DMCA
Wireless Network Information Flow: A Deterministic Approach (2009)
| Citations: | 292 - 42 self |
BibTeX
@MISC{Avestimehr09wirelessnetwork,
author = {A. Salman Avestimehr and et al.},
title = { Wireless Network Information Flow: A Deterministic Approach},
year = {2009}
}
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Abstract
In contrast to wireline networks, not much is known about the flow of information over wireless networks. The main barrier is the complexity of the signal interaction in wireless channels in addition to the noise in the channel. A widely accepted model is the the additive Gaussian channel model, and for this model, the capacity of even a network with a single relay node is open for 30 years. In this paper, we present a deterministic approach to this problem by focusing on the signal interaction rather than the noise. To this end, we propose a deterministic channel model which is analytically simpler than the Gaussian model but still captures two key wireless channel properties of broadcast and superposition. We consider a model for a wireless relay network with nodes connected by such deterministic channels, and present an exact characterization of the end-to-end capacity when there is a single source and one or more destinations (all interested in the same information) and an arbitrary number of relay nodes. This result is a natural generalization of the celebrated max-flow min-cut theorem for wireline networks. We then use the insights obtained from the analysis of the deterministic model to study information flow for the Gaussian wireless relay network. We present an achievable rate for general Gaussian relay networks and show that it is within a constant number of bits from the cut-set bound on the capacity of these networks. This constant depends on the number of nodes in the network, but not the values of the channel gains or the signal-to-noise ratios. We show that existing strategies cannot achieve such a constant-gap approximation for arbitrary networks and propose a new quantizemap-and-forward scheme that does. We also give several extensions of the approximation framework including robustness results (through compound channels), half-duplex constraints and ergodic channel variations.
Keyphrases
deterministic approach wireless network information flow signal interaction constant number exact characterization end-to-end capacity deterministic model general gaussian relay network approximation framework gaussian model ergodic channel variation signal-to-noise ratio robustness result new quantizemap-and-forward scheme arbitrary number single relay node wireless network gaussian wireless relay network arbitrary network constant-gap approximation deterministic channel model information flow relay node single source celebrated max-flow min-cut theorem several extension main barrier wireless channel cut-set bound natural generalization deterministic channel wireless relay network additive gaussian channel model channel gain achievable rate wireline network key wireless channel property half-duplex constraint compound channel
