Research On Detecting Technology Of Railway Frequency-Shift Keying Signal

Railway is the important infrastructure of the transportation, safty of train plays a key role to the railway system for high-efficient and normal operation. Railway frequency-shift keying signal controls operation of locomotive, which has a close relationship with safty of railway in the contemporary. So railway frequency-shift keying signal should be timely and accurate detected in order to discover hidden dangers and problems that need to be solved, which guarantees the normal work of railway and which is one of the important methods for safty of railway. It has the extremely vital significance to research detecting technology of railway frequency-shift keying signal.The paper studies in depth mathematical model and multi-frequency characteristic of railway frequency-shift keying signal that due to carrier frequency and modulation frequency is not the only, and it discusses the essential reason of spectrum leak. The paper uses frequency domain interpolation algorithm to find the interpolation between real frequency and the adjacent discrete frequency, then it utilizes interpolation to recover the true frequency of the signal, the paper combines home-made 18 information railway frequency-shift keying signal's characteristics of having twin peaks and UM-71 characteristics of one peak to detect the parameters of railway frequency-shift keying signal of two formats, at last the detecting method is simulated through MATLAB to validate the parameters of railway frequency-shift keying signal.The paper analyzes TMS320F2812 of DSP and builds the testing system of railway frequency-shift keying signal with TMS320F2812 as the center, which includes two parts, the first one is the design of hardware platform that focuses on analysing processor of DSP and designing the main circuit module, the second one is the development of validating and demonstrative platform in PC. Then detection algorithm is transplanted into hardware platform of DSP using CCS environment and the detected data were sent to the validating and demonstrative platform in PC through serial port bus in order to analyse the results. At last the results of experiments prove that the testing system can detect carrier frequency, low frequency, offset frequency, upper side frequency, lower side frequency, and resolutions and errors of the frequencies all meet the requirements of index.