Blind Parameters Estimation for Time-Frequency Overlapped Satellite Signals

Accurate blind estimation of the symbol timing offset (STO) and carrier frequency offset (CFO) in time-frequency overlapped satellite (TFOS) signals is crucial for monitoring such signals without pilot sequences. To address this challenge, this letter proposes a novel high-precision joint blind estimation algorithm for STO and CFO in TFOS signals. Specifically, we construct an objective function parameterized by STO and CFO using the cyclic correlation functions (CCFs) of TFOS signals. Furthermore, we develop the improved water flow optimizer (IWFO) method to efficiently search for the optimal solutions of the objective function, achieving superior convergence performance. Numerical results show that the proposed algorithm requires an extremely low sampling rate, supports multiple modulation schemes, and markedly outperforms benchmark algorithms in terms of estimation accuracy.