A study on optimal termination target of synchronous H-ARQ for the next generation cellular system

In 3.9G cellular systems, which have many specific components, operators have to manipulate many parameters of each component. One of the critical parameters is the termination target of H-ARQ. It is supposed that the termination target influences system performance in terms of both throughput and delay because the termination target involves a trade-off between the gain of high modulation order and the loss of continuous resource assignment by H-ARQ. The link-level performance of turbo coded H-ARQ has already been reported, however, the influence of the termination target on system performance is still to be fully studied. The purpose of this study is to determine the optimal termination target and to examine which parameter influences sector throughput. It was found that the optimal termination target depends on the propagation model and average SINR. By selecting the optimal termination target, the system throughput can achieve 20 % gain compared to a system using a non-optimal termination target.