A Reconfigurable Subarray Architecture and Hybrid Beamforming for Millimeter-Wave Dual-Function-Radar-Communication Systems

TL;DR

This paper introduces a reconfigurable subarray architecture with hybrid beamforming for millimeter-wave dual-function radar-communication systems, optimizing performance and energy efficiency through advanced algorithms.

Contribution

It proposes a novel reconfigurable subarray architecture and joint optimization method for hybrid beamforming in mmWave DFRC systems, enhancing efficiency and performance.

Findings

Improves energy efficiency by over 83% compared to other architectures.

Achieves effective communication and radar sensing with moderate hardware complexity.

Provides convergence and complexity analysis of the proposed algorithms.

Abstract

Dual-function-radar-communication (DFRC) is a promising candidate technology for next-generation networks. By integrating hybrid analog-digital (HAD) beamforming into a multi-user millimeter-wave (mmWave) DFRC system, we design a new reconfigurable subarray (RS) architecture and jointly optimize the HAD beamforming to maximize the communication sum-rate and ensure a prescribed signal-to-clutter-plus-noise ratio for radar sensing. Considering the non-convexity of this problem arising from multiplicative coupling of the analog and digital beamforming, we convert the sum-rate maximization into an equivalent weighted mean-square error minimization and apply penalty dual decomposition to decouple the analog and digital beamforming. Specifically, a second-order cone program is first constructed to optimize the fully digital counterpart of the HAD beamforming. Then, the sparsity of the RS architecture is exploited to obtain a low-complexity solution for the HAD beamforming. The convergence and complexity analyses of our algorithm are carried out under the RS architecture. Simulations corroborate that, with the RS architecture, DFRC offers effective communication and sensing and improves energy efficiency by 83.4% and 114.2% with a moderate number of radio frequency chains and phase shifters, compared to the persistently- and fullyconnected architectures, respectively.