UltraWideband Technology UWB

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Ultra-Wideband Technology(UWB)

• EE 206A
• Spring, 2002
• Robert Tseng
• Jacob Kuo

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Objectives

• Introduction
• What is UWB
• Why it is attractive
• Who
• Basic Model
• Transmitter Model
• Receiver Model

• Performance
• BER
• Pros and Cons
• Industry Advocators
• Industry Contesters
• Conclusion

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Introduction

• What is UWB?
• A series of very short baseband pulses with time
  duration in nano-seconds that exist on ALL
  frequencies simultaneously, like a blast of
  electrical Noise.
• Synonyms
• Nonsinusoidal Communication Technology
• Impulse Radio
• Baseband Pulse Technology

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• Why is UWB attractive?
• Capacity a channel is linearly proportional to
  its bandwidth. UWB can go up to 2 Giga-Hz in
  bandwidth.
• Spread spectrum transmission in which the data
  sequence occupies a bandwidth in excess of the
  minimum bandwidth necessary to send it. It uses
  only several frequencies, one at a time.
• Successor to spread spectrum UWB uses every
  frequency there is, use them all at same time.
• Simplicity its essentially a base-band system
  (Carrier free), for which the analog front-end
  complexity is far less than that for a
  traditional sinusoidal radio. (See Figures at
  next page.)

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Traditional Sinusoidal Radio
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UWB Impulse Radio
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When was UWB invented and by whom?

• Tough question, but easy answer! There have been
  many claims to the honor however, Dr. Gerald F.
  Ross, currently President of ANRO Engineering,
  Inc., first demonstrated the feasibility of
  utilizing UWB waveforms for radar and
  communications applications back in the late
  1960s and early 1970s.
• Gerrys pioneering insight into the value and
  applications of this technology over 30 years ago
  has been instrumental in shaping UWB technology
  to the point it has reached today with
  applications ready to meet market demands for
  high-speed wireless and precision
  radar/positioning applications.
• Gerry was recognized by the National Academy of
  Engineering for his efforts in ultra wideband
  technology, and elected a Member in 1995.

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Basic Transmitter Model

• Transmitter Model with typical time hopping
  format with Pulse-Position Modulation (PPM)
• Step 1 Define monocycle waveform
• S(k) is the kth transmitted signal
• w(t) represents the transmitted monocycle
  waveform
• Step 2 Shift to the beginning of Time frame
• Tf is the pulse repetition time or frame time
• j is the j th monocycle that sits at the
  beginning of each time frame.

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• Step 3 Pseudorandom Time Hopping
• To eliminate catastrophic collisions in multiple
  accessing
• Cj (k) are time hopping code, periodic
  pseudorandom codes
• Tc is the additional time delay that associate
  with the time hopping code
• Step 4 Data Modulation
• dj (k) is the primary data sequence of the
  transmitter
• Data are transmitted every Ns monocycles per
  symbol
• The symbol d is the time shift that applies to
  the monocycle, and we define such operation
  happens when 1 is transmitted.

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Receiver Block Diagram for the reception of the
first users signal
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Receiver Model

• Signal at Receiver
• Aks(k) models the attenuation of transmitter ks
  signal
• N(t) is the white Gaussian noise
• tauk is time asynchronisms between clocks of
  transmitter and the receiver
• Correlation template signal
• V(t) is the pulse shape defined as the difference
  between two pulses shifted by the modulation
  parameter d. It will then be correlated with the
  received signal for a statistical test

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• The optimal decision rule (one monocycle)
• Pulse correlator output aj
• Test statistic a (one symbol)
• if a gt0 , the symbol transmitted is 0, else it
  is 1

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Performance

• With simulation studies, to maintain BER of 10-3,
  10-4, and 10-5 in a communication system with no
  error control coding, SNR spec must be 12.8 dB,
  14.4 dB, and 15.6 dB.
• We shall see the next figure, which the number of
  users versus additional required power (? P) for
  multiple access operation with ideal power
  control is plotted.

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Pros

• High data capacity.
• Multiple Access provided by time hopping scheme.
  Can support close to 30,000 users at 19.2kbps
  with BER of 10-3 or a 6 users system with a peak
  speed of 50mbps.
• Low power.
• Transmitting at microwatts (one tenth thousandth
  power of cell phone) results in very low harmful
  interference to other radio systems. Usually
  below the noise floor and undetectable.
• Longer battery life for mobile devices.
• Resilient to distortions and fading (Great for
  indoor usage).
• Spread spectrum property overcomes frequency
  selective fading.
• High information redundancy and frequency
  diversity provides protection against multi-path
  distortion.
• Simplicity translate to lower hardware cost.
• No carrier frequency translate analog front-end
  has simpler implementation than traditional
  sinusoidal radio.
• Security
• UWB is inherently secure Only a receiver that
  knows the schedule of the transmitter can
  assemble the apparently random pulses into a
  coherent message.

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Cons

• Interference with GPS.
• Global positioning satellite currently have more
  than 10 million users and its primarily
  applications are used for the safety of public.
  (I.e. aircraft flight and approach guidance.) UWB
  presents a problem to GPS because their frequency
  overlaps, and GPS signal is particular sensitive
  to interference (It as SNR level around 164
  dBW.)
• Limited on range
• Output power is limited in order to keep down the
  noise floor due to its overlapping frequency
  bandwidth with other radio systems.
• One kilometer with high gain antenna.
• Ten to twenty meter with regular antenna.
• Affects on economy and current businesses.
• Speculations on UWB making current billion dollar
  FCC licensed frequencies worthless.
• Increased competition for local cable or phone
  company. Making their existent investments on
  cable and equipments obsolete.
• Side Note.
• FCC adopted a First Report and Order that permits
  the marketing and operation of certain types of
  new products incorporating UWB technology, Feb
  14,2002.
• Biggest loser Increase the noise floor level for
  radio astronomer.

