Reduced search space scheme for detection of spatial division multiplexing

In this paper, we introduce a suboptimal detection scheme for the spatial division multiplexing (SDM) using multiple transmit and receive antennas. As a conventional detection method, zero-forcing (ZF) detection shows inferior performance to the optimal maximum likelihood (ML) scheme because it does not exploit a pattern of the weighted noise characterized by singular values and vectors of a corresponding channel matrix. Therefore, the proposed scheme fines the tentative solution with the reduced candidates near the ZF filtering output. And the search space is extend in the direction of minimizing the ML cost function and we find the final solution to overcome the ZF performance loss. The proposed detector has low complexity while keeping the performance comparable to the ML and other detection methods.