cellular technology

Summary in slides

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 (Is TDMA of the same efficiency as FDMA?))

• 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