Robust MIMO Beamforming for Cellular and Radar Coexistence

TL;DR

This paper proposes a robust MIMO beamforming method that optimizes radar detection probability while maintaining downlink communication performance, enabling spectrum sharing between radar and cellular systems.

Contribution

It introduces a convex lower-bound optimization approach for robust beamforming in MIMO systems, addressing coexistence with radar under imperfect CSI.

Findings

Enhanced radar detection probability with beamforming

Effective spectrum sharing between radar and communication

Robust performance under CSI uncertainties

Abstract

In this letter, we consider the coexistence and spectrum sharing between downlink multi-user multiple-input-multiple-output (MU-MIMO) communication and a MIMO radar. For a given performance requirement of the downlink communication system, we design the transmit beamforming such that the detection probability of the radar is maximized. While the original optimization problem is non-convex, we exploit the monotonically increasing relationship of the detection probability with the non-centrality parameter of the resulting probability distribution to obtain a convex lower-bound optimization. The proposed beamformer is designed to be robust to imperfect channel state information (CSI). Simulation results verify that the proposed approach facilitates the coexistence between radar and communication links, and illustrates a scalable trade-off between the two systems' performance.