A Cooperative System Using an Adaptive Relaying Protocol and Rateless Codes

In this paper, a full-duplex compress-and-forward (CF) protocol for cooperative communication systems using Raptor codes is first investigated. It is verified that the throughput of the full-duplex CF protocol is superior to that of the full-duplex decode-and-forward (DF) protocol when the relay-to- destination channel has a much higher quality compared to the source-to-relay channel, while the full-duplex DF protocol works more effectively than the full-duplex CF protocol in the reverse situation. A full-duplex adaptive relaying protocol that is devised based on both CF and DF protocols is then proposed. In the proposed protocol, the CF and DF protocols are adaptively switched, depending on the channel conditions of the wireless links. In addition, the throughput of the overall system is enhanced using an outer Raptor code. Simulation results show that the proposed scheme smoothly switches between the two conventional protocols to cope with different channel conditions.