A Structured Generalization of Decode-and-Forward Strategies for Multiple-Relay Networks

This paper presents a structured characterization of a class of decode-and-forward (DF) strategies for arbitrary multirelay networks. In contrast to conventional DF strategies in which each relay transmits the bin index of the source message only, the proposed generalized DF strategies allow each relay to decode a selection of messages from other nodes and forward bin indices for them. A tree structure is utilized to characterize the dependencies of messages on each other. Based on this tree structure, closed-form expressions for the achievable rates of these DF schemes are derived. The proposed DF strategy improves the previous multirelay DF rates and gives the capacity of new forms of degraded multirelay networks.