Intelligent Reflecting Surface Based Passive Information Transmission: A Symbol-Level Precoding Approach

Intelligent reflecting surfaces (IRS) have been proposed as a revolutionary technology owing to its capability of adaptively reconfiguring the propagation environment in cost-effective and hardware-efficient fashion. While application IRS passive reflector enhance performance wireless communications has widely investigated literature, using transmitter recently is emerging new concept attracting steadily growing interest. In this paper, we propose two novel IRS-based information transmission systems advanced symbol-level precoding. One standalone system, where operates serving multiple receivers by adjusting elements reflect unmodulated carrier signals. The other joint reflection not only enhances transmissions for primary (PIRs) reflection, but also simultaneously delivers additional secondary receiver (SIR) embedding into signals at symbol level. Two typical optimization problems, i.e., power minimization quality-of-service (QoS) balancing, are systems. Simulation results demonstrate feasibility effectiveness our algorithms, compared benchmark schemes.