Transcript forward-looking Directional Ultra Wideband (UWB) Channel Characterization By Dr. Ali Hussein Muqaibel King Fahd University of Petroleum & Minerals Electrical Engineering Department 1st CIT research Open Day 30-Mar-08

forward-looking
Directional Ultra Wideband
(UWB) Channel Characterization
By
Dr. Ali Hussein Muqaibel
King Fahd University of Petroleum & Minerals
Electrical Engineering Department
1st CIT research Open Day
30-Mar-08
1
Topics
Communication
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Definition
Advantageous
CRITICALITIES
Applications
Prototypes
Modulation
Multiple Access UWB Communication
UWB Coexistence Issues
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Electromagnatics
Transient Theory
Signal Processing
Radar
Channel Measurements
Channel Modelling (Temporal / Directional)
Research Areas in UWB Communication
Research groups & Companies
UWB is an “old” technology with the potential to
significantly impact the traditional way of
managing the spectrum
2
What is UWB ?
 An UWB transmitter is defined as an intentional radiator that, at any
point in time, has a fractional bandwidth of greater than or equal to 0.2
or occupy a bandwidth greater than 500 MHz regardless of the
fractional bandwidth [FCC].
 Generally exhibits a transient impulse response.


Impulse Radio-UWB Communication uses fairly short (sub-nano) pulses
instead of continuous waves to transmit information.
OFDM-UWB.
Density
Power Spectral
SIGNAL STRENGTH
AT DISTANCE R
25% to >100%
< 1%
1/F
3
FREQUENCY (F)
Channel Capacity of UWB
 Shannon’s Channel Capacity Theorem:
C  B * log2 (1 SNR)
14
x 10
Channel Capacity (Bits/sec)
12
8
Computed
Bandwidths
1 MHz
10 MHz
20 MHz
30 MHz
40 MHz
50 MHz
60 MHz
70 MHz
80 MHz
90 MHz
100 MHz
200 MHz
500 MHz
1 GHz
UWB
10
8
6
500 Mbps
4
2
0
-10
NB
0
10
SNR (dB)
20
30
40
4
Historical Perspective on Ultra-Wideband (UWB)
History
 Today’s Environment
 UWB Revolution
<1900 Hertz
 Scarcity of available
 By 2000 Large
generated pulsed
spark discharge
In 1940’s used for
radar
In 1970’s matured
as solution for
covert military
communications
In 1990’s
developed for
location and
positioning
applications
spectrum for new
applications
 Proliferation of digital
consumer electronics
devices
 Advances in
microprocessor power
 Numerous
improvements in
process technology
(such as SiGe, CMOS
and GaAs)
companies had
applied UWB to
networking
applications
 UWB meets
requirements for high
throughput
applications
 Recycles scarce
spectrum
5
Promised!: UWB System Advantages
• New technology: considerable development potential.
• Nearly "all-digital", with minimal RF electronics.
• An LPD signature produces minimal interference to proximity systems ,
minimal RF health hazards and is hardly interceptible.
• Extremely high data rate performance in multi-user network applications.
• Can provide very fine range resolution and precision distance and/or
positioning measurement capabilities.
• Relativity immune to multipath cancellation effects as observed in mobile and
in-building environments.
• Low Power Consumption
6
UWB CRITICALITIES
• Coexistence (FCC)
• Multi-user capability
• Real world performance
mobile B
NORMAL
mobile A
• Implementation complexity
mobile C
Interference level
• Cost and competitiveness
• Connectivity with narrowband systems
Do many UWB devices operating within a small area cause serious
interference to existing licensed services ?
7
Some UWB Applications
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Wireless USB
Digital Video Networks
Short range radios
High Speed (tens Mb/s) WLANs, microphones, etc.
Precision Geo-location Systems
Industrial RF Monitoring Systems
Collision Avoidance Sensors
 Motion and Intrusion Detection Radar
 Automobile and aircraft proximity radar, including precision
automatic landing
 Subsurface in-ground penetration radar
8
Networking
 Personal Area Networking (PAN), connecting cell
phones, laptops, PDAs, cameras, MP3 players.

