Iterative Relay Scheduling with Hybrid ARQ for Type-2 relays

Abstract

We propose an iterative relay scheduling with hybrid ARQ (IRS-HARQ) which realizes fast jump-in/successive relaying and subframe decoding to facilitate user equipment (UE or type-2) relays for next-generation cellular systems (e.g., LTE-Advanced), especially when operating in an open-loop and transparent mode. The proposed IRS-HARQ aims to increase the achievable data rate by iteratively scheduling a relatively better UE relay closer to the end user in a probabilistic sense, provided that the UE relay-to-end user link should be operated in an open-loop and transparent mode. The latter is due to the fact that not only there are no dedicated control channels between the UE relay and the end user but also a new cell is not created. Under this open-loop and transparent mode, we implement the IRS-HARQ by partially exploiting the channel state information, based on the overhearing mechanism of ACK/NACK for HARQ.