双音多频DTMF信号是音频电话中的拨号信号,将DTMF信号的检测集成到含有数字信号处理器(DSP)的系统中,是一项较有价值的研究课题.笔者设计出TI公司浮点DSP芯片C6711中的实现方案,通过20个并行的哥兹柔信号滤波器能成功地使双音多频信号的检测变得迅速和简单,采用谐音检测可以显著地提高检测系统的准确性.
The Dual Tone Multi - Frequency DTMF is the dialing signal in the new generation of telephone. It is a worthy engineering application to gather DTMF detection to the Digital Signal Processor system. This article puts forward a scheme to implement Goertzel algorithms and DTMF detection in the use of a Texas Instruments C6711 floating point DSP. DTMF detection is performed using 20 parallel Goertzel filters, which makes the detecting accurate, quick and simple. It is proved that precision of detected system has been improved greatly by resonance sound detection.