Symbol-level random network coded cooperation with hierarchical modulation in relay communication

In order to effectively minimize packet error rate in error prone wireless networks, a novel cooperative communication strategy jointly using symbol-level random network coding and hierarchical modulation is proposed in this paper. The source broadcasts random network coded symbols with hierarchical modulation to the relays and the destination. In following time slots, the relays, which have successfully decoded the original packet, transmit additional random network coded symbols to the destination. When the proposed scheme is applied in multihop relay consumer device networks which comprise a set of consumer devices, error free transmission with high efficiency can be achieved. We show with simulation results that the proposed joint symbol-level random network coding and hierarchical modulation strategy achieves a substantial gain compared to the channel coded cooperation scheme.