  We consider a state-dependent full-duplex relay channel with the state of the
channel non-causally available at only the relay. In the framework of
cooperative wireless networks, some specific terminals can be equipped with
cognition capabilities, i.e, the relay in our model. In the discrete memoryless
(DM) case, we derive lower and upper bounds on channel capacity. The lower
bound is obtained by a coding scheme at the relay that consists in a
combination of codeword splitting, Gel'fand-Pinsker binning, and a
decode-and-forward scheme. The upper bound is better than that obtained by
assuming that the channel state is available at the source and the destination
as well. For the Gaussian case, we also derive lower and upper bounds on
channel capacity. The lower bound is obtained by a coding scheme which is based
on a combination of codeword splitting and Generalized dirty paper coding. The
upper bound is also better than that obtained by assuming that the channel
state is available at the source, the relay, and the destination. The two
bounds meet, and so give the capacity, in some special cases for the degraded
Gaussian case.
