EE194 Software Defined Radio

1
EE194 Software Defined Radio

• 802.11b Modem Presentation

2
Theory of Operation

• Frequency Range
• 2.4Ghz ISM Band
• 2.4 to 2.497 GHz
• Up to 14 partially overlapping channels available
• 3 non-overlapping channels
• Modulation and Data Rates
• Direct sequence spread spectrum (DSSS)
• 1 Mb/s
• Differential binary phase shift keying (DBPSK)
• 2 Mb/s
• Differential quadrature phase shift keying
  (DQPSK)
• 5.5 and 11 MB/s
• Quadrature phase shift keying (QPSK)

3
Performance Metrics

• Speed
• Up to 11 Mbit/s
• Dynamic rate scaling
• Range
• 45m indoors
• 90m outdoors
• Transmit Power
• 1-200 mW

4
Applications

• Wireless Local Area Networks
• Network Bridging
• Wireless VoIP

5
Implementation

• Single chips incorporating MAC layers, baseband
  processors, and CPUs are available from many
  vendors including TI, Broadcom, and Intel.

6
References

• Wikipedia Wi-Fi
• http//en.wikipedia.org/wiki/Wifi
• IEEE 802.11 Technical Tutorial Introduction IEEE
  802.11 Architecture
• http//www.qsl.net/n9zia/wireless/pdf/802.11.pdf