METHOD OF SYNCHRONIZING M-SEQUENCE Russian patent published in 1994 - IPC

FIELD: information translation. SUBSTANCE: radio-frequency phase-manipulated sequence is converted incoherently into two quadrature video-frequency components. Binary and temporal quantization is carried out by means of reference sync pulses which have repetition period being equal to duration of element of phase-manipulated sequence; the sync pulses are delayed for a half duration of the element. Reference and set phase-manipulated sequence mutual correlation function is formed in each quadrature. Values of correlation function are compared with set criteria of detection. Moment of time is registered when detection takes place. Two gates which have repetition period equal to duration of phase-manipulated sequence are formed. These gates are shifted one relatively the other for a half element of phase-manipulated sequence. Time interval is measured between pulses in quadrature and between moment of detection. Gate is delayed for a value of the interval. Sign of difference in values of mutual correlation functions is determined. Integral accumulation of values of difference of mutual correlation functions are performed in any quadrature for specified number of periods of phase-manipulated sequence. Accumulated sums of differences of values of mutual correlation functions are compared with limit values. Time delay is carried out for reference sync pulses for value which depends proportionally on accumulated difference of values of mutual correlation function. EFFECT: reduced time of search when initial phase of the signal is not determined. 3 dwg