Degrees of freedom of wireless networks - What a difference delay makes

Viveck R. Cadambe, Syed A. Jafar

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

39 Scopus citations

Abstract

We explore the impact of propagation delay on the degrees of freedom of wireless interference networks. For K > 2 user interference channel we show through an example that propagation delays can increase the degrees of freedom by upto a factor of K/2. We provide an example of node placement for a 4 user interference network such that the propagation delays for line-ofsight communication allow perfect interference alignment. We show that even if nodes are randomly placed, one can almost surely achieve sufficient interference alignment to approach the upperbound on the degrees of freedom by choosing the basic symbol duration small enough. An analogy with deterministic channel models is pointed out as an interesting mechanism to translate propagation delay based interference alignment schemes to delay-free Gaussian channel models.

Original languageEnglish (US)
Title of host publicationConference Record of the 41st Asilomar Conference on Signals, Systems and Computers, ACSSC
Pages133-137
Number of pages5
DOIs
StatePublished - Dec 1 2007
Event41st Asilomar Conference on Signals, Systems and Computers, ACSSC - Pacific Grove, CA, United States
Duration: Nov 4 2007Nov 7 2007

Publication series

NameConference Record - Asilomar Conference on Signals, Systems and Computers
ISSN (Print)1058-6393

Other

Other41st Asilomar Conference on Signals, Systems and Computers, ACSSC
CountryUnited States
CityPacific Grove, CA
Period11/4/0711/7/07

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All Science Journal Classification (ASJC) codes

  • Signal Processing
  • Computer Networks and Communications

Cite this

Cadambe, V. R., & Jafar, S. A. (2007). Degrees of freedom of wireless networks - What a difference delay makes. In Conference Record of the 41st Asilomar Conference on Signals, Systems and Computers, ACSSC (pp. 133-137). [4487180] (Conference Record - Asilomar Conference on Signals, Systems and Computers). https://doi.org/10.1109/ACSSC.2007.4487180