频域抗干扰算法在GNSS高精度测量型接收机中的应用

发布时间：2019-05-12 00:36

【摘要】：目前全球存在四个独立的卫星导航系统,统称为全球导航卫星系统(GNSS),中国的北斗卫星导航系统于2012年底建成并投入使用,多个卫星导航系统增加了用户可观测的卫星数量,也增加了可观测的频点数量。多系统的组合应用是提高位置精度和可靠性的有效手段。卫星导航系统可以提供导航、授时、测量等应用模式,其高精度测量模式的应用范围越来越广泛。而实际作业环境中存在较多的电磁干扰,最为常见是窄带干扰。频域干扰抑制技术实现较为简单,常被用来剔除窄带干扰信号。本文选用门限检测方式的频域抗干扰算法方案,将其应用于GNSS高精度测量型接收机中,通过仿真试验、实物测试两种方法验证所选方案的有效性。本文首先对选用的频域抗干扰算法的原理进行研究,分析了重叠合成的算法结构,窗函数的特性,时频域变换算法等组成部分,对N-sigma算法、简化干扰抑制算法进行了对比研究,给出了所选频域抗干扰算法的各项参数。通过仿真,对信号与干扰的相关性进行分析,生成连续波、扫频波、窄带噪声等不同干扰信号,用卫星信号、高斯白噪声、干扰信号组成输入信号,使用频域抗干扰算法进行干扰滤除,分析滤除干扰后的信号相关性变化。然后建立了跟踪环路模型,对含有不同干扰形式的输入信号进行干扰滤除并跟踪,统计伪码跟踪相位误差值、载波相位跟踪误差值,分析不同干扰条件时,两种环路测量精度的变化情况。最后,将频域抗干扰算法在GNSS高精度测量型接收机中实现,对设计中遇到的资源限制、功耗高等实际问题给出具体解决方法。对接收机进行抗干扰测试,使用零基线测量方法,对固定电平下不同类型的干扰信号进行抑制,分析了对接收机伪距、载波距离观测量精度的影响。测试结果表明:频域抗干扰算法可以抑制固定电平下的不同类型干扰信号,但测量型接收机的观测量精度、基线解算结果会受到不同程度影响;在测试条件下,受到影响的测试结果仍满足精度要求,因此所选频域抗干扰方案可应用于GNSS高精度测量型接收机中。
[Abstract]:At present, there are four independent satellite navigation systems around the world, collectively known as the Global Navigation Satellite system (GNSS), the BeiDou Satellite Navigation system of China, which was completed and put into operation at the end of 2012. Multiple satellite navigation systems increase the number of observable satellites, as well as the number of observable frequency points. The combined application of multi-system is an effective means to improve the position accuracy and reliability. Satellite navigation system can provide navigation, timing, measurement and other application modes, and its high-precision measurement mode is more and more widely used. However, there are more electromagnetic interference in the actual working environment, the most common is narrowband interference. Frequency domain interference suppression technology is simple to implement and is often used to eliminate narrowband interference signals. In this paper, the frequency domain anti-jamming algorithm scheme of threshold detection method is selected and applied to the GNSS high-precision measuring receiver. The effectiveness of the selected scheme is verified by two methods of simulation test and physical test. In this paper, the principle of anti-jamming algorithm in frequency domain is studied firstly, and the structure of overlapping synthesis algorithm, the characteristic of window function, the algorithm of time-frequency domain transform and so on are analyzed, and the N-sigma algorithm is analyzed. The simplified interference suppression algorithms are compared and the parameters of the selected frequency domain anti-interference algorithm are given. Through simulation, the correlation between signal and interference is analyzed, and different interference signals, such as continuous wave, sweep wave, narrow band noise and so on, are generated. The input signal is composed of satellite signal, Gaussian white noise and interference signal. The frequency domain anti-interference algorithm is used to filter the interference, and the signal correlation change after filtering interference is analyzed. Then the tracking loop model is established to filter and track the input signals with different interference forms, and the pseudo-code tracking phase errors and carrier phase tracking errors are counted, and the different interference conditions are analyzed. The variation of measurement accuracy of two kinds of loops. Finally, the frequency-domain anti-jamming algorithm is implemented in the GNSS high-precision measurement receiver, and the concrete solution to the practical problem of resource limitation and high power consumption encountered in the design is given. The anti-interference test of the receiver is carried out, and the zero-baseline measurement method is used to suppress different types of interference signals at a fixed level, and the influence on the pseudo-range and carrier distance measurement accuracy of the receiver is analyzed. The test results show that the frequency-domain anti-jamming algorithm can suppress the different types of interference signals at a fixed level, but the measurement accuracy of the measurement receiver and the baseline solution result will be affected to some extent. Under the test conditions, the affected test results still meet the accuracy requirements, so the selected frequency domain anti-interference scheme can be applied to GNSS high-precision measurement receiver.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN967.1

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