Incremental Code Relaying Protocol for Cooperative Communications

In this paper, the application of rate-compatible punctured convolutional (RCPC) code into coded cooperation relay system is studied. As opposed to conventional coded cooperation systems, RCPC is attractive for its better spectral efficiency. In addition, the broadcast nature of relay transmission provides a new dimension to the system in the form of implicit feedback channel from relay to source. This allows the source node to justify the quality of information bits at relay node and react accordingly by taking over relay´s role to transmit the additional parity. At the destination, selection code combining is then performed, which provides a diversity benefit to the underlying RCPC code. The performance of the proposed scheme in terms of the number of correctly decoded bits (goodput), bit error probability, and the required number of slots for message transmission are then analysed. Extension to the case where there are multiple relays to assist the transmission is also discussed.