N.A. Cherepanova - Student, Department «Radio Systems», Tomsk State University of Control Systems and Radioelectronics E-mail: b.a.d.wolf@yandex.ru F.N. Zakharov - Ph.D. (Eng.), Research Scientist, Department «Radio Systems», Tomsk State University of Control Systems and Radioelectronics E-mail: ZakharovFN@main.tusur.ru

There are multipath propagation signals in most of radio lines. The appearance reflected detained on arrival time signal leads to dis-tortion of the shape of the correlation peak of a signal and, as a result, to a shift in the assessment of real moment of arrival. In this paper presents the method of determining moment of arrival a signal, based on the use of the nonlinear quadratic Teager-Kaiser (TK) operator. The advantages of non-linear TK operator are simplicity and efficiency in determining moment of arrival the desired signal. TK operator applied to the correlation function is triangular in shape, provides clean temporary peak position alignment on a triangular pulse. Signal maximum on output TK operator coincides with the moment of arrival the direct pulse. Delayed pulse corresponds to a count with lower amplitude. This allows you to select the moment of arrival the reflected signals and evaluate their delay. The algorithm of the TK operator was realized in MATLAB on the example of receiving single and multiple video pulses with different amplitudes, time delay, and the presence of white Gaussian noise with a given intensity. Cases of signal reception in noise in the absence and presence of multipath were considered. As the noise was considered white Gaussian random process with zero mean. Stability of the TK operator in the presence of varying intensity noise was examined. As the sustainability assessment criteria was considered the probability of a correct evaluation of the moment of arrival a direct pulse. The probability for each value of the parameters determined by the 1000 realizations of the random noise. The full error in determining moment of arrival direct pulse in the presence of noise and delayed pulse was assessed. It was shown that TK operator well separates moments of arrival video pulses with different delays up to the time quantization step when the ratio S/N is not less than 5-7 dB. The complete error in determining moment of arrival on the average does not exceed five counts. When S/N ratio of less than 3 dB the probability of a correct evaluation of the moment of arrival of the direct signal is not more than 50%, and the total error in determining moment of arrival of the direct signal increases greatly. In the absence of multipath error is greater than the presence of delayed pulse. It was found that when the delay pulse by one count probability of correct estimation is less than five delay counts and close to 100% only when the ratio S/N is not less than 20 dB.

 

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