Effects of Non-Uniform Windowing in a Rician-Fading Channel and Simulation of Adaptive Automatic Repeat Request Protocols

Abstract

Two aspects of digital communication were investigated. In the first part, a FFT-based, M-ary FSK receiver in a Rician-fading channel was analyzed to determine the benefits of non-uniform windowing of sampled received data. When a frequency offset occurs, non-uniform windowing provided better FFT magnitude separation. The improved dynamic range was balanced against a loss in detectability due to signal attenuation. With large frequency offset, the improved magnitude separation outweighed the loss in detectability. An analysis was carried out to determine what frequency deviation is necessary for non- uniform windowing to out-perform uniform windowing in a slow Rician-fading channel. Having established typical values of probability of bit errors, the second part of this thesis looked at improving throughput in a digital communications network by applying adaptive automatic repeat request (ARQ) protocols. The results of simulations of adaptive ARQ protocols with variable frame lengths is presented. By varying the frame length, improved throughput performance through all bit error rates was achieved.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1990
Accession Number
ADA236940

Entities

People

  • Chris G. Kmiecik

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Attenuation
  • Automatic
  • Bessel Functions
  • Classification
  • Coast Guard
  • Computers
  • Digital Communications
  • Doppler Effect
  • Dynamic Range
  • Engineering
  • Frequency
  • Frequency Shift
  • Gaussian Processes
  • Probability
  • Random Variables
  • Security
  • Simulations

Fields of Study

  • Engineering

Readers

  • Radio communications and signal processing.