Single-chip ARM Based Frequency-shift Signal Integrated Acquisition System

China's railway has widely adopted ZPW-2000A none-insulation frequency-shift automatic blocking System. High accuracy detection of the frequency shift signal parameters is important to ensure train driving safety. With the accelerating of the speed, frequency-shift signal detection system established based on traditional detection method is facing great challenges in China.This paper proposed a single-chip solution for ZPW-2000A railway frequency-shift signal detection based on the analysis of the spectral characteristics of frequency-shift signal. As the energy of frequency-shift signal concentrated in the vicinity of the carrier frequency, we used under-sampling technology to reduce the sampling rate, applied Zoom-FFT algorithm to amplify the frequency-shift signal, in order to increase the resolution of low-frequency detection. As the energy of the discrete spectrum of Hanning Window concentrates approximately at the origin of coordinates, we used energy centrobaric correction method to improve the upper/down side frequency detection accuracy.The above algorithm has been successfully applied on STM32F103RET6, the ARM processor based on the most state-of-art Cortex-M3 structure, realized separation of the main and accessory frequency of ZPW-2000A signal, low-frequency detection, upper/down side frequency detection on single-chip processor for the first time. Test results demonstrate that this system can increase the accuracy of railway frequency-shift signal detection effectively, and has high integration level and reliability.