Demodulator for four-phase PSK microwave system - adjusts phase offset of carrier to improve system error rate at particular carrier-to-noise ratio

摘要

The demodulator for PSK microwave has a carrier signal recovery circuit (1) and two demodulator units (2, 3). The output of the carrier recovery circuit is connected through a variable phase offset circuit (5), to a phase reference input of the first demodulator unit, and to a similar input of the second demodulator unit through a 90 deg. phase shifteR. The output signals from the demodulator units are fed to an output terminal and to a monitoring unit for supplying control signals to the variable phase offset circuit through a control circuit.