In this paper, we study a Gaussian relay-interference network, in which relay (helper) nodes are to facilitate competing information flows between different source-destination pairs. We focus on two-stage relay-interference networks where there are weak cross links, causing the networks to behave like a chain of Z Gaussian channels. Our main result is an approximate characterization of the capacity region for such ZZand ZS networks. We propose a new interference management scheme, termed interference neutralization, which is implemented using structured lattice codes. This scheme allows for over-the-air interference removal, without the transmitters having complete access the interfering signals. This scheme in conjunction a new network decomposition technique provides the approximate characterization. Our analysis of these Gaussian networks is based on insights gained from an exact characterization of the corresponding linear deterministic model.
Bibliographical noteFunding Information:
Manuscript received May 01, 2010; revised October 15, 2010; accepted January 12, 2011. Date of current version April 20, 2011. S. Mohajer and C. Fragouli were supported in part by the ERC Starting Investigator Grant 240317. D. N. C. Tse was supported in part by the U.S. NSF under grant CCF-0830796. The material in this paper was presented in part at the IEEE International Symposium on Information Theory (ISIT), Seoul, South Korea, July 2009.
- Deterministic model
- Gaussian wireless network
- interference neutralization
- lattice codes
- relay-interference network
- structured codes