Reconfigurable Intelligent Surface-Aided Emitter Localization

Localization of radio-frequency (RF) transmitters using time difference of arrival (TDOA)-based methods is one of the conventional passive techniques that admits noncooperative source position finding, but suffers from challenging requirements such as precise intersensor synchronization and high-throughput transmission data links. A tradeoff governing the TDOA systems is in the sensor placement configuration. The more distance the sensors are placed, the more accurate localization is carried out, while the cost for the synchronization and data link increases, at the same time. In this work, a novel reconfigurable intelligent surface (RIS)-aided localization system is proposed that enjoys precise location accuracy while reducing the required expenses. The study reveals that the new setup, utilizing the beam-scanning property of the RIS sensors, improves the localization algorithm and outperforms the conventional approach. Also, comparisons with Cramér Rao lower bound (CRLB) are provided, which confirms the efficiency of the proposed method. Several numerical examples indicate the effectiveness of the proposed method, especially in a low signal-to-noise ratio (SNR) regime.