Efficient Optimal Ordering Achieving DFE Algorithms in MIMO Systems

Recent theoretical and experimental studies indicate that spatial multiplexing (SM) systems have enormous potential for increasing the capacity of corresponding multiple input multiple output (MIMO) channels in rich scattering environments. In this paper, we describe two fast detection algorithms for the standard BLAST receiver. The first algorithm covers the nulling and cancellation (NC) detection interface that applies inflation and deflation recursion to the initialization and iteration stages, respectively. The second algorithm utilizes the QR decomposition (QRD) detection interface that reuses Cholesky decomposition and back substitution, leading to an alternative low complexity detector. Compared with the conventional fastest method, our new algorithms reduce the complexity of the preprocessing by a factor of about 2. Furthermore, they are also implementation friendly by avoiding the recursive permutation and permitting the function reuse.