Within a resource block allotted to the primary user (PU), both protocols are made to support secondary users without sacrificing the PU’s quality of service (QoS). The suggested protocols exceed benchmark schemes, as shown by numerical findings that confirmed the theoretical analysis. Under the given conditions, CR-Flex-DO achieved up to 1.7 bps/Hz greater ergodic rates than CR-Fix-DO.