Wirtinger derivative: 令 z = x + j y z=x+jy z=x+jy,则 f ( z ) f(z) f(z) 对 z z z 和 z z z 的共轭 z ∗ z^* z∗ 求导结果为 ∂ ∂ z = 1 2 ( ∂ ∂ x − i ∂ ∂ y ) \frac{\partial}{\partial z}=\frac{1}{2}\left(\frac{\partial}{\partial x}-i\frac{\partial}{\partial y} \right) ∂z∂=