Elazreg, A.M. Abdurahman, F.M. Chambers, Jonathon Distributed closed-loop quasi-orthogonal space time block coding with four relay nodes: overcoming imperfect synchronization In this paper, closed-loop quasi-orthogonal space time block coding (QO-STBC) is exploited within a four relay node transmission scheme to achieve full-rate and increase the available diversity gain provided by earlier two relay approaches. The problem of imperfect synchronization between relay nodes is overcome by applying a parallel interference cancellation (PIC) detection scheme at the destination node. Bit error rate simulations confirm the advantages of the proposed methodology for a range of levels of imperfect synchronization and that only a small number of iterations is necessary within the PIC detection Closed-loop quasi-orthogonal space time block coding (CL QO-STBC);Closed-loop phase rotated feed-back;Linear processing and parallel interference cancellation detection (PIC);Mechanical Engineering not elsewhere classified 2009-12-01
    https://repository.lboro.ac.uk/articles/conference_contribution/Distributed_closed-loop_quasi-orthogonal_space_time_block_coding_with_four_relay_nodes_overcoming_imperfect_synchronization/9554858