基于自适应滤波的北斗导航抗干扰技术研究

发布时间：2018-01-02 00:34

本文关键词：基于自适应滤波的北斗导航抗干扰技术研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：卫星导航在生产和生活中不可或缺,然而随着电磁环境日益复杂,导航信号的脆弱性使其在通信中极易受到干扰而产生错误定位甚至失去导航定位功能,所以导航抗干扰技术显得尤为重要。本文基于自适应滤波技术对北斗导航系统的抗干扰算法进行了研究,主要工作包括:1、采用带中心单元的7元圆环阵做接收阵列,研究了基于LCMV准则的空域滤波算法,结合功率倒置算法和最小方差无失真响应算法,分析了空域滤波的抗干扰性能。2、对空时自适应抗干扰(STAP)算法进行了建模仿真,分析了干扰个数和延时单元个数对算法性能的影响,并与空域算法进行了性能对比,由于具有更多的抗干扰自由度,空时算法滤波性能更优,但伴随计算量大的问题。3、研究了空频自适应(SFAP)滤波算法,作为空时改进的频域实现结构,分析了干扰环境和频域子带个数对抗干扰性能的影响,验证了空频算法具有更小的计算量、更好的带内一致性,推导出空时与空频算法基于LCMV阵列的等价条件。4、研究了空时频三维联合抗干扰算法,进一步提升了自适应权值自由度,提升了抗干扰裕度,仿真结果表明该算法在多宽带环境下具有优越性能。5、最后在FPGA上对空频算法进行实现,结合MATLAB仿真结果完成硬件调试,并给出了实测结果和性能分析。
[Abstract]:Satellite navigation is indispensable in production and daily life. However, with the increasing complexity of electromagnetic environment, the vulnerability of navigation signal makes it vulnerable to interference in communications, resulting in mispositioning or even loss of navigation and positioning function. Therefore, navigation anti-jamming technology is particularly important. Based on adaptive filtering technology, this paper studies the anti-jamming algorithm of Beidou navigation system, the main work includes: 1. The spatial filtering algorithm based on LCMV criterion, combined with power inversion algorithm and minimum variance distortion free response algorithm, is studied by using a 7-element ring array with center elements as receiving array. The anti-jamming performance of spatial filtering is analyzed. The space-time adaptive anti-jamming algorithm is modeled and simulated. The influence of the number of interference and delay unit on the performance of the algorithm is analyzed. Compared with the spatial algorithm, because of more anti-interference degrees of freedom, the space-time algorithm has better filtering performance, but accompanied by a large amount of computation problem .3. The space-frequency adaptive SFAP-based filtering algorithm is studied as an improved space-time implementation structure in frequency domain. The influence of interference environment and the number of sub-bands in frequency domain on the anti-jamming performance is analyzed. It is proved that the space-frequency algorithm has less computation and better intra-band consistency. The equivalent condition of space-time and space-frequency algorithm based on LCMV array is derived, and the space-time-frequency 3D joint anti-jamming algorithm is studied. The adaptive weight degree of freedom is further improved, and the anti-interference margin is improved. The simulation results show that the algorithm has superior performance in multi-wideband environment. Finally, the space-frequency algorithm is implemented on FPGA. Combined with the simulation results of MATLAB, the hardware debugging is completed, and the measured results and performance analysis are given.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN967.1

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