The influence of spatial and temporal correlation on the capacity of MIMO channels

Wireless communication systems employing multiple antennas at both the transmitter and receiver have been shown to offer significant gains over single antenna systems. Recent studies on the capacity of multiple-input multiple output (MIMO) channels have focused on the effect of spatial correlation. The joint effect of spatial and temporal correlation has not been well studied. In this paper a geometric channel model is presented which considers motion of the receiver and non-isotropic scattering at both ends of the radio link. A joint space-time cross-correlation function is derived and variates with this correlation are generated using the vector autoregressive stochastic model. The outage capacity of this channel is considered where the effects of antenna spacing, antenna array angle, degree of non-isotropic scattering and receiver motion are investigated. When n transmit and n receive antennas are employed, it is shown that capacity still increases linearly with respect to n despite the presence of spatial and temporal correlation.