The Design Of A Balise Telegram Signal Generator Based On The FFFIS Encoding Strategy And FPGA

The rapid development of the national economy of China requires the railwaytransport to be faster, safer and more automatic. In order to meet the requirements, atrain control system named CTCS(Chinese Train Control System) was independentlyresearched and developed in China. The train control system reduces the humaninterventions to a running train and provides a precision, safe and efficient automaticcontrol. The balise system which is used as a communication system between a trainand the ground is a key part of the train control system and is very important to thesafety of a running train. At present, the balise technology of China is mainly introducedfrom the European train control system. Therefore, it’s very important for theimprovement of the independent innovation capacity and the technical level of the traincontrol system of China to research the technology of the balise system.The telegram signal of a balise system is the carrier of the information between arunning train and the ground. It’s derived from encoding the original information. Theexisting method of encoding in China is basically by software and beforehand and it’sinefficient.So it’s an important direction of the development of the balise technology torealize the real-time encoding of the telegram.Moreover, the C interface of a balisesystem is used to transmit telegrams from the LEU(Lineside Electronic Unit) to thebalise. The C interface involves the way to send and manage the messages of the LEU.It’s an important structure of the baliser system.In this thesis, a balise telegram signal generator which can encode and sendtelegrams was designed and implemented base on the research of the real time encodingand the C interface technology.First, the working principle of the balise system is introduced and the demandanalysis and the global design of the telegram singal generator are made in this thesis.Secondly, the European FFFIS(Form Fit Function Specification) coding strategy isanalyzed and the encoding process is divided by function.For each module the detailedalgorithm based on FPGA is designed.Then the C interface technology and the messages sending rules are analyzed and the way to manage and send messages isresearched and designed.Finally, the rest of the generator are designed.The digital logic circuits are designed and simulated on the Quartus II developmentplatform while the analog circuits are designed and simulated on the Multisimdevelopment platform. And the PCB is designed on the Protel developmentplatform.Finally, plated and set up the circuits, download the program of the FPGA andcompleted the design and manufacture of the generator.The balise telegram signal generator designed in this thesis can encode telegramsand send them circularly. And the signal of the generator meets the technical indicatorsof the C interface. The generator has been used in the tests of the balise detectionsystem which is designed by the project group. It performed well in the tests and thecorrectness of the design has been verified.