Flexible Hybrid Beamforming for Spectrally Efficient 6G Joint Radar-Communications

TL;DR

This paper proposes a flexible hybrid beamforming approach for MIMO joint radar-communications systems in 6G, optimizing spectral efficiency by adaptively selecting RF chains and managing interference.

Contribution

It introduces a novel joint spectral efficiency maximization method with flexible hybrid beamforming and RF chain selection considering radar-communication interference.

Findings

Enhanced spectral efficiency compared to baseline methods

Effective interference management between radar and communication

Adaptive RF chain selection improves system performance

Abstract

Joint radar-communications (JRC) benefits from multi-functionality of radar and communication operations using same hardware and radio frequency (RF) spectrum resources. Thus JRC systems possess very high potential to be employed into the sixth generation (6G) standards. This paper designs a flexible beamformer for multiple-input multiple output (MIMO) JRC with maximized spectral efficiency (SE). Hybrid beamforming is implemented which constitutes lesser number of RF chains than number of transmitter antennas. We jointly express JRC rate with communication and radar entities including a weighting factor which depicts the dominance of one operation over the other. The joint-SE based proposed method optimally selects the number of RF chains with flexible hynrid beamforming design. Furthermore, when the communication operation takes place the proposed method takes into account the interference occurring from the radar operation and vice-versa. Fractional programming based selection procedure is used for flexible beamforming and optimal number of RF chains while considering interference of each operation. Simulation results are presented and compared with different baselines to show effectiveness of the proposed flexible hybrid beamforming method.