Ultra-Wideband Research and Implementation

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

2. Introduction Overview Brief History of UWB Consumer Electronics Demand Spectrum Overview Modulation QPSK OFDM Progress Baseband Transmitter Radio Frequency (RF) Transmitter Receiver Progress Baseband Receiver Requirements Equipment List Schedule Patents Future Plans Questions Presentation Outline

3. Introduction to UWB • Ultra-wideband technology is a wireless transmission technique approved for unlicensed use in 2002 under the FCC Part 15 • Ideal for portable multimedia devices because of its inherent low power consumption and high bit rates

4. Why Research UWB? • UWB is likely to revolutionize the consumer electronic market in the near future. • Wireless USB devices • Wireless communication for High-Definition devices • UWB has the power to eliminate the majority of wires to and from multimedia devices

5. Overview • Brief History • IEEE 802.15.3a • ECMA 368 and 369 • Consumer Electronics Demand • High data-rate wireless transmissions • Low power consumption for portable devices • UWB allows data rate equivalent to USB 2.0 (480 Mb/s)

6. Project Summary • The goal of this project is to complete a scaled-down version of a UWB transceiver. • Specifically, we will focus on the following: • Understanding the theory • Simulink modeling • DSP implementation • RF Modeling/simulation • RF transceiver hardware fabrication • Testing

7. 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 Wireless Transmission Methods

8. UWB Spectrum Overview • Power spectral density • -41.3 dBm/MHz • FCC part 15 limit • Frequency Range • 3.1 to 10.6 GHz • Sub-bands

9. Modulation • QPSK or 4-QAM • Gray Coded Mapping • Symbols • Used for data rates from80 to 200 Mb/s • I and Q • 16-QAM or DCM • Used for data rates from320 Mb/s to 480 Mb/s

10. OFDM • Benefits • Resistance to multi-path fading • Spectrum • Full ECMA standardized UWB spectrum • Scaled-down project spectrum

11. OFDM

12. Baseband Transmitter • To facilitate all of the modulation techniques for UWB, a TI C6000 Series DSP platform will be used. • Block Diagram

13. Current Progress • Simulink Modeling • Simple transmitter, channel, receiver completed

14. Simulink Simulations Received – SNR = 30 dB BER = 0.0 Transmitted Spectrum & Symbols Received – SNR = 20 dB BER = 0.013 Received – SNR = 10 dB BER = 0.310

15. Radio Frequency Hardware • Transmitter • Block Diagram • Direct Quadrature Modulator • Modulates the I and Q components • Pre-fabricated chip will be purchased

16. Quadrature Modulator • Block Diagram • A local oscillator will provide the carrier frequency that is desired. • Mixers shift the I and Q baseband frequencies to the carrier frequency. • The two components are combined to produced the RF signal.

17. Filtering • Band-pass filters are needed to prevent any spurious frequencies from the mixing process to be transmitted.

18. Amplification • Power Amplifiers • Required to boost signal strength before transmission. • This stage will present challenges regarding maximum output power allowed by the FCC for UWB transmissions. • The design will depend on the quadrature modulator specifications which are TBD.

19. Antenna • A UWB antenna will either be designed or purchased. • Several types to consider: • Omni-directional • Dipole • Directional • Horn • Yagi • Patch

20. Antenna • Antenna design will be challenging due to the wide bandwidth of the UWB spectrum. • To meet the FCC Effective Isotropic Radiated Power (EIRP) guideline, antenna gain must be taken into consideration.

21. Receiver • Block Diagram

22. Receiver Components • Pre-select filter • Band-pass filter to allow only the frequencies desired into the receiver. • Low Noise Amplifier (LNA) • Boosts the weak incoming signal to increase signal to noise ratio. • Increased receiving range. • For UWB, noise figure must be very low.

23. Receiver Components • Down Conversion • Local Oscillator • Mixers • Filters • Removing spurious components from the mixing process

24. Current Progress • Initial Quadrature Modulator research • Hittite Microwave Corporation • This chip only needs a localoscillator and power forexternal connections. • Problems • Output power is too high

25. Current Progress • The FCC limit on power spectral density for UWB is -41.3 dBm/MHz. • This corresponds to 7.413 x 10-5 mW/MHz • For the total bandwidth of a UWB transmission, the total EIRP is 39 microwatts, or -14.1 dBm. • This will present a challenge in the transceiver design.

26. Baseband Receiver • Using an identical DSP board, the analog RF signal will be sampled, and then processed in the reverse order of the baseband transmitter. • Its function is to restore the original input data.

27. Functional Requirements • Baseband Transmitter • The baseband signal bandwidth shall be determined at a later time, but shall be less than 528 MHz.

28. Functional Requirements • RF Transmitter • The maximum power spectral density of the transmission shall not exceed -41.3 dBm/MHz. • The EIRP shall not exceed -14.1 dBm. Thus, the maximum output power shall be less than 39 microwatts if using an isotropic radiator. • The transmitter shall have a local oscillator at precisely at 3.432 GHz. • The transmitted bandwidth shall lie in the region of 3.168 and 3.696 GHz. • The transmitter shall not interfere with any other wireless devices.

29. Functional Requirements • The receiver shall be immune to other non-UWB RF signals. • The receiver shall have an oscillator that is capable of adjusting to frequency drifts, with a nominal frequency of precisely 3.432 GHz.

30. UWB Development Kits • The first several weeks were spent trying to find a suitable development kit that would allow testing to be done on the technology. • Five companies were found • Two were out of our budget range • Two were under development • The last one did not meet our specifications

31. Equipment List

32. Schedule

33. Patents and Standards Patents Number Description 7139454 Ultra-wideband fully synthesized high-resolution receiver and method 7099422 Synchronization of ultra-wideband communications using a transmitted-reference preamble 7061442 Ultra-wideband antenna 7020224 Ultra-wideband correlating receiver Patent Applications Number Description 20060165155 System and method for ultra-wideband (UWB) communication transceiver 20060062277 Ultra-wideband signal amplifier 20060045134 Ultra-wideband synchronization systems and methods Standards ECMA 368 High Rate Ultra Wideband PHY and MAC Standard ECMA 369 MAC-PHY Interface for ECMA-368

34. Future Work • Baseband processor • Increase complexity • Research UWB channels • Determine maximum feasible sampling rate • Purchase DSP board • Implement synchronous coherent detection for receiver • RF Transmitter • Find a suitable quadrature modulator • Determine and purchase hardware • Model and Design • Fabricate hardware • Antenna research • RF Receiver • LNA Design and modeling • Determine and purchase hardware • Fabricate hardware • Testing

35. Questions ? ? ?