Advanced Techniques to Improve the Performance of OFDM Wireless LAN

Abstract

OFDM systems have experienced increased attention in recent years and have found applications in a number of diverse areas including telephone-line based ADSL links, digital audio and video broadcasting systems, and wireless local area networks (WLAN). Orthogonal frequency-division multiplexing (OFDM) is a powerful technique for high data-rate transmission over fading channels. However, to deploy OFDM in a WLAN environment, precise frequency synchronization must be maintained and tricky frequency offsets must be handled. In this thesis, various techniques to improve the data throughput of OFDM WLAN are investigated. A simulation tool was developed in Matlab to evaluate the performance of the IEEE 802.1la physical layer. We propose a rapid time and frequency synchronization algorithm using only the short training sequence of the IEEE 802.1la standard, thus reducing the training overhead by 50%. Particular attention was paid to channel coding, block interleaving and antenna diversity. Computer simulation showed that drastic improvement in error rate performance is achievable when these techniques are deployed.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2004
Accession Number
ADA424608

Entities

People

  • Michail Segkos

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies
  • Human Systems
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Algorithms
  • Channel Coding
  • Communication Systems
  • Computational Science
  • Computer Programming
  • Digital Communications
  • Frequency Division Multiplexing
  • Graphical User Interface
  • Inter-Carrier Interference
  • Modulation
  • Multiple Access
  • Multiple Input Multiple Output
  • Multiplexing
  • Orthogonal Frequency Division Multiplexing
  • Random Variables
  • Signal Processing
  • Wireless Communications

Fields of Study

  • Computer science

Readers

  • Radio communications and signal processing.
  • Systems Analysis and Design