基于复数概念的正交信号，对于DSP的初学者而言，可能没有什么比j算子、复数、虚部、实部和正交等数据及概念更令他们头痛的了。如果你对复数和1j − 的物理含义不是那么明确的话，不必感到懊恼，因为你有很好的同伴。为何甚至是世界上最伟大的数学家之一的卡尔·高斯都曾经说过，虚数j算子是“虚幻的幻影”。本文将对这个“幻影”做出一些解释，这样，你就不必打电话到“正交信号心理咨询热线”寻求帮助了。-Quadrature signals are based on the notion of complex numbers and perhaps no other topic causes more heartache for newcomers to DSP than these numbers and their strange terminology of j-operator, complex, imaginary, real

, and orthogonal.　If you re a little unsure of the physical meaning of complex numbers and the j　-1　operator, don t feel bad because you re in good company.　Why even Karl Gauss, one the world s greatest mathematicians, called the j-operator the　shadow of shadows .　Here we ll shine some light on that shadow so you ll never have to call the Quadrature Signal Psychic Hotline for help.