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UltraWideband Research and Implementation

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Wireless communication for High-Definition devices ... Pseudo-random code / spreading / time interleaving. Forward Error Correcting ... – PowerPoint PPT presentation

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Title: UltraWideband 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
Presentation Outline
  • Introduction
  • Overview
  • Project Summary
  • Spectrum Overview
  • Modulation
  • Project Issues
  • Time Constraints
  • Sampling Rates
  • ADC / DAC issue
  • Project Schedule
  • Website Updates
  • Project Milestones
  • Model
  • Block Diagram
  • Frame Synchronization
  • Integration with CCS and DSPs
  • Hardware
  • 2/3 of Hardware Received
  • LO Tested

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 rates 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 pair.
  • Specifically, we are focusing on the following
  • Understanding the theory
  • Simulink modeling
  • DSP implementation
  • RF transceiver hardware
  • Testing

7
UWB Spectrum Overview
  • Power spectral density
  • -41.3 dBm/MHz
  • FCC part 15 limit
  • Frequency Range
  • 3.1 to 10.6 GHz
  • Sub-bands

8
Modulation
  • QPSK or 4-QAM
  • Gray Coded Mapping
  • Symbols
  • Used for data rates from80 to 200 Mb/s
  • I Q
  • 16-QAM or DCM
  • Used for data rates from320 Mb/s to 480 Mb/s

9
OFDM
10
OFDM
  • Benefits
  • Resistance to multi-path fading
  • Spectrum
  • Full ECMA standardized UWB spectrum
  • Scaled-down project spectrum

11
Project Issues
  • Due to Time Constraints
  • Power Limitation
  • Must be overlooked for this initial project
  • Output of quadrature modulators exceed
    limitations
  • Transmission Bandwidth / Data Rate
  • ACD and DAC are not sufficient
  • Audio Development Kit
  • UWB Coding Specifications 20 Met
  • Pseudo-random code / spreading / time
    interleaving
  • Forward Error Correcting
  • Data frame will not include full preambles /
    headers

12
Project Issues
  • Sampling Times
  • Simulink requires information at equal times
  • Must be very careful when changing sampling rates
  • ADC / DAC Issues
  • DAC
  • Need to Transmit In Phase and Quadrature Phase
    Components
  • DACs can only output real numbers
  • Two DACs are required
  • Board only has one DAC
  • Daughter Boards Required
  • Both
  • With faster converters, wider bandwidths possible

13
Overall Tx / Rx Block Diagram
14
Simulink Model
  • Model
  • Frame Synchronization
  • Preamble Complete

15
Updated Project Schedule
16
Updates on Project Website
  • UWB Website Updates

17
Progress
  • DSP Platforms received
  • C6416 DSK

18
Integration of Simulink with CCS
  • To use the DSP boards, all that has to be added
    to the model is the C6416DSK block.
  • Simulink has a blockset for this model
  • Allows use of ADC and DAC
  • LEDs
  • DIP Switches
  • Software Reset
  • Running the model automatically launches CCS
    which converts the model to C-code and uploads it.

19
Simple DSP Test with CCS
  • DSP Platform Hardware
  • Tested with Simulink and Code Composer Studio
    (CCS)
  • Used a FIR Filter for a quick test

20
Simple Test Cont.
  • Once we figured out how to successfully upload
    models, we did a quick FIR filter model to test
    the model.
  • Sampling rate 32 kHz
  • Passband 0 to 5 kHz
  • Stopband 6 kHz
  • Results
  • Did a quick frequency sweep of the filter through
    the DSP to visually confirm the DSP was working

21
(No Transcript)
22
RF Hardware
  • The RF local oscillator and direct quadrature
    modulator have arrived.

23
Local Oscillator Test
  • The oscillator was tested on the spectrum
    analyzer to verify that it met the specifications
    stated in the data sheet.
  • Data sheet specs
  • Tunable from 3.35 to 3.55 GHz
  • Typical power output 4.7 dBm (1.5 minimum)
  • Current draw 41 mA
  • Harmonic levels -7 and -16 dBc

24
Local Oscillator
  • Tests performed
  • Output frequency vs. tuning voltage
  • Output power vs. tuning voltage
  • Harmonic power levels
  • The frequency vs. tuning voltage matched up with
    the data sheet nicely
  • The output power was much lower than the specs
    (on the order of 0.5 to 1.2 dBm)
  • Determined the loss of the coax, DC block, and
    connectors to be around 1 dB. Therefore, results
    are more normal
  • Harmonic Power levels matched data sheet specs

25
Local Oscillator
26
Local Oscillator
27
Local Oscillator
28
Local Oscillator
29
Local Oscillator
30
Local Oscillator
31
Future hardware testing
  • Quadrature Modulator
  • Quadrature De-Modulator
  • Interconnecting all the hardware for testing
  • Transmission lines as channel before wireless
  • Signal leaves DSP on a 3.5mm audio jack, and must
    be received by the modulator with an SMA
    connector.
  • Impedance mismatches?

32
Hardware Connections
33
Future Work
  • Current To Do List
  • Previous To Do List
  • Baseband processor
  • Increase complexity
  • Research UWB channels (no longer implementing)
  • 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 (no longer implementing)
  • Fabricate hardware (no longer implementing)
  • Antenna research (no longer implementing)
  • RF Receiver
  • LNA Design and modeling (N. L. I.)
  • Determine and purchase hardware
  • Fabricate hardware (N. L. I.)
  • Testing
  • Transmitter
  • Implement Daughterboard DACs and ADCs
  • Receiver
  • Complete Frame Synchronization
  • Pulse on Frame Start
  • Frame Alignment
  • Implement Carrier Synchronization
  • Using the Pilot Signals correct for the phase
    error.
  • Testing
  • System Integration
  • Full system testing
  • Bandwidth measurements
  • Bit Error Rates
  • Other common communication systems measurements.

34
Questions
?
?
U W B Standards
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