High-precision correlation-domain time delay estimation method based on fractional filters
Jie Song, Baiyu Li, Yuqing Wang, Zongnan Li, Zukun Lu, Guangfu Sun · IET conference proceedings. · 2025
Time delay estimation is a crucial methodology in multi-station passive localization systems for non-cooperative signal sources. However, the accuracy of contemporary techniques for evaluating time delay differences is constrained by the limitations of the sampling rate. This study introduces a high-precision correlation domain time delay estimation approach that utilizes fractional filters. The methodology encompasses the design of fractional delay filters and the calculation of time delay differences through a dual-path architecture, thereby improving precision within the correlation domain. Simulation results indicate that this technique yields superior accuracy in time delay estimation, achieving deviations of less than 20 nanoseconds at a sampling rate of 25 MHz.