小波去噪结合双谱分析在载波通信中的应用研究

发布时间：2018-03-21 20:00

  本文选题：小波去噪　切入点：双谱　出处：《昆明理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：国内外的相关研究机构对中压电力载波的相关特性进行了细致的研究与大量的测试。中压电力载波通信与其他通信方式有着明显的不同,中压线路中的分支以及配电变压器的数量很多,不容易使用阻波器,而且实际的信道中含有着噪声。中压载波通信应用较为广泛,涉及到诸多领域,不过由于中压载波电力线的载波通信信道中会出现信号噪声大、干扰强、环境复杂等特点,而这些特点都会导致电力线载波通信的信号衰减,影响信号的稳定性,采用何种方法解决以上问题是实现中压电力载波通信技术的核心内容。本文的主要研究内容如下：(1)本文利用相关设备测得中压载波信号,对试验中测得的载波信号进行分析,利用信号处理滤出混杂的噪声和干扰,将载波信号转换为容易传输、处理、研究与辨别的形式。根据对电力载波传输信号状态的研究,分析其整个过程中的诸多信息,对电力载波的现状以及发展做出明确判断。(2)针对中压电力线通信载波中存在着的噪声干扰问题,提出了一种小波去噪结合双谱分析的方法。主要以采集到的中压宽带电力线通信信号为依据,在时频域内对信号进行小波去噪处理,进而建立AR模型,将小波变换后的信号再进行双谱计算。在处理信号以及提取信号特征方面,利用小波和双谱的特点,小波去噪结合双谱计算比传统的双谱分析方法效果更好,采用小波变换域双谱分析方法,对中压宽带电力通信中通信信号提取更加明显。(3)本文利用MATLAB进行仿真,进而得到中压载波信号的双谱图,从未进行小波去噪的几种环境下的双谱图可知,随着周围电压的升高其双谱图中出现的波峰也逐渐加大,等高线上的能量分布也变得更加分散；小波去噪后的双谱图,由于主要干扰被去除,因此不同环境下的几种信号特征在双谱图上较为相似,谱峰较为平稳,等高线的能量分布也较为集中。
[Abstract]:Relevant research institutions at home and abroad have carried out detailed research and a large number of tests on the related characteristics of the medium voltage power carrier. The medium voltage power carrier communication is obviously different from other communication modes. The number of branches and distribution transformers in medium voltage lines is many, it is not easy to use dampers, and the actual channel contains noise. The medium voltage carrier communication is widely used and involves many fields. However, because of the characteristics of high noise, strong interference and complex environment in the carrier communication channel of medium voltage carrier power line, these characteristics will lead to the attenuation of the signal of power line carrier communication and affect the stability of the signal. The main research content of this paper is as follows: 1) this paper uses the related equipment to measure the medium voltage carrier signal, and analyzes the carrier signal measured in the experiment. By using signal processing to filter out mixed noise and interference, the carrier signal is converted into a form of easy transmission, processing, research and discrimination. According to the study of the state of power carrier transmission signal, a lot of information in the whole process is analyzed. To make a clear judgment on the current situation and development of power carrier.) aiming at the problem of noise interference in medium voltage power line communication carrier, A method of wavelet denoising combined with bispectral analysis is proposed in this paper. The wavelet denoising processing of the signal is carried out in time-frequency domain according to the collected wideband power line communication signal, and then the AR model is established. In the aspect of signal processing and signal feature extraction, wavelet denoising combined with bispectrum calculation is more effective than traditional bispectral analysis method. Wavelet transform domain bispectrum analysis method is used to extract the communication signal more obviously in the medium voltage wideband power communication. In this paper, the MATLAB is used to simulate, and then the bispectral diagram of the medium voltage carrier signal is obtained. The bispectral images in several environments that have never been de-noised by wavelet can be seen that with the increase of the ambient voltage, the peak in the bispectrum gradually increases, and the energy distribution on the contour becomes more dispersed. Because the main interference is removed, the characteristics of several signals in different environments are similar on the bispectrum, the spectral peak is more stable, and the energy distribution of the contour is also more concentrated.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN913.6
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本文编号：1645328