A.S. Kozlov, V.N. Malyshev

The technique of the typical for serial interfaces tasks of detection of the fact of data transfer and blind assessment of their speed on an observable compound of a signal and noise in case of a priori unknown speed and the data format is considered. Spectrum and correlation analysis in such conditions are ineffective. For tasks solution use of the cepstrum analysis is offered. power cepstrum maxima, corresponding to periodic components in a signal range, allow to create hypotheses about values of bit speed of an analysable digital flow. The cepstrum analysis allows quickly and it is rather safe to reveal existence of a digital data stream and to evaluate its speed, including in case of the low relations signal/noise, in the presence of additive and multiplicative noises. The cepstrum analysis is suitable also for the analysis of a compound of several digital flows differing in the speed. Results of numerical modeling and examples of data handling of full-scale experiment are provided.