Variable-rate variable-power MQAM for fading channels

Soon Ghee Chua, Andrea Goldsmith

Research output: Contribution to journalConference articlepeer-review

69 Scopus citations


We propose a variable power and rate adaptive MQAM modulation scheme for high-speed data transmission on fading channels. We show that using just five or six different signal constellations achieves within 1-2 dB of the maximum spectral efficiency. We also obtain the exact efficiency loss for a smaller constellation set. In addition, we compare our technique with a fixed-rate scheme which inverts the channel fading. Assuming perfect power control, the fixed-rate scheme exhibits a 5-10 dB loss in spectral efficiency relative to our adaptive technique. We conclude by discussing performance degradation caused by channel measurement errors.

Original languageEnglish (US)
Pages (from-to)815-819
Number of pages5
JournalIEEE Vehicular Technology Conference
StatePublished - 1996
Externally publishedYes
EventProceedings of the 1996 IEEE 46th Vehicular Technology Conference. Part 1 (of 3) - Atlanta, GA, USA
Duration: Apr 28 1996May 1 1996

All Science Journal Classification (ASJC) codes

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


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