The employment of intelligent reflecting surfaces (IRSs) is a potential and promising solution to increase the spectral and energy efficiency of wireless communication networks. Despite their many advantages, IRS-aided communications have limitations as they are subject to high propagation losses. To overcome this, the phase rotation (shift) at each element needs to be designed in such a way as to increase the channel gain at the destination. However, this increases the system's complexity as well as its power consumption. In this paper, we present an analytical framework for the performance of random rotation-based IRS-aided communications. Under this framework, we propose four low-complexity and energy efficient schemes, based on a coding or a selection approach. Both of these approaches employ random phase rotations and require limited knowledge of channel state information. Specifically, the coding-based schemes use time-varying random phase rotations to produce an equivalent time-varying channel. On the other hand, the selection-based schemes select a partition of the IRS elements based on the received signal power at the destination. Analytical expressions for the achieved outage probability and energy efficiency of each scheme are derived. It is demonstrated that all schemes can provide significant performance gains as well as full diversity order.
翻译:智能反射表面(IRS)的使用是提高无线通信网络光谱和能源效率的一个潜在和有希望的解决办法。尽管具有许多优势,IRS辅助通信具有局限性,因为它们在传播方面损失巨大。要克服这一点,每个要素的阶段轮换(轮班)的设计方式必须能够增加目的地的频道收益。然而,这增加了系统的复杂性及其电力消耗。在本文件中,我们提出了一个用于随机旋转的IRS辅助通信功能的分析框架。在这个框架内,我们提出四种低兼容性和节能计划,其依据是编码或选择方法。这两种方法都采用随机阶段轮换,需要有限的频道状态信息知识。具体地说,基于编码的组合计划使用时间变化的随机周期旋转来产生一个等量时间变化的频道。另一方面,基于选择的计划根据在目的地收到的信号能量选择了IRS元素的分区。我们提出了四种低兼容性和节能计划,根据编码或选择方法提出了四种低兼容性和节能计划。这两种方法都采用随机阶段轮换,需要有限的频道状态信息知识。具体地说,基于时间变化的随机随机的随机周期旋转,产生一个相等的频道频道。另一方面,选择计划根据在目的地获得的信号能量进行分置。我们可以分析每种计划取得显著的成绩。它。它能和充分的成绩。它能。