Abstract: There is disclosed a digital demodulator for the demodulation of an m-phase shift keying modulated signal. The demodulator comprises a sampling and quantizing circuit which samples and quantizes in-phase and in-quadrature components of the modulated analog signal and a carrier recovery circuit for reconstructing the carrier. The sampling and quantizing circuit quantizes the in-phase and in-quadrature components by means of a number of different quantization thresholds. This device is used in communications systems, particularly terrestrial and satellite microwave links and computer-to-computer links.

Abstract: The spread-spectrum signal (S1) is converted into a one-bit quantized binary signal (S2) and this signal is coupled to a plurality of parallel detection circuits (10), each of said detection circuits being adapted to detect a distinct code epoch. Each detection circuit (10) receives concurrently a shifted version of a binary reference code (CR) and produces a signal (B3) having a first binary state when the received signal corresponds to the code epoch of the detection circuit and having a second binary state should it be otherwise. The output signals (B3) are combined and/or encoded to identify the correct code epoch in order to demodulate the received signal. The invention is used in communication systems receivers.