Ultra-Wideband%20Research%20and%20Implementation

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Ultra-Wideband Research and Implementation

• By Jarrod Cook and Nathan Gove
• Advisors
• Dr. Brian Huggins
• Dr. In Soo Ahn
• Dr. Prasad Shastry

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Presentation Outline

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

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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

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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

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Comparison of UWB with other schemes

• 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

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One Disadvantage of UWB
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Initial Project Goals

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

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Initial Project Goals

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

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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

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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

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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

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Brief History (1865-2002)

• 1865 - Experiments by Heinrich Hertz

• 1900s to 1950s - Communications goes Narrowband

1970s to 1980s UWB impulse radio invented

• 2002 FCC approved UWB for unlicensed use under
  Part 15

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Brief History (2002-current)

• 2003 January IEEE 802.15.3a task group created

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

• Modulation
• p/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

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UWB Theory of Operation

• OFDM

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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

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UWB Theory of Operation

• Multiband OFDM (MB-OFDM)
• Benefits
• Reduces Complexity
• Increases Robustness

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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

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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

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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.

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Project Implementation

• Overall Model Block Diagram

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Transmitter Simulink Model
Transmitter Spectrum
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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

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Project Implementation

• Overall Model Block Diagram

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Receiver Simulink Model
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Receiver Frame Sync.
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Receiver Frame Sync.
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Receiver Simulink Model
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Receiver Symbol Sync.

• Adapted Luke Vercimaks Model to work with UWB
  model.
• Lukes Project was implementation of OFDM Radio
  with 802.11 wireless standard (2006).

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Receiver Simulink Model
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RF Hardware

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

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RF Hardware
Quadrature Modulator
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RF Hardware
Quadrature Demodulator
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RF Hardware

• Modulator Specifications

• Demodulator Specifications

• DC to 700 MHz Baseband input
• Up to 6 dBm output power
• 100 MHz to 4 GHz RF frequency range.

• 100 MHz to 4 GHz RF frequency range.

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Overall Hardware setup
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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

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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.

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Results Transmitter

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

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Results Transmitter
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Results Receiver Sync.
Unsynchronized
Synchronized
Transmitted
Frame
Symbol
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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.

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RF Results
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RF Results
Local Oscillator Signal
Modulated data
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RF Results
In-phase input to modulator
In-phase output from demodulator
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Final Project Schedule
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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.

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Conclusion

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

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