A novel broadband MIMO/OFDM system using adaptive modulation and adaptive diversity

Yahan Pan, Khaled Letaief, Zhigang Cao, Yonghong Qiu

Research output: Contribution to journalArticle

1 Citation (Scopus)


OFDM (Orthogonal frequency division multiplexing) has been widely regarded as an effective modulation technique for mitigating the effects of ISI in a frequency selective fading channel and for providing reliable high-data transmission over wireless links. Adaptive modulation combined with adaptive transmit and receive diversity can achieve further increases in system's capacity and bandwidth efficiency, as well as in QoS improvement in conventional OFDM systems. In this paper, we propose a novel broadband MIMO/ OFDM system using adaptive modulation and adaptive transmit and receive diversity. By applying an EVD on each sub-carrier channel matrix, joint optimal transmit and receive antenna weights as well as maximal SNR on each sub-carrier are obtained. Then, by employing adaptive modulation on each sub-carrier, the maximal SNR on each sub-carrier obtained by adaptive transmit and receive diversity is further maximized through adaptive bit assignment and power assignment on each sub-carrier under the constraint of power and overall bit rate. Simulation results show that the proposed system can achieve better performance than an adaptive antenna array based OFDM system without adaptive modulation over multipath fading channels.

Original languageEnglish
Pages (from-to)384-388
Number of pages5
JournalChinese Journal of Electronics
Issue number3
Publication statusPublished - Jul 2005
Externally publishedYes



  • Adaptive antenna arrays
  • Adaptive modulation
  • Joint transmit and receive diversity
  • MIMO/OFDM (Multi input multi output/Orthogonal frequency division multiplexing)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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