Abstract
We consider the problem of multiterminal source-channel communication where a number of distributed and possibly correlated sources are transmitted through an orthogonal multiple access channel to a common destination. We provide a characterization of the optimal tradeoff between the transmission cost Γ and the distortion vector D as measured against individual sources. Our approach consists of two steps: 1) a multiple-letter characterization of the rate-distortion region of the multiterminal source coding and 2) a source-channel separation theorem ensuring that all achievable pairs of (Γ, D) can be obtained by combining the rate-distortion region and the orthogonal multiple access channel capacity region. As a corollary, we determine the optimal power and distortion tradeoff in a quadratic Gaussian sensor network under orthogonal multiple access, and show that separate source and channel coding strictly outperforms the uncoded (amplify-forward) transmission, and is in fact optimal in this case. This result is in sharp contrast to the case of nonorthogonal multiple access for which separate source and channel coding is not only suboptimal but also strictly inferior to uncoded transmission.
Original language | English (US) |
---|---|
Pages (from-to) | 3255-3264 |
Number of pages | 10 |
Journal | IEEE Transactions on Information Theory |
Volume | 53 |
Issue number | 9 |
DOIs | |
State | Published - 2007 |
Bibliographical note
Funding Information:Manuscript received November 8, 2005; revised February 27, 2007. This work was supported in part by the National Science Foundation under Grant DMS-0610037 and by the USDOD ARMY under Grant W911NF-05-1-0567. The authors are with the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 USA (e-mail: xiao@ece. umn.edu; luozq@ece.umn.edu). Communicated by R. R. Müller, Associate Editor for Communications. Color versions of Figures 1–3, 5, and 6 in this correspondence are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TIT.2007.903142
Keywords
- Gaussian sensor networks
- Multiterminal source coding
- Rate-distortion region
- Source-channel separation theorem
- Uncoded transmission