The Optimization Rearch Of Channel Encoding And Receiving Process In The Balise Information Transmission System

The development of China railway and the growing of the train speed have put forward higher requirements on the information sent to on-board equipment. As a vital equipment used for wayside-onboard information transmission within the train control system, Balise has been achieved domestic production and domestic services, playing an important role in the high-speed railway signaling system.Balise Telegram is the Information transmission carrier. So its fast encoding, reliable transmission and complete reception is an important condition to ensure the safety of high-speed train operation. At present, domestic using FPGA and other hardware devices so that Balise Telegram encoding time is greatly reduced, but the encoding process in accordance with the European coding strategy steps strictly, there is still room for improvement. In addition, telegram with better performance is more advantageous to channel transmission, but there is no public literature at home and abroad on telegram optimization. And there also has no public research results on the telegram buffer problem in the Balise group telegram receiving process. Therefore the research of Balise Telegram fast encoding, optimization and reception have important practical significance.This paper analyzes the current status of telegram encoding, transmission and reception. Then each process is optimized. Main work in this paper is shown as follow:1) Describe the generation process and transfer process of Balise Telegram, clarify the requirements of telegram transmission channel to Balise Telegram, and analyze time requirements of the Balise group telegram receiving process.2) Randomly select real Balise user telegrams of Wuhan-Guangzhou PDL, encode the830user bits in VC++6.0environment to generate1023bits transmission telegram, propose an improved encode method. Use conventional coding algorithm and improved coding method to generate the first legitimate telegram, and test the time to verify the fast of proposed improved encoding method.3) Propose optimization factors according to the requirements of transmission channel and shaping constraints, and select optimized telegram also in VC++6.0environment. Then use MATLAB/SIMULINK to test and verify the BER (Bit Error Ratio) of optimized telegram is lower than the BER of regular telegram.4) Complete the model of Balise group telegram receiving process under adverse communication condition by using the model checking tool UPPAAL. Simulate the telegram buffer size and the minimum distance of adjacent Balise groups when the train passes a Balise group consists of8Balises.