METHOD OF DEMODULATING DIFFERENTIAL PHASE-SHIFT KEYING MODULATION SIGNALS (VERSIONS) Russian patent published in 2012 - IPC H04L13/18 H04L27/00 

FIELD: information technology.

SUBSTANCE: method relates to methods of receiving digital signals transmitted via differential phase-shift keying (DPSK) modulation. The method is characterised by that a signal is received and filtered and its amplitude is equalised; a reference signal is generated and correlation function thereof is calculated, the correlation function is successively integrated and its value is recorded; the modulus of the difference between values of the correlation functions at different time intervals is calculated and compared with a preset threshold value; the received data entry is assigned a value "one" or "zero" based on the comparison result, wherein the threshold value at each decision-making step is corrected depending on the ratio of "ones" and "zeros" in the demodulated signal. The disclosed versions are distinguished by different methods of correcting the threshold value.

EFFECT: high noise immunity owing to adaptive change of the threshold value for making a decision on the received symbol depending on probability of appearance of logic "ones" and "zeros" in the output sequence of the demodulator in conditions of variation of the level of demodulated signal in a wide range.

7 cl, 3 dwg