DMT调制，就是把整个通信信道在频域上划分很多子信道，在每个子信道上仍然采用QAM或类似的带通信号进行传输。其中QAM的通带中心频率应该与相应的子信道的中心频率一致。-DMT modulation, that is, the entire communication channel in the frequency domain divided on a lot of channel in each channel is still used on QAM or similar bandpass