重离子治癌加速器高速数据传输系统设计与实现

Design and implementation of high-speed data transmission system for the heavy ion therapy accelerator

根据重离子治癌加速器的特点提出了新的一种数据传输方法,在FPGA上实现了DPSK(Differential Phase Shift Keying)调制解调,加入了奇偶校验、BCH编解码、扰码与帧同步系统来提高系统的可靠性,传输信道采用SFP光纤传输,提高了传输的速率,降低了设计成本。本文主要描述系统软硬件的设计和实现细节,重点分析了在传输过程中如何使用FPGA编程方法提高系统的可靠性和稳定性。该系统经过严格压力测试,做到百万次传输无误差,已在重离子治癌加速器现场实际使用,在加速器控制领域首次实现了FPGA结合光纤的DPSK调制解调高速数据传输,对同类系统有较好的借鉴参考作用。

Background： Heavy ion therapy accelerator is introduced to reconstruct a dedicated synchrotron for medical treatment based on HIRFL-CSR （Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring）. Synchronous transmission of HIRFL-CSR uses the 400 kHz baseband signal with optical fiber. Purpose： The bandwidth and reliability of heavy ion therapy accelerator need to be improved for practical application. Methods： Differential phase shift keying （DPSK） modulation and demodulation method has been adopted, combined with the parity check, BCH codec, scrambling and frame synchronization system, to improve the reliability of system. Further improvement on both hardware and software implementation is taken to avoid any error in transmission process. Results： Experimental results show that the error times reduced to zero by using two boards to send and receive data. It is proved that the system can transmit data correctly and effectively. Conclusion： The system can accurately finish the data transmission with high reliability for the high-speed data transmission system of the heavy ion therapy accelerator. It has been directly applied to the scene of the heavy ion therapy accelerator.