Reserch On GSM-R System Information Secure Transmission

Currently, GSM-R system as a dedicated wireless communication system for China’s high-speed rail, its safety and stability will directly affect the operational efficiency. However, in terms of safety, GSM-R system is an open transmission system, which may be suffered from the attack of outside information anytime and is regarded as a non-safety system. Thus, how to efficiently reduce the bit error resulted by either channel interference or signal fading, as well as ensure the safety and reliability of information transmission in the GSM-R system is worthy of study.This paper investigates the performance of the current GSM-R system information secure transmission scheme, and finds out that it cannot satisfy the current requirements of the high-speed railway. By analyzing the advantages and disadvantages of the various error correction coding techniques, and integrating with the transmission characteristics of the GSM-R system, Turbo code has been adopted to optimize the scheme. Then in-depth research the performance of Turbo codes, discuss decoding algorithm, interleaving length, and the number of iterations impact on the Turbo decoding performance. Based on the analysis, this paper illustrates a solution regarding GSM-R system information safety transmission. It is a HARQ solution that emphases on FEC and takes ARQ as a supplement. According to the simulation platform based on transmission control scheme designed in this paper, a simulation analysis of the scheme performance has been conducted.Through the frame error rate, throughput, and the average number of retransmissions to measure the performance of the program, including the Chase integration and the influence made by IR combining two distinct integration methods. The simulation result demonstrates that the performance of IR integration is better than that of Chase integration. In addition, compared with not used HARQ, a system using HARQ can increase the system throughput and reduce the frame error rate, thereby improving the security and reliability of the system。In order to verify the validity of the rational design of the program, two programs involved in this paper have been comparatively analyzed. Simulation results indicate that the error rate of Turbo code is lower under the same conditions of SNR, which can significantly improve the safety and reliability of the system.In the end, this paper briefly analyzes the influence of GSM-R system information securely transmission on rail, as well as conducts a MFC platform based simulation in the situation of train degraded operation.