Lattice Coding Increases Multicast Rates for Gaussian Multiple-Access Networks
Proceedings of 45th Annual Allerton Conference on Commununication, Control and Computation, Monticello, IL, September 2007.
Download
Adobe Portable Document Format - [PDF]
Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder.
Abstract
We study the multicasting problem for additive white Gaussian noise (AWGN) networks with both point-to-point and multiple-access links. The recent discovery of network coding has shown that routing is suboptimal for networks of point-to-point channels: messages must be mixed at intermediate nodes. We showed in earlier work that if a network includes multiple-access channels (MACs) then converting these channels into bit pipes with a channel-network separation-based approach is also suboptimal: the MACs should be used to compute functions reliably as part of an overall network code. In this paper, we give a lattice-based coding strategy for reliably computing linear functions over Gaussian MACs. We then give a computable statement of rates achieved by the resulting network code. In many interesting cases, our achieved rates are higher than those accessible to a separation-based scheme. Our results show that structured codes can be used to derive achievable rates for multi-user communication problems that have been outside the reach of standard i.i.d. random coding arguments.
Reference
B. Nazer and M. Gastpar, Lattice Coding Increases Multicast Rates for Gaussian Multiple-Access Networks. Proceedings of the 45th Annual Allerton Conference on Commununication, Control and Computation, Monticello, IL, September 2007.
BibTeX
@INPROCEEDINGS(bn_mg_allerton07, AUTHOR = "B.~Nazer and M.~Gastpar", TITLE = " Lattice Coding Increases Multicast Rates for Gaussian Multiple-Access Networks", BOOKTITLE = "Proceedings of 45th Annual Allerton Conference on Commununication, Control and Computation", MONTH = "September", ADDRESS = "Monticello, IL", YEAR = "2007")