Ultra-Wideband Research and Implementation

1. Ultra-Wideband Research and Implementation By Jarrod Cook and Nathan Gove Advisors: Dr. Brian Huggins Dr. In SooAhn Dr. Prasad Shastry

2. Presentation Outline • Introduction • Brief History • Benefits of UWB • Initial Project Goals • Actual Project Goals • Project Achievements • Project Issues • Results • Future Work • Conclusion • Questions?

3. Introduction to UWB • Ultra-wideband technology is a wireless transmission technique approved for unlicensed use in 2002 under the FCC Part 15 • Ultra-Wideband is defined by the FCC as a transmission whose bandwidth is either: • 20% of its center frequency • At least 500 MHz wide

4. Benefits of UWB • UWB allows devices to transmit data up to USB 2.0 speeds (480 Mb/s) • Power spectral density is extremely low (-41.3 dBm/MHz) • Low power consumption

5. Narrowband Advantages Range Conservation of spectrum Cost Disadvantages Power consumption Limited bandwidth Limited data rates Wideband Advantages High data rates Low power consumption Spectrum coexistence Disadvantages Range Power output regulations to prevent interference Comparison of UWB with other schemes

6. One Disadvantage of UWB

8. Initial Project Goals • Bring UWB technology and research to the Bradley ECE department. • UWB development kit was to be researched and purchased for testing.

9. Initial Project Goals • Testing could lead to other projects in the UWB area. • Connect a computer with a USB device.

10. Initial Project Goals • The idea was to test the development kit thoroughly and match the results with UWB performance specs. • Spectrum measurements • Data rate measurements • Bit Error Rate (BER) • Transmission range • Power consumption • Antenna and RF characteristics

11. Why these goals failed • Upon doing research for companies working on development kits, the list was narrowed down to five companies: • Staccato Communications • Focus Enhancement • Wisair • Alereon • PulsON Time Domain

12. Why these goals failed • None of these companies worked out. • Staccato Communications – Too expensive • Focus Enhancement – Still in development • Wisair – Too expensive • Alereon – Still in development • PulsON Time Domain – Wrong modulation scheme

13. Brief History (1865-2002) • 1865 - Experiments by Heinrich Hertz • Marconi’s Morse-Code Telegraph • First Patents Filed for UWB related Technologies • Companies started to sell UWB products • - 1901 • - 1950s & 60s • - 1980s & 90s • 1900s to 1950s - Communications goes Narrowband • 1970s to 1980s – UWB impulse radio invented • 2002 – FCC approved UWB for unlicensed use under Part 15

14. Brief History (2002-current) • 2003 January – IEEE 802.15.3a task group created • IEEE task group narrowed proposals to two (MB-OFDM & DS) • - May 2003 • WiMedia releases UWB specs and goes to ECMA Int. for standardization • IEEE 802.15.3a task group was mutually shut down without any conclusion • - January 2006 • - 2004 • 2003 to 2004- WiMedia Alliance was created (or MBOA) • 2005- ECMA releases its UWB Standard (ECMA 368 & 369) • WiMedia Alliance is working with global agencies to get ECMA UWB Standards approved world wide • Currently –

15. UWB Theory of Operation • Basic UWB Transmitter Block Diagram

16. UWB Theory of Operation Modulation • π/4 QPSK or 4-QAM • Gray Coded Mapping • Used for data rates from80 to 200 Mb/s • 16-QAM or DCM • Used for data rates from320 Mb/s to 480 Mb/s

17. UWB Theory of Operation OFDM

18. UWB Theory of Operation OFDM • Benefits • Resistance to multi-path fading • Spectrum • Full ECMA standardized UWB spectrum UWB Spectrum • 3.1 to 10.6 GHz • 14 Sub-bands • -41.3 dBm/MHz • FCC part 15 limit

19. UWB Theory of Operation Multiband OFDM (MB-OFDM) • Benefits • Reduces Complexity • Increases Robustness

20. Actual Project Goals • Developing a scaled-down transceiver pair by using: • Simulink to create the baseband modulation models for the transmitter and receiver • Digital Signal Processing (DSP) platforms to perform the baseband modulation • Radio Frequency (RF) components to perform quadrature modulation and up conversion

21. Actual Project Goals • Time constraints shaped the project goals and outcomes: • Use a wired connection between Tx and Rx • Antenna research and design • Power limitations

22. Actual Project Goals • Consulted “Software Defined Radio” by Vercimak and Weyeneth • Used the paper for guidance on some of the difficult aspects of the transmitter and receiver.

23. Project Implementation Overall Model Block Diagram

24. Transmitter Simulink Model Transmitter Spectrum

25. Transmitter Preamble • UWB Preamble Time Frequency Code 5 • The only TF code that was for transmission in the 1st sub band of band number one. • Preamble Length = 165 repeated 24 times • Autocorrelation of Preamble

26. Project Implementation Overall Model Block Diagram

27. Receiver Simulink Model

28. Receiver – Frame Sync.

29. Receiver – Frame Sync.

30. Receiver Simulink Model

31. Receiver – Symbol Sync. • Adapted Luke Vercimak’s Model to work with UWB model. • Luke’s Project was implementation of OFDM Radio with 802.11 wireless standard (2006).

32. Receiver Simulink Model

33. RF Hardware • RF components were ordered from Hittite Microwave Corporation. • Quadrature Modulator • Quadrature Demodulator • Voltage Controlled Oscillator

34. RF Hardware Quadrature Modulator

35. RF Hardware Quadrature Demodulator

36. RF Hardware Modulator Specifications Demodulator Specifications 100 MHz to 4 GHz RF frequency range. • DC to 700 MHz Baseband input • Up to 6 dBm output power • 100 MHz to 4 GHz RF frequency range.

37. Overall Hardware setup

38. Project Issues / Challenges • Speed of converters on hardware • DACs and ADCs max freq. = 96kHz • For real UWB freq. = 528 MHz required • Daughter-boards with faster converters • Complexity of integration with Simulink is its own Senior Project. • Code-composer limitations • Max of 7 simultaneous periodic sample rates. • Transmitter had 5-6 / Receiver had 13-15

39. Project Issues / Challenges • Simulink Learning Curve • Common misconception: • “Simulink Blocks will automatically take care of all the little details.” • Simulink requires that information being processed must enter a block at the same rate. • Very useful tool but has many subtleties.

40. Results – Transmitter • Able to port the Simulink model with Code-composer studio onto the DSP boards.

41. Results – Transmitter

42. Results – Receiver Sync. Transmitted Unsynchronized Synchronized Frame Symbol

43. RF Results • Used HP ESG Signal Generator for I/Q baseband signals and local oscillator. • Tested the modulator and demodulator using time and frequency domain measurements. • All of the RF subsystem worked correctly.

44. RF Results

45. RF Results Local Oscillator Signal Modulated data

46. RF Results In-phase input to modulator In-phase output from demodulator

47. Final Project Schedule

48. Future Project Goals • Purchase a full-scaled development kit (if one exists). • Purchase Daughter Boards for the current TI DSPs. • New DSP platform with faster onboard peripherals. • Use the faster system to implement a high-speed wireless data system.

49. Conclusion • UWB will revolutionize consumer electronics. • It allows speeds up to USB 2.0 (480 Mb/s). • Low interference/coexistence. • Low power consumption.

50. Questions ? ? U W B Standards PS: Dr. Ahn is limited to a maximum of 3 questions.