Degrees of freedom (DoF) of locally connected interference channels with cooperating multiple-antenna transmitters

Aly El Gamal, V. Sreekanth Annapureddy, Venugopal V. Veeravalli

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We consider locally connected K-user MISO interference channels where each transmitter has N antennas and is connected to the receiver with the same index as well as [L/2] successively preceding receivers and [L/2] following receivers. We assume that each receiver is interested in one message, which can be available at a maximum of M transmitters. Under these assumptions, we study the available degrees of freedom as well as the optimal way to assign messages to transmitters. For the case where each message is assigned to the transmitter with the same index, we know from [1] that [KN/N+1] DoF is achievable for the considered locally connected channel using interference alignment as the number of symbol extensions goes to infinity. In this work, we show that a simple linear strategy employing zero forcing transmit beams achieves min {2MN/M(N+1)+L, 1} per user degrees of freedom. In particular, the N/N+1 per user DoF is achievable by coding over only one channel realization, for any value of M ≥ L/N+1. Moreover, we show that the proposed scheme is optimal among a class of linear strategies where each receiver is either inactive or enjoys interference-free communication. Finally, we generalize the upper bound proved for Wyner's asymmetric channel model (L = 1) in [2], and show that message assignments satisfying a local cooperation constraint are optimal for a general setting of the parameters.

Original languageEnglish (US)
Title of host publication2012 IEEE International Symposium on Information Theory Proceedings, ISIT 2012
Pages1538-1542
Number of pages5
DOIs
StatePublished - Oct 22 2012
Event2012 IEEE International Symposium on Information Theory, ISIT 2012 - Cambridge, MA, United States
Duration: Jul 1 2012Jul 6 2012

Publication series

NameIEEE International Symposium on Information Theory - Proceedings

Other

Other2012 IEEE International Symposium on Information Theory, ISIT 2012
CountryUnited States
CityCambridge, MA
Period7/1/127/6/12

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Information Systems
  • Modeling and Simulation
  • Applied Mathematics

Fingerprint Dive into the research topics of 'Degrees of freedom (DoF) of locally connected interference channels with cooperating multiple-antenna transmitters'. Together they form a unique fingerprint.

Cite this