METHOD AND DEVICE FOR RECEIVING FREQUENCY-MODULATED SIGNAL

摘要

The object of the present invention is to provide a train detection system which is highly resistant to noise. In a method for using a frequency modulated signal as a train detection signal and judging train decision by existence of demodulation due to a reduction in the received signal level caused by a short-circuit of the axle, as a method for optionally setting a threshold value of train decision, when applying the amplitude-dependent demodulation process, by combining the gain process of amplifying the amplitude of a signal, the limiter process of limiting the amplitude of the output signal of the gain process to a fixed value, and the filter process of removing harmonics generated by the limiter process at the previous stage of the demodulation process and by optionally setting the lower limit value of the demodulatable signal level by the gain, a process of optionally setting a threshold value of train decision is realized.