信号系统的Matlab仿真毕业设计.docVIP

毕业设计论文 DTMF信号系统的Matlab仿真 摘 要 双音多频（Dual Tone Multi Frequency, DTMF）信号是音频电话中的拨号信号，由美国ATT贝尔公司实验室研制，并用于电话网络中。这种信号制式具有很高的拨号速度，且容易自动检测识别，很快就代替了原有的用脉冲计数方式的拨号制式。这种双音多频信号制式不仅用在电话网络中，还可以用于传输十进制数据的其他通信系统中，用于电子邮件和银行系统中。这些系统中用户可以用电话发送DTMF信号选择语音菜单进行操作。 DTMF信号系统是一个典型的小型信号处理系统，它要用数字方法产生模拟信号并进行传输，其中还用到了D/A变换器；在接收端用A/D变换器将其转换成数字信号，并进行数字信号处理。本文着重介绍了一种快速的频率检测算法——GEORTZEL算法的原理，以及该算法在双音多频拨号检测系统中的应用。并根据此算法设计出了相应的滤波器，利用MATLAB在计算机上对双音多频的信令产生及检测接收系统进行了仿真测试。 关键词：双音多频，Goertzel算法，数字信号处理，傅里叶变换； Ⅰ Abstract Dual-tone multi-frequency signaling (DTMF) is tone dialing signals , developed by ATT , and used in telephone networks. This signal system has a high rate of speed dial and easy automatic identification, soon took the place of the original dial-up form of pulse counting method used. This dual-tone multi-frequency signaling system is not only used in the telephone network , can also be used in other communication systems to transfer decimal data, e-mail and banking system. These system users can select send DTMF signals by telephone voice menu for operation. DTMF signaling system is a typical small signal processing system , it is to use digital methods to produce the analog signal and transmission , which also used the D / A converter; at the receiving end with D / A converter to convert it into a ditigal signal, and digital signal processing. This article specially introduced the theory of a fast check algorithm --GEORTZEL algorithm, and its application in detecting the double tone multi frequency system. We designed the corresponding filter according to the algorithm the same time，and we imitate the whole dialing process of the system through the MATLAB in the computer at last. Keywords： Dual-tone multi-frequency (DTMF); GEORTZEL algorithm; Digital signal processing?(DSP); Fourier transfer; ……………………………………………………………………………… Ⅰ Abstract ……………………………………………………………………………Ⅱ 1.绪论…………………………………………………………………………………1 1.1 引言…………………………………………………………………………1 1.2 数字信号简介………………………………………………………………1 1.3 数字滤波器