Research Of Railway Orthogonal Frequency Shift Signal And Implementation On C6722 System

The rapid development of Chinese railway transport set new demands to the accuracy and reliability of cab signal devices. Under such a background, the domestic 18-information frequency shift signal can not satisfy the request of domestic high speed train. As to the problems brought by the irrational setting of frequency points of this signal, this paper put forward an improvement plan of the orthogonal frequency shift signal to reach the improved relative optimal performance on the premise of retaining the domestic frequency-shift signal devices.On the other hand, as the performance of micro programmable processor has improved continuously, DSP chip are developing toward high performance, low power consumption, fusion strengthening and applications expand. C6000 series floating-point processor produced by TI company in recent years are replacing VC33 floating-point processor produced in the 1990s. This paper uses the TMS320C6722DSP teaching experimental system as hardware platform, validates the result of proposed orthogonal transformation of frequency shift signal and inquires into applications of this serious DSP on railway.At present,as the traditional front-background programming structure is still used in processing of domestic frequency-shift signal, the development is difficult, the development cycle is long and the cost is not easy to control. In consideration of this situation, the uCOS-â…¡operating system is transplanted to the C6722 platform as the embedded RTOS according to the foreign railway signal system using embedded real-time operating system in this paper. Letting the kernel control the interrupt handling and intertask communication, requirements of real-time property, safety and portability are satisfied efficiently,the difficulty of development is reduced and the expansibility of system is improved.