Genie-aided Outer Bounds on the Capacity of Interference Channels

AN outer bound on the capacity region of the two-user Gaussian interference channel (IFC) is derived. The idea is to let a genie give each receiver just enough information to decode both messages. The bound includes two earlier outer bounds of Sato and Carleial as special cases and improves on them. A generalization of the bound to discrete memoryless IFCs is shown to be equivalent to another bound of Carleial's. As a result, the new bound for the Gaussian IFC can alternatively be derived from a rather straightforward extension of an existing bound.