Timing Advance Estimation With Robustness to Frequency Offset in Satellite Mobile Communications

Timing advance (TA) estimation based on Zadoff-Chu (ZC) sequences is susceptible to carrier frequency offset (CFO), especially in high-dynamic satellite mobile communication scenarios with large Doppler shift. To solve this problem, a novel random access (RA) preamble sequence is first constructed by combining the real and imaginary part of a root ZC sequence, which entirely inherits the excellent correlation properties of the ZC sequence. With the aim of mitigating the adverse impact of large CFO, we further present a multi-peak joint detection algorithm that can obtain accurate TA value in once correlation operation without additional resource consumption and computational complexities. Numerical results consist with the mathematical analysis, and exhibit the robustness of the proposed method to large CFO in terms of error detection probability (EDP) and timing mean square error (MSE).