V.I. Kalinin - Ph.D. (Phys.-Math.), Head of Laboratory, Frjazino Branch of IRE V.A.Kotel\'nikova RAS. E-mail: val.kalinin@mail.ru V.V. Chapursky - Dr.Sc. (Eng.), General Research Scientist, Bauman Moscow State Technical University. E-mail: valch2008@yandex.ru

In data transmission systems with noise carrier waves relative methods of modulation are applied. Thus transmitted continuous noise waveform is obtained by summation of reference noise generator fluctuations with its delayed copy modulated on a sign or a time delay by a binary sequence of information symbols. Two known version of chaotic transfer systems [4,5] are considered: DCSK - Differential Chaos Shift Keying and CDSK - Correlation Delay Shift Keying. The discrete approach at the analysis of data transfer fidelity in [4,5] is not acceptable for continuous analogues of DCSK and CDSK systems, in particular, at use of ultrawidedband (UWB) noise waves in radio channels of a GHz range and correlated noise waves in low-frequency radio- and hydroacoustic channels. The reason is the assumption of the sample independence of discrete carrying sequence and impossibility of the account of nonidentical signals delays in transmitting and receiving parts of system. In case of continuous noise waves with arbitrary correlation and relative modulation methods for the listed data transfer systems the analysis of bit error rate (BER) probability was not spent earlier. In the given work continuous analogues of transfer noise systems such as DCSK and CDSK are considered. It is shown, that dependence of average output effect of the receiver for these systems has the oscillatory character determined by the form of correlation function of noise wave fluctuation. Continuous noise systems are critical to delays inequality in transmitting and receiving parts, and the absolute size of inequality should be much less of the quarter-period of a noise wave spectrum medium frequency. It is established that the dispersion of noise signal in the propagation channel for analog CDSK system (with the doubled transfer speed) has small changes with a information bit change. At reduction of delays on practicability reasons these changes can be increased up to significant sizes, and modulation in a propagation channel can be find out, that will demand special ways of dispersion alignment in a channel. For CDSK system BER as a function of the average signal energy to spectral density ratio are received. The best characteristics under the threshold signal/noise ratio at BER = 10-5 meet to bases of noise wave 200...1000, output signal/noise 22-24 dB and the input signal/noise in the channel - 1,0 - - 6,5 dB. The further investigations in the given area are connected with reduction of requirements to delays identity in transmitter and receiver of noise transfer systems by the quadrature channel account. Also the matter of interest is the methods of a noise wave dispersion alignment in a propagation channel for the purpose of data transfer systems hiding increas.

 

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