针对弱信号检测的抗干扰方法研究

发布时间：2018-04-26 17:54

本文选题：弱信号检测 + 干扰消除　；参考：《国防科学技术大学》2014年硕士论文

【摘要】：随着电磁学中信号处理技术和信号处理能力的不断进步和发展,射电望远镜在空间分辨率和灵敏度等方面的检测性能得到显著提升。而随着检测能力的提高,射电望远镜的观测对射频干扰(RFI)愈加敏感。与此同时无线电业务应用领域的不断扩大以及望远镜自身产生的射频干扰的增加,进一步加剧了RFI对观测效果的影响。现代射电望远镜巨大的数据传输速率,使得对观测数据的抗干扰处理变得越来越困难,为了能够充分利用这些大型射电仪器的科学价值,对射电天文观测数据的抗干扰处理已成为新一代望远镜需要克服的主要障碍和亟待解决的突出问题。本文针对上述科学背景,并充分结合弱信号观测的科学目标,着重开展了包括抗干扰方法评价准则建立、抗干扰处理方法研究以及抗干扰试验设计在内的三个方面的研究工作。首先围绕射电天文观测典型后端应用科学目标,建立总的适合于射电天文观测要求的抗干扰方法评价准则,同时结合典型抗干扰方案对信号接收模型进行了建模。其次,在对传统干扰源模型重构抗干扰方法和传统自适应滤波抗干扰方法研究的基础上,通过引进辅助天线改善模型重构法在低干噪比条件下的干扰信号估计精度;通过优化自适应算法变步长参数的变化函数关系,加快抗干扰收敛速度、减小干扰消除稳态误差。最后,设计一套射电天文弱信号抗干扰试验方案并对试验中的多通道高速同步采集记录系统进行性能测试分析。
[Abstract]:With the progress and development of signal processing technology and signal processing ability in electromagnetism, the detection performance of radio telescope in spatial resolution and sensitivity has been greatly improved. With the improvement of detection ability, radio telescope observation becomes more sensitive to RF interference (RFI). At the same time, the continuous expansion of radio applications and the increase of radio frequency interference (RF) produced by telescopes further aggravate the influence of RFI on the observation effect. The huge data transmission rate of modern radio telescopes makes anti-interference processing of observation data more and more difficult. In order to make full use of the scientific value of these large-scale radio instruments, The anti-interference processing of radio astronomical observation data has become the main obstacle to be overcome and a prominent problem to be solved urgently in a new generation of telescopes. In view of the above scientific background and the scientific target of weak signal observation, this paper focuses on three aspects, including the establishment of anti-jamming evaluation criteria, the research of anti-jamming treatment methods and the design of anti-jamming experiments. Based on the application of scientific targets in the typical back-end of radio astronomical observation, a general evaluation criterion of anti-interference method for radio astronomical observation is established. At the same time, the signal receiving model is modeled with the typical anti-jamming scheme. Secondly, on the basis of the research of the traditional interference source model reconstruction and the traditional adaptive filter anti-jamming method, the estimation accuracy of the interference signal under the condition of low signal-to-noise ratio is improved by introducing the auxiliary antenna. By optimizing the function relation of variable step size parameters of adaptive algorithm, the convergence speed of anti-interference is accelerated and the steady-state error is reduced. Finally, a set of radio weak signal anti-jamming test scheme is designed and the performance of multi-channel high-speed synchronous acquisition and recording system is tested and analyzed.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.23

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