A novel mapping criterion scheme for MCS selection in CDMA based HARQ systems

Two important considerations in designing a HS-DPA system are algorithms for the selection of coding and modulation schemes based on the channel quality of the link and algorithms for the selection of the user to whom a particular slot is assigned. In this paper, our special focus is put on the mapping criteria between signal-to-interference-and-noise ratio (SINR) and modulation and coding scheme (MCS), taking into account frame error rate (FER) and HARQ information. We propose a simple criterion to optimize the mapping between SINR and MCS to maximize the throughput. Supposed that the max transmission times is pre-determined, based on the SINR estimated, the FER and the probability of each retransmission contributing to the throughput are calculated. Simulation results comparing performance of the proposed methods and traditional counterparts are presented, it is shown that our new algorithm outperforms conventional methods and is more easily to be implemented.