Abstract
In this paper, we focus on the performance imimprovement of the network coding (NC) based hybrid automatic repeat request chase combining (HARQ-CC) scheme. First, considering the joint detection method with the conventional log- likelihood ratio (LLR) calculation, we design the optimal pair of constellation mappings for bit error rate (BER) minimization. Furthermore, we propose a novel remapping-based joint detection algorithm: threshold- based optimal accumulation order selection (TH-OAOS) algorithm for LLR maximization to improve the system performance. The simulation results show that the proposed optimal constellation mappings significantly outperforms the conventional original mappings in terms of error performance. Moreover, the error performance of the proposed TH-OAOS algorithm for LLR maximization is far better than the case of the conventional LLR calculation.