Optimization of Mapping Rules in High-Rate Coded Hybrid ARQ Protocol in HSDPA System

The optimization of mapping rule in hybrid ARQ(HARQ) protocol of high speed downlink packet access(HSDPA) system is presented,especially for full incremental redundancy(FIR) and partial incremental redundancy(PIR) with high rate Turbo code.The retransmission priorities of various encoded bits are analyzed and the presented scheme provides higher reliabilities to the bits that have higher priorities to achieve unequal error protection optimization.Furthermore,the reliabilities of encoded bits among initial and retransmissions are attempted to be averaged.Simulation results showed that this scheme can achieve performance gain for PIR and FIR with high code rates with only slight increases in complexity.