Patent ID: 8194793

Claim:
A multi-stage frequency offset estimation and compensation method comprising: providing a binary phase shift keying (BPSK) modulated input carrier signal, which comprises a periodic pseudo-noise (PN) sequence with more than one period of length; performing multi-stages of a primary-level frequency offset estimation and compensation procedure to convert a provided input carrier signal fed into a first stage to a last corrected carrier signal out from a last stage of the multi-stages of the primary-level frequency offset estimation and compensation procedure by way of one stage after another wherein when the current stage is the first stage, the provided input carrier signal is set as the input carrier signal of the current stage, whereas when the current stage is beyond the first stage, the corrected carrier signal from the previous stage is fed forward and set as the input carrier signal of the current stage; and performing one time an advance-level frequency offset estimation and compensation procedure using the last corrected carrier signal as an input signal; wherein, the primary-level frequency offset estimation and compensation procedure comprises: estimating a frequency offset of the current stage with an unmodulated portion of the input carrier signal; and compensating the frequency of the input carrier signal of the current stage for the estimated frequency offset so as to obtain the corrected carrier signal of the current stage; the advance-level frequency offset estimation and compensation procedure comprises: estimating the frequency offset of the current stage with periodically repeated chips of the periodic PN sequence; and compensating the frequency of the input carrier signal of the current stage for the estimated frequency offset so as to obtain the corrected carrier signal of the current stage.