Date Added: Jul 2011
The authors investigate efficient scheduling algorithms for a relay-aided broadcasting system using random network codes, where their objective is to maximize the transmission efficiency. The broadcast from a Base-Station (BS) is divided into an information phase and a redundancy phase, where the half-duplex relay assists in the redundancy phase. Time-division transmission is used over packet-erasure channels, where the erasure probabilities of the BS-to-relay and relay-to-user links are lower than the BS-to-user links. Following the information phase, each user provides feedback on the status of received packets to the BS and the relay, which in turn both generate redundancy packets for the redundancy phase. To improve efficiency, they formulate a scheduling problem for the transmissions of redundancy packets from the BS and the relay.