Abstract: Based on the block diagonalization (BD) for multiuser Multiple-input Multiple-output (MIMO) downlink channel, a vector precoding (VP) combined with geometric mean decomposition (GMD) based on minimum mean square error (MMSE) criterion is proposed. The multiuser multi-antennas channel is decomposed into parallel effective sub-channels, and then the mean square error (MSE) of transceiver signal is obtained based on the effective sub-channel. The VP combined with GMD is derived based on MMSE criterion, and the perturbation vector contains the perturbation vector expanding constellation and residual interference vector. The MSE expression is then achieved based on the derivation results, and the realization block diagram is concluded finally. The simulation results show that the proposed algorithm outperforms the conventional BD method and its expanded method in bit error rate (BER).

Key words: vMIMO system, mean square error, vector precoding, block diagonalization