Limited feedback design for V-BLAST

We present a quantized precoding scheme for the V-BLAST system. The precoding matrix is decomposed into the multiplication of a beamforming matrix and a power allocation matrix. They are obtained by solving an optimization problem that maximizes the minimum post-detection SINR of the MMSE-SIC receiver under a total power constraint. The beamforming matrix is constrained to be in a predetermined codebook. We show that the precoder of UCD- VBLAST happens to be the optimal solution of the problem. Therefore, the proposed scheme can be regarded as a natural but nontrivial limited feedback version of UCD-VBLAST Simulation results are presented to demonstrate the effectiveness of the proposed scheme.