Towards optimum Hybrid ARQ with rateless codes for real-time wireless multicast

For guaranteeing quasi-error free delivery of realtime multicast services over wireless networks, an efficient greedy algorithm is proposed for optimizing the parameters of a HARQ scheme with rateless codes under strict delay and bandwidth constraints. We take systematic Raptor codes as an example for analyzing the optimum performance of the HARQ scheme. The results show that the optimum performance can be obtained by combining the optimum HARQ and FEC. Additionally, the simulation results show that the proposed optimization framework can be used for evaluating the tight lower bound performance of the HARQ, which indicates that it is suitable for designing optimum HARQ scheme with guaranteeing the target quasi-error free delivery requirements very well.