Track Carrier Ofdm-based Communications Technology Research

With the continuous development of the society, people put forward higher demand on the railway transportation system.As the speed of trains more and more higher, the density of the running trains on the railway must increase. In order to adjust and control the trains better, and ensure the security of the railway transportation system,more and more track signal need to be transmitted through the track circuit. Although, the frequency-shift keying (FSK) signal is a kind of mature technology,and have been used in many countries.there are still some disadvantages which we need to over come.Therefore,this paper try to find a more suitable technique for the track circuit signal, in order to improve the security and anti-interference of track circuit.Firstly, the paper make a detailed description on the track circuit and frequency-shift automatic blocking, and analyzes the wide-used FSK signal in time domain and frequency domain。For the problems and shortcomings in practice,the paper analyzes the track circuit communication channel characteristics, and then proposed a method which based on orthogonal frequency division multiplexing (OFDM) technology for multi-carrier signal transmission, the theory on OFDM technology has been introduced in detail, and establish a simulation system which based on orthogonal frequency division multiplexing (OFDM) technology for multi-carrier signal transmission, and make an analysis on modulation ,demodulation,key technique,signal sender and receiver design of the OFDM simulate modem。Finally, the paper discusses the performance of the communication system performance based on OFDM technology.