RIS-enabled cooperative symbiotic radio communications with movable antennas

Abstract

This paper proposes a cooperative commensal and parasitic (CCP) scheme for reconfigurable intelligent surface (RIS) enabled symbiotic radio communications, utilizing movable antennas to improve the performance of both primary and secondary systems by dynamically updating their positions. Two types of RIS utilize the CCP scheme to send their respective secondary information to the primary user (PU) by reusing the primary signals from the base station (BS). A primary transmission rate maximization problem is formulated and further solved by a proposed two-layer alternating optimization algorithm with advanced techniques. Numerical results show that compared to the scheme with fixed position antennas, our proposed scheme can increase the primary transmission rate by 11.7%, demonstrating its effectiveness.