Type-II Hybrid ARQ Protocol and Its Applications in Slotted Aloha DS-CDMA

摘要

In spread spectrum communication system where the channel state temporarily changes, it is preferable to change error-correcting capability in the hybrid ARQ scheme according to the channel state. In this paper, Type-II hybrid ARQ(ARQ-II) protocol in slotted CDMA network is analyzed. Perforamnce of ARQ-II in slotted DS_CDMA is obtained using sim;lified Gaussian approximation. Comparisons of type - I hybrid ARQ (ARQ - I) and ARQ-II in slotted Aloha DS-CDMA (SSA) are performed and results are given. It is shown that ARQ-II can be regarded as a multirate strategy that performs an information rate adaptation at the DLC(Data Link Control) Layer.