论文标题
毫米波蜂窝网络中RIS辅助覆盖范围增强
RIS-Assisted Coverage Enhancement in Millimeter-Wave Cellular Networks
论文作者
论文摘要
使用毫米波（MMWAVE）带宽是实现第五代（5G）细胞系统中高数据速率的一个关键推动力。但是，由于高方向性和对阻塞的敏感性，MMWave信号遭受了巨大的路径损失，从而限制了其在小规模部署中的采用。为了增强5G及以后的MMWave通信的覆盖范围，可以部署大量可重构的智能表面（RISS），这些智能表面（RISS）被动地反映了MMWave信号向所需的方向。通过这种动机，在这项工作中，我们研究了使用随机几何形状的RIS辅助大规模MMWave细胞网络的覆盖范围，并得出了RI的峰值反射功率表达以及封闭形式的下行链路信号与干扰比（SIR）覆盖率（SIR）覆盖率。这些分析结果阐明了在MMWave Sir覆盖范围增强中部署RIS的有效性，同时揭示了主动基站（BSS）和被动RISS之间密度比的主要作用。此外，结果表明，部署被动反射器与在MMWave覆盖范围增强中配备更活跃的天线一样有效。仿真结果证实了封闭形式表达式的紧密度，并根据派生表达式证实了我们的主要发现。
The use of millimeter-wave (mmWave) bandwidth is one key enabler to achieve the high data rates in the fifth-generation (5G) cellular systems. However, mmWave signals suffer from significant path loss due to high directivity and sensitivity to blockages, limiting its adoption within small-scale deployments. To enhance the coverage of mmWave communication in 5G and beyond, it is promising to deploy a large number of reconfigurable intelligent surfaces (RISs) that passively reflect mmWave signals towards desired directions. With this motivation, in this work we study the coverage of an RIS-assisted large-scale mmWave cellular network using stochastic geometry, and derive the peak reflection power expression of an RIS and the downlink signal-to-interference ratio (SIR) coverage expression in closed forms. These analytic results clarify the effectiveness of deploying RISs in the mmWave SIR coverage enhancement, while unveiling the major role of the density ratio between active base stations (BSs) and passive RISs. Furthermore, the results show that deploying passive reflectors is as effective as equipping BSs with more active antennas in the mmWave coverage enhancement. Simulation results confirm the tightness of the closed form expressions, corroborating our major findings based on the derived expressions.
