Abstract:

Relay is considered as an effective method to improve the coverage of high data rates，group mobility，and ce11-edge throughput and provide the coverage in new areas. However，traditiona1 relay strategies were mostly discussed based on channe1 capacity. A specific hybrid-relay selection and scheduling strategy based on retransmission scheme was proposed. Through the consideration of four relay routing methods in two-hop relay networks，a hybrid-relay was designed，combining MAC 1ayer and physica1 1ayer. An adaptive selection and scheduling method to choose which routing mode relay should perform was also presented. More performance gain，compared with the existence of just one relay routing method and no relay system，could be enhanced by using this hybrid-relay selection and scheduling strategy. Moreover，it had been discussed that this hybrid relay just increases a 1ittle protoco1 complexity but does not change relay architecture.

Key words: relay, LTE-Advanced, retransmission, selection, scheduling