Wireless Data Transmission Based On Spread Spectrum Technology

It is an important way to realize heavy-load transportation by using the technology of multi-locomotive and wireless synchronous control system to operate combined trains. In order to achieve multi-locomotive by less economic input based on the existing line and locomotive equipments, We need to study the use of distributed power control locomotive technology based on wireless communication to improve the capacity of the railways.The reliability of wireless data transmission is an important factor to influence safe operation of wireless synchronous control trains.However, the railway wireless communication channel is very bad, turns,tunnels, mountains,high pressure along the railway catenary and a variety of unexpected interferences will affect the reliability of wireless transmission. At Present,the study of wireless data transmission system in domestic and foreign mainly focus on GSM - R(GSM for Railway)system.GSM-R system has the advantage of a wide range of network covering, it can transfer information anytime and anywhere.But its low transmission speed is difficult to adapt to transmit voice, video, images and other large volume of information requests. The use of wireless spread spectrum technology with appropriate pseudo-random spreading sequences and modem technology for information transmission,not only has strong anti-interference, multipath fading, strong anti-invisibility and secrecy,but also has a faster speed.This paper introduces wireless synchronization control system and the composition of the functional module;discusses the spread spectrum communication techniques and the advantages of spread spectrum transmission compared to fixed-frequency transmission;compares several commonly used direct sequence spread spectrum chips. Then it gives the system hardware design, elaborates wireless transmission module and interface circuit design. This paper analyzes the system's software control flow based on hardware platform. Finally, the wireless transmission system is experimentally verified, and the results achieved are summed up.