基于FPGA的角跟踪接收机误差信号平滑算法的实现  

Implementation of error signal smoothing algorithm for angle tracking receiver based on FPGA

作　　者：王玉凡 高玉龙[1] 吴兆平 王恺宇 WANG Yufan;GAO Yulong;WU Zhaoping;WANG Kaiyu(China Academy of Space Technology(Xi’an),Xi’an 710000,China)

机构地区：[1]中国空间技术研究院西安分院,西安710000

出　　处：《空间电子技术》2022年第3期79-83,共5页Space Electronic Technology

摘　　要：在星间链路自跟踪系统中,角跟踪接收机中误差信号的抖动大小决定系统天线跟踪精度和稳定度。为降低误差信号的抖动,结合工程实际应用情况,在FPGA上实现一种16点加权平均滑动窗算法。该算法首先对误差信号进行频谱分析,找出误差信号的频率分布范围。然后根据误差信号采样率和误差信号的频率分布范围,确定加权滑动窗点数和加权系数。最后在FPGA上对该算法进行实现,实现过程中采用桶形移位器方式,将15次加法和1次除法运算降低为1次加法,1次减法和1次截位操作,FPGA资源使用量显著降低。实际测试结果表明,该算法能有效对角跟踪接收机误差信号进行平滑,从而解决角跟踪接收机在低信噪比、高信息速率情况下误差信号抖动不满足指标要求的问题。误差信号抖动由0.25 V左右降低为0.06 V左右,这一方式显著改善了系统性能。In the inter-statellite link self-tracking system.The jitter size of the error signal in the angle tracking receiver determines the antenna tracking accuracy and stability.In order to reduce the jitter of error signal,a 16-point weighted average sliding window algorithm is implemented on FPGA in this paper.The algorithm firstly analyzes the frequency spectrum of the error signal and finds out the frequency distribution range of the error signal.Then according to the sampling rate of error signal and frequency distribution range of error signal,the weighted sliding window number and weighting coefficient are determined.Finally,this algorithm was implemented on FPGA.In the process of implementation,bucket data shift was adopted to reduce 15 addition and 1 division operations to one addition,one subtraction and one truncation operation,and the FPGA resource usage was reduced by 90%.The actual test results show that the algorithm can effectively smooth the error signal of the angular tracking receiver,thus solving the problem that the error signal jitter does not meet the requirement of the index in the case of low SNR and high information rate.The error signal jitter is reduced from about 0.25 V to about 0.06 V,which significantly improves the system performance.

关 键 词：FPGA 误差信号 滑动窗 

分 类 号：V556[航空宇航科学与技术—人机与环境工程]