Railway frequency shift signal anti-interference method based on blind source separation

Abstract

The invention relates to railway frequency shift signal anti-interference device and method based on blind source separation. The device comprises a two-channel collection and AD conversion module, a time sequence control module and a digital signal processing module used for executing anti-interference method treatment, wherein the two-channel collection and AD conversion module collects railwaytrack signals and converts the railway track signals to digital signals, and the time sequence control module is respectively connected with the two-channel collection and AD conversion module and the digital signal processing module. The invention can eliminate interference of amplitude modulation signals which are in aliasing with a frequency shift signal time-frequency domain to enhance the signal to noise ratio of locomotive signal detection, utilize a blind source separation algorithm based on geometric transformation to separate out amplitude modulation interference signals or neighboring line interference signals which are in aliasing in frequency shift signals and utilize a wavelet threshold denoising method to lower white noise interference contained in the signals before blind source separation, thereby strengthening the stability of the blind source separation algorithm.

Description

technical field [0001] The invention belongs to the field of signal processing and relates to an anti-jamming method for railway signals, in particular to an anti-jamming method for railway frequency-shifting signals based on blind source separation. Background technique [0002] In railway transportation, in order to associate train transportation management with signal equipment, steel rails are usually used as signal transmission wires, and insulation is installed on the joints at both ends of a certain track section, one end transmits power, and the other end receives power. One track circuit after another. In my country, the main applications are the domestic frequency shift blocking system and the French UM71 frequency shift automatic blocking system. For frequency-shift automatic blocking, the track signal transmitted in the track line is a 2FSK signal using frequency-shift keying, and the frequency-shift signal that transmits different information on the track is us...

AI Technical Summary

Problems solved by technology

[0005] However, the above methods have the following disadvantages: the traditional frequency-domain filtering method is powerless to the noise in the frequency band of the frequency-shifted signal, and the wavelet packet filtering method and the EMD method have a significant effect on filtering, but they are not suitable for the noise mixed with the frequency-shifted signal. For AM signals with similar frequency spectrum or when the energy of the frequency-shifted signal is low, the interference components in the frequency-shifted signal cannot be filtered out.

The method based on fractal dimension and the detection method of competitive neural network are computationally complex, and the detection effect will be greatly affected in a strong noise environment, resulting in detection failure

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