Correlator frequency discriminator based carrier synchronization algorithm

The effect of large frequency offset on the performance of a digital segmented matched filter (SMF) DS/BPSK receiver is investigated, and an SMF based frequency discriminator is presented. The proposed algorithm employs the outputs of the segmented correlator and the whole period correlator to form a correlator frequency discriminator (CFD) which has a tracking range of 0.75 times the symbol rate and maximum working range up to symbol rate. The noiseless characteristics and outputs of SNR of CFD and four-quadrant frequency discriminator (FQFD) are explored. Then a combined frequency synchronization scheme is recommended for DS/BPSK receivers with a large initial frequency error, which extends the frequency search bin and shortens the carrier acquisition time.