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Copyright 2004 VTVT Lab, Virginia Tech
1
UWB Applications and UWB Applications and TechnologiesTechnologies
Presentation for PersonalTelco Project
Nathaniel August
VTVT (Virginia Tech VLSI for Telecommunications) GroupDepartment of Electrical and Computer Engineering
Virginia TechBlacksburg, VA 24061, USA
nateaugu@vt.edu, www.ee.vt.edu/~ha
March 31, 2004
Copyright 2004 VTVT Lab, Virginia Tech
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OverviewOverview
IntroductionHistoryDefinitionSignaling
Industry ActivitiesIEEE Standardization Efforts
Copyright 2004 VTVT Lab, Virginia Tech
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Virginia TechVirginia Tech
Copyright 2004 VTVT Lab, Virginia Tech
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DefinitionDefinition
In terms of bandwidth Ultra Wideband BW >> Wideband BW >> Narrowband BW
Narrowband
Pow
er S
pect
ral
Den
sity
(dB
)
UWB
Wideband
Frequency
Copyright 2004 VTVT Lab, Virginia Tech
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HistoryHistory
James Maxwell develops theory of EM waves: Maxwell’s Equations
Heinrich Hertz produces these waves and detects them
Guglielmo Marconi applies EM waves for telegraphy
1870
1890
Early wireless is
UWB!
Copyright 2004 VTVT Lab, Virginia Tech
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HistoryHistory
Marconi and Hertz used “spark gap” transmissions
Charge builds on the capacitor until the air is ionizedCurrent briefly flows in the circuitResulting transmission is a few cycles of a damped sinusoid
Did not take advantage of ultra wide bandwidthUsed mainly with Morse code and telegraphy
The circuit produces a
visible spark
Copyright 2004 VTVT Lab, Virginia Tech
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HistoryHistory
Narrowband transmitters appear
Government regulates the spectrum and divides it into bands
AM & FM radio, television appear
Ionospheric propagation
Wideband OFDM & CDMA
Claude Shannon develops information theory
1900
1950
“Dark ages”of
narrowband
Copyright 2004 VTVT Lab, Virginia Tech
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HistoryHistory
Military investigates UWB for communications and radar
Patents and publications on UWB
Commercial products appear with FCC waiver
FCC formally reserves spectrum for UWB
1950
2002
UWB Renaissance
MSSI
Copyright 2004 VTVT Lab, Virginia Tech
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FCC DefinitionFCC Definition
Ultra wideband fractional bandwidth is greater than 0.20 or absolute bandwidth is greater than 500 MHz or more.
The FCC doesn’t regulate the method to achieve the ultra wide bandwidth.
Frequency (Hz)
Pow
er S
pect
ral
Den
sity
(dB
)
fL fHfC
-10dB UWB: (fH – fL) > 0.20*fC or
(fH – fL) > 500 MHz
NB: (fH – fL) < 0.01*fC
Copyright 2004 VTVT Lab, Virginia Tech
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Typical UWB Emission LimitsTypical UWB Emission Limits
For indoor systems
0.96 1.61
1.993.1 10.6
GPSband
Copyright 2004 VTVT Lab, Virginia Tech
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UWB AdvantagesUWB Advantages
Wide bandwidth leads to dual capabilitiesHigh data rate communicationsHigh precision (sub-centimeter) radar
-10 0 10 20 30 400
2
4
6
8
10
12
14 x 108
SNR (dB)
Cha
nnel
Cap
acity
(Bits
/sec
)
500 Mbps
UWB
NB
1 MHz10 MHz20 MHz30 MHz40 MHz50 MHz60 MHz70 MHz80 MHz90 MHz100 MHz200 MHz500 MHz1 GHz
Computed BandwidthsSNR)(1log*BC 2 +=
Copyright 2004 VTVT Lab, Virginia Tech
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UWB AdvantagesUWB Advantages
