Reconfigurable intelligent surface (RIS)-empowered communication has emerged as a novel concept for customizing future wireless environments in a cost- and energy-efficient way. However, due to double path loss, existing fully passive RIS systems that purely reflect the incident signals into preferred directions attain an unsatisfactory performance improvement over the traditional wireless networks in certain conditions. To overcome this bottleneck, we propose a novel transmission scheme, named hybrid reflection modulation (HRM), exploiting both active and passive reflecting elements at the RIS and their combinations, which enables to convey information without using any radio frequency (RF) chains. In the HRM scheme, the active reflecting elements using additional power amplifiers are able to amplify and reflect the incoming signal, while the remaining passive elements can simply reflect the signals with appropriate phase shifts. Based on this novel transmission model, we obtain an upper bound for the average bit error probability (ABEP), and derive achievable rate of the system using an information theoretic approach. Moreover, comprehensive computer simulations are performed to prove the superiority of the proposed HRM scheme over existing fully passive, fully active and reflection modulation (RM) systems.
翻译:重新配置智能表面(RIS)的动力通信已成为以成本和节能方式定制未来无线环境的新概念,但是,由于双轨路损耗,现有完全被动的RIS系统纯粹将事件信号反映为偏好方向,在某些条件下与传统无线网络相比的性能改善不令人满意。为了克服这一瓶颈,我们提出了一个新型传输计划,名为混合反射调节(HRM),利用RIS及其组合的主动和被动反射元素,从而能够在不使用任何无线电频率(RF)链的情况下传递信息。在HRM计划中,使用额外电源放大器的积极反射元素能够放大和反映收到的信号,而其余的被动元素仅能以适当的阶段变化反映信号。基于这一新的传输模式,我们获得了平均差错概率(ABEP)的上限,并利用信息理论方法获得系统的可实现率。此外,还进行了全面的计算机模拟,以证明拟议的HRM计划优于现有的完全被动、完全活跃和反射调(RM)系统。