Design Of Orbit Shift Frequency Signal Frequency Detection Device Based On DSP

Since the policy of reform and opening-up for30years. China’s economydevelopment rapidly, transportation into the fast lane. In the number oftransportation of goods and passengers the growed fast. In the transportation, railtransport occupies the central position. Developing transportation could promotethe ceonomy of the China. If you want to improve the efficiency of track use, youmust increase the travel speed of the train. But this is followed by the need toimprove control and reasonable allocation of train operation, the only way toensure smooth and efficient train operation.Frequency shift of the train control and traffic information transfer orbittrack by track circuit to send a signal completed. The orbit frequency shift signalis a frequency shift keying signal.It is carrying the information of thelow-frequency modulation signal modulated high-frequency carrier signal, thefrequency of the carrier signal with the low frequency signal, a regular variation,information transmission.How to ensure the normal work of the track circuit control system and trackthe frequency shift signal distortion-free transmission is particularly important.This article discusses the track circuit frequency shift automatic blocking systemusing a real-time signal detection and analysis device. It uses AT89S52and DSPas the core, dual-processor architecture. The apparatus includes a signal samplingmodule, signal processing and control module, the data is uploaded to the hostcomputer communication module function modules, and test interface circuit, anexternal memory interface circuits, LCD liquid crystal display interface circuit,protection circuit, filter circuit, the resetcircuit, etc. The system works. First trackacquisition frequency shift signal to obtain a digital signal, and then, by fastFourier transform analysis of the collected signal to obtain the carrier frequency,the upper frequency and the lower frequency of the main information, thereby effectively demodulate the low-frequency modulation signal transferedinformation. Finally, system simulation test, the low-frequency signals to passinformation demodulation, which show that the system can track the frequencyshift signal testing and analysis capabilities.