Research on variable step length synchronization method in MSD

Most synchronized methods of pulse code frequency modulation (PCM/FM) system need to add additional software on the receiving end, so the cost is larger. In view of the characteristic, early-late gate code synchronization and lift the carrier synchronization method based on MSD are studied in PCM/FM signal software demodulation system based on multi-symbol detection (MSD). The method takes advantage of the MSD itself to use local materials, simple to add and subtract local time delay and frequency offset can reach synchronization requirements. Time and frequency synchronization method of variable step are studied and the relationship between several indicators is simulated in low SNR environment. The method ensures the synchronization of rapid implementation in the case of low system cost and has certain engineering application value.