Dr. Hatim Zaghloul Chairman and CEO

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Dr. Hatim Zaghloul Chairman and CEO
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Who are the OFDM Forums Principal Members?
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The Evolution of W-OFDM Technology

• May 1998 Wi-LAN is the preferred supplier to
  Tele2(UK) to build a national network at 3.6GHz
• November 1998 Wi-LANs patented W-OFDM
  technology is brought to life with functioning 30
  Mbps prototype
• June 1999 Wi-LAN breaks industry barriers with
  launch of high-speed 30 Mbps wireless networking
  product at 2.4GHz (not FCC certified)
• January 2000 Wi-LAN demonstrates first mobile
  application of W-OFDM technology
• June 2000 Prototype ASIC chips using W-OFDM
  technology developed
• February 2001 Wi-LAN signs a contract for
  national networks in six European countries and
  ships 3GHz W-OFDM units

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Channel Estimation and Erasure Locating

• Channel Estimation Equalization Vector
• The complex reciprocal of each subcarrier in the
  average OFDM training symbol.
• Erasure Locating
• The magnitudes vector created by the channel
  estimator is used to determine which Reed Solomon
  symbols within an RS codeword are likely to be in
  error. These suspect errors can be removed from
  the FEC in the receiver thus improving its
  performance by an order of magnitude.
• Phase Whitening
• The signal vector is multiplied times a random
  phase before the IFFT in the transmitter which
  reduces the peak to average ratio requirement.
  Phase whitening is superior to data scrambling
  since scrambling only assures that the data does
  eventually make it through.

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Typical Channel Response
Multipath Channel Response (dB)
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Channel Estimation and Erasure Locating
Channel Estimation With Noise, Equalized Channel,
and Erasures
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Summary of Benefits to IEEE 802.16.3 FWA

• OFDM is spectrally efficient
• OFDM can be used in TDD or FDD modes
• OFDM is scalable for various channel requirements
• OFDM is robust to channel impairments caused by
  multipath
• FEC with erasures compliment OFDM very well,
  especially when the channel is Non-ideal.Errors
  due to multipath/jammers may be predictable and
  erasable

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W-OFDM PermitsObstructed LOS (OLOS)
.47 Miles, 67 dBi RSSI, 3 dB Null Depth, Nominal
Data Rate
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W-OFDM PermitsNon Line of Site (NLOS)
.6 Miles, -70 dB RSSI, 6 dB Null Depth, Nominal
Throughput
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Other Technologies forNon- Line of Sight

• Routed Mesh Network Architecture
• Traffic can be routed around obstructions rather
  than needing to deploy additional base stations
  that can simplify line-of-sight problems in
  densely populated diverse geographical locations.

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US Patent 5,282,222W-OFDM

• Wide-band Orthogonal Frequency Division
  Multiplexing
• (US patent and Canadian Patent )
• A Method and Apparatus for Multiple Access
  Between Transceivers in Wireless Communications
  Using OFDM Spread Spectrum
• By Virtue of these patents, two-way high speed
  communications using any form of OFDM requires a
  license from Wi-LAN.
• Wi-LAN is committed to enabling and promoting
  IEEE and ETSI standards activities and has agreed
  to license its patents, when and if required, to
  companies developing products complying with
  their standards.