The Simulation System Of Railway Signal Transmission And On-board Cab Signal Receiving

The railway signal system is brought and developed to ensure traffic safety, improve transport efficiency and working conditions. Railway signal sends instructions and information to control the train line, time interval and speed, displays current train line and equipment status, so as to ensure the safety of high-speed train traffic. Future development of railway signal is to achieve a higher degree of automation and intelligent in order to ensure traffic safety and improve efficiency.In this paper, a simulation system for railway signal transmission and on-board cab signal receiving is conceived and implemented. The system uses a DSP chip TMS320VC33 as data processor and a TMS320VC5509A as a controller. Other parts of the system include a signal generator, an experimental rail transmitting device, a receiving loop, a receiving demodulator and an eight-signal display device. The system simulates the railway signal's working process, including transmission, receiving, decoding and controlling of the eight-signal display device. The system supports all the existing railway signal standards used in China.The demodulation part of the system uses a mixed method which combines frequency domain analysis with time domain analysis. It also makes use of the techniques of frequency pattern recognition and signal quality classification to realize the automatic identification and real-time demodulation of the four standard railway signals.The simulation system of railway signal transmission and on-board cab signal receiving achieves the champion in the national DSP competition organized by TI in 2008. This system can provide not only an experimental and demonstrating module for the teaching purpose, but also a platform for cab signal simulation for the purpose of research and development. Replacing the generated input signal with actual railway signals, some functions of a cab signal can be simulated to assist the research of new algorithms and features of cab signals. It can also be used to search for any error or failure of spot railway signal. Therefore, the system can find wide applications.