Pulsed time division multiple access is recommended for psedudolite satellite signal to eliminate the near-far effect, which is different from global navigation satellite system signal design. However, in this case, the initial frequency bias obtained from acquisition is not precise enough for the carrier tracking loop to converge due to the signal's pulse modulation, as the rolling-off of auto-correlation function is insensitive to slight frequency changes. This Letter proposes an approach to narrowing the initial frequency error by mapping from code Doppler to carrier Doppler, in which the former one can be obtained from a delay lock loop (DLL). Simulation results demonstrate the validity of the proposed method in the initialisation of frequency pull-in process owing to the fixed proportion existed in the code and carrier Doppler.