Thanks for your reply, but your notation is difficult to understand. I guess you mean it is double the half gaussian distribution. What I want to know is the name of the new distribution (if there is any, haven't got one so far) expressed in therms of mean and variance of the original Gaussian distribution.
Thank you and sorry for my poor explanation in my first post.
Sorry, this answer is misleading as well. The amplitude (absolute value) of "complex" Gaussian with independent real and imag component is Rayleigh. For uni-Gaussian, its absolute value follows another distribution with support [0,+inf) and the half Guassian shape. (Simple calculation from probability theory works.)