Term Project: ULTRA WIDE-BAND COMMUNICATIONS

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Term ProjectULTRA WIDE-BAND COMMUNICATIONS

• Prepared and Presented by
• Alain Eid

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Contents

• Introduction to UWB
• Definition of UWB
• IEEE 802.15.3a Standard
• Wireless Alternatives
• Multi-Bands Design
• UWB Transceivers
• Technology Challenges
• Conclusion

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Chronology Research on UWB

• Is it a New Technology?
• The first impulse system patent was awarded in
  1954
• The basic concept was first described in 1960
• The first landmark patent of UWB was awarded in
  1973
• It has been used since 1980 in military Radar
  applications
• The term UWB was first used in 1989 by DoD
• Up to 1994, all UWB studies were classified
• A substantial change occurred in 2002 when UWB
  was made public (by FCC)
• The Answer is NO

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Definition of UWB
UWB spectral mask for indoor communications
systems
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Definition of UWB (Continued)
US Spectrum Allocation for Unlicensed Use
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IEEE 802.15.3a Standard
IEEE 802.15.3a Summary Requirements
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Wireless Alternatives

• In order to understand where UWB fits in with
  the current trends in wireless communications, we
  need to consider the general problem that
  communications systems try to solve.
  Specifically, if wireless were an ideal medium,
  we could use it to send
• a lot of data
• very far
• very fast
• for many users
• all at once

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Wireless Alternatives (Continued)

• Unfortunately, it is impossible to achieve all
  five attributes simultaneously for systems
  supporting unique, private, two-way communication
  streams.
• One or more have to be given up if the others are
  to do well. Original wireless systems were built
  to bridge large distances in order to link two
  parties together.
• However, recent history of radio shows a clear
  trend toward improving on the other four
  attributes at the expense of distance.

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Wireless Alternatives (Continued)

• Four trends are driving short-range wireless in
  general and ultra-wideband in particular
• The growing demand for wireless data capability
  in portable devices at higher bandwidth but lower
  in cost and power consumption than currently
  available.
• Crowding in the spectrum that is segmented and
  licensed by regulatory authorities in traditional
  ways.
• The growth of high-speed wired access to the
  Internet in enterprises, homes, and public
  spaces.
• Shrinking semiconductor cost and power
  consumption for signal processing.

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Wireless Alternatives (Continued)
Spatial Capacity Comparison Between IEEE 802.11,
Bluetooth and UWB
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Wireless Alternatives (Continued)
Channel Capacity for Additive, White Gaussian
Noise
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Multi-Bands Design

• UWB has been defined in the past as a method to
  encode information using impulses.
• These impulses can be modulated either with
  position, or with amplitude or with phase.
• The transmitter feeds these impulses to a very
  large bandwidth, non-resonating antenna, or
  sometimes the antenna itself shapes the impulses
  to the required frequency of operation.
• UWB companies have developed proprietary
  techniques to generate and detect such impulses,
  using non-resonating components.
• These impulses are especially effective for radar
  systems, where the resolution is proportional to
  the bandwidth, but have proven difficult to
  realize in CMOS so far.

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Multi-Bands (Continued)
Multi-Band Signals Sequence
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Multi-Bands (Continued)
Multi-Band Signal Reference
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UWB Transceivers
Multi-Bands Transceiver Block Diagram
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UWB Transceivers (Continued)
UWB Transceivers Typical Performance
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UWB Applications

• Desktops and Laptop PCs
• High resolution printers, scanners, storage
  devices
• Connectivity to mobile and CE devices
• Mobile Devices
• Multimedia files, MP3, games, video
• Personal connectivity
• CE Devices
• Cameras, DVD, HDTV
• Personal connectivity
• Military Communications
• Radars and Sensing

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Technology Challenges

• Short-range wireless systems based on narrowband
  carrier modulation VS High data rates to transmit
  video over air.
• Spatial capacity VS System performance and
  spectral efficiency of UWB radio devices.

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Technology Challenges (Continued)

• Mutual interference between UWB devices VS Level
  of QoS.
• Modulation and channel coding VS Multi-User
  capacity.
• Peak power VS Optimization of transmission
  techniques.
• Excessive clock speed, synchronization, power
  consumption VS MEMS and SOI

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Conclusion

• The recently FCC frequency allocation for UWB has
  generated a lot of interest in UWB technologies.
• 7500MHz of spectrum for unlicensed use.
• Transmit signal must occupy at least 500MHz at
  whole times.
• UWB is the most promising technology to support
  the rigorous requirements 110, 200 and 480Mbps.
• The new UWB technology emerging today, mostly as
  a consequence of the recent FCC spectrum
  allocation, is based on multi-bands.
• There are still many technologys challenges
  ahead, mostly around the high level of
  integration that UWB products requires they need
  to be developed at low cost and low power to meet
  the vision of integrated connectivity for PAN.