M-QAM Modem Verification

Abstract

The objective of this program was to verify the technical feasibility of the variable mode M-ary Quadrature Amplitude Modulation (M-QAM) concepts. Specifically, the adaptive predistortion and baseband equalizer techniques were to be breadboarded and evaluated for M-QAM modes for M = 4, 16, and 64. The breadboard was to operate within the constraints of FCC docket 19311 and achieve spectral efficiencies of 1.5, 3.0, and 4.5 bits/sec/Hz for M = 4, 16, and 64. The breadboard was constructed and tested and the adaptive predistortion and baseband equalizer techniques proven feasible. Performance curves are presented for the various modes (M = 4, 16, and 64) for back-to-back operation as well as through a simulated microwave link. Performance for various levels of TWT power backoff when predistortion is enabled or disabled and when the baseband equalizer is enabled or disabled are presented. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1982
Accession Number
ADA116142

Entities

People

  • Joseph C. Grabowski
  • Linz A. Lord Jr.
  • Robert C. Davis
  • Robert D. Stultz

Organizations

  • Harris Corporation

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplitude
  • Bandwidth
  • Coding
  • Composite Materials
  • Converters
  • Degradation
  • Demodulators
  • Efficiency
  • Equalization
  • Filtration
  • Modulation
  • Modulators
  • Simulations
  • Simulators
  • Spectrum Analyzers
  • Symbols
  • Transmitters

Readers

  • Electronics Engineering
  • Radio communications and signal processing.