Capacity to within a constant gap for a class of Interference Relay Channels

In this paper, we derive a new outer and two inner bounds for a class of Interference Relay Channels (IRCs) which includes the Gaussian IRC as a special case. The inner bounds are based on the idea of rate-splitting at the sources with either decode-and-forward (DF) or compress-and-forward (CF) at the relay. Our main contribution lies in showing for a wide range of regimes of the Gaussian IRC that either the DF or the CF inner bound achieves the upper bound to within a constant gap regardless of the channel parameters.