Train Radio Communication System Based On Direct Sequence Spread Spectrum Technology

The spread spectrum communication, the optical fiber communication and the satellite communication are called the three big high-tech communication transmission mode in the information times. The spread spectrum communication, which signal cabin holds the bandwidth is larger than the information essential necessary; The frequency band expansion is completes through an independent code sequence; Uses the same code in the receiving end to carry the related synchronized receive, the despread and restores the information data. The spread spectrum technology does not frequency other systems.After the train raises its speed, the movement sector is longer, set it strict request to the train safety. The establishment real-time detecting system, has provided the powerful safety to the train traffic. At present, the wireless data transmission system in domestic and foreign, mainly uses GSM-R (GSM for Railway) system. The GSM network coverage is broad, but the transmit speed is low, therefore does not suit transmit the large capacity informations, such as sound, video and so on. But uses the spread spectrum communication, by the appropriate modulation demodulation technology, the data transmit speed is higher than the GSM network, therefore very good solution GSM-R system insufficiency.This article mainly embarked from the spread spectrum technology practical application demand, discusses the question which needs to solve railway movement and the service process in present. First the article introduced the spread spectrum technology, and design the spread spectrum communication system, then elaborated expands the system straight each performance, finally using System View sofeware expanded the system to carry on the simulation, the simulation conclusion indicated, used the spread spectrum technology to transmit the data, the transmission speed, the antijamming, the antimultiple access and so on each performance all could satisfy the request.