短波地空通信多普勒频移对DTMF信号解码影响

Effect to DTMF decoding of Doppler shift in ground-air HF communication

DTMF信号具有优良的抗干扰性能和一定的抗多普勒频移的能力,广泛应用于语音信道的低速数据通信.文中分析了地-空短波通信的多普勒频移、基于Goertzel算法的DTMF信号解码基本原理和基本过程;在语音噪声背景下,基于Goertzel算法,解算了16个频点的信号幅值,对地-空短波通信的多普勒频移对DTMF信号解码性能的影响进行了仿真,得出了在语音和多普勒频移干扰的背景下,信噪比高于9dB时,基本可实现DTMF信号的高可靠检测的结论.

DTMF has perfect anti-interference and some anti-Doppler shift ability and is widely used for low rate communication in audio channel. This paper analyzes the Doppler shift of ground-air communication in HF, the principle and process of DTMF decoding based on Goertzel algorithm. The algorithm only calculates 16 frequencies’ amplitude to simulate the decoding of DTMF based on Goertzel algorithm in HF environment with Doppler shift. The conclusion is that the algorithm can achieve perfect detection performance of DTMF with the SNR above 9dB in audio and Doppler shift interference environment.