Transmission strategy of fountain code in cooperative networks with multiple relay nodes

In this paper, transmission of fountain code over cooperative networks is considered. While it is known that fountain code is optimal for sending data to multiple receivers, extra care is needed when it is used in cooperative networks. On one hand, the presence of relay node can help to improve the overall performance. On the other hand, multiple relay nodes introduce the problem of mutual interference, which can potentially degrade the performance. This work proposes an amplitude modulation scheme to address the above issue. By appropriately scaling the output signal at each node according to their unique identifier, separability of data from several transmitters at the destination can be achieved. A numerical analysis highlighting the advantage of the proposed scheme is then presented.