27,010 research outputs found
State of the cognitive interference channel: a new unified inner bound
The capacity region of the interference channel in which one transmitter
non-causally knows the message of the other, termed the cognitive interference
channel, has remained open since its inception in 2005. A number of subtly
differing achievable rate regions and outer bounds have been derived, some of
which are tight under specific conditions. In this work we present a new
unified inner bound for the discrete memoryless cognitive interference channel.
We show explicitly how it encompasses all known discrete memoryless achievable
rate regions as special cases. The presented achievable region was recently
used in deriving the capacity region of the general deterministic cognitive
interference channel, and thus also the linear high-SNR deterministic
approximation of the Gaussian cognitive interference channel. The high-SNR
deterministic approximation was then used to obtain the capacity of the
Gaussian cognitive interference channel to within 1.87 bits.Comment: Presented at the 2010 International Zurich Seminar on Communications
- an 2nd updated version
A New Achievable Scheme for Interference Relay Channels
We establish an achievable rate region for discrete memoryless interference
relay channels that consist of two source-destination pairs and one or more
relays. We develop an achievable scheme combining Han-Kobayashi and noisy
network coding schemes. We apply our achievability to two cases. First, we
characterize the capacity region of a class of discrete memoryless interference
relay channels. This class naturally generalizes the injective deterministic
discrete memoryless interference channel by El Gamal and Costa and the
deterministic discrete memoryless relay channel with orthogonal receiver
components by Kim. Moreover, for the Gaussian interference relay channel with
orthogonal receiver components, we show that our scheme achieves a better sum
rate than that of noisy network coding.Comment: 18 pages, 4 figure
An Achievable Rate Region for Three-Pair Interference Channels with Noise
An achievable rate region for certain noisy three-user-pair interference
channels is proposed. The channel class under consideration generalizes the
three-pair deterministic interference channel (3-DIC) in the same way as the
Telatar-Tse noisy two-pair interference channel generalizes the El Gamal-Costa
injective channel. Specifically, arbitrary noise is introduced that acts on the
combined interference signal before it affects the desired signal. This class
of channels includes the Gaussian case.
The rate region includes the best-known inner bound on the 3-DIC capacity
region, dominates treating interference as noise, and subsumes the
Han-Kobayashi region for the two-pair case.Comment: 9 pages, 3 figures; abbreviated version to be presented at IEEE
International Symposium on Information Theory (ISIT 2012
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