深空接收机同步算法设计及实现

Design and Implementation of Synchronization Algorithm for Deep Space Receiver

针对深空通信链路信号衰减大、传输时延长并存在大多普勒频移的特点,提出了一种基于CCSDS协议标准接收信号的同步算法,采用Costas反馈环进行载波同步,利用早迟门恢复定时时钟,通过相关性检测帧头解决相位模糊问题,最后对相位误差进行估计并补偿。在此基础上,设计并实现了适合于现场可编程门阵列(FPGA)定点运算特点的同步简化等效电路。基于Xilinx FPGA平台的实测结果表明,文章同步算法的硬件电路实现简单,在15dB信噪比的高斯白噪声情况下能较好地实现时间、频率的跟踪与锁定,可为未来深空接收机的优化设计提供有益参考。

Abstract. This paper proposes a kind of receiver synchronization algorithm based on CCSDS to solve the problems of large link loss, path delay and large Doppler shift in deep space communica- tion. This algorithm mainly includes Costas loop, early-late gate, frame header detection and phase compensation. Furthermore, this paper designs a synchronous circuit easily implemented with FPGA, and finally the performance of this design is tested on a FPGA of Xilinx. The result shows that this algorithm has simple structure of hardware circuit and high performance of track- ing and locking time and frequency in the Gaussian white noise of 15dB SNR, with useful refer- ences for the future optimization design of deep space receiver.