1. UCB PHYSICAL LAYER Jean Walrand U.C. Berkeley www.eecs.berkeley.edu/~wlr

2. UCB Overview Digital Link Optical Copper Wireless

3. UCB Digital Link Structure: 

4. UCB Digital Link (continued) Examples 

5. UCB Digital Link (continued) Frequency and Propagation: 

6. UCB Digital Link (continued) Limitations: 

7. UCB Digital Link (continued) Baseband: Not self-clocking 

8. UCB Digital Link (continued) Baseband: Self-Clocking 

9. UCB Digital Link (continued) Optical: Self-Clocking 4B/5B or 8B/10B Basic Idea: Introduce enough transitions so that the signal contains the clock.

10. UCB Digital Link (continued) Broadband: PSK and BPSK

11. UCB Digital Link (continued) Spectrum of BPSK (150 bps, carrier 600 Hz) => 150Hz Other modulation schemes: 2 to 7 bps per Hz Note: Shannon Capacity is W log 2 (1 + S/N)

12. UCB Optical Link Components:

13. UCB Optical Link (continued) Fibers:

14. UCB Optical Link (continued) Attenuation

15. UCB Key Ideas: Synchronize Transmitters for easy ADM Enable slipping between PATH and Line Optical Link (continued) SONET

16. UCB Optical Link (continued) SONET Frame

17. UCB Copper Link Common Modulation: QPSK

18. UCB Copper Link (continued) ADSL DMT: Divides bw into channels of 4kHz Uses QAM in each channel, based on SNR