  We consider a state-dependent parallel Gaussian channel with independent
states and a common cognitive helper, in which two transmitters wish to send
independent information to their corresponding receivers over two parallel
subchannels. Each channel is corrupted by independent additive Gaussian state.
The states are not known to the transmitters nor to the receivers, but known to
a helper in a noncausal manner. The helper's goal is to assist a reliable
communication by mitigating the state. Outer and inner bounds are derived and
segments of the capacity region is characterized for various channel
parameters.
