Research On The Combining Schemes Of Space-Time Codes And HARQ For MIMO Systems

Multiple input Multiple output (MIMO) have become one of the techniques attracted increasingly significant attention in the wireless mobile area due to their high capacity and good immunity to the channel fading. The two merits are embodied in that the capacity is improved through spatial multiplexing as using BLAST method, the spatial diversity is attained by using STTC and STBC to ensure the communication link reliably. However, the ARQ protocol is still required to guarantee the reliable data transmission. The HARQ technique can attain more excellence performance than traditional ARQ.HARQ is able to ensure the error-free data transmission nearly while it may drop the throughput of the system. So it is very available and significant to combine the MIMO and HARQ .it is just what we will research.At first, we briefly review the space time code and HARQ techniques, based on that, we propose a algorithm combined STC and HARQ. The proposed scheme combined the STBC and VBLAST, split the code matrix of STBC into several VBLST codes for transmission by using HARQ.The simulation of comparing OSTBC-HARQ and QOSTBC-HARQ approves that our proposed algorithm is excellent on the BER, throughput and delay performance.Based on the STC-HARQ algorithm, we proposed a new STC-HARQ algorithm based on the constellation arrangement, and discuss the STC-HARQ algorithm based on constellation arranging per whole code matrix and constellation arranging per row of code matrix .The simulation results show that this algorithm attain better performance than the STC-HARQ algorithm without constellation arrangement when high rank modulation is used.