Much higher data rates than Bluetooth or 802.11.
 Can be integrated into automotive in-car services and
entertainment.
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Download driving directions from PDA/laptop for use
by on-board navigation system using GPS.
Download audio and videos for passenger.
9
UWB Radar
 Radar signal ‘changes’ as it travels and is reflected and
absorbed (causing additions, subtractions, differentiations and
integrations).
 Conventional Radar uses sinusoidal and quasi-sinusoidal
signals
 These ‘changes’ cause amplitude and time shift
 UWB radar uses pulses
 These ‘changes’ cause amplitude and time shifts but also
change in the shape of the waveform
 Many possible levels of complexity depending on the
application.
 More information can be extracted with more complex
processing.
10
Vehicular Short Range Radar (SRR)
 UWB radar allows detection of moving targets without using

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Doppler effect.
Ability to measure both stationary and moving objects on and
nearby the road.
Calculation of the cartesian position of the objects requires a
high ranging accuracy as well as target separation capability
necessitating large bandwidth.
Different materials and environments distort of pulses differently.
This information could be used for better object identification.
(Need for accurate channel models).
Reduce post detection signal processing, esp. for some radar
applications that require fast Fourier and inverse fast Fourier
transforms, because of the time resolution of the UWB system.
11
Information Services
Info-station concept
 Road side ‘markers’ containing UWB transmitters.
 Short burst of very high rate data (100s of Mbps for 1-3
sec at a time)
 Messages could contain road conditions, construction,
weather advisories.
 Allow for emergency assistance communication.
12
Information Services
Info-station concept
 Service station
 While, pumping gas, latest
video or other content could
purchased for download and
viewing later at home or by
passengers in the vehicle.
13
Vehicular Radar
Collision
Avoidance/Detection
 Driver aid/alert to avoid
collisions.
 Aid for airbag/restraint
deployment
 Resolution to distinguish
cars/people/animals on or
near road
Image from presentation by Prof. Dr. Knoll of SARA at
2nd Workshop on introduction of Ultra Wideband
Services in Europe
14
Collision Avoidance Example
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600 MHz instantaneous BW
High-speed, dual tunnel
detector
Range
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Reference: Fontana, R. “Ultra Wideband
Technology - The Wave of the Future?” ITC/USA
2000, Oct. 2000.
1 - 50 feet against human
target
1 - 200 feet against pickup
truck
Clutter resistant
Extremely low false alarm
rate
15
Vehicular Radar
Road Conditions Sensing
 UWB radar has the resolution to sense road
conditions (i.e. dips, bumps, gravel vs. pavement).
 Information to dynamically adjust suspension,
braking, and other drive systems.
16
Communication Prototypes
Time Domain has built several prototypes including the following:
•A full duplex 1.3 GHz system with an average output power of 250 microWatts,
and a variable data rate of either 39 kbps or 156 kbps. The radio has been tested
to beyond 16 kilometers (10 miles).
•A full duplex 1.7 GHz walkie-talkie with an average output power of 2 milliWatts,
a data rate of 32 kbps and a range of 900 meters. The unit was also capable of
measuring the distance between radios with an accuracy of 3 cm (0.1 ft).
•A simplex 2.0 GHz data link with an effective average output power of 50
microWatts, a data rate of 5 Mbps at bit error rate (BER) of 0 with no forward
error correction (FEC) and a range of 10 meters (32 ft) through two walls inside
an office building.
17
UWB Products, Location
Aether Wire & Locations (AWL)
Development of pager-sized units that are capable of
localization to submeter accuracy over 100-meter distances
in networks of up to a few hundred localizers.
 A prototype localizer consists of two chips

