E.G. Egisapetov - Ph.D. (Eng.), Senior Research Scientist, JSC STC «Module». E-mail: kei@module.ru

We consider communication system using phase-shift keyed noise-like signals. In such communication systems, the detection of the start pulse signal (clock signal) is produced using a detector consisting of a matched filter and an adaptive threshold device. After separation of the envelope of the carrier frequency and its digitization to the input of the detector receives a binary sequence X jumps of the phase of the carrier frequency. In a consistent filter in each step of the income sequence X is calculated correlation function of this sequence and the reference sequence, which was modulated within the carrier phase of the clock. With such a noise-like signal detection can occur «false detection», associated with the excess of the side peaks of the correlation function of the adaptive threshold. According to the «false detection» starts processing of «false information elements» signal. A method of forming and detecting sync noise-like signal, which can significantly reduce the number of «false alarms», issued by the detector. The method is to «tint» sync some Walsh function. With this method of forming a modulating sequence of clock pulses in the detector are fixed two events: the excess value of the correlation function of the adaptive threshold and the presence in the observed signal of the Walsh performing the role of a «tint». In the case of «false detection» signal at the input of the detector will not contain the desired Walsh functions. In the case of exceeding the adaptive threshold of the primary peak of the correlation function signal at the input of the detector will contain the desired Walsh function.

 

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