Train control information simulation for ATP of urban railway transit

Automatic train protection (ATP) system of urban railway transit is very important for safe operation, where the effective transmission of train control information is the most significant factor. In the research of nationalization for the ATP system, carried out by the Ministry of Constructions and Ministry of Railways of China, the frequency shift keying (FSK) approach is adopted to modulate the train control information, as it does not need to estimate the phase of the carrier wave. This paper introduces a computer simulation method of FSK, and solves some of the key techniques, such as how to make the FSK simulation into a real-time system with continuous phase as well as dynamically changed the codes and frequencies of FSK. The computer simulated FSK was implemented in an ATP simulation system and was shown to be effective.