MU-MIMO Communications With MIMO Radar: From Co-Existence to Joint Transmission

Abstract

Beamforming techniques are proposed for a joint multi-input-multi-output (MIMO) radar-communication (Rad-Com) system, where a single device acts both as a radar and a communication base station (BS) by simultaneously communicating with downlink users and detecting radar targets. Two operational options are considered, where we first split the antennas into two groups, one for radar and the other for communication. Under this deployment, the radar signal is designed to fall into the null-space of the downlink channel. The communication beamformer is optimized such that the beampattern obtained matches the radar's beampattern while satisfying the communication performance requirements. To reduce the optimizations' constraints, we consider a second operational option, where all the antennas transmit a joint waveform that is shared by both radar and communications. In this case, we formulate an appropriate probing beampattern, while guaranteeing the performance of the downlink communications. By incorporating the SINR constraints into objective functions as penalty terms, we further simplify the original beamforming designs to weighted optimizations, and solve them by efficient manifold algorithms. Numerical results show that the shared deployment outperforms the separated case significantly, and the proposed weighted optimizations achieve a similar performance to the original optimizations, despite their significantly lower computational complexity.

Joint Radar and Communication Design: Applications, State-of-the-Art, and the Road Ahead

“…This is because for a multi-path channel, the received symbol will be seriously distorted by the dispersed signals arriving from Non-LoS (NLoS) paths, where all the sidelobe and the mainlobe power may contribute. To this end, the authors of [89] proposed several beamforming designs to enable joint MIMO radar transmission and MU-MIMO communication, in which the communication signal was exploited for target detection, hence it would not affect the DL data rate. The joint beamforming matrix is optimized to approach an ideal radar beampattern, while guaranteeing the DL SINR and the power budget.…”

A Dual-Function Radar Communication System Using Index Modulation

“…Since permutation matrices are orthogonal, this is equal to 13 Denote by code i j the codeword induced by Σ −1 i Σ j . Then,…”

“…Codeword design approaches are also proposed to further facilitate decoding, at the cost of reducing the information rate. The main advantage of MAJoRCom over previously proposed DFRC systems, e.g., [10]- [13], [17], [20], is that it provides the ability to communicate without affecting the radar subsystem, while supporting the usage of simple narrowband transceivers.…”

MIMO Radar and Cellular Coexistence: A Power-Efficient Approach Enabled by Interference Exploitation

“…Nevertheless, these works focus on the theoretical performance analysis rather than practical waveform design. As an enabler, the approach of embedding communication information in the radar waveform has been proposed in [5]- [8], where important trade-offs have been revealed.…”