Coherent demodulating arrangement for use in digital radio communications system.

摘要

A coherently demodulating arrangement includes a quasi-coherent demodulator (34) which implements coarse coherent demodulation on an incoming IF signal using a variable frequency which is applied from a controllable local oscillator (32). The frequency of the local oscillator is controlled such that the frequency difference between the IF signal and the output of the local oscillator falls automatically in a predetermined range.