Channels with nosy "noise"

Coding over channels whose state can depend non- causally on the entire transmitted codeword and message are studied. The channel model is a variation on the arbitrarily varying channel (AVC) with state constraints. The randomized coding capacity of this channel is shown to be equal to the randomized coding capacity C
_r
in the case where the jammer does not know the codeword, and common randomness of O (log n) bits is sufficient to achieve this capacity.