High-resolution time delay estimation using a combined correlator-based and phase measurement approaches.

Abstract

Time delay estimation is a fundamental step in source localization or beamforming applications. It has attracted considerable research attention over the past few decades in many fields including radar, sonar, seismology, geophysics, and ultrasonics. Various techniques are reported in the literature, mainly the correlator‐based methods. However, with these approaches, when the time delay is not an integral multiple of the sampling rate, it is necessary to either increase the sampling rate or use interpolation to get better resolution. In this paper, we present a new approach for time delay estimation based on combining the correlator‐based technique and the phase information obtained from the received signal. A cross‐correlation based approach is applied first to get an initial estimate then the DFT is applied to a window of the signal starting at this initial estimate to calculate a related phase. This phase will define an additional fractional inter‐sample time delay, which is corrected to provide more ...