On achievable rates of two-path successive relaying

This letter studies the achievable rates of the two-path relay channel (TPRC), where two half-duplex relays successively in turn forward messages from a source to a destination. It is shown that the conventional analogue and digital relaying schemes incur non-negligible throughput losses due to a socalled "inter-relay-interference (IRI)" phenomenon. This letter presents a new digital relaying scheme at the source transmitter to mitigate the IRI by applying the "dirty-paper-coding (DPC)" technique. It is shown that the proposed scheme achieves the capacity of the symmetric TPRC.