Introduction - If you have any usage issues, please Google them yourself
The effects of multipath include constructive and destructive interference, and phase shifting of the signal.
This causes Rayleigh fading, named after Lord Rayleigh. The standard statistical model of this gives a distribution known as the Rayleigh distribution.
Rayleigh fading with a strong line of sight content is said to have a Rician distribution, or to be Rician fading.