Actual size
with Dime
TX (Driver2)
RX (Aether5)
18
Reference: http://www.aetherwire.com/
Trinity Chip Set
 Xtreme Spectrum Inc. has
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released Trinity chip set.
Data rates of 25, 50, 75 and
100 Mbps.
MAC, baseband processor,
RF transceiver, LNA, and
antenna
Streaming video
applications.
Wireless Fast Ethernet,
USB2, and 1394.
19
PulsON ASICs
 Time Domain Corporation is marketing
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Image from Kelley, D., Reinhardt, S., Stanley, R.,
Einhorn, M. “PulsON Second Generation Timing Chip;
Enabling UWB Through Precise Timing”, Proc. of the
IEEE Conference on Ultra Wideband Systems and
Technology 2002.
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PulsON family of UWB silicon products.
Indoor wireless networking, 100's Mbps
Indoor personnel and asset tracking
systems.
Precision measurement systems for
surveying and measurement.
Radar, 20 cm accuracy
Through wall sensing.
Industrial sensing for robotic controls.
Automotive sensing for collision
avoidance.
Security bubbles for home and industrial
security systems.
20
UWB Products, Communications
MultiSpectral Solutions Inc.
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Communications, Mobile ad hoc Network (MANET)
128 kbps voice, 115.2 kbps data or 1.544 Mbps (T1)
Range: 1-2 km (node-to-node) with omni antennas
Reference: Fontana, R. “Ultra Wideband
Technology - The Wave of the Future?” ITC/USA
2000, Oct. 2000.
21
UWB Products, Location
MultiSpectral Solutions Inc.
 High resolution, geolocation
system, 3-D positioning
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Sub-foot resolution
Range
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Up to 2 km outdoors
Up to 100 meters
indoors
UWB Geopositioning
Example
Reference: Fontana, R. “Ultra Wideband
Technology - The Wave of the Future?” ITC/USA
2000, Oct. 2000.
Reference: Fontana, R. “Ultra Wideband
Technology - The Wave of the Future?” ITC/USA
2000, Oct. 2000.
22
Received Signal
 Multiple Access, when the physical layer is UWB, is achieved by
using time hopping codes
 When the number of users is Nu , the received signal is:
Nu

st     wrec (t   k (u)  jT f  c (jk ) (u)Tc  d ( kj /)N s  (u))  n(t , u)
k 1 j  
J=0
J=1
J=2
J=3
k=1
k=2
k=3
k=4
Nu =4
Tf
Tc
23
Pulse Position Modulation
Reference Signals
1.5
Transmitted Gaussian Monocycle Waveform Wtr
received signal bit=0
received signal bit=1
template signal v(t)
1
1
Gaussian Monocycle
0.8
0.5
0.4
0.2
amplitude
Amplitude / Normalized to A
0.6
0
-0.2
-0.4
0
-0.6
-0.5
-0.8
-1
0
0.5
1
1.5
2
Time (ns)
-1
-1.5
0
0.1
0.2
0.3
0.4
0.5
0.6
t in nanoseconds
0.7
0.8
0.9
1
wrec (t  0.35)  [1  4 (t /  m )2 ] exp (4 t /  m  ) with  m  0.2877
2
24
Gaussian, Monocycle and Doublet Waveforms
Gaussian, Gaussian Monocycle and Doublet Waveforms
Gaussian, Gaussian Monocycle and Doublet in Frequency Domain
1
Gaussian
Gaussian Monocycle
Doublet
0
0.8
10
Amplitude / Normalized to 1
Amplitude / Normalized to A
0.6
0.4
0.2
0
-0.2
-0.4
-2
10
-4
10
-6
10
-0.6
Gaussian
Gaussian Monocycle
Doublet
-0.8
-1
0
0.1
0.2
0.3
•
•
•
•
•
0.4
Time (ns)
0.5
0.6
0.7
-8
10
0.8
0
2
4
6
8
Frequency (GHz)
10
12
2GHz (>1Mhz) , noise like.
fc typically 650 MHz – 5MHz.
Tightly controlled pulse-to-pulse interval.
Pulse width 0.2 –1.5 nanoseconds.
Pulse-to-Pulse interval 100-1000 nano-seconds.
25
Co-existence Issue: Reply Comments
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1.
2.
Wide agreement that this technology is very promising, there is a very
broad applications range
Strong concern to allow the UWB devices operate below 2 GHz or even
below 3 GHz.
4.
they should be licensed !
This technology should not use (re-use the paid spectrum by others) the
spectrum for free !
This technology is still immature and we don’t know what the interference
problems may rise
Extend the period of time to complete the interference tests

