A Simplified ML Approach in Suppression of Directional Interference for STBC MIMO System

When the orthogonal space-time block code (STBC), or the Alamouti code, is applied in multiple-input multiple-output (MIMO) communication systems, with a simple signal decoupling at the receiver, the optimum reception can be achieved. However, in the military application fields the performance deteriorates significantly in presence of directional interferences from certain directions. While few methods for suppressing the directional interferences exist, in this paper, a reception scheme based on a linear separation processing is proposed to suppress the directional interferences. It´s capable of reaching the maximum likelihood (ML) boundary, as long as the interference is Gaussian distributed. Moreover, the absence of direct computation of inverse matrix decreases the complexity of processing at the receiver. Finally, simulations are given to verify these conclusions.