SIGNAL DETECTOR Russian patent published in 2006 - IPC G01S13/04 

FIELD: communication equipment, applicable in long-range space communication systems for signal detection at a reception in the conditions of a priory uncertainty or instability of the signal carrier frequency caused, in particular, by the presence of a considerable value of the Doppler frequency drift in the communication channel.

SUBSTANCE: in the known signal detector having a threshold device, whose output serves as the detector output, and series-connected band-pass filter, whose input serves as the detector input, and a phase discriminator, according to the invention, the second phase discriminator is connected to the output of the band-pass filter, the time constant of both band-pass filters is inversely proportional to the half width of the bandwidth of the band-pass filter, the second inputs of both phase discriminators are connected to the sinusoidal oscillator, whose signal frequency equals the center frequency of the input signal band, the second input of the first phase discriminator is coupled to the signal oscillator directly, and the second input of the second phase discriminator - via a phase shifter, the output of the first phase discriminator is connected to the inputs of the first and second multipliers and the first memory cell, whose output is coupled to the second inputs of the first and third multipliers, the output of the second phase discriminator is connected to the inputs of the third and fourth multipliers and to the input of the second memory cell, whose output is coupled to the second inputs of the second and fourth multipliers, the outputs of the first and fourth multipliers are connected to the inputs of the first adder, the outputs of the second and third multipliers are connected to the inputs of the subtracter, the output of the third multiplier is connected to the subtracting input of the subtracter, whose output is coupled to the input of the first squarer via the first low-pass filter, the output of the first adder is connected to the input of the second squarer via the second low-pass filter, the bandwidth of the first and second low-pass filters is inversely proportional to the length of the input signal symbol lass the time constant of the memory cell, the outputs of both squarers are coupled to the input of the threshold device via series-connected second adder and the third low-pass filter, and the value of the time constant of the third low-pass filter is not less than the duration of the input signal symbol.

EFFECT: opportunity of signal detection at reception of signals with different modulation ratios in the conditions of a priory uncertainty or instability of the signal carrier frequency caused, in particular, by the presence of a considerable value of the Doppler frequency drift in the communication channel because of the autocorrelation processing of the signal mixture with noise that is invariant to the signal frequency, taking into account the fact that the signal correlation interval exceeds the noise correlation interval by many times.

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