Selbstentzerrerapparat fuer die Verwendung bei kohaerent phasenverschoben verschluesselten Signalen

Circuitry for detecting and measuring distortion components in a differentially coherent phase shift keyed signal received at a receiver after transmission over a transmission facility and further circuitry for altering the amplitude and phase of the received signal by an amount indicative of the measured value. The equalizer measures both pre and post pulse distortion products in producing the adjusted output signal. The disclosure also illustrates a special preamble which may be used prior to the main message to hasten the measurement and adjustment process time over the time required if random sampled data is used in the measurement process. The equalizer algorithm utilizes the fact that the phase and amplitude of prepulse and postpulse interference of any particular pulse can be measured relative to the main pulse by making the other interference pulses and the main pulse orthogonal.