Adaptive and Fast Combined Waveform-Beamforming Design for mmWave Automotive Joint Communication-Radar

TL;DR

This paper introduces an adaptive, fast combined waveform-beamforming method for mmWave automotive joint communication-radar systems, improving radar estimation accuracy and maintaining communication quality through optimized compressed sensing and beamformer shifts.

Contribution

It proposes a novel adaptive waveform-beamforming design that enhances radar channel estimation and balances communication and radar performance in mmWave automotive JCR systems.

Findings

Low radar channel MSE achieved

Minor communication distortion increase

Effective wide field-of-view radar estimation

Abstract

Millimeter-wave (mmWave) joint communication-radar (JCR) will enable high data rate communication and high-resolution radar sensing for applications such as autonomous driving. Prior JCR systems that are based on the mmWave communications hardware, however, suffer from a limited angular field-of-view and low estimation accuracy for radars due to the employed directional communication beam. In this paper, we propose an adaptive and fast combined waveform-beamforming design for the mmWave automotive JCR with a phased-array architecture that permits a trade-off between communication and radar performances. To rapidly estimate the mmWave automotive radar channel in the Doppler-angle domain with a wide field-of-view, our JCR design employs a few circulant shifts of the transmit beamformer and apply two-dimensional partial Fourier compressed sensing technique. We optimize these circulant shifts to achieve minimum coherence in compressed sensing. We evaluate the JCR performance trade-offs using a normalized mean square error (MSE) metric for radar estimation and a distortion MSE metric for data communication, which is analogous to the distortion metric in the rate distortion theory. Additionally, we develop a MSE-based weighted average optimization problem for the adaptive JCR combined waveform-beamforming design. Numerical results demonstrate that our proposed JCR design enables the estimation of short- and medium-range radar channels in the Doppler-angle domain with a low normalized MSE, at the expense of a small degradation in the communication distortion MSE.