2 research outputs found
On the Multiple Access Channel with Asynchronous Cognition
In this paper we introduce the two-user asynchronous cognitive multiple
access channel (ACMAC). This channel model includes two transmitters, an
uninformed one, and an informed one which knows prior to the beginning of a
transmission the message which the uninformed transmitter is about to send. We
assume that the channel from the uninformed transmitter to the receiver suffers
a fixed but unknown delay. We further introduce a modified model, referred to
as the asynchronous codeword cognitive multiple access channel (ACC-MAC), which
differs from the ACMAC in that the informed user knows the signal that is to be
transmitted by the other user, rather than the message that it is about to
transmit. We state inner and outer bounds on the ACMAC and the ACC-MAC capacity
regions, and we specialize the results to the Gaussian case. Further, we
characterize the capacity regions of these channels in terms of multi-letter
expressions. Finally, we provide an example which instantiates the difference
between message side-information and codeword side-information.Comment: arXiv admin note: substantial text overlap with arXiv:1402.161
Asynchronous Transmission over Single-User State-Dependent Channels
Several channels with asynchronous side information are introduced. We first
consider single-user state-dependent channels with asynchronous side
information at the transmitter. It is assumed that the state information
sequence is a possibly delayed version of the state sequence, and that the
encoder and the decoder are aware of the fact that the state information might
be delayed. It is additionally assumed that an upper bound on the delay is
known to both encoder and decoder, but other than that, they are ignorant of
the actual delay. We consider both the causal and the noncausal cases and
present achievable rates for these channels, and the corresponding coding
schemes. We find the capacity of the asynchronous Gel'fand-Pinsker channel with
feedback. Finally, we consider a memoryless state dependent channel with
asynchronous side information at both the transmitter and receiver, and
establish a single-letter expression for its capacity.Comment: The paper "On channels with asynchronous side information" was split
into two separate papers: the enclosed paper which considers only
point-to-point channels and an additional paper named "On the multiple access
channel with asynchronous cognition" which discusses the multiuser setup