空间太阳望远镜高速数据传输系统设计

空间太阳望远镜(SST)是中国未来重要的太阳观测卫星，中国科学院国家天文台和航天部五院目前正在开展该卫星的研制工作。本文介绍高数据传输速率(60Mbps)的科学数据传输系统(DTS)，该系统将SST每天采集的超大容量科学数据传送到卫星地面站，其协议与国内卫星地面站现有协议兼容。文中分析SST对DTS的系统需求；计算DTS系统星地传输链路的系统余量；侧重描述DTS的信道编码卡(CEC)的详细设计，包括设计原理、方法和实验室基带测试系统，CEC格式化海量存储器中的科学数据，插入伪随机编码(PN)及帧同步信号，生成的数据流适应四相相移键控(QPSK)射频调制及地面数据恢复系统的需求。本文最后讨论DLS检错和纠错编、解码(EDEC)的实现方法，以及如何分别利用软件、硬件或可编程器件实现系统功能优化分配。我们已研制出CEC地面样机及其测试设备，并成功验证了CEC的全新设计方法，如使用较低的工作频率完成高数据速率的传送等。

SST high rate data transmission system design

The Space Solar Telescope (SST),an important solar observing satellite in the future,is being developed under the corporation of National Astronomical Observatories,Chinese Academy of Sciences and Chinese Airspace Department.A dedicated high date rate data transmission system (DTS) for SST is introduced.It will be used to transmit the super-large volume science data of the satellite down to ground station.The protocol of DTS is completely compatible with that of the present satellite ground station in China.SST system requirement for DTS is analyzed.Satellite-ground station link calculation is done to estimate the DTS system margin.Detailed design is focused on the DTS Channel Encoding Card (CEC),includes design principle,developing method and base-band test system.CEC translates the parallel data stored in the Mass Memory of the onboard Science Data Processing Unit (SDPU) to serial formatted data streams,inserts pseudo-noise (PN) codes into the streams,which fit for quadrature phase shift keying (QPSK) radio modulation.At last,some discussions are also given concerning the implementation of DLS error detection coding and error correction coding (EDEC) and the base-band testing system.Optimized function distribution among software,hardware and firmware is discussed.Now the CEC ground model with its electronic ground support equipment (EGSE) has been developed.Some new methods and ideas in CEC design have been successfully verified.