it is about how the TDM will be do in the matlab

vdsp 下音频的采集与传输，可以适用于音频检测或音源定位等-vdsp collection and transmission of audio, audio detection, or can be applied to audio positioning

This application note surveys selected echo cancellation techniques for use in TDM telephony/packet telephony applications. An echo canceller is a system encompassing many interconnected sub-blocks incorporating DSP algorithms and control operations.