Saturday, September 27, 2008

cellular technology


1. Start of the cellular technology, the need for new commercial applications of wireless
2. the bottleneck of capacity
3. Examine capacity of FDMA, TDMA, and CDMA
  • TDMA:FDMA 7(theoretically), 3(practically)
  • CDMA:FDMA 40(theoretically), 10 (practically)
4. Why cellular is better than broadcast?
5. Digital wireless with TDMA, CDMA
  • advanced of digital ICs
  • price drop
6. Major issues with CDMA
  • near-far field effect
  • hand-off

  • 7. and their solutions
    • Power control
    • soft handoff
    8. Make use of dead time in telephone conversations, about 65% of the time
    • variable-rate coder

    reference: Chap. 1~Chap. 6, Dave Mock, the Qualcomm Equation, AMACOM, 2005

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