Multiple-input-multiple-output (MIMO) systems promise to provide significant increases in system capacity for future wireless communication systems. However, realization of the highest potential capacity of a MIMO system requires a high signal-to-noise ratio and, even more practically, any interference from other access points or other systems has to be considered. The unpredicted interference is normally treated as additional noise (colored-noise) in a MIMO system and this significantly reduces the expected system capacity. An architecture for MIMO iterative array processing with LMMSE turbo equalization is proposed to eliminate cochannel interference (CCI), multiple antenna interference (MAI) and intersymbol interference (ISI) in order to maintain the high capacity of the MIMO system. This architecture performs iterative operations between MIMO beamforming, soft interference cancellation, channel estimation and turbo equalization. Also, a theoretical study of MIMO capacity with beamforming under CCI is presented.