Abstract

A receiver for demodulating differential phase shift keying data, the data having bit values dependent upon whether the phase of a carrier is inverted or not inverted during a bit interval, the receiver having a phase locked loop oscillator for locking up with the phase of the carrier, a phase detector for sensing differences in phases between the oscillator signal and the incoming data, an oscillator controller for controlling the output phase of the oscillator in response to the phase detector, a phase sense detector which detects whether or not the carrier has been inverted, a data clock responsive to the oscillator and to the phase sense detector for providing a data clock signal defining a bit interval, and a bit detector responsive to the phase sense detector, the data clock and the oscillator for integrating the incoming data.