Achievable Rate Regions for Two-Way Relay Channel Using Nested Lattice Coding

Abstract

This paper studies Gaussian Two-Way Relay Channel where two communication\nnodes exchange messages with each other via a relay. It is assumed that all\nnodes operate in half duplex mode without any direct link between the\ncommunication nodes. A compress-and-forward relaying strategy using nested\nlattice codes is first proposed. Then, the proposed scheme is improved by\nperforming a layered coding : a common layer is decoded by both receivers and a\nrefinement layer is recovered only by the receiver which has the best channel\nconditions. The achievable rates of the new scheme are characterized and are\nshown to be higher than those provided by the decode-and-forward strategy in\nsome regions.\n