摘要
卫星双向时间频率传递是目前世界上最准确的远距离时间比对技术之一。它是将两个地面站的时间信号通过卫星发送给对方站,时间信号的传输通过扩频码实现,因此扩频码速率是影响其比对精度的一个重要因素。文章首先给出了扩频通信的相关理论,然后通过设计比较试验,分析了不同扩频码速率对钟差测量的影响,特别是不同扩频码速率对设备时延的影响。试验结果证明扩频码速率越高,测量结果的不确定度越低,与理论分析一致。但受通信带宽的限制,扩频码速率不能无限扩大。文章根据实测验证,给出了卫星双向比对设备测试的码速率的选取原则建议。
Two-way satellite time and frequency transfer （TWSTFT） is one of the most accurate meanfor remote clock comparison, which sends local clock signal to the other station through the satellitesimultaneously. The spread spectrum code rate is an important factor which affect the precision of the time comparison because the transmission of time signal is realized through the spread code. This paper firstlyintroduces the theory of spread spectrum communication, and then analyzes the influence of differentspread-spectrum code rates on measurement of clock error by test experiment, especially the influence ofdifferent spread-spectrum code rates on the device delay. The test results show that the higher thespread-spectrum code rate, the small the measuring uncertainty, it is consistent with the theoretical analysis.However, due to the limitation of communication bandwidth, the spread-spectrum code rate can not beextended infinitely. Based on the experimental data, the selection of spread-spectrum code rates forTWSTFT device testis proposed.
出处
《时间频率学报》
CSCD
2017年第3期146-154,共9页
Journal of Time and Frequency
基金
国家自然科学基金资助项目(61127901)
关键词
卫星双向时间频率传递
卫星双向时间传递
扩频码速率
设备时延
钟差测量
two-way satellite time and frequency transfer
two-way satellite time transfer
spread-spectrumcode rate
device delay
measurement of clock error
