16 进制的正交振幅调制是一种振幅相位联合键控信号。16QAM 的产生有 2 种方法：

（1）正交调幅法，它是有 2 路正交的四电平振幅键控信号叠加而成；

（2）复合相移法：它是用 2 路独立的四相位移相键控信号叠加而成。-Quadrature amplitude modulation is a hex key signal amplitude and phase combined. 16QAM produce two kinds of methods: (1) quadrature amplitude modulation method, which is four-level quadrature amplitude shift keying signal 2 superposition　(2) composite phase shift method: it is with 2 independent quadrature phase shift keying signal superposition.