A NAK based hybrid type II ARQ scheme for cdmaOne/cdma2000 systems

Hybrid ARQ techniques make use of all the advantages of FEC coding as well as ARQ techniques and are very efficient over noisy and fluctuating channels. This paper proposes a new hybrid type II ARQ scheme which uses the same code rate in successive retransmissions. This simplifies the transmitter and receiver designs to a large extent as compared to other hybrid schemes proposed earlier. The retransmission scheme suggested is very similar to that of the widely accepted TIA/EIA/IS-707 RLP. This NAK (negative ACK)-based retransmission mechanism and the simplified transmitter/receiver architectures help to minimize the delays at the transport and link layers. The proposed scheme performs well with a cdma2000 similar physical layer and hence is suitable for 3G environments as well. The results presented in this paper are based on detailed simulation of the proposed scheme using Network Simulator