Capacity of a mobile multiple-antenna wireless link with isotropically random Rician fading

We analyze a multiple-antenna wireless link with M antennas at the transmitter and N antennas at the receiver in a Rician fading channel. The Rician model is a non-standard model with a Rayleigh component and a rank-one isotropically random specular component. We derive a novel lower bound on capacity which enables the computation of achievable rate regions for many cases. This lower bound is also valid for the case of purely Rayleigh fading channels, where it has not been feasible, in general, to compute capacity, or mutual information. Our numerical results also indicate that the Rayleigh model is surprisingly robust: under our Rician model, up to half of the received energy can arrive via the specular component without significant reduction in capacity compared with the purely Rayleigh case. Further details can be found in Godavarti et al. (2001)