A novel MU-MIMO-OFDM scheme with the RBD precoding for the next generation WLAN

Multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) is the core technology for the next generation wireless local area network (WLAN). Broader coverage and higher spectral efficiency are the main goals of the next generation WLAN. Multi-user MIMO (MU-MIMO) is a promising way to meet this requirement. In this paper, a novel regularized block diagonalization (RBD) precoded MU-MIMO-OFDM scheme with signal space diversity (SSD) is proposed to improve the performance of MU-MIMO-OFDM scheme on the basis of IEEE 802.11ac standard. The proposed scheme takes advantage of the modulation diversity of rotated constellation, the time-frequency diversity of OFDM and the space diversity of MU-MIMO together. Besides, the RBD precoding not only can reduce the interference from other users, but also can decrease the effect of noise. Simulation results show that the proposed RBD-precoded scheme outperforms the conventional bit interleaved coded modulation (BICM) scheme without SSD by 3.0dB signal noise ratio (SNR) gain. What´s more, the RBD precoding obtains 1.8dB SNR gain than the block diagonalization (BD) precoding.