Rate Region Characterization for Semantics and Bits Based Multiuser Communications

The coexistence of semantic communication (SemCom) and bit-based communication (BitCom) towards next-generation wireless networks is investigated. First, a semantic and bit uplink communication framework is proposed, where a near user (N-user) and a far user (F-user) upload information to the access point employing BitCom and SemCom, respectively. For effectively accommodating the two different users, orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) schemes are proposed. The semantic-versus-bit rate region achieved by each scheme is characterized. The analytical performance comparison shows that NOMA is always superior to OMA, but for the F-user, employing SemCom may not always outperform BitCom. The presented numerical examples verify the analytical result.