An efficient resource-allocation scheme for spatial multiuser access in MIMO/OFDM systems

Ying Jun Zhang, Khaled Ben Letaief

Research output: Contribution to journalArticle

187 Citations (Scopus)


Fast adaptive transmission has been recently identified as a key technology for exploiting potential system diversity and improving power-spectral efficiency in wireless communication systems. In this paper, an adaptive resource-allocation approach, which jointly adapts subcarrier allocation, power distribution, and bit distribution according to instantaneous channel conditions, is proposed for multiuser multiple-input multiple-output (MIMO)/orthogonal frequency-division multiplexing systems. The resultant scheme is able to: 1) optimize the power efficiency; 2) guarantee each user's quality of service requirements, including bit-error rate and data rate; 3) ensure fairness to all the active users; and 4) be applied to systems with various types of multiuser-detection schemes at the receiver. For practical implementation, a reduced-complexity allocation algorithm is developed. This algorithm decouples the complex multiuser joint resource-allocation problem into simple single-user optimization problems by controlling the subcarrier sharing according to the users' spatial separability. Numerical results show that significant power and diversity gains are achievable, compared with non-adaptive systems. It is also demonstrated that the MIMO system is able to multiplex several users without sacrificing antenna diversity by using the proposed algorithm.

Original languageEnglish
Pages (from-to)107-116
Number of pages10
JournalIEEE Transactions on Communications
Issue number1
Publication statusPublished - 1 Jan 2005



  • Adaptive resource allocation
  • Multiple-input multiple-output (MIMO)
  • Multiuser detection (MUD)
  • Orthogonal frequency-division multiplexing (OFDM)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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