Change search
ReferencesLink to record
Permanent link

Direct link
Pilot-assisted ergodic interference alignment for wireless networks
KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.ORCID iD: 0000-0001-9853-2977
KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.ORCID iD: 0000-0002-7926-5081
2014 (English)Conference paper (Refereed)
Abstract [en]

This paper considers the ergodic block fading multi-user Gaussian interference channel (IC) in which each source desires to communicate to an intended destination. We assume that there is no CSI a priori available at terminals. We develop achievable rate results and compute the associated degrees of freedom by using a pilot-assisted interference alignment scheme. In this scheme, each source first sends known pilot symbols via which the destinations estimate channel gains,  and the destinations then broadcast the estimated channel gains via orthogonal feedback channels. The estimated channel gains are used to perform interference alignment for data transmission. The pilot transmission power can be different from the data transmission power. By allocating more power to pilot transmission, channel gains can be estimated more accurately which implies less power left for data transmission. We find the optimum power allocation to pilot symbols and data symbols. Our study recommends, in large networks, to allocate more power to channel training instead of data transmission. In addition, our results reveal that for a K-user ergodic IC with a coherence time T, the total degrees of freedom 1/2Kopt(1-Kopt/T) is achievable, where Kopt=min{K,T/2} is the optimum number of users selected to be active in the network. This recommends to perform a user selection in large networks (K>T/2), and apply channel training and interference alignment within the set of selected users.

Place, publisher, year, edition, pages
2014. -6190 p.
, International Conference on Acoustics Speech and Signal Processing ICASSP, 1520-6149
Keyword [en]
Interference alignment, pilot, training, channel estimation, power control
National Category
Communication Systems Signal Processing Telecommunications
Research subject
URN: urn:nbn:se:kth:diva-143784DOI: 10.1109/ICASSP.2014.6854793ISI: 000343655306044ScopusID: 2-s2.0-84905270226ISBN: 978-1-4799-2893-4ISBN: 978-147992892-7OAI: diva2:708661
2014 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2014; Florence; Italy; 4 May 2014 through 9 May 2014

QC 20150123

Available from: 2014-03-28 Created: 2014-03-28 Last updated: 2015-01-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Farhadi, HamedSkoglund, Mikael
By organisation
Communication TheoryACCESS Linnaeus Centre
Communication SystemsSignal ProcessingTelecommunications

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 188 hits
ReferencesLink to record
Permanent link

Direct link