MIMO-OFDM scheme based on Permutation spreading

In this paper, a novel transmission scheme is developed to effectively combine permutation spreading technique with MIMO-OFDM to obtain improved bit error rate performance in the presence of frequency selective fading channels with low system complexity. Unlike conventional MIMO-OFDMA, where users are separated in different frequency bands (subchannels), and each user is coded separately using STBC or SFBC, the proposed new scheme enables multi access by joint code design across multiple antennas, subcarriers, and users. Such system will benefit from the combined space and frequency domain freedom as well as multiuser diversity. Hence, better spectrum efficiency is achieved while improving bit error rate performance with respect to signal-to-interference ratio.