星间链路发射机时延零值的数字标定算法  

Digital Calibration Algorithm for the Delay of Crosslink Transmitter

作　　者：崔小准[1] 康成斌[1] 刘安邦[1] 刘崇华[1] 刘天雄[1] 

机构地区：[1]中国空间技术研究院总体部,北京100094

出　　处：《宇航学报》2014年第9期1044-1049,共6页Journal of Astronautics

基　　金：国家重大专项基金项目(DHZXO1A02008)

摘　　要：针对传统示波器观察法不适合星间链路发射机时延零值的高精度标定问题,提出了一种采用数字信号处理技术的标定算法。对星间链路发射机输出微波信号和卫星时间基准产生的秒脉冲信号进行双通道同步过采样,对秒信号的电平阶跃段进行直线拟合,确定零值起始参考点;对发射机信号采样数据进行抽取,对抽取后的样本进行部分相关捕获,完成信号的相位初始捕获后,初始同步点前后一个样本点范围内精细搜索,确定发射信号中的伪码起始点;根据采样频率以及测试电缆和衰减器的时延校正值,计算得到星间链路发射机零值。分析和试验结果表明,与国际上通用的示波器直接观察法比较,提出方法克服了整码片模糊问题,标定精度提高一个数量级。The traditional absolute calibration based on oscilloscopic observation is not suitable for crosslink transmitter. A new calibration algorithm is developed by using a digital signal processing technique. The output signal of crosslink transmitter and the pulse per second signal are sampled in synchronization. At first, the delay reference is determined according to straight line fitting for the signal level stepping segment. The sampling data of crosslink transmitting signal is decimated and then phase acquisition processing is made to determine the initial synchronization point. A fine search for the start of the pseudo-random code has been processed between front and rear of the initial synchronization point. Finally, the transmitter delay can be obtained according to the sampling frequency and the calibration delay of the test cable and attenuator. Compared with the oscilloscopic observation method, the analysis and test results show that the proposed technique has overcome the faults caused by whole chip ambiguity and the calibration accuracy can be improved by an order of magnitude.

关 键 词：导航卫星 星间链路 发射机 时延 标定 

分 类 号：V416.6[航空宇航科学与技术—航空宇航推进理论与工程] TN98[电子电信—信息与通信工程]