1. EE551 Signal Processing and Communication Theory James K Beard, Ph.D. jkbeard@temple.edu Thursday, September 1, 2005

2. September 1, 2005 EE551 Handout2 Essentials Text: Bernard Sklar, Digital Communications, Second Edition Prerequisites  EE521 or equivalent  Consent of Instructor or Dr. Silage  SystemView CD-ROM with text Full version in two weeks Office  E&A 709  Hours Thursday afternoons and By Appointment

3. September 1, 2005 EE551 Handout3 Sklar Chapter 5 Information source Format Source encode Encrypt Channel encode Multi- plex Pulse modulate Bandpass modulate Freq- uency spread Multiple access X M I T Format Source decode Decrypt Channel decode Demul- tiplex Detect Demod- ulate & Sample Freq- uency despread Multiple access RCVRCV Channel Information sink Bit stream Synch- ronization Digital baseband waveform Digital bandpass waveform Digital output Digital input Optional Essential Legend: Message symbols Channel symbols From other sources To other destinations Message symbols Channel impulse response

4. September 1, 2005 EE551 Handout4 Parameters in the Link Budget See Sklar  Figure 5.1  paragraph 5.2.3 Flagged parameters are  Atmospheric loss  Feeder loss  Terrestrial noise, galactic/star noise

5. September 1, 2005 EE551 Handout5 The Base Equations in Communications Link Analysis Link Budget Equation E b /N 0 from SNR Antenna Gain

6. September 1, 2005 EE551 Handout6 The Link Margin Equation Link Budget Equation Definition of Link Margin

7. September 1, 2005 EE551 Handout7 Link Margin Margin is the excess Eb/N 0 over that required to meet link specifications of BER and availability

8. September 1, 2005 EE551 Handout8 TV Link Budget (Table 5.1 p. 265) Up 6 GHz, Down 4 GHz

9. September 1, 2005 EE551 Handout9 Link Availability Percentage of time that the link meets requirements or specifications Causes of time variations  Weather  Fading changes due to motion  Antenna pointing loss changes due to motion  Polarization loss changes

10. September 1, 2005 EE551 Handout10 Antenna Gain and Noise Figure Antenna Gain Noise Figure of One or Two System Blocks

11. September 1, 2005 EE551 Handout11 Noise Temperature Most appropriate for space systems For cascaded blocks

12. September 1, 2005 EE551 Handout12 Study Problems Problem 5.1 page 299  Simple free-space problem  Simple antenna gain problem Problem 5.2 is similar with a step toward designing a link Problem 5.3 – what happens if you modify a large-dish satellite TV system Problem 5.4 – a more difficult noise figure problem

13. September 1, 2005 EE551 Handout13 Next Time Read Sklar Chapter 5 through 5.5 We will  Reprise an overview of this material  Do a couple of examples (feel free to submit suggestions)  Go through the homework problems suggested Lecture on the Second half of Chapter 5 from 5.6 thorough the end