Capacity of a class of cognitive radio channels: Interference channels with degraded message sets
This correspondence is motivated by two different scenarios. The first is a cognitive radio system where a cognitive radio knows a "dumb" radio's message and the second is a sensor network in a correlated field where sensors possessing a nested message structure assist one another's information transmission. Both scenarios are modeled using the framework of discrete memoryless interference channels with degraded message sets (IFC-DMS), a setting where one of the two transmitters in an interference channel knows both the messages to be conveyed to the receivers. Both inner and outer bounds are provided for a class of IFC-DMS channels. The case of the Gaussian interference channels with degraded message sets is also investigated. In this case, achievability and converse arguments are presented for a class of "weak" interference channels, resulting in a characterization of this class' capacity region.
cognitive radio interference channel dirty-correspondence coding network information theory