8 research outputs found
Empirical Coordination with Channel Feedback and Strictly Causal or Causal Encoding
In multi-terminal networks, feedback increases the capacity region and helps
communication devices to coordinate. In this article, we deepen the
relationship between coordination and feedback by considering a point-to-point
scenario with an information source and a noisy channel. Empirical coordination
is achievable if the encoder and the decoder can implement sequences of symbols
that are jointly typical for a target probability distribution. We investigate
the impact of feedback when the encoder has strictly causal or causal
observation of the source symbols. For both cases, we characterize the optimal
information constraints and we show that feedback improves coordination
possibilities. Surprisingly, feedback also reduces the number of auxiliary
random variables and simplifies the information constraints. For empirical
coordination with strictly causal encoding and feedback, the information
constraint does not involve auxiliary random variable anymore.Comment: 5 pages, 6 figures, presented at IEEE International Symposium on
Information Theory (ISIT) 201
Information Design for Strategic Coordination of Autonomous Devices with Non-Aligned Utilities
In this paper, we investigate the coordination of autonomous devices with
non-aligned utility functions. Both encoder and decoder are considered as
players, that choose the encoding and the decoding in order to maximize their
long-run utility functions. The topology of the point-to-point network under
investigation, suggests that the decoder implements a strategy, knowing in
advance the strategy of the encoder. We characterize the encoding and decoding
functions that form an equilibrium, by using empirical coordination. The
equilibrium solution is related to an auxiliary game in which both players
choose some conditional distributions in order to maximize their expected
utilities. This problem is closely related to the literature on "Information
Design" in Game Theory. We also characterize the set of posterior distributions
that are compatible with a rate-limited channel between the encoder and the
decoder. Finally, we provide an example of non-aligned utility functions
corresponding to parallel fading multiple access channels.Comment: IEEE Proc. of the Fifty-fourth Annual Allerton Conference Allerton
House, UIUC, Illinois, USA September 27 - 30, 201
Strong Coordination over Multi-hop Line Networks
We analyze the problem of strong coordination over a multi-hop line network
in which the node initiating the coordination is a terminal network node. We
assume that each node has access to a certain amount of randomness that is
local to the node, and that the nodes share some common randomness, which are
used together with explicit hop-by-hop communication to achieve strong
coordination. We derive the trade-offs among the required rates of
communication on the network links, the rates of local randomness available to
network nodes, and the rate of common randomness to realize strong
coordination. We present an achievable coding scheme built using multiple
layers of channel resolvability codes, and establish several settings in which
this scheme is proven to offer the best possible trade-offs.Comment: 35 pages, 9 Figures, 4 Tables. A part of this work were published in
the 2015 IEEE Information Theory Workshop, and a part was accepted for
publication in the 50th Annual Conference on Information Sciences and System
State Leakage and Coordination of Actions: Core of the Receiver's Knowledge
We revisit the problems of state masking and state amplification through the
lens of empirical coordination by considering a state-dependent channel in
which the encoder has causal and strictly causal state knowledge. We show that
the problem of empirical coordination provides a natural framework in which to
jointly study the problems of reliable communication, state masking, and state
amplification. We characterize the regions of rate-equivocation-coordination
trade-offs for several channel models with causal and strictly causal state
knowledge. We introduce the notion of `core of the receiver's knowledge' to
capture what the decoder can infer about all the signals involved in the model.
We exploit this result to solve a channel state estimation zero-sum game in
which the encoder prevents the decoder to estimate the channel state
accurately.Comment: preliminary draf
Joint Empirical Coordination of Source and Channel
In a decentralized and self-configuring network, the communication devices
are considered as autonomous decision-makers that sense their environment and
that implement optimal transmission schemes. It is essential that these
autonomous devices cooperate and coordinate their actions, to ensure the
reliability of the transmissions and the stability of the network. We study a
point-to-point scenario in which the encoder and the decoder implement
decentralized policies that are coordinated. The coordination is measured in
terms of empirical frequency of symbols of source and channel. The encoder and
the decoder perform a coding scheme such that the empirical distribution of the
symbols is close to a target joint probability distribution. We characterize
the set of achievable target probability distributions for a point-to-point
source-channel model, in which the encoder is non-causal and the decoder is
strictly causal i.e., it returns an action based on the observation of the past
channel outputs. The objectives of the encoder and of the decoder, are captured
by some utility function, evaluated with respect to the set of achievable
target probability distributions. In this article, we investigate the
maximization problem of a utility function that is common to both encoder and
decoder. We show that the compression and the transmission of information are
particular cases of the empirical coordination.Comment: accepted to IEEE Trans. on I