RIS-Assisted Radar NLOS Target Detection

Abstract

Reconfigurable Intelligent surface (RIS) has been envisioned as a promising technique for the 6th generation (6G) communications. Generally, a RIS is consist of a number of reflective elements that collaboratively adjust the direction of incident signals, and is considered to have the advantages of combating fading and shadowing problems in communication systems. In this article, by exploiting these RIS advantages, we propose to utilize the concept of RIS for the non-line-of-sight (NLOS) target radar detection. More specifically, we opt for using semi-definite relaxing (SDR) to obtain the optimal phase shift of RIS for each detection angle to build a code-book for all the optimal phase shifts, which can then be used for detecting the direction of target. The Doppler frequency shift can also be obtained via processing the echo with maximum power. Simulation results show that RIS is capable of significantly improving the coverage of radar detection.