How can I approximate the Rician Distribution through the Gaussian Distribution? Which are the techniques used to approximate a distribution into another? I know that I can model a Gaussian Distribution through the parameters of mean and variance. However how can I approximate Rice Distribution through the Gaussian Distribution? There is some good reference covering that? 

You can generate a Rayleigh distribution simply as: 
    x_rayleigh = ( randn(1, 1e6) + 1i*randn(1, 1e6) ) / sqrt(2);

This is a complex normal distribution with zero mean and variance 1/2 per dimension. So the amplitude of x_rayleigh follows a Rayleigh distribution. The phase of x_rayleigh will be uniform. 
Now if you add a line-of-sight component in the above random variable, the amplitude will be Rice distributed. 
    x_rice = 1 + ( randn(1, 1e6) + 1i*randn(1, 1e6) ) / sqrt(2);

The histogram of the absolute value of the generated random variable is shown in the figure. 
