Abstract: The time-frequency transmission technology based on two optical combs has been able to achieve stable time-frequency transmission in experiment. However, the linear optical sampling algorithm will suffer from Doppler effect when there is relative motion on both sides of the two optical combs. In order to accurately calculate the time delay and frequency shift of the interference signal caused by Doppler effect, a joint estimation algorithm of time difference and frequency offset based on wide-band cross ambiguity function is studied. Several groups of interference signal are simulated under specific parameters when the optical comb delay is 38.78 fs and the relative speed is between 0 and 1800 m/s. In this speed interval, the delay error is 0 and the speed error is less than 0.3 m/s. Compared with the narrowband cross ambiguity function, the proposed algorithm has better performance of time and frequency scale estimation at high speed.

Key words: quantum information, quantum precision measurement, linear optical sampling, Doppler effect, time difference and frequency offset, wide-band cross ambiguity function