  The best known inner bound for the 2-user discrete memoryless interference
channel is the Han-Kobayashi rate region. The coding schemes that achieve this
region are based on rate-splitting and superposition coding. In this paper, we
develop a multicoding scheme to achieve the same rate region. A key advantage
of the multicoding nature of the proposed coding scheme is that it can be
naturally extended to more general settings, such as when encoders have state
information or can overhear each other. In particular, we extend our coding
scheme to characterize the capacity region of the state-dependent deterministic
Z-interference channel when noncausal state information is available at the
interfering transmitter. We specialize our results to the case of the linear
deterministic model with on/off interference which models a wireless system
where a cognitive transmitter is noncausally aware of the times it interferes
with a primary transmission. For this special case, we provide an explicit
expression for the capacity region and discuss some interesting properties of
the optimal strategy. We also extend our multicoding scheme to find the
capacity region of the deterministic Z-interference channel when the signal of
the interfering transmitter can be overheard at the other transmitter (a.k.a.
unidirectional partial cribbing).
