Transmit Antenna Selection for Rank-deficient Spatial Multiplexing Systems

Abstract

In this work, we propose and analyze a diversity optimal transmit antenna selection for rank-deficient spatial multiplexing (SM) systems with linear or decision-feedback (DF) receivers based on the fixed-complexity sphere decoder (FSD) ordering. A regularized FSD (RFSD) transmit antenna selection algorithm is proposed by utilizing the regularized (or augmented) channel matrix in order to alleviate the rank-deficiency of the Gram channel matrix. In each iteration of the RFSD algorithm, one column of the channel matrix, the one corresponding to the row of the pseudo-inverse of the regularized channel matrix with the maximum norm, is forced to be zero until L columns remain for transmission. The diversity optimality of the proposed technique is shown by analysis and some computer simulations.