北斗导航接收机旁瓣对消技术的研究

发布时间：2018-07-11 10:28

本文选题：北斗接收机 + 自适应旁瓣对消　；参考：《南京邮电大学》2017年硕士论文

【摘要】：作为全球四大卫星导航系统之一的“北斗二号”卫星系统能够在全球范围内为用户提供高精度、全天时、全天候的导航、定位和授时信息,在国防、抗震救灾、航海、航空等众多领域都得到了广泛的应用。但是由于导航卫星距离地面十分遥远,传输过程中电磁环境又比较复杂,导致进入到地面接收机的卫星信号电平非常低,因此接收机很容易受到各种干扰。如何使用户实现实时精确导航和快速定位,提高接收机的抗干扰能力成为当前迫切需要解决的问题。论文以北斗导航系统为研究对象,结合北斗导航接收机旁瓣相消系统的项目,实现了三辅助通道自适应旁瓣相消模块的设计,使得主天线旁瓣区域的宽带干扰信号得以抑制。论文首先给出了宽带条件下的自适应旁瓣相消系统的结构,详细分析了采样协方差矩阵求逆(SMI)算法的原理及推导公式。讨论了权值运算中矩阵求逆方法的选择问题,确定使用Cholesky分解法进行矩阵求逆可降低运算的复杂度。最后,针对实际要求建立仿真模型,把采集到的带有干扰的北斗卫星信号作为系统的输入信号,经过自适应抗干扰系统各个模块的处理,最终得到测试结果。根据仿真分析,所设计的自适应旁瓣对消系统能够较好地抑制宽带干扰,对消比能够达到15dB以上,满足设计要求。另外,对干扰源数目、干扰强度、延迟阶数等因素对抗干扰性能的影响进行了具体的仿真分析。
[Abstract]:The "Beidou two" satellite system, one of the four largest satellite navigation systems in the world, can provide high precision for users worldwide. All day, all-weather navigation, positioning and timing information have been widely used in many fields, such as national defense, earthquake relief, navigation, aviation and so on. However, the navigation satellite is very remote from the ground. In the distance, the electromagnetic environment in the transmission process is very complex, which leads to the low level of the satellite signal that enters the ground receiver, so the receiver is easily disturbed. How to realize real-time accurate navigation and fast positioning and improve the anti-interference ability of the receiver has become an urgent problem to be solved. The paper is guided by the Beidou. As the research object, combined with the project of the Beidou navigation receiver sidelobe cancellation system, the design of the three auxiliary channel adaptive sidelobe cancellation module is designed to suppress the wideband interference signal of the sidelobe region of the main antenna. The principle and derivation formula of the covariance matrix inversion (SMI) algorithm are discussed. The problem of selecting the inverse method of matrix in the operation of weight value is discussed, and the complexity of the calculation is reduced by using the Cholesky decomposition method to reduce the matrix. Finally, a simulation model is established for the actual requirements, and the collected Beidou satellite signals are taken as the system. The input signal is processed by each module of the adaptive anti-jamming system and the test results are finally obtained. According to the simulation analysis, the designed adaptive sidelobe cancellation system can better suppress the wideband interference, and the cancellation ratio can reach more than 15dB and meet the design requirements. In addition, the number of interference sources, the intensity of interference, the delay order and so on are antagonizing. The influence of interference performance is analyzed in detail.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN965.5

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