5 research outputs found
Capacity Bounds for a Class of Interference Relay Channels
The capacity of a class of Interference Relay Channels (IRC) -the Injective
Semideterministic IRC where the relay can only observe one of the sources- is
investigated. We first derive a novel outer bound and two inner bounds which
are based on a careful use of each of the available cooperative strategies
together with the adequate interference decoding technique. The outer bound
extends Telatar and Tse's work while the inner bounds contain several known
results in the literature as special cases. Our main result is the
characterization of the capacity region of the Gaussian class of IRCs studied
within a fixed number of bits per dimension -constant gap. The proof relies on
the use of the different cooperative strategies in specific SNR regimes due to
the complexity of the schemes. As a matter of fact, this issue reveals the
complex nature of the Gaussian IRC where the combination of a single coding
scheme for the Gaussian relay and interference channel may not lead to a good
coding scheme for this problem, even when the focus is only on capacity to
within a constant gap over all possible fading statistics.Comment: 23 pages, 6 figures. Submitted to IEEE Transactions on Information
Theory (revised version