On the robustness of space-time coding for spatially and temporally correlated wireless channels

The robustness of space-time coding techniques for wireless channels that exhibit both temporal and spatial correlation is investigated. A general space-time covariance model is developed and employed to evaluate the exact pairwise error probability for several space-time codes. A significant degradation in the performance of space-time coding techniques is observed for cases where the scatterers are located in close proximity to the mobile and the spacing between transmit antennas is a fraction of a wavelength. The conditions for which the commonly used assumption of independent transmission paths is valid are investigated as a function of the scattering radius and the spacing of the transmit and receive antennas.