A new and better design of quasi-orthogonal space time block codes (QOSTBC) based on random rotation and pre-coding

Aim. The introduction of the full paper reviews some papers in the open literature, points out their main shortcomings and proposes what we believe to be a new and better design, which is explained in sections 1 through 3. Their core consists of: (1) to enhance the performance of QOSTBC in the MIMO fading channels, our new transmission design randomly rotates each information symbol vector; hence, the inter-symbol interference among multiple antennas is allocated more randomly; (2) the receiver of the MIMO transmission system carries out equalized decoding and at the same time feeds back the channel information which includes channel-related information and mean values; then the transmitter chooses pre-coding matrixes and completes self-adaptive coding in accordance with the feedbacks. The simulation results, given in Figs. 2 and 3, and their analysis show preliminarily that our new design can greatly reduce the bit error rate (BER) of the transmission system and enhance its overall performance compared with the transmission systems without pre-coding.