Intelligent reflecting surface (IRS) is a new and promising paradigm to substantially improve the spectral and energy efficiency of wireless networks, by constructing favorable communication channels via tuning massive low-cost passive reflecting elements. Despite recent advances in the link-level performance optimization for various IRS-aided wireless systems, it still remains an open problem whether the large-scale deployment of IRSs in wireless networks can be a cost-effective solution to achieve their sustainable capacity growth in the future. To address this problem, we study in this paper a new hybrid wireless network comprising both active base stations (BSs) and passive IRSs, and characterize its achievable spatial throughput in the downlink as well as other pertinent key performance metrics averaged over both channel fading and random locations of the deployed BSs/IRSs therein based on stochastic geometry. Compared to prior works on characterizing the performance of wireless networks with active BSs only, our analysis needs to derive the power distributions of both the signal and interference reflected by distributed IRSs in the network under spatially correlated channels, which exhibit channel hardening effects when the number of IRS elements becomes large. Extensive numerical results are presented to validate our analysis and demonstrate the effectiveness of deploying distributed IRSs in enhancing the hybrid network throughput against the conventional network without IRS, which significantly boosts the signal power but results in only marginally increased interference in the network. Moreover, it is unveiled that there exists an optimal IRS/BS density ratio that maximizes the hybrid network throughput subject to a total deployment cost given their individual costs, while the conventional network without IRS is generally suboptimal in terms of throughput per unit cost.
翻译:在无线网络中大规模部署IRS是一个具有成本效益的解决方案,以便在未来实现可持续能力增长。为了解决这个问题,我们在本文件中研究一个新的混合无线网络,由活跃的基础站和被动的IRS组成,通过调整大规模低成本被动反射元素建立有利的通信频道,从而大幅提高无线网络的光谱和能效。尽管最近在各种IRS辅助无线系统的连接级性业绩优化方面有所进展,但是,在无线网络中,大规模部署IRS/IRS系统能否成为实现无线网络未来可持续能力增长的具有成本效益的解决方案。为了解决这一问题,我们在本文件中研究一个新的混合无线网络网络网络,包括活跃的基础站和被动的IRS,并描述其可实现的空间密度传输空间性能,在下行链路段和其他相关的关键性业绩衡量标准中,可实现的空间性静电路路路路流的可实现的空间性能增长,同时通过静电路流网络的快速运行率分析,通过常规流流电路路流成本进行大幅提升。