【摘要】 本文分析了在通信系统有着广泛应用的双音多频DTMF(DUAL TONE MULTI FREQUENCY)并设计了针对DTMF信号的接收及判别系统。系统根据ITU-T Q.24要求,能够正确的接收和判读输入信号。整个设计采用了有限冲击相应FIR滤波器完成对DTMF输入信号的滤波,保证了滤波输出信号的线性相位,同时采用非相干过零检测电路进行检测,易于数字电路实现,并利用现场可编程门阵列实现了整个设计,使整个电路结构合理,实现简单。更多还原

【Abstract】 The article mainly focuses on the analysis and design of the receiver for DTMF, and judges the received signal according to the standard of ITU-T Q.24. By using FIR to build the band pass filter and detecting the band-passed DTMF signals with zerocross method. It makes the digital circuit flexible and easy to implement on FPGA or other platforms.更多还原