小波变换在跳频通信中的应用研究

Study on the Application of Wavelet Analysis in Frequency Hopping

小波变换是信号的时间-频率分析方法,它具有多辨分析的特点,它能有效地检测和识别跳频信号,在跳频通信中有极其重要的作用．按照跳频信号的数学模型分析,小波变换(WT)与快速傅立叶变换(FFT)、短时傅立叶变换(STFT)相比较,具有明显的优越性．通过对中频信号的有限个采样点的分析处理,提取出跳频信号的特征参数,并运用Matlab语言设计出仿真程序,可以证明小波分析跳频信号具有可行性．

To analyze and detect the feature of frequency hopping signal exactly is a crucial prerequisite to carrying out disturbance to follow the track of signal. How to analyze and get eigenvalue of the signal of frequency hopping is the capital task of this thesis. 1）The principles of frequency hopping communication are described briefly, according to which the math formula of frequency hopping signal is established, and the relation between the main technical index and anti-jamming is also described accurately. When the above-mentioned work is done, the signal can be analyzed and processed properly. 2）This thesis simply introduces and compares Fourier Transform（FT）, Short-time Fourier Transform（STFT） and Continuous Wavelet Transform（CWT）. Because frequency hopping signal is time-varying signal, it presents the new idea and principles which can get eigenvalue of the signal by CWT with Morlet wavelet and it describes the principles, method and process in particular. 3）When the theoretic basis is established, to visualize the result, the thesis uses software to simulate it. In the work, MATLAB is applied to simulate the results of wavelet analysis. It also supplies a model for practice system. In a word, the thesis just supplies a theoretical model for practice system, and simulates it on computer. The simulation shows that the method is feasible and effective.