Interference Channel aided by an Infrastructure Relay

A Gaussian interference channel with an infrastructure relay (ICIR) is investigated. The relay has finite-capacity links to both sources and destinations that are orthogonal to each other and to the underlying interference channel. A general achievable rate region is presented by using the relay both to convey additional information from the sources (signal relaying) and to ease interference cancellation (interference forwarding). Outer bounds to the capacity region are also derived, and used to determine a number of regimes of interest where either signal relaying only or both signal relaying and interference forwarding are optimal.