We introduce an interference channel with oblivious encoders, which models a
situation in which the encoders are ignorant of the codebooks of one another.
We
assume that the decoders are cognizant of the codebooks. We study the capacity
region of a two-user Z-interference channel with oblivious encoders, and prove
that an optimal strategy of the interfered user is to use random constant
composition codes. Further, we establish the result that the capacity region
of
this channel, in the weak interference regime, is equal to the Han-Kobayashi
region of the ordinary Z-Interference channel.