Fine synchronization of a signal in the presence of time shift caused by doppler estimation error

摘要

A radio frequency receiver includes a receiving circuit for receiving and decoding an incoming radio frequency signal including a correlation signal. The receiver also includes a timing estimation circuit. The timing estimation circuit comprises a signal buffer receiving a plurality of correlation signal segments, and a first peak detection and Doppler estimation circuit for determining a first timing of a first segment and the associated first Doppler shift. The timing estimation circuit also comprises a memory coupled to the signal buffer, the memory receiving a plurality of segment correlation metrics, and a second peak detection and Doppler estimation circuit for determining a second timing of a second segment and the associated second Doppler shift. Further included in the timing circuit is a final correlation circuit for determining a final timing estimate based on the first Doppler shift, the second Doppler shift, and the first timing estimate and based on the correlation metrics of at least some of the plurality of correlation segments.