34,851 research outputs found
Joint Network and Gelfand-Pinsker Coding for 3-Receiver Gaussian Broadcast Channels with Receiver Message Side Information
The problem of characterizing the capacity region for Gaussian broadcast
channels with receiver message side information appears difficult and remains
open for N >= 3 receivers. This paper proposes a joint network and
Gelfand-Pinsker coding method for 3-receiver cases. Using the method, we
establish a unified inner bound on the capacity region of 3-receiver Gaussian
broadcast channels under general message side information configuration. The
achievability proof of the inner bound uses an idea of joint interference
cancelation, where interference is canceled by using both dirty-paper coding at
the encoder and successive decoding at some of the decoders. We show that the
inner bound is larger than that achieved by state of the art coding schemes. An
outer bound is also established and shown to be tight in 46 out of all 64
possible cases.Comment: Author's final version (presented at the 2014 IEEE International
Symposium on Information Theory [ISIT 2014]
Harnessing Bursty Interference in Multicarrier Systems with Feedback
We study parallel symmetric 2-user interference channels when the
interference is bursty and feedback is available from the respective receivers.
Presence of interference in each subcarrier is modeled as a memoryless
Bernoulli random state. The states across subcarriers are drawn from an
arbitrary joint distribution with the same marginal probability for each
subcarrier and instantiated i.i.d. over time. For the linear deterministic
setup, we give a complete characterization of the capacity region. For the
setup with Gaussian noise, we give outer bounds and a tight generalized degrees
of freedom characterization. We propose a novel helping mechanism which enables
subcarriers in very strong interference regime to help in recovering interfered
signals for subcarriers in strong and weak interference regimes. Depending on
the interference and burstiness regime, the inner bounds either employ the
proposed helping mechanism to code across subcarriers or treat the subcarriers
separately. The outer bounds demonstrate a connection to a subset entropy
inequality by Madiman and Tetali.Comment: A shorter version of this work will appear in the proceedings of ISIT
201
Multiaccess Channels with State Known to One Encoder: Another Case of Degraded Message Sets
We consider a two-user state-dependent multiaccess channel in which only one
of the encoders is informed, non-causally, of the channel states. Two
independent messages are transmitted: a common message transmitted by both the
informed and uninformed encoders, and an individual message transmitted by only
the uninformed encoder. We derive inner and outer bounds on the capacity region
of this model in the discrete memoryless case as well as the Gaussian case.
Further, we show that the bounds for the Gaussian case are tight in some
special cases.Comment: 5 pages, Proc. of IEEE International Symposium on Information theory,
ISIT 2009, Seoul, Kore
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