Ultra-wideband (UWB) Signals for Communications and Localization

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Ultra-wideband (UWB) Signals for
Communications and Localization

• Sinan Gezici
• Assistant Professor
• Dept. of Electrical and Electronics Eng.
• Bilkent University
• gezici_at_ee.bilkent.edu.tr

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Ultra-wideband (UWB)

• Definition
• (Absolute) bandwidth 500 MHz
• Babs fH fL
• Fractional bandwidth 0.2
• Bfrac (fH fL) / fC 0.2

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Regulations for UWB

• FCC in the US allows transmission in 3.1-10.6 GHz
  band
• Coexists with incumbent systems
• Low power spectral density (-41.3 dBm/MHz)
• Large spreading factors

UWB
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UWB Signals

• 3 common signaling formats
• OFDM UWB
• DS-CDMA UWB
• Impulse radio (IR) UWB
• A train of short duration (sub-nanosecond) pulses
  with a low
• duty cycle

One information symbol
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Advantages of UWB (1/2)

• High data rate Large bandwidth increases capacity

For AWGN channels

• Low power/cost Simple transceiver
  architectures with low power consumption are
  possible

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Advantages of UWB (2/2)

• Precise position estimation (localization) High
  time resolution

TimeT1
Transmitted Signal
Object
Radar Transceiver
TimeT2
Reflected Signal
Device
Object
Range 0.5(T2-T1)c c Speed of light
15 m

• Penetration through obstacles Large
  frequency band facilitates penetration through
  objects
• Low probability of detection Similar to white
  noise for other systems

http//www.radarvision.com
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Applications (1/2)

• Communications
• High data rate e.g. wireless USB, WPAN
• Low data rate IEEE 802.15.4a, wireless sensor
  networks

http//www.soumu.go.jp
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Applications (2/2)

• Radar and localization

E. M. Staderini 2002
http//www.radarvision.com
Other applications e.g., thru-wall monitoring,
rescue operations after an earthquake.
Medical applications e.g., non-invasive patient
monitoring, respiration and heartbeat rate
estimation