Up today, nationally published research results on the methods used in HA modems have studied and shown the major methods; the ASK method and the DS/SS method. In this paper, we applied the DPSK reception method on the PSK method so that solved the acquisition and tracking problem of the signal synchronization which is the defect of PSK. Also, it has been designed to fit in the CISRP and CENELEC specification so that make sure of no effects on other part of the system.