Exact performance analysis of hybrid adaptive modulation schemes in multi-channel system

Sang Do Lee, Young-Chai Ko

Research output: Contribution to journalArticle

3 Citations (Scopus)


In this paper, we analyze the performance of a multi-channel system with the conventional adaptive modulation (AM) and two hybrid schemes, the adaptive modulation with diversity combining (AMDC) and the adaptive modulation with power loading (AMPL), respectively. In order to achieve higher spectral efficiency and more efficient usage of channel resources under the total transmit power constraint and the required bit error rate (BER), the AMDC jointly uses discrete-rate adaptation and diversity combining scheme, and the AMPL jointly uses discrete-rate adaptation and sub-optimal discrete-power loading. We derive exact closed-form expressions of the performance of a multi-channel system with the conventional adaptive modulation (AM) and these hybrid schemes, in terms of the spectral efficiency, the average BER and the outage probability. We also analyze the impact of imperfect channel estimation on the error performance and validate our analytical results by simulations. Numerical results show that both the AMDC and the AMPL offer higher spectral efficiency than the conventional AM, assuming the perfect channel estimation. However, AMDC offers better performance and reliability than AMPL, under imperfect channel estimation with complex Gaussian error.

Original languageEnglish
Article number5090001
Pages (from-to)3206-3215
Number of pages10
JournalIEEE Transactions on Wireless Communications
Issue number6
Publication statusPublished - 2009 Jun 1



  • Adaptive modulation
  • And channel estimation error
  • Diversity
  • Multi-channel systems
  • Power loading

ASJC Scopus subject areas

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

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