  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.
