Capacity of Strong and Very Strong Gaussian Interference Relay-Without-Delay Channels
In this paper, the authors study the interference relay-without-delay channel which is an interference channel with a relay helping the communication. They assume the relay's transmit symbol depends not only on its past received symbols but also on its current received symbol, which is an appropriate model for studying amplify-and-forward type relaying when the overall delay spread is much smaller than the inverse of the bandwidth. For the discrete memoryless interference relay-without-delay channel, they show an outer bound using genie-aided outer bounding. For the Gaussian interference relay-without-delay channel, they define strong and very strong interference relay-without-delay channels and propose an achievable scheme based on instantaneous Amplify-and-Forward (AF) relaying.