卫星导航链路抗干扰技术研究

发布时间：2018-05-18 08:06

本文选题：卫星导航系统 + 滤波器　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：卫星导航系统在军事通信领域中具有很高的应用价值。面对越来越复杂的空间干扰环境,卫星导航链路的抗干扰技术研究更有着重大的意义。在传统的通信链路中,现有通信抗干扰算法可达到很理想的误码率要求,但其没有考虑对测距算法的影响。为了满足载波相位测距算法对相位的严格要求,在研究经典时域抗干扰算法的基础上,本文提出了一种新的针对卫星导航链路的抗干扰系统实现方案,并利用MATLAB对该系统进行了性能仿真分析,仿真结果表明:与现有抗干扰系统相比,新的抗干扰系统能够减小对信号相位的影响。本论文的主要工作如下:1.分析了两种经典的抗干扰技术:时域干扰抑制和变换域干扰抑制。重点研究了时域自适应滤波算法和滤波器的实现,并指出FIR滤波器具有良好的线性相位特性。2.研究了卫星导航信号的载波相位测量原理。指出相位测量算法对载波相位有着非常严格的要求,且其测量精度比伪码测距算法还要高,但需要解决整周期模糊问题。另外,还对锁频环的基本原理和对称系数FIR滤波器的设计方法进行了分析和研究。3.提出了一种基于BPSK调制的直接序列扩频抗干扰系统实现方案。以扫频干扰为例,改变陷波器在系统中所处的位置,对该抗干扰系统进行性能仿真,观察抗干扰技术对导航信号相位的影响,并给出了系统的误码性能曲线。4.基于FPGA硬件开发平台,具体分析了下变频、锁频环、陷波器等关键子模块的实现难点,并利用Verilog HDL语言完成了抗干扰模块的FPGA实现。对该抗干扰模块进行仿真验证,将其输出结果与MATLAB仿真结果进行对比可得:抗干扰模块的FPGA实现满足设计系统的性能指标要求。
[Abstract]:Satellite navigation system has high application value in military communication field. In the face of more and more complex space jamming environment, it is of great significance to study the anti-jamming technology of satellite navigation link. In the traditional communication link, the existing communication anti-jamming algorithm can meet the ideal bit error rate requirement, but it does not consider the influence on the ranging algorithm. In order to meet the strict requirements of the carrier phase ranging algorithm, a new anti-jamming system for satellite navigation link is proposed based on the study of classical time-domain anti-jamming algorithm. The performance of the system is simulated by MATLAB. The simulation results show that compared with the existing anti-jamming system, the new anti-jamming system can reduce the influence on the signal phase. The main work of this thesis is as follows: 1. Two classical anti-jamming techniques, time domain interference suppression and transform domain interference suppression, are analyzed. The realization of adaptive filtering algorithm and filter in time domain is mainly studied, and it is pointed out that FIR filter has good linear phase characteristic. The principle of carrier phase measurement of satellite navigation signal is studied. It is pointed out that the phase measurement algorithm has very strict requirements for carrier phase, and its measurement accuracy is higher than that of pseudo code ranging algorithm, but it needs to solve the whole period ambiguity problem. In addition, the basic principle of frequency locked loop and the design method of symmetric coefficient FIR filter are analyzed and studied. A scheme of direct sequence spread spectrum anti-jamming system based on BPSK modulation is proposed. Taking the sweep interference as an example, the position of the notch filter in the system is changed, the performance of the anti-jamming system is simulated, the influence of anti-jamming technology on the phase of navigation signal is observed, and the error performance curve of the system is given. Based on the hardware development platform of FPGA, this paper analyzes the difficulties in the realization of the key sub-modules, such as downconversion, frequency locking loop, notch filter and so on, and implements the anti-jamming module with FPGA using Verilog HDL language. The simulation results of the anti-jamming module are compared with the results of MATLAB simulation. The FPGA implementation of the anti-jamming module meets the performance requirements of the design system.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN967.1

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