List Decoding for Bidirectional Broadcast Channels with Unknown Varying Channels

The concept of bidirectional relaying shows the potential to improve the performance in wireless networks such as sensor, ad-hoc, and even cellular systems. It applies to three-node networks, where a relay node establishes a bidirectional communication between two other nodes. In the first phase of a decode-and-forward protocol, the two nodes transmit their messages to a relay node, which decodes them. In the succeeding bidirectional broadcast phase, the relay broadcasts a re-encoded composition of them so that both nodes can decode the other´s message using their own message as side information. We assume that the transmission is affected by unknown varying channels. Unfortunately, the unknown variation of the channel can lead to channels which completely prohibit any reliable communication. In this work, we analyze the bidirectional broadcast phase under list decoding and show that this decoding technique can improve the performance significantly in the sense that it allows to transmit reliably in scenarios where usual decoding schemes fail.