Time Delay Estimation

TL;DR: This chapter reviews some recently developed algorithms for time delay estimation, with the emphasis placed on their performance analysis and comparison in reverberant environments.

Abstract: Time delay estimation has been a research topic of significant practical importance in many fields (radar, sonar, seismology, geophysics, ultrasonics, hands-free communications, etc.). It is a first stage that feeds into subsequent processing blocks for identifying, localizing, and tracking radiating sources. This area has made considerable advances in the past few decades, and is continuing to progress, with an aim to create processors that are tolerant to both noise and reverberation. This chapter reviews some recently developed algorithms for time delay estimation. The emphasis is placed on their performance analysis and comparison in reverberant environments. In particular, algorithms reviewed include the generalized cross-correlation algorithm, the multichannel cross-correlation algorithm, and the blind channel identification technique based algorithms. Furthermore, their relations and improvements are also discussed. Experiments based on the data recorded in the Varechoic chamber at Bell Labs are provided to illustrate their performance differences.