A Novel Wireless Communication Paradigm for Intelligent Reflecting Surface Based Symbiotic Radio Systems

This paper investigates a novel intelligent reflecting surface (IRS)-based symbiotic radio (SR) system architecture consisting of transmitter, an IRS, and information receiver (IR). The primary transmitter communicates with the IR at same time assists IRS in forwarding to IR. Based on IRS’s symbol period, we distinguish two scenarios, namely, commensal SR (CSR) parasitic (PSR), where different techniques for decoding signals are employed. We formulate bit error rate (BER) minimization problems both scenarios by jointly optimizing active beamformer base station phase shifts subject minimum requirement. Specifically, CSR scenario, penalty-based algorithm is proposed obtain high-quality solution, semi-closed-form solutions derived based Lagrange duality Majorization-Minimization methods, respectively. For PSR apply bisection search-based method, successive convex approximation, difference programming develop computationally efficient algorithm, which converges locally optimal solution. Simulation results demonstrate effectiveness algorithms show that able achieve lower BER than benchmark schemes.