Overlays existing spectrum“Like a freight train down a highway without any cars noticing”
Excellent immunity to interference from other radio systems or multipathsExtremely difficult to intercept – wide spectrum and low-energyLow power and low cost
Simple hardware structure; typically no carrierCMOS solution in near future
Unlicensed for communications and measurement use
Copyright 2004 VTVT Lab, Virginia Tech
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ApplicationsApplications
Location FindingPosition location –inventoryRF IDPlanetary exploration
Wireless Communications Systems
Home networking /PANRoadside Info-stationShort range radiosMilitary communicationsWireless sensor networks
High Resolution Radar and Sensing
Vehicle radarSee-through-the-walls (Police, fire, rescue)Ground penetrating radar Medical imagingSurveillance
Copyright 2004 VTVT Lab, Virginia Tech
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UWB SignalingUWB Signaling
Design space ranges fromSingle, narrow pulsesMultiple narrowband (continuous wave) signals
Proposed Solutions to 802.15.3a
I-UWB
DS-CDMA MB-OFDM
MC-UWB
SingleSignal
MultipleSignals
Copyright 2004 VTVT Lab, Virginia Tech
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Pulse Based SignalingPulse Based Signaling
0-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Gaussian monocycle in time domain
Time
Nor
mal
ized
am
plitu
de
0 2 4 6 8 10 12 14 16
x 109
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10Gaussian monocycle in frequency domain
Frequency (Hz)
Nor
mal
ized
Spe
ctru
m [d
B]
τ=0.12 ns
fc=2.65 GHz
Single signal has better short range multipath immunity and moreaccurate rangingNo carrier means low hardware complexity and low powerPulse shapes
Gaussian, Hermetian Families
Copyright 2004 VTVT Lab, Virginia Tech
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Modulation TypesModulation Types
Binary Modulation: data 1 0 1Pulse Position Modulation (PPM)
Pulse Amplitude Modulation (PAM)
On Off Keying (OOK)
Bi-phase Shift Keying (BPSK)
Copyright 2004 VTVT Lab, Virginia Tech
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DSDS--UWB (CDMA) SignalingUWB (CDMA) Signaling
Pulses modulated onto a carrierThe carrier is spread (multiplied) by a sequence of [+1, -1]More protection from interferenceEach spreading sequence is a channel
0.52 0.53 0.54 0.55 0.56 0.57 0.58 0.59 0.6 0.61 0.62-1.5
-1
-0.5
0
0.5
1
1.5
Time (us)
Am
plitu
de (V
)
DS-UWB WaveformPN Sequence
Copyright 2004 VTVT Lab, Virginia Tech
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Multicarrier Multicarrier SystemsSystems
Several narrowbandcarriersModulation just like narrowband systemsAggregate bandwidth is ultra wide by FCC’s definitionEx: MB-OFDM
f0
f1
f2
f3
f4
f5One symbol duration
Copyright 2004 VTVT Lab, Virginia Tech
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Industry ActivityIndustry Activity
Copyright 2004 VTVT Lab, Virginia Tech
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Time Domain Corporation (TDC)Time Domain Corporation (TDC)
Founded in 1987Targets communications and location aware applicationsPatented PPM modulationPatented time hopping multiple accessPulsOn chipset (SiGe)
First commercial solutionReceived special FCC waiver for 0.1 – 1.3 GHz operation5 Mbps, 1-16 km rangeInitially targeted sub $200 handset market
http://www.timedomain.com/
Copyright 2004 VTVT Lab, Virginia Tech
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MultiSpectralMultiSpectral Solutions Inc. Solutions Inc. (MSSI)(MSSI)
Founded in 1989Most product consist of COTS components
