Novel MIMO HARQ Schemes Jointly Utilizing Chase Combining

In this paper we propose several novel HARQ schemes for MIMO system which jointly utilize bit-wise soft- information (BWSI) chase combining. Retransmission mechanisms to obtain ARQ diversity are developed. We present the detection algorithm and how to jointly utilize the BWSI derived from former retransmission to improve BER performance. Finally we propose a new retrans scheme using channel codes based on BWSI feedback, which can achieve better performance compared to normal HARQ with acceptable complexity.