  The generalized degrees of freedom (GDoF) of the symmetric two-user Gaussian
interference relay channel (IRC) is studied. While it is known that the relay
does not increase the DoF of the IC, this is not known for the more general
GDoF. For the characterization of the GDoF, new sum-capacity upper bounds and
lower bounds are derived. The lower bounds are obtained by a new scheme, which
is based on functional decode-and-forward (FDF). The GDoF is characterized for
the regime in which the source-relay link is weaker than the interference link,
which constitutes half the overall space of channel parameters. It is shown
that the relay can indeed increase the GDoF of the IRC and that it is achieved
by FDF.
