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.
['Zhanji Wu', 'Xiang Gao', 'Yongtao Shi']
A novel MU-MIMO-OFDM scheme with the RBD precoding for the next generation WLAN