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UWB Advocators

• Intel
• First - Intel is actively engaging the industry
  to help determine a reliable model that systems
  engineers can use to help study the performance
  of UWB systems.
• Second Intel is investigating several receiver
  designs that will help to improve the robustness
  and long-term viability of this technology.
• Third - the feasibility for high-level silicon
  integration in order to yield a very low-cost and
  low-power solution.
• Intel itself has not yet decided to enter the
  market for UWB chips or systems, according to
  Manny. The Santa Clara, Calif.-based company is
  still in the RD phase with the technology.
• Using discrete radio-frequency (RF) components,
  Intel demonstrated a UWB-enabled system that
  supported data rates at speeds of 100 megabits
  per second, said Ben Manny, director of wireless
  technology development at Intel Architecture
  Labs. The company aims to push this wireless
  technology to 500 Mbits per second, Manny said in
  an interview at IDF.

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• Time Domain Corp.,
• based in Huntsville, Ala., has petitioned the FCC
  for a waiver so that by the middle of next year,
  it can begin selling a system that will permit
  police officers and special weapons and tactics
  teams to see through walls and doors to detect
  the location of people. The company is also
  planning a covert communications system that will
  both carry voice communications and display
  locations of a counter-terrorism or SWAT team's
  members.
• Time Domain has harnessed UWB technology in
  silicon-based solutions, which are embodied in a
  family of PulsON chipsets. The PulsON chipset
  has been designed to enable hundreds of
  applications in existing products as well as
  future products and industries. Time Domain's
  chipsets are expected to be available in 2002.
  Time Domain is now producing PulsON Application
  Demonstrators (PADs), which integrate the first
  generation PulsON 100 Silicon Germanium chips
  into a single PC board. Early adopters are
  joining our PulsON Developer Program(SM) to
  incorporate PulsON silicon solutions into their
  applications and products.
• Siemens invested 5 million in Time Domain
• Qwest bought 5 of time domain
• Other supporters
• Motorola, Siemens, IBM, Sony

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Start-Up Companies

• Aether Wire Location www.aetherwire.com
• General Atomics www.ga.com
• Multispectral Solutions www.multispectral.com
• Pulse-Link www.pulse-link.net
• Pulsicom Technologies (Israel) www.pulsicom.com
• Time Domain www.timedomain.com
• XtremeSpectrum www.xtremespectrum.com
• Zircon www.zircon.com

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UWB Contesters

• Sprint PCS (PCS ) and other wireless carriers,
  which paid a king's ransom for their spectrum
  rights, fear the interference caused by UWB.
• Still others, including the US Department of
  Defense and the airline industry, are heavily
  involved in other wireless technologies (e.g.
  GPS), felt that UWB should not be allowed at all
  below 4.2 GHz, 6 GHz or even higher.

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Conclusion

• Impact on the market
• Troubles in existing communication businesses
• UWB offers a better and cheaper service
• Value of existing infrastructure drops
• UWB will occupy certain part of radio spectrum
  that are exclusively licensed to some companies
• Boosting up the range of high-speed internet
  services
• Solves the last-mile problem

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• Losers
• Local phone companies, cable TV companies, mobile
  phone companies and internet service providers,
  who have old infrastructure
• Regulated communication companies who has
  exclusive license to some parts of the radio
  spectrum
• Radio Astronomers, the level of noise threshold
  is raised.
• Winners
• Companies best adapted to UWB
• PCS vendor new UWB radio to its short range
  sites
• Optical backbone provider UWB increases its
  bandwidth
• TV networks can extend their market range.

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References

• Impulse Radio Robert.A. Scholtz and Moe Z Win
  Invited Paper, IEEE PIMRC 97, Helsinki
• Impulse Radio How It Works Moe Z Win and
  Robert.A. Scholtz IEEE Communications Letters,
  Vol. 2, No. 1, January 1998
• Multiple Access with Time-Hopping Impulse
  Modulation R.A. Scholtz Invited Paper, MILCOM
  93 Conference
• Assessing Interference of Ultra-Wideband
  Transmitters with the Global Positioning System -
  A Cooperative Study
• G. Roberto Aiello and Gerald D. Rogerson,
  Interval Research Corporation Per Enge,
  Department of Aeronautics and Astronautics,
  Stanford University
• The 100 Mile-Per-Gallon CarburetorHow Ultra Wide
  Band May (or May Not) Change the WorldBy Robert
  X. Cringelyhttp//www.pbs.org/cringely/pulpit/pul
  pit20020124.html
• Webb on Wireless
• William Webb kicks off his column for Wireless
  Europe by arguing that ultra-wide band will not
  replace WLAN or Bluetooth technologies.
• By William Webb
• http//wireless.iop.org/article/feature/3/1/8
• NEW PUBLIC SAFETY APPLICATIONS AND BROADBAND
  INTERNET ACCESS AMONG USES ENVISIONED BY FCC
  AUTHORIZATION OF ULTRA-WIDEBAND TECHNOLOGY
• by Federal Communications Commission
• http//www.fcc.gov/Bureaus/Engineering_Technology
  /News_Releases/2002/nret0203.html