ML法能够很好的估计信号的信噪比,包括邓氏关联度、绝对关联度、斜率关联度、改进绝对关联度,保证准确无误，是学习通信的好帮手。- ML estimation method can be a good signal to noise ratio, Including Deng s correlation, absolute correlation, correlation of slope, improved absolute correlation, Ensure accurate communication is learning a good helper.