On the achievable degrees of freedom of partially cooperative X networks with delayed CSIT
2012 (English)In: 2012 IEEE Global Communications Conference (GLOBECOM), New York: IEEE , 2012, 2450-2454 p.Conference paper (Refereed)
We investigate the achievable degrees of freedom (DoF) in K-user X networks (K × K X networks) with delayed channel state information at transmitters (CSIT), where partial cooperation (i.e. message sharing) is potentially allowed among transmitters. We consider two possible cooperation scenarios. In the first scenario one of the transmitters serves as a super node which can obtain the messages of the other transmitters. By proper interference alignment (IA) design, we prove that a DoF 2K over K+1 can be achieved almost surely. In the second scenario, there is no super node but each transmitter shares its message to its left-side neighbor. We show that when K = 3, DoF 7 over 5 is achievable. In both cases, the achieved DoF are shown to be improved compared with non-cooperative X networks. Moreover, we use a simple example to show that sharing a subset of messages may also improve DoF.
Place, publisher, year, edition, pages
New York: IEEE , 2012. 2450-2454 p.
, IEEE Global Telecommunications Conference (Globecom), ISSN 1930-529X
Delayed CSIT, Interference alignment, Non-cooperative, Partial cooperation, Supernodes
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-105503DOI: 10.1109/GLOCOM.2012.6503484ISI: 000322375102134ScopusID: 2-s2.0-84877682511ISBN: 978-146730921-9OAI: oai:DiVA.org:kth-105503DiVA: diva2:571189
2012 IEEE Global Communications Conference, GLOBECOM 2012; Anaheim, CA; United States; 3 December 2012 through 7 December 2012
FunderICT - The Next Generation
QC 201212072012-12-072012-11-212013-11-28Bibliographically approved