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Ultra-Wide Band (UWB) is a communication technology used in wireless networking to achieve high bandwidth connections with low power spectral density. - What is UWB? - Why UWB? - How it works? - Conclusion
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Ultra Wide Band (UWB)Mohammad DayehComputer and Communication Engineer
Outline
Outline
What is UWB?
Why UWB?
How it works?
Conclusion
What is UWB?Introduction & Definition
Definition – What is UWB?Ultra-Wide Band (UWB) is a communication technology used in wireless networking to achieve high bandwidth connections with low power spectral density.
high data throughput for communications devices
high precision for location and imaging devices
high resolution for sensing devices
ultra low power (microwatts)
limited interference with conventional radio systems
short signal pulses over a broad spectrum
high wireless data rates in excess of 100Mbit/s (480 Mbps up to 1.6 Gbps at distances up to a few meters)
data rates drop considerably at longer distances
FCC Definition
Fractional Bandwidth > 20% of fc
fH : higher 10dB down pointfL : lower 10db down pointfc : central frequency
Bandwidth > 500 MHz
Example:fL=1GHz and fH=3GHz → FB = 1 GHz
UWB Spectrum
UWB is a form of extremely wide spread spectrum where RF energy is spread over gigahertz of spectrum
UWB signals can be designed to look like imperceptible random noise to conventional radios
Narrowband (30kHz)
Wideband CDMA (5 MHz)
UWB (Several GHz)
Frequency
Part 15 Limit( -41.3dBm/Hz )
Unlicensed Spectrum
Although UWB technology operates at the same or lower power levels currently allowed for numerous applications under the FCC’s unlicensed Part 15 rules, a change of the rules is needed to accommodate this new form of wireless technology.
Basic requirement of Part 15: Thou shalt not create harmful interference.
1 2 3 4 5 6
Pow
er
Frequency (GHz)
Part 15
2.4 GHz UNII Bands
Unlicensed National Information Infrastructure
Principles of UWBTime Domain
Extremely short pulses
Very low duty cycle
Frequency Domain
Ultra wide spectrum Low power spectral density Acceptable interference with
other users
Why UWB?Advantages and Applications
Why UWB - Advantages Spectrum reuse
Use frequencies from 3.1 to 10.6 GHz coexist with other users (sharing spectrum)
High data rate in short range, high throughput 500 Mbps at 10 feet
Multipath immunity Path delay >> pulse width
Low power Baseband modulation (no carrier) Long battery life of portable devices
Low cost and single chip architecture Nearly all digital, simple analog module Silicon based, standards-based radios
Non-interfering to other communication systems It appears like noise for other systems
ThroughputUWB throughput between 802.11a and 802.11b
Low Power UWB Comparable to High Power Wireless Systems
Communications
Ultra Wide Band technology enable wide variety of applications
Intelligent Sensors
Radar Medical Applications
Ground Penetrating
RadarWireless PAN Telemetry
Replace cables between devices
Biofeedback-based
rehabilitation
Home Applications
Through-Wall Radar
Intelligent Transport System
Intelligent Driving and Parking Aids
Medical Imaging
Military Communicatio
ns
Share live multimedia
content between
devices at high data rate
Why UWB - Applications
Automotive Radar
Tank Level Probing Radar
High Speed Wireless USB
Wireless High Definition
Video
Position location and
tracking
Cable Free Environment
How UWB works?Multiple Access TechniquesModulation SchemesTransmitter and Receiver
Multiple Access Techniques
Time Hopping → TH-UWB
Direct Sequence → DS-UWB
Time Hopping: TH-UWB
Ns = 6 (6 frames per symbol) Time Hopping sequence = {2,1,2,3,1,0} Tf = 4Tc
Time Hopping: TH-UWB (continue)
Direct Sequence: DS-UWB
Modulation Schemes
Pulse Position Modulation (PPM)
Binary Phase Shift Keying (BPSK)
Bi-Orthogonal Keying (BOK)
Pulse Amplitude Modulation (PAM)
On/Off Keying (OOK)
Modulation ExamplesPulse Position Modulation (PPM) Usually used with TH-
UWB
Example: 4-ary PPM with data 01
Bipolar Signaling (BPSK) Very energy efficient Usually used in TH-UWB and
DS UWB
Example: BPSK with data 1
Bi-Orthogonal Keying (BOK) PPM + BPSK Used in Std 802.15.3
Example: 4-ary BOK with data 10
Modulation ExamplesPulse Amplitude Modulation (PAM) Poor energy efficiency
Example: 4-ary PAM with data sequence: 01, 11, 00, 10
On/Off Keying (OOK) Simple implementation Poor energy efficiency
Example: OOK with data sequence: 1, 0, 0, 1
Transmitter and Receiver
Standards: Range and Data rate
WLAN™IEEE 802.11
WPAN™IEEE 802.15
WMAN™IEEE 802.16
802.15.1“Bluetooth”
802.15.3“High Data Rate” MAC & 2.4 GHz PHY
Task Group 3aAlt PHY (UWB)
802.15.4“Zigbee” 2.4 GHz
LAN/MAN Standards Committee (Wireless Areas)
802.15.2Coexistence
MBWAIEEE 802.20
Regulatory TAGIEEE 802.18
Coexistence TAGIEEE 802.19
Study Group 4a(UWB?)
Standardization
Wireless Personal Area Networks using UWB as PHY options IEEE standard of 802.15.3a for high data rate IEEE standard of 802.15.4a for low data rate
IEEE 802.15.3ao DS-UWB vs. MB-OFDM-UWBo Proposal with drawn on Jan 2006o Market will decide the surviving technology
IEEE 802.15.4a (Draft)o Communicationso High precision ranging and locationo In progress
Conclusion
Conclusion
UWB is currently an interesting topic for researchers and is at the stage of development.
A radio platform that connects seamlessly with the existing networking protocols and cost effectively enables connectivity solutions between CE peripherals will shift the home entertainment environment. It will enable multiple usage models from cable replacement to the high data rate streaming of video and audio and other entertainment media.
Q & AAny Question? Comments? Suggestions?
The End