Opportunistic multichannel aloha: Distributed multiaccess control scheme for OFDMA wireless networks

Kai Bai, Junshan Zhang

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


The authors consider multiaccess control for the uplink in orthogonal-frequency-division-multiple-access wireless networks, where subcarriers are grouped into clusters. A multichannel random access, based on local channel state information (CSI), was investigated, and an opportunistic multichannel Aloha (OMC-Aloha) was proposed accordingly. A key step is to build a mapping from a user's CSI to its transmission probability and subcarrier allocation. For the sake of comparison, the throughput of the optimal centralized scheduling was also characterized by using the Extreme-Value Theory of order statistics. The authors show that the OMC-Aloha is asymptotically order optimal, in the sense that the only performance loss compared to the optimal centralized scheduling is due to the contention inherent in random access. In addition, they examine the proportional fairness in heterogeneous systems.

Original languageEnglish (US)
Pages (from-to)848-855
Number of pages8
JournalIEEE Transactions on Vehicular Technology
Issue number3
StatePublished - May 2006


  • Distributed multiaccess control
  • Diversity
  • Fading channel
  • Multichannel aloha
  • Orthogonal frequency division multiple access (OFDMA)

ASJC Scopus subject areas

  • Automotive Engineering
  • Aerospace Engineering
  • Electrical and Electronic Engineering
  • Applied Mathematics


Dive into the research topics of 'Opportunistic multichannel aloha: Distributed multiaccess control scheme for OFDMA wireless networks'. Together they form a unique fingerprint.

Cite this