Wireless technology for communicationsPrecision asset location systemsMicro air vehicle obstacle/collision avoidance systemUWB intrusion detection system for long range perimeter surveillance
Communications Asset Location Collision Avoidance
*
http://www.multispectral.com/
Copyright 2004 VTVT Lab, Virginia Tech
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IntelIntel
Developed a channel modelInvestigated feasibility for CMOS integrationWireless USB – supports the processorBacks MB-OFDM approach for 802.15.3a
Achieved 100 Mbps (Feb. 28, 2002)http://www.intel.com/labs
Copyright 2004 VTVT Lab, Virginia Tech
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XtremeXtreme Spectrum Inc. (XSI)Spectrum Inc. (XSI)
Founded in 1998, bought by Motorola in fall 2003Targets home networkingPatented bi-phase modulationBacks DS-CDMA approach for 802.15.3aTrinity chipset
First FCC compliant commercial systemSiGe technology3.1 – 10.6 GHz rangeDemonstrated 100 Mbps systemUses 802.15.3 MAC< 200 mW total power
http://www.xtremespectrum.com/
Copyright 2004 VTVT Lab, Virginia Tech
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Standardization ActivitiesStandardization Activities
Copyright 2004 VTVT Lab, Virginia Tech
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UWB Standardization EffortsUWB Standardization Efforts
IEEE 802.15.3a – high data rate communicationsIEEE 802.15.4a – low data rate communications and radar (everything else)
Copyright 2004 VTVT Lab, Virginia Tech
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IEEE 802.15.3aIEEE 802.15.3a
Copyright 2004 VTVT Lab, Virginia Tech
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IEEE 802.15.3/3aIEEE 802.15.3/3a
IEEE 802.15.3 is an existing standard for WPANsDefines MAC layer and Bluetooth PHY layer
IEEE 802.15.3a proposes UWB PHYProposed applications
Replacement of high speed cable at home: Multi-cluster home network (XtremeSpectrum Inc.)Wireless peripheral at future office: Wireless USB (Intel)Wearable peripheral for CE (consumer equipment), health, or fashion of human beings (General Atomics)
Copyright 2004 VTVT Lab, Virginia Tech
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WPAN ApplicationsWPAN ApplicationsFuture home/office multi-cluster network
Home Office Cluster
(infrastructure)
USB Cluster (ad-hoc)
1394 Home Entertainment
Cluster (infrastructure-
based)
Kids’ room Cluster (ad-hoc or
infrastructure-based)
UMPW HUB
Gateway (OSGi)
Wired Backbone (HPNA, HomePlug, Ethernet, …) or 802.11a wireless Bridge (54-108Mbps)1394 Backbone
Reference: P802.15.3a 02/031r0 CFA
Copyright 2004 VTVT Lab, Virginia Tech
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Multiband OFDM PHY ProposalMultiband OFDM PHY Proposal
Has largest industry backing - Intel and TI are major backersNo silicon yetNot much different than 802.11a or 802.11g
ModulationSerial
toParallel
IFFT... Parallel
toSerial
...InputData
To RF
OFDM System
Copyright 2004 VTVT Lab, Virginia Tech
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Multiband OFDM PHY ProposalMultiband OFDM PHY Proposal
528 MHz bands with 128 narrowband tonesBands grouped into 4 distinct groups
f3432MHz
3960MHz
4488MHz
5016MHz
5808MHz
6336MHz
6864MHz
7392MHz
7920MHz
8448MHz
8976MHz
9504MHz
10032MHz
Band#1
Band#2
Band#3
Band#4
Band#5
Band#6
Band#7
Band#8
Band#9
Band#10
Band#11
Band#12
Band#13
GROUP A GROUP B GROUP C GROUP D
Time
9.5 ns Guard Time Cyclic Prefix 60.6 ns
312.5 ns
242.4 ns Information
Period=937.5 ns
3168
3696
4224
4752
Freq
uenc
y(M
Hz) #1
#2
#3
Copyright 2004 VTVT Lab, Virginia Tech
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DSDS--CDMA PHY ProposalCDMA PHY Proposal
Backed by Motorola/XtremeSpectrumSuccessfully demonstrated similar technology
