| 摘要 |
FIELD: radio engineering, communication.SUBSTANCE: method of processing hydroacoustic noise-like phase-shift keyed signals includes receiving a signal s(t), digitising the signal, obtaining y, pre-equalising the amplitudewhereperforming shift into the low-frequency region and determining the real componentand the imaginary component of the signal(fis the centre frequency of the noise-like phase-shift keyed signal being processed, fis the sampling frequency of the signal processing system, Nis the processing window length, which must be equal to an integer number of periods in sampling frequency readings, i.e. N=n·T·fwhere n=1, 2, 3?), for the obtained signal(- imaginary unit) using a low-pass filter, suppressing high-frequency components,is the pulse response of the filter, Nif the length of the pulse response of the filter), decimating the sampling frequency with an interval Nof the signalwhere Nis the sampling interval, which is equal to the radio of the sampling frequency fof the source signal and the doubled cutoff frequencyafter which the sampling frequency of the signal becomes equal to f=2f=?f, repeating signal amplitude equalisationand for the obtained signal, calculating the value of a correlation functionwhere Nis the duration of the processed signal in sampling frequency readings f, mis the reference correlator signal in symbol form, calculating a threshold valuewhere n is the number of symbols in the modulating pseudorandom sequence, k is an integer defined by a given false response probability ?, wherein k?n and is selected as the greatest number for which the conditionis satisfied, whereis the number of combinations i throughcomparing the value of the correlation function Ywith the threshold value Y, and presence of a signal is determined when the value of the correlation function exceeds the threshold value.EFFECT: improved noise-immunity when detecting a hydroacoustic signal in real operating conditions with low hardware computational power. |
