Achievable rate of a two-way relay channel with structured code under Rayleigh fading

This paper presents an achievable rate for a two-way relay channel under a Rayleigh fading environment. A two-way relay channel has two source nodes that exchange their information through a common relay node. This paper assumes that there is no direct channel between source nodes and that the relay operates in full-duplex mode. An achievable scheme is proposed based on the nested lattice codes for the uplink, i.e., from a source node to a relay node, and also based on the structured binning for the downlink, i.e., from the relay node to a destination node. In addition, this paper derives a closed-form expression for a cut-set bound for the two-way relay channel under fading. It is observed that the achievable rate region for the two-way relay channel under fading is strictly below the cut-set bound and is achievable through structured codes.