Block spread OFDMA system with space-time coded MIMO over frequency selective fading channels

This paper proposes a block spread orthogonal frequency division multiple access (BS-OFDMA) system with a combined space-time coded multiple-input multiple-out (STC-MIMO) scheme called STC-MIMO BS-OFDMA for transmission over frequency selective fading channels. In this system, a novel block spreading approach is firstly applied to effectively achieve precoding in the OFDMA system with lower complexity for improving the multipath diversity performance. The STC-MIMO is then incorporated to take advantage of the spatial diversity. The signal model and architecture of the proposed system are presented, and simulations are carried out to confirm the expected performance improvement.