3 4 5 6 7 8 9 10 11-40-35-30-25-20-15-10-50
GHz
dB
3 4 5 6 7 8 9 10 11-40-35-30-25-20-15-10-50
GHz
dB
3 4 5 6 7 8 9 10 11-40-35-30-25-20-15-10-50
GHz
dB
-1 0 1-1
-0.5
0
0.5
1Low Band25 to 400 Mbps
High Band25 to 900 Mbps
Multi-BandUp to 1.35 Gbps
LongWavelet
-1 0 1-1
-0.5
0
0.5
1
MidWavelet
-1 0 1-1
-0.5
0
0.5
1
DuplexWavelet
Copyright 2004 VTVT Lab, Virginia Tech
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Multiband OFDM vs. DSMultiband OFDM vs. DS--CDMACDMA
Interferences to othersMB-OFDM worse than AWGN or DS-CDMA at same power
FadingMB-OFDM has deep fade effect compared with DS-CDMA
Multipath Energy collectionMB-OFDM collects channel energy due to narrow tonesDS-CDMA uses rake receiver
PerformanceMB-OFDM maintains rate over longer rangeDS-CDMA has higher data rate / lower power at short rangeDS-CDMA has more accurate ranging ability
Copyright 2004 VTVT Lab, Virginia Tech
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Current StatusCurrent Status
Deadlocked since last summerMotorola brought a new proposal to last week’s meetingMotorola also promoted a 2 PHY solution using common signalingMB-OFDM is developing their own MAC outside of IEEE
Deadlock
MB-OFDMDS-CDMA
Copyright 2004 VTVT Lab, Virginia Tech
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IEEE 802.15.4aIEEE 802.15.4a
Copyright 2004 VTVT Lab, Virginia Tech
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IEEE 802.15.4a ApplicationsIEEE 802.15.4a Applications
Location aware applicationsLocating people – firefighter rescue, identify friendly soldier’s locations, track childrenLocating and tagging assets – autonomous manifesting for shipping, inventory control for warehouses, RFID, supply chain managementSmart homes – open doors, find keys, manage TV, radio, computers for individual preferences as individuals move throughout a home
Densely packed environmentsReal time tracking of assets on pallets in trucks or shipsWire replacement for remote sensors in industrial settingsSensor networks
Copyright 2004 VTVT Lab, Virginia Tech
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IEEE 802.15.4a CriteriaIEEE 802.15.4a Criteria
Full criteria release in May 2004Current requirements
Low data rate (1 Kbps - 10 Kbps)Support for 1000s of nodesMesh networkingMandatory location awarenessMandatory support for mobilityMax range of 30 m, more for asset trackingPower less than 1 mW – operate for years on battery life or energy scavenging
Proposals accepted after May 2004
Copyright 2004 VTVT Lab, Virginia Tech
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Research at Virginia TechResearch at Virginia Tech
CMOS UWB radio implementationChannel measurement and modelingAccurate ranging for asset locationEnergy efficient UWB radios for wireless ad hoc and sensor networksMAC protocols
EnergyDetector 0
0fFilter
1f
1−nf
ADCs
LNA
ResolvingMultipath
ConstructorTemplate
CorrelatorDomain
Frequency
BlockDecision
SamplerDomainFrequency HarvesterEnergy
Thresholdand
Combine
PulseSense
Pulse Sense Block
EnergyDetector 1
EnergyDetector n-1
Filter
Filter
Copyright 2004 VTVT Lab, Virginia Tech
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SummarySummary
UWB characteristicsLow power License freeWorld wide availabilityCan trade high data rate for distanceDual communication and radar capability
Standardization efforts802.15.3a MAC has been approved, while PHY is still being deliberated802.15.4a PHY has yet to be defined
Future trendsUWB offers great potentials for home networking, wireless sensors, and location aware systems.
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