DIFFERENTIAL PHASE-BASED FREQUENCY OFFSET ESTIMATION METHOD AND APPARATUS

摘要

A differential phase-based frequency offset estimation method. The method comprises: updating a received pilot frequency data cache when a pilot frequency symbol is received; extracting the currently received pilot frequency symbol from the received pilot frequency data cache, determining an initial frequency offset estimation, and determining a phase difference value according to the initial frequency offset estimation; pre-processing two adjacent pilot frequency symbols stored in the received pilot frequency data cache, and respectively calculating phases corresponding to the two pilot frequency symbols; amending the phases corresponding to the two pilot frequency symbols according to the initial frequency offset estimation and the phase difference value; if it is judged that the amended phase is a normal value, then respectively updating two groups of phase sliding window caches; calculating an average phase value respectively according to phase values in the two groups of phase sliding window caches, and determining a maximum likelihood frequency offset estimation value according to the average phase value; and updating a frequency offset estimation result sliding window cache according to the maximum likelihood frequency offset estimation value, and performing smooth filtering processing on the cached maximum likelihood frequency offset estimation value to obtain the maximum likelihood frequency offset estimation value at a current moment.