Indoor Localization for MmWave wireless System Using Diversity Property of RIS Device

Indoor localization, which aims to provide localization level with centimeter accuracy, is becoming one of key research topics for beyond 5G/6G systems. In addition, wireless system over mmWave band will be more efficient candidate which can achieve higher bandwidth efficiency due to large bandwidth resource and more accurate localization due to high space resolution of mmWave signal. In recent years, a new and powerful low-cost reconfigurable intelligent surface (RIS) has been proposed and be employed to configure a smart wireless environment for the capacity enhancement of many wireless technologies. RIS can control wireless channel by changing the direction of the reflected signal. Therefore, for one receiver location, system can generate many location-related data by using different RIS propagation pattern. This diversity property can be used for the improvement of localization accuracy. Based on this property, in this paper, we will propose a low-complexity fingerprint-based localization for mmWave system. The simulated results confirm its efficiency even if the RIS cell has only limited phases for usage.