Spatial Diversity in Radar Detection via Active Reconfigurable Intelligent Surfaces

TL;DR

This paper explores how active reconfigurable intelligent surfaces can enhance radar detection by providing additional spatial diversity, optimizing system parameters to improve detection probability within power constraints.

Contribution

It introduces the use of active RISs in radar systems, optimizing parameters to maximize detection probability, and compares performance with passive RIS and standalone radar.

Findings

Active RISs improve radar detection performance.

Optimized system parameters enhance detection probability.

Active RISs outperform passive RIS and standalone radar.

Abstract

Active reconfigurable intelligent surfaces (RISs) are a novel and promising technology that allows controlling the radio propagation environment while compensating for the product path loss along the RIS-assisted path. In this letter, we consider the classical radar detection problem and propose to use an active RIS to get a second independent look at a prospective target illuminated by the radar transmitter. At the design stage, we select the power emitted by the radar, the number of RIS elements, and their amplification factor in order to maximize the detection probability for a fixed probability of false alarm and a common (among radar and RIS) power budget. An illustrative example is provided to assess the achievable detection performance, also in comparison with that of a radar operating alone or with the help of a passive RIS.