A Novel TPA Scheme for SVD-Assisted Multi-User MIMO Downlink with Imperfect CSI

In this paper, we investigate the Singular Value Decomposition (SVD)-Assisted multi-user multiple-input multiple-output (MU-MIMO) downlink transmission in the presence of imperfect channel state information (ICSI), and propose an effective transmit power allocation (TPA) scheme. The original equal power allocation (EPA) has been adopted in perfect CSI case. However, EPA doesn´t exploit the CSI and ignores the Bit Error Rate (BER) difference among all singular values. The proposed TPA scheme takes the smallest singular value into account and improves the system performance efficiently. Apart from that, it can exploit the power allocation operation to mitigate the residual interference induced by ICSI. Simulation results reveal that, compared with the original algorithm, the TPA scheme can maintain the BER performance corresponding to the largest singular value and ameliorate that corresponding to the smallest singular value. Furthermore, with ICSI, the proposed TPA scheme can be proved to be more robust to the CSI imperfection.