Question

What will be variance for rayleigh fadding channel?

Answer 1

. In principle, you can consider h as complex random variable with zero mean and unit variance of power. Since h has real and imaginary components that are independent from each other, then it is reasonable to assume that half of the power in the real component and the remaining half of power is on the imaginary component.

2. Yes, it is NOT necessary for h to be of unit variance. And still we get Rayleigh fading for the magnitude of h.

3. Yes, you can. The resulted h as you described is a complex Gaussian of zero mean and unit variance.

4. Yes, you can. Then, each element of the 2*2 MIMO matrix, will follow a complex Gaussian distribution of zero mean and unit variance.

Answer 2

Rayleigh fading models assume that the magnitude of a signal that has passed through such a transmission medium (also called a communicationchannel) 


will vary randomly, or fade, according to a Rayleigh distribution — the radial component of the sum of two uncorrelated Gaussian random variables.