Functional-Decode-Forward for the General Discrete Memoryless Two-Way Relay Channel

TL;DR

This paper introduces two functional-decode-forward coding strategies for the general discrete memoryless two-way relay channel, demonstrating their potential to achieve higher sum rates than existing methods.

Contribution

It proposes novel functional-decode-forward strategies that decode functions of messages at the relay, improving sum rate performance in two-way relay channels.

Findings

Functional-decode-forward with linear codes outperforms other strategies in sum rate.

The proposed methods are applicable to general discrete memoryless two-way relay channels.

Numerical examples confirm the superiority of the new strategies.

Abstract

We consider the general discrete memoryless two-way relay channel, where two users exchange messages via a relay, and propose two functional-decode-forward coding strategies for this channel. Functional-decode-forward involves the relay decoding a function of the users' messages rather than the individual messages themselves. This function is then broadcast back to the users, which can be used in conjunction with the user's own message to decode the other user's message. Via a numerical example, we show that functional-decode-forward with linear codes is capable of achieving strictly larger sum rates than those achievable by other strategies.