Hybrid Digital-Analog Beamforming and MIMO Radar with OTFS Modulation

TL;DR

This paper proposes a hybrid digital-analog beamforming approach combined with OTFS modulation for joint radar target detection, parameter estimation, and communication in automotive scenarios, demonstrating near-optimal performance.

Contribution

It introduces a novel hybrid beamforming scheme integrated with OTFS for simultaneous radar and communication functions in mmWave MIMO systems.

Findings

Reliable detection of multiple targets with sufficient antennas

Achieves Cramér-Rao lower bound for radar parameter estimation

Effective joint radar and communication performance

Abstract

Motivated by future automotive applications, we study some joint radar target detection and parameter estimation problems where the transmitter, equipped with a mono-static MIMO radar, wishes to detect multiple targets and then estimate their respective parameters, while simultaneously communicating information data using orthogonal time frequency space (OTFS) modulation. Assuming that the number of radio frequency chains is smaller than the number of antennas over the mmWave frequency band, we design hybrid digital-analog beamforming at the radar transmitter adapted to different operating phases. The first scenario considers a wide angular beam in order to perform the target detection and parameter estimation, while multicasting a common message to all possible active users. The second scenario considers narrow angular beams to send information streams individually to the already detected users and simultaneously keep tracking of their respective parameters. Under this setup, we propose an efficient maximum likelihood scheme combined with hybrid beamforming to jointly perform target detection and parameter estimation. Our numerical results demonstrate that the proposed algorithm is able to reliably detect multiple targets with a sufficient number of antennas and achieves the Cram\'er-Rao lower bound for radar parameter estimation such as delay, Doppler and angle-of-arrival (AoA).