Throughput Maximization Algorithm in Relay-based Wireless Communication System with HARQ and AMC

In recent years, relay topics are widely considered in wireless communication standards. In the relay issues, the link adaptation in relay channel is a hot study topic. In traditional wireless communication systems, the most famous link adaptation method is the mechanisms of adaptive modulation and coding (AMC). In practical system design, the AMC mechanism is usually implemented with fixed switching thresholds for the modulation and coding schemes (MCS), and suffers performance degradation. Although the hybrid automatic repeat request (HARQ) is designed to offer robust transmissions and hence alleviates the performance degradation due to the use of unfavorable MCS, it also introduces the problem of retransmission latency. However, when the system operates in relay channel, in additional to the direct source destination (S-D) link, there are also source-relay (S-R) and relay-destination (R-D) links needed to be considered to optimize the whole system performance. To improve the performance of the AMC systems in relay channel, a novel algorithm considering both AMC and HARQ characteristics will be developed in this study to maximize the system throughput.