通信信号的调制识别算法研究 毕业论文.doc

摘 要 通信信号调制类型的自动识别广泛应用于信号确认、干扰辨识、无线电侦听、电子对抗和信号监测等领域。 本文首先对各种通信信号进行了理论分析，在此基础上针对模拟调制信号和数字调制信号采用了基于决策论方法的调制方式识别算法，讨论了判决门限的选择，并利用MATLAB软件进行了计算机仿真。在信噪比为10dB时，对模拟调制和数字调制的识别成功率均不低于99%。本文的调制识别算法是基于决策论方法，该方法具有运算量小，识别效果好等优点。最后，本文对模拟调制信号的瞬时频率、调幅系数和调频系数以及数字调制信号的瞬时频率和码元速率均做了理论分析与参数提取，并且进行了计算机仿真，通过计算机仿真结果证明了该方法的可行性。 关键词：信号分析，调制方式识别，模拟调制，数字调制，决策论ABSTRACT The auto identification of modulation style of communication signal is widely being used in many kinds of domain, such as signal surveillance detection, interference recognization, radio interception, and electronic countermeasures. First in this Paper, various kinds of communication signala are analysed on theories. based on which, aimed at analog and digital modulations, the choice of the verdict threshold is discussed using arithmetic for modulation style identification based on decision-theoretic, after that, the whole modulation process is studied by using MATLAB. When the SNR equals to 10dB, the probability of success in the modulation style identification is no less than 99%. The decision-theoretic on which our arithmetic is based has some advantages as computational advantage and good identification effect. In the end, theoretical analysis and computer simulation have been done about the instantaneous frequency detection aimed at analog and digital modulations, at the same time, the detection methods of the amplitude frequency modulation coefficient for analog signals and the code speed for digital modulation signals are studied, and the feasibility of the methods is well verdicted by computer simulations. Key Words: analysis of signals, identification of modulation style, analog modulation, digital modulation, decision-theoretic.目 录 第一章 引言 1 1.1研究背景 1 1.2发展概况 1 1.3调制样式识别过程的框架结构 3 1.4本文特点与组织方向 4 第二章 调制识别基础 6 2.1模拟通信信号 6 2.1.1调幅信号（AM） 6 2.1.2双边带信号(DSB) 8 2.1.3单边带信号(SSB) 8 2.1.4调频信号(FM) 9 2.2数字通信信号 10 2.2.1幅度键控调制(ASK) 10 2.2.1.1二进制振幅键控信号(2-ASK) 10 2.2.1.2 M进制振幅调制信号 11 2.2.2相移键控调制(PSK) 11 2.2.2.1二进制相移键控信号(2-PSK) 12 2.2.2.