The CF-DF approach for relay networks based on multiple descriptions with the shared binning

Abstract

Decode-and-forward (DF) and compress-and-forward (CF) are well-known strategies to transmit information over the relay channel. There are several methods which generalize these strategies to relay networks, among them, the unified CF-DF strategy is one with relatively good performance and less complexity. In this method the nodes are divided into two groups: DF relay nodes and CF relay nodes, where the DF relay nodes fully utilize the help of the CF relay nodes. Here we present a modified CF-DF approach in which the CF relay nodes form multiple description coding. This method let different DF relay nodes and the destination receive the relay observation at different quality levels. In comparison with similar approaches, here the key point is that we use the shared binning for all descriptions at a CF relay node. This strategy reduces the complexity of the obtained achievable rate and yielding the better performance at the same time. Simulation results for Gaussian relay networks show that our proposed achievable rate includes the previously proposed ones.