A single-chip solution for railway frequency-shift signal detection

Frequency-shift automatic blocking system has been widely applied in China´s railway system. High-precision detection of the frequency-shift signal is important to railway driving safety. In this paper, a new algorithm for railway frequency-shift signal detection on the basis of frequency-domain analysis was presented. The main and accessory frequencies of railway signal were separated using FIR digital filtering technology. By combining under sampling technology, Zoom-FFT and energy centrobaric correction technology, detection of the low frequency and the upper/down side frequency of the railway signal were realized. This algorithm has been verified on ARM processor, test results demonstrate that this solution has the advantages of high accuracy, low complexity, good reliability and low cost, which is fit for railway frequency-shift signal detection.