Effects of Space on MIMO Capacity: A New Closed Form Upper Bound

We present a new upper bound on capacity for multiple-input multiple-output (MIMO) wireless fading channels which is more general and realistic than previous capacity expressions. By including spatial information at the antenna arrays we derive a closed form upper bound on capacity which uses the physics of signal propagation combined with statistics of the scattering environment. This expression gives the capacity of a MIMO system in terms of antenna placement and scattering environment and leads to valuable insights into the factors determining capacity for a wide range of scattering models. Index Terms MIMO systems, wireless, capacity, diversity, correlation, multi-element antenna arrays, multipath channels, nonisotropic scattering