4,598 research outputs found
On lossy transmission of correlated sources over a multiple access channel
We study lossy communication of correlated sources over a multiple access channel. In particular, we provide a joint source-channel coding scheme for transmitting correlated sources with decoder side information, and study the conditions under which separate source and channel coding is optimal. For the latter, the encoders and/or the decoder have access to a common observation conditioned on which the two sources are independent. By establishing necessary and sufficient conditions, we show the optimality of separation when the encoders and the decoder both have access to the common observation. We also demonstrate that separation is optimal when only the encoders have access to the common observation whose lossless recovery is required at the decoder. As a special case, we study separation for sources with a common part. Our results indicate that side information can have significant impact on the optimality of source-channel separation in lossy transmission
Lossy Source Transmission over the Relay Channel
Lossy transmission over a relay channel in which the relay has access to
correlated side information is considered. First, a joint source-channel
decode-and-forward scheme is proposed for general discrete memoryless sources
and channels. Then the Gaussian relay channel where the source and the side
information are jointly Gaussian is analyzed. For this Gaussian model, several
new source-channel cooperation schemes are introduced and analyzed in terms of
the squared-error distortion at the destination. A comparison of the proposed
upper bounds with the cut-set lower bound is given, and it is seen that joint
source-channel cooperation improves the reconstruction quality significantly.
Moreover, the performance of the joint code is close to the lower bound on
distortion for a wide range of source and channel parameters.Comment: Proceedings of the 2008 IEEE International Symposium on Information
Theory, Toronto, ON, Canada, July 6 - 11, 200
Joint Source-Channel Coding over a Fading Multiple Access Channel with Partial Channel State Information
In this paper we address the problem of transmission of correlated sources
over a fast fading multiple access channel (MAC) with partial channel state
information available at both the encoders and the decoder. We provide
sufficient conditions for transmission with given distortions. Next these
conditions are specialized to a Gaussian MAC (GMAC). We provide the optimal
power allocation strategy and compare the strategy with various levels of
channel state information.
Keywords: Fading MAC, Power allocation, Partial channel state information,
Correlated sources.Comment: 7 Pages, 3 figures. To Appear in IEEE GLOBECOM, 200
- …