Link adaptation based MIMO systems with easy V-BLAST detection

Link adaptation by adaptive modulation and power allocation in a V-BLAST system is considered. The conventional detection order of the ZF-SIC (zero forcing based successive interference cancellation) algorithm has been found to be not optimal for link adaptive V-BLAST. Some new detection ordering methods have been proposed. However, these new detection orders are determined with high computational complexity. Some priori knowledge inherently introduced by link adaptation signaling information is ignored at the receiver. In this contribution, by taking advantage of the priori knowledge about modulation mode and transmit power, two new detection ordering methods are proposed, by which the detection order can be fully known prior to data detection. Thus the ZF-SIC algorithm can be simplified by calculating all ZF weighting vectors iteratively without M_T-1 times complex Moore-Penrose inverse operations of the channel matrix.