METHOD OF DEMODULATING PHASE-SHIFTED SIGNALS Russian patent published in 2016 - IPC H03D3/00 

FIELD: communications.

SUBSTANCE: invention relates to methods of demodulating phase-shift keyed signals and can be used in systems for detecting or homing guidance and telemetry in underwater equipment. In this method the amplified signal is limited or is digitized by transitions via zero, is converted into binary code and stored in random-access memory, a bearing frequency is measured and compared with threshold level. Binary signal of random-access memory is subject to decoding in the form of a code, the maximum level signal corresponding to decrypted code and is subtracted from incoming from RAM signal. Obtained carrier is subjected to direct Boolean transformation over Galois field GF(2n), then the conjugated conversions and the obtained vector is successively subjected to unitary conversion over Galois field GF(2n) and Walsh conversion. After threshold level the bearing demodulated frequency is determined.

EFFECT: higher noise-immunity of demodulating phase-shifted signals through full synchronisation of modulation signal using invariant sequences independent from randomness phase of received signal.

1 cl, 3 dwg, 3 tbl