On the capacity of a class of relay channels with orthogonal components and noncausal state information at source

We study the capacity of a class of state-controlled relay channels with orthogonal channels from the source to the relay and from the source and relay to the destination. The channel states are assumed to be known, non-causally, to only the source. This model is useful for relaying in the context of cognition and certain interference-aware networks. For the discrete memoryless case, we establish lower bounds on the channel capacity. For the memoryless Gaussian case, we establish lower and upper bounds on the channel capacity. The upper bound is strictly better than the cut-set upper bound, and is tight for certain special cases.