Date Added: Nov 2009
The authors define a class of Z-interference channels for which they obtain a new upper bound on the capacity region. The bound exploits a technique first introduced by Korner and Marton. A channel in this class has the property that, for the transmitter - receiver pair that suffers from interference, the conditional output entropy at the receiver is invariant with respect to the transmitted codewords. They compare the new capacity region upper bound with the Han/Kobayashi achievable rate region for interference channels. This comparison shows that their bound is tight in some cases, thereby yielding specific points on the capacity region as well as sum capacity for certain Z-interference channels.