Substream selection in wireless MIMO systems for complexity reduction

Although MIMO channels offer the potential to dramatically improve the channel capacity, the incurred implementation complexity and massive computation requirements have made MIMO difficult to be integrated in today's wireless systems. In this paper, we attempt to introduce a dominant block diagonal permutation technique to reduce the dimensionality of the overall MIMO receiver. As such, we may trade small performance degradation for significantly reduced computation complexity, which may finally lead to a low power real time MIMO receiver design. In particular, a large channel transfer function matrix is decomposed into many weakly coupled submatrices by a proper permutation. Finding such a decomposition is formulated as an NP-hard combinatorial problem, and a special generic algorithm based procedure has been developed.