Adaptively induced fluctuations for multiuser diversity: Two-dimensional parameters and cellular interference

Rahul Dangui, Bruce Hajek

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


This study extends recent work on using adaptive phase fluctuations to enhance multiuser diversity in the downlink of a cellular network. Feedback at the base station is limited and Rayleigh fading is assumed. Our main findings are presented along three main axes. First, we study a single-cell environment with adaptive fluctuations induced between multiple transmit antennae at the base station. Phase fluctuations of three transmit antennae are induced based on a two-dimensional mapping of their relative phases. A modest improvement of about 0.3 dB is obtained over the twoantennae case. Second, we take into account the effects of intercell interference. The effect of neighboring cells using the same transmission frequency and executing the same adaptive algorithm is accounted for. Our simulations and analysis probe the consequences of the fact that intercell interference noise is burstier than thermal noise.We find that asymptotically, as the number of users converges to infinity, the interference from a single interfering base station does not decrease the throughput. However, for moderate number of users, even if the interference is from one base station (burstiest interference), the effect of interference is nearly as bad as thermal noise with equivalent power. The performance is also observed to be insensitive to the phase variation strategy of the interfering station. Third, fairness issues are taken into account. We observe that fairness decreases throughput but we still observe a multiuser diversity gain.

Original languageEnglish (US)
Title of host publicationVTC 2005-Fall
Subtitle of host publicationMid Way Through the Decade - Technology Past, Present and Future
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages5
ISBN (Electronic)0780391527
StatePublished - 2005
Event62nd Vehicular Technology Conference, VTC 2005 - Dallas, United States
Duration: Sep 25 2005Sep 28 2005

Publication series

NameIEEE Vehicular Technology Conference
ISSN (Print)1550-2252


Other62nd Vehicular Technology Conference, VTC 2005
Country/TerritoryUnited States


  • Fairness mechanisms
  • Intercell interference
  • Monte Carlo simulations
  • Multiple antennae
  • Multiuser diversity
  • Power control
  • Propagation
  • Rayleigh fading channels
  • Scheduling algorithms
  • Wireless communications

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics


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