KMS of Xinjiang Astronomical Observatory, CAS
| 基于自适应滤波器的射频干扰消除技术研究 | |
| Alternative Title | Research on Radio Frequency Interference MitigationBased on Adaptive Filter |
李浩然
| |
| Subtype | 硕士 |
| Thesis Advisor | 陈卯蒸 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 天文技术与方法 |
| Keyword | 天线 射频干扰消除 自适应滤波 小波滤波 数字信号处理 |
| Abstract | 每年，越来越多的超高频、甚高频和微波波段的射电频谱为新的商业以及军事企业提供支持，这些活动对射电天文观测都造成了严重的影响，甚至极其偏远的观测台站也受到了干扰。我们应当警惕这种形式的射电频段污染。国际电信联盟所保护的射电频谱带宽远远小于射电望远镜要求的接收机灵敏度的带宽。所以，射频干扰已经发展成为影响射电天文观测的主要问题。在新疆奇台将要建造110米大口径全可动射电望远镜，实现从150MHz-117GHz 频率全覆盖。更宽的工作频率对天线的射频干扰抑制提出了更高要求。工程师应当采取相应措施来解决射频干扰问题。 针对射频干扰消除问题，作者做了一系列的研究工作。首先，对射频干扰消除的手段进行了全面的认识与总结。调研了自适应滤波、小波滤波、动态阈值滤波和检测屏蔽等方法，也认识到台址射电频谱管理的重要性。其次，着重研究分析了LMS(Least Mean Square)自适应滤波算法和小波系数相关性去噪算法的工作过程与设计原理。在LMS算法的基础上，经过多次数据的实验以及多次参数组合的调试，提出了一种较好适应脉冲星观测消干扰的PLMS(PulsarLeast Mean Square)算法。在尝试使用小波滤波算法时，逐步发现单纯的小波滤波效果并不是特别优秀，但是小波分解却能够将单通道原始信号分解成多通道的原始信号和参考信号，如果对接自适应滤波器就可以进一步完成消干扰。由此，提出了单通道的基于小波分解的自适应滤波构想。最后，以主流的数字天文观测终端 ROACH 开发板为基础进行仿真实验和初步开发。首先使用Matlab Simulink软件搭建基本的设计图，接着使用 Xilinx System Generator 对设计进行编译，最后将设计烧写入 ROACH 开发板中，进行初步的调试。 |
| Other Abstract | Every year, more and more ultra high frequency, very high frequency and microwave band radio spectrum are provided for new commercial and military enterprises, these activities caused serious influence to radio astronomical Observations, even extremely remote observation stations are also disturbed. We should abandon this form of the pollution of radio frequency bands. The protected Radio bandwidth by the International Telecommunication Union is far less than the bandwidth of the receiver sensitivity required by the radio telescope. So, radio frequency interference has become the main problem that affects the radio astronomy observation. In Qitai, Xinjiang 110 meters large aperture all mobile radio telescope will be constructed to achieve full coverage from the 150MHz-117GHz frequency. A wider operating frequency of the antenna of the radio frequency interference suppression puts forward higher requirements. The Engineers shall take appropriate measures to solve the problem of radio frequency interference. Aiming at the problem of radio frequency interference cancelled, the author has made a series of research work. First of all, the mean of eliminating radio frequency interference is a comprehensive understanding and summary. The author not only make some research on adaptive filtering, wavelet filtering, dynamic threshold filtering, detection of shielding and other methods, but also recognize the importance of radio management. Secondly, it focuses on the analysis of the LMS (Least Mean Square) adaptive filtering algorithm and wavelet coefficient correlation denoising algorithm working process and design principles. Based on the LMS algorithm, the PLMS(Pulsar Least Mean Square) algorithm is proposed, which is better adapted to the interference of pulsar observation, through the experiment of multiple data and the debugging of several parameter combinations. The author try to use the wavelet filtering algorithm and gradually find that pure wavelet filtering effect is not particularly outstanding, while the wavelet decomposition to the original single channel signal can be decomposed into multichannel—the original signal and the reference signal, then adaptive filter can complete step of eliminating interference. Therefore, the idea of adaptive filtering based on wavelet decomposition of single channel is proposed. Finally, based on the ROACH development board of the mainstream digital astronomical observation terminal, the simulation experiment and preliminary development are carried out. First the author use Simulink software to build the basic design and then use the Xilinx System Generator to compile the design and finally it will be designed to be packaged into the ROACH development board, to carry out a preliminary test. |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/1717 |
| Collection | 研究生学位论文 射电天文研究室 |
| Affiliation | 中国科学院新疆天文台 |
| Recommended Citation GB/T 7714 | 李浩然. 基于自适应滤波器的射频干扰消除技术研究[D]. 北京. 中国科学院大学,2016. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| 李浩然-学位论文.pdf（2331KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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