Equipping reflecting elements at the active intelligent reflecting surface (AIRS) enhances signal amplification capability but meanwhile incurs non-negligible amplification noise, which thus challenges the determination of elements allocation for maximizing achievable rate in multi-cooperative AIRS and passive IRS (PIRS) jointly aided wireless communication system. To tackle this issue, we consider the downlink communication from a single-antenna transmitter (Tx) to a single-antenna receiver (Rx), which aided by a pair of AIRS and PIRS with two different deployment orders. Specifically, we target to determine the number of AIRS/PIRS elements over both transmission orders under given deployment budget for the achievable rate maximization. Our analysis illustrates that the PIRS should be allocated more elements than the AIRS for achieving optimized rate and linear signal-to-noise ratio (SNR) scaling orders are attained in both schemes. Simulation results are provided to evaluate the proposed algorithm and compare the rate performance of the AIRS and PIRS jointly aided wireless system with various benchmark systems.

翻译：在联合有源智能反射面(AIRS)与无源智能反射面(PIRS)辅助的多协作无线通信系统中，为AIRS配备反射单元可增强信号放大能力，但同时也引入不可忽略的放大噪声，这对实现可达速率最大化的单元分配决策构成挑战。针对此问题，我们考虑由单天线发射端(Tx)至单天线接收端(Rx)的下行链路通信场景，该链路由一对AIRS和PIRS以两种不同部署顺序协同辅助。具体而言，我们旨在给定部署预算下，确定两种传输顺序中AIRS/PIRS的单元数量分配以实现可达速率最大化。分析表明，为达到优化速率，PIRS应分配比AIRS更多的单元，且两种方案均可实现线性信噪比(SNR)缩放阶数。仿真结果验证了所提算法的有效性，并对比了AIRS与PIRS联合辅助无线系统与多种基准系统的速率性能。