4,214 research outputs found
The Arbitrarily Varying Broadcast Channel with Degraded Message Sets with Causal Side Information at the Encoder
In this work, we study the arbitrarily varying broadcast channel (AVBC), when
state information is available at the transmitter in a causal manner. We
establish inner and outer bounds on both the random code capacity region and
the deterministic code capacity region with degraded message sets. The capacity
region is then determined for a class of channels satisfying a condition on the
mutual informations between the strategy variables and the channel outputs. As
an example, we consider the arbitrarily varying binary symmetric broadcast
channel with correlated noises. We show cases where the condition holds, hence
the capacity region is determined, and other cases where there is a gap between
the bounds.Comment: arXiv admin note: substantial text overlap with arXiv:1701.0334
On AVCs with Quadratic Constraints
In this work we study an Arbitrarily Varying Channel (AVC) with quadratic
power constraints on the transmitter and a so-called "oblivious" jammer (along
with additional AWGN) under a maximum probability of error criterion, and no
private randomness between the transmitter and the receiver. This is in
contrast to similar AVC models under the average probability of error criterion
considered in [1], and models wherein common randomness is allowed [2] -- these
distinctions are important in some communication scenarios outlined below.
We consider the regime where the jammer's power constraint is smaller than
the transmitter's power constraint (in the other regime it is known no positive
rate is possible). For this regime we show the existence of stochastic codes
(with no common randomness between the transmitter and receiver) that enables
reliable communication at the same rate as when the jammer is replaced with
AWGN with the same power constraint. This matches known information-theoretic
outer bounds. In addition to being a stronger result than that in [1] (enabling
recovery of the results therein), our proof techniques are also somewhat more
direct, and hence may be of independent interest.Comment: A shorter version of this work will be send to ISIT13, Istanbul. 8
pages, 3 figure
Multiaccess Channels with State Known to Some Encoders and Independent Messages
We consider a state-dependent multiaccess channel (MAC) with state
non-causally known to some encoders. We derive an inner bound for the capacity
region in the general discrete memoryless case and specialize to a binary
noiseless case. In the case of maximum entropy channel state, we obtain the
capacity region for binary noiseless MAC with one informed encoder by deriving
a non-trivial outer bound for this case. For a Gaussian state-dependent MAC
with one encoder being informed of the channel state, we present an inner bound
by applying a slightly generalized dirty paper coding (GDPC) at the informed
encoder that allows for partial state cancellation, and a trivial outer bound
by providing channel state to the decoder also. The uninformed encoders benefit
from the state cancellation in terms of achievable rates, however, appears that
GDPC cannot completely eliminate the effect of the channel state on the
achievable rate region, in contrast to the case of all encoders being informed.
In the case of infinite state variance, we analyze how the uninformed encoder
benefits from the informed encoder's actions using the inner bound and also
provide a non-trivial outer bound for this case which is better than the
trivial outer bound.Comment: Accepted to EURASIP Journal on Wireless Communication and Networking,
Feb. 200
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