基于可变带宽激励信号族优化设计的广义群时延测量方法

Group delay is an important parameter to measure the transmission network for signal transmission time delay and signal distortion effects . High precision measurement of group delay and assess the impact on the pseudo-code and carrier phase measurement is very important to ensure satellite navigation systems accuracy. Traditional definition of group delay and phase-frequency characteristic measurement method is based on the differential with such drawbacks : the contradiction between measurement resolution and measurement accuracy , can not quantitatively describe the effect of phase distortion of the transmission network on signal distortion , difficult to establish correspondence with time delay of navigation system signals. To solve these problems , from the original physical concepts of group delay , this project discusses the definition of a generalized model of group delay , going through directly the definition and measurement of group delay without phase-frequency characteristics . On this basis , we propose a general group delay measurement method based on variable bandwidth pumping signal group, with the optimize design of waveform and signal bandwidth. Finally, the assessment of uncertainty and consistency of the measurement method is carried out. The research results of this project on group delay defination model and measurement mechanism can not only be used for satellite navigation, deep space exploration , such time delay measurement system, but also to expand the signal and transmission network delay characteristics describe methods, evern to establish theoretical foundation for the new group delay measurement instrument development.

群时延是衡量传输网络对信号传输时间延迟及信号失真影响的重要参数。对群时延进行高精度测量并评估其对伪码和相位测量的影响，对确保卫星导航系统精度指标具有重要意义。基于相频特性微分的传统群时延定义和测量方法有如下缺点：存在测量分辨率与测量精度不可兼得的矛盾，无法定量描述传输网络相位畸变对信号失真的影响，难以与导航系统信号传输时延建立对应关系。针对上述问题，本项目从群时延的原始物理概念出发，探讨建立广义群时延的定义模型，不经过相频特性直接定义和测量群时延。在此基础上，提出一种基于可变带宽激励信号族的广义群时延测量方法，并对激励信号带宽和波形进行优化设计，最后对该测量方法的不确定度和一致性进行评估。本项目在群时延定义模型和测量机理上的研究成果，可为卫星导航、深空探测等时延测量系统提供技术支撑，也拓展了信号与传输网络时延特性的描述方法，为新型群时延测量仪器的研制奠定了理论基础。

针对传统群时延定义和测量中存在问题，本项目结合影响群时延的物理因素，针对导航系统关键设备展开研究，对天线、变频器件、滤波器等的时延特性进行全面分析研究，建立了更通用的群时延定义和测量方法。在激励信号优选和评估、信号谱型优化设计、信号体制设计、群时延测量评估等方面取得了一系列成果，完成了预定的5个方面研究内容。此外，结合群时延测量方法的工程应用，还开展了高精度群时延测量实现方法和系统应用方面的研究。本项目累计发表论文40余篇，申请专利8项，培养博士生4人、硕士生4人。本项目研究成果丰富了对群时延基本物理概念的认识，研究成果可以应用于卫星导航、航天测控等高精度测量系统。