Multiple-Target Doppler Frequency Estimation in ISAC With Clock Asynchronism

Abstract

Doppler frequency estimation is a challenging problem in integrated sensing and communication systems with clock asynchronism between transmitter and sensing receiver. Existing techniques have various limitations and are generally ineffective in multi-target sensing. In this correspondence, we propose an array-based scheme for multiple-target Doppler frequency estimation. We first develop a novel algorithm for angle-of-arrival (AoA) estimation, and then use the estimated AoA to construct orthogonal projections to separate static paths and each dynamic path for clock asynchronism compensation and Doppler frequency estimation. Simulation and experiment results are provided and demonstrate that the proposed scheme is effective in multiple-target scenarios, and its accuracy outperforms some state-of-the-art methods in single-target scenarios.