1. Communication Theory as Applied to Wireless Sensor Networks
muse

2. Objectives
Understand the constraints of WSN and how communication theory choices are influenced by them
Understand the choice of digital over analog schemes
Understand the choice of digital phase modulation methods over frequency or amplitude schemes
muse

3. Objectives (cont.)
Understand the cost/benefits of implementing source and channel coding for sensor networks
Understand fundamental MAC concepts
Grasp the importance of node synchronization
Synthesize through examples these concepts to understand impact on energy and bandwidth requirements
muse

4. Outline Sensor network constraints Digital modulation
Source coding and Channel coding
MAC
Synchronization
Synthesis: Energy and bandwidth requirements

5. WSN Communication Constraints
Energy!
Communication constraints

6. Data Collection Costs Sensors Activation Conditioning A/D
Communication constraints

7. Computation Costs Node life support Simple data processing
Censoring and Aggregation
Source/Channel coding
Communication constraints

8. Communication Costs
Communication constraints

9. Putting it all together
Communication constraints

10. Outline Sensor network constraints Digital modulation
Source coding and Channel coding
MAC
Synchronization
Synthesis: Energy and bandwidth requirements

11. Modulation
Review
Motivation for Digital
Modulation

12. The Carrier
Modulation

13. Amplitude Modulation (AM)
DSB-SC (double sideband – suppressed carrier)
Modulation

14. Frequency representation for DSB-SC (the math)
Modulation

15. Frequency representation for DSB-SC (the cartoon)
Modulation

16. Demodulation – coherent receiver

17. DSB-LC (or AM as we know it)
Modulation

18. Frequency representation of DSB-LC
Modulation

19. Amplitude Modulation
Modulation

20. Frequency Modulation (FM)

21. Frequency Modulation
Modulation

22. Phase Modulation
Modulation

23. SNR Performance
Modulation
Fig. Lathi

24. Digital Methods
Digital Modulation

25. Quadrature Modulation
Digital Modulation

26. BPSK
Digital Modulation

27. QPSK
Digital Modulation

28. Constellation Plots
Digital Modulation

29. BER Performance vs. Modulation Method
Digital Modulation
Fig. Lathi

30. BER Performance vs. Number of Symbols
Digital Modulation
Fig. Lathi

31. Outline Sensor network constraints Digital modulation
Source coding and Channel coding
MAC
Synchronization
Synthesis: Energy and bandwidth requirements