Abstract: Under the assumption that the channel state information (CSI) is known only to the receiver, a simplified optimum bit and power allocation method is proposed for multiple-input multiple-output (MIMO) systems that uses V-BLAST as a detection algorithm to maintain fixed target link quality.Due to different ordering in detection resulting in different equivalent gains, forward ordering, revere ordering and optimal ordering, respectively, are considered in the simulation.When M-ary QAM is used with a target symbol error ratio (SER) of 10^-5 in the proposed method, it is found that the spectral efficiency performance of the revere ordering is better than forward ordering, but worse than the singular value decomposition (SVD) based scheme.The reverse is true in case the transmit power constraint is high enough.

Key words: V-BLAST, detection ordering, CSI, bit and power allocation, MIMO