Channel (broadcasting)

Spectral efficiency

MIMO

Beamforming

Wireless

Base station

Multi-user MIMO

Communications system

Algorithm

Engineering

Signal-to-noise ratio (imaging)

Electronic engineering

Interference (communication)

Computer science

Real-time computing

Radar

Telecommunications

IEEE Wireless Communications Letters

Reconfigurable intelligent surface (RIS) has been considered in wireless communication systems to improve spectral efficiency. This letter addresses the spectrum sharing problem between multiple-input-multiple-output (MIMO) radar and multi-user MISO communication systems, where RIS is exploited to deal with the interference imposed by the base station (BS). We aim to maximize the radar detection probability by jointly optimizing the BS transmit beamformer and RIS phase shift matrix, subject to the users' signal-to-interference-plus-noise-ratio and power consumption constraints. Due to the coupled variables, the formulated problem is challenging to solve; hence, we convert it into a better tractable form and propose an alternating algorithm to handle the resulting problem. The simulation results validate the effectiveness of RIS in controlling interference and improving radar detection probability.

RIS-Assisted Spectrum Sharing Between MIMO Radar and MU-MISO Communication Systems