1. Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications

2. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications2 CUBAN Scenario Copied from: “In-depth description of the Research Proposal Co-Optimized Ubiquitous Broadband Access Networks” (CUBAN)

3. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications3 Key Points Cross-layer optimization Uplink and downlink

4. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications4 Cross-Layer Optimization versus packets per time slot Copied from: “Cross-Layer Design for Wireless Networks”, S. Shakkottai and T. Rappaport

5. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications5 Energy-constrained Modulation Optimization Assumption: Both the transmitter and the receiver operate on batteries Goal: Find the best modulation strategy to minimize the total energy consumption required to send a given number of bits Based on: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai “Energy-constrained Modulation Optimization for Coded Systems”, S. Cui, A. Goldsmith and A. Bahai

6. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications6 Energy-constrained Modulation Optimization Analysis for: –MQAM, MFSK –AWGN and Rayleigh fading channels –Coded / uncoded case Based on: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai “Energy-constrained Modulation Optimization for Coded Systems”, S. Cui, A. Goldsmith and A. Bahai

7. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications7 Energy-constrained Modulation Optimization In short range applications, the circuit energy consumption is non negligible compared with the transmission energy Based on: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai “Energy-constrained Modulation Optimization for Coded Systems”, S. Cui, A. Goldsmith and A. Bahai

8. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications8 Energy-constrained Modulation Optimization Copied from: “Energy-constrained Modulation Optimization”, S. Cui, A. Goldsmith and A. Bahai

9. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications9 Energy-constrained Modulation Optimization bits have to be transmitted in a deadline The transceiver spends a time to transmit those bits Trade off: the transmission energy decreases with, but the circuit energy consumption increases with Based on: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai “Energy-constrained Modulation Optimization for Coded Systems”, S. Cui, A. Goldsmith and A. Bahai

10. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications10 Energy-constrained Modulation Optimization Example: Uncoded MQAM for AWGN channels Copied from: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai

11. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications11 Energy-constrained Modulation Optimization Copied from: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai

12. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications12 Energy-constrained Modulation Optimization Copied from: “Modulation Optimization under Energy Constraints”, S. Cui, A. Goldsmith and A. Bahai

13. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications13 Adaptive Transmission Schemes Use transmitter – receiver pair n when Copied from: “Adaptive Coding and Modulation: A Key to Bandwidth-Efficient Multimedia Communications in Future Wireless Systems”, K. Hole and G. Øien

14. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications14 Adaptive Transmission Schemes The channel model specifies a pdf for the amplitude of Copied from: “Adaptive Coding and Modulation: A Key to Bandwidth-Efficient Multimedia Communications in Future Wireless Systems”, K. Hole and G. Øien

15. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications15 Energy Optimal Scheduling under Average Throughput Constraint Goal: Adapt radio settings (e.g. modulation, error code, …) in response to changes in the wireless channel in order to minimize the energy consumption under an average throughput constraint Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

16. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications16 Energy Optimal Scheduling under Average Throughput Constraint System model: Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

17. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications17 Energy Optimal Scheduling under Average Throughput Constraint Assumptions: –The channel (Rayleigh fading) varies slowly enough to be estimated efficiently –Infinite number of samples Only knowledge of the channel statistics is required, instead of that of the exact future behaviour Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

18. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications18 Energy Optimal Scheduling under Average Throughput Constraint Problem: Find the values of the thresholds Assumption:The incremental power for adding one extra bit is monotonically increasing Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

19. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications19 Energy Optimal Scheduling under Average Throughput Constraint Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

20. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications20 Energy Optimal Scheduling under Average Throughput Constraint Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

21. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications21 Energy Optimal Scheduling under Average Throughput Constraint Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

22. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications22 Results Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

23. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications23 Results Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

24. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications24 Results Based on: “Energy Efficient Wireless Scheduling: Adaptive Loading in Time”, C. Schurgers and M. Srivastava

25. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications25 Remarks – Ideas – Discussion Conclusions from p2: –Minimize energy consumption instead of maximizing spectral efficiency when determining the thresholds –The analysis has been done for situations where the electronics power is negligible compared to the transmission power Based on: “Energy Optimal Scheduling under Average Throughput Constraint”, C. Schurgers and M. Srivastava

26. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications26 Research Objective 1 Design an adaptive transmission scheme (i.e. determine the thresholds,,… ) for short range wireless channels in order to minimize energy consumption under an average throughput constraint

27. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications27 Research Objective 1 Remarks: –The electronics (circuit) power is not considered negligible when compared to the transmit power. A model comparable to the one in p1 will be used –In a first stage, MQAM modulation (no coding) and Rayleigh fading –The throughput constraint should be set by the application layer

28. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications28 Research Objective 1 It would be interesting to find out how far the transceiver designed using the above scheme is from the from the actual channel capacity Based on: “Adaptive Coding and Modulation: A Key to Bandwidth-Efficient Multimedia Communications in Future Wireless Systems”, K. Hole and G. Øien

29. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications29 Other Ideas Nakagami-m channels –See what happens with p1 –Research objective 1 OFDM based schemes, with adaptive transmission on subchannels Coding: Trellis codes / Turbo codes

30. Thursday, February 26 2004Bandwidth-Efficient, Energy-Constrained Short Range Wireless Communications30 Other Ideas Antenna diversity – SC / MRC Try to find more accurate / complete models for the electronics power consumption, try to find the best possible transceiver structure in terms of power consumption Network and data link layers joint optimization