Generalized Non-Iterative Time Delay Estimation Based on Taylor Interpolation Model

Time delay estimation (TDE) has been extensively studied in the past for off-grid cases since the time delay of the target does not fall on the sampling point (on-grid) usually. In this paper, two generalized non-iterative time delay estimation methods are proposed. The maximum range cell sampling point of signal powers after pulse compression is used as a rough estimate of the time delay, while multiple points around the peak location are employed to obtain the fine estimate. Based on the Taylor expansion model, the explicit generalized expressions of two methods for the fine estimate of the time delay are derived without the knowledge of the closed-form signal expression. The proposed methods can be applied in applications where the linear frequency modulation (LFM) signal and the nonlinear frequency modulation (NLFM) signal (without closed-form expression) are employed, and only the sampling values of several points around the peak location are required. Compared with existing methods, improved estimation performance can be achieved by both methods.