Worldwide regulation
3.
26
Regulatory Issues
 FCC has released First Report and Order (R&O) permitting the
manufacture of UWB devices (April 22, 2002).
 Defined 3 types of UWB devices
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Imaging Systems.
Communications and Measurement Systems.
Vehicular Radar.
 Below 960 MHz, all types must meet FCC § 15.209 limits.
27
FCC Mask for Vehicular Radar
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Must have a center frequency
greater than 24.075 GHz.
Requires use of a directional
antennas or other method that will
attenuate the emissions 38
degrees or higher above the
horizontal plane in the 23.6-24.0
GHz band by additional 25 dB
“High enough in frequency to
permit the use of an antenna small
enough to be mounted on an
automobile.” -FCC R&O
28
FCC Mask for Comm/Meas
 Transmit only will
operating with a
receiver.
 Indoor

Must show that they
will not operate when
taken outside (ex:
require AC power).
 Handheld (outdoor)

Operate in a peer-topeer mode without
location restriction.
29
FCC Mask for Imaging (Low Freq)
 GPR, wall imaging,
through wall imaging.
 -10 dB bandwidth below
960 MHz
 Use restricted to those
licensed under Part 90
rules and complete a
coordination procedure
with the Government.
30
FCC Mask for Imaging (Mid Freq)
 Through-wall and
surveillance systems
 -10 dB bandwidth between
1.99 and 10.6 GHz
 Use restricted to those
licensed under Part 90
rules and complete a
coordination procedure with
the Government.
31
FCC Mask for Imaging (High Freq)
 GPRs, wall, and medical
imaging devices
 -10 dB bandwidth
between 3.1 and 10.6
GHz
 Must complete a
coordination procedure
with the Government.
32
Channel Measurement
 Propagation for communications and radar system.
 Interference to narrowband communications and
other electronics.
 Resistance of UWB to interference.
 Must understand channel effects to fully exploit the
unique properties of UWB.
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
Affects communications waveform/modulation/receiver
design.
Material/shape/range of objects affect radar signature.
33
Measurement Metrics
 Path loss
 Impact of environment
 Impact of signal type/frequency band
 Multipath characteristics
 Number of multipath components
 Multipath amplitude distribution
 Multipath Delay distribution
 Spatial variation (fading)
 Spectral Characteristics
 Impact of modulation, center frequency, distance
 Material penetration/attenuation measurements
 Drywall, concrete, windows, office partitions, etc.
 Angle (Direction of Arrival)
34
Channel Measurement Environments
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Indoor
 Within a room (LOS, NLOS),
Between rooms/floors, Down
hallways
 Will investigate the impact of
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distance
Rx/Tx Antenna Height
antenna polarization
Indoor-to-outdoor
Outdoor
 Campus environment
 Rural, Hilly, Impact of foliage
 Urban
 “Low altitude”
 Impact of distance (up to ~1km)
 Mobility (Pedestrian, Vehicular)
In Vehicle
 Automotive, airliner
Ex: Indoor Measurements
Ex: Outdoor Measurements
35
Time Domain (TD) Measurement Setup
Running
LabView® 6.0i
Tektronics 11801/HP
54120A
Digitizing Oscilloscope
LN Amplifiers
Data Acquisition
Unit
trigger
input
Channel
Balun and
wideband transmitting antenna
Balun and
wideband receiving antenna
pretrigger
trigger
Pulse Generator
Pico-second Pulse Labs model
4050A/4100
Step Generator
Driver
36
Bandpass Pulse Sounder
Pulse Shaping
Filter
fo=1850 MHz
BW = 250 MHz
Antenna
Mixer
Output
BPF
BPF
UWB pulse
transmitter
Antenna
fo= 29 GHz
BW = 300 MHz
Power
Amp
Local
Osc
27.5 GHz
Mixer
Output
BPF
Input
BPF
Low Noise
Amplifier
fo= 29 GHz
BW = 300 MHz
Local
Osc
27.5 GHz
fo=1850 MHz
BW = 250 MHz
UWB receiver
37
Frequency Domain (FD) Measurement Setup
Channel
Balun and
wideband horn transmitting antenna
Balun and
wideband horn receiving antenna
Vector Network Analyzer with
Swept Frequency Oscillator
Y(ω)
X(ω)
Port 2
Port 1
S-parameter test set
Inverse DFT
Processing
Data Acquisition unit
38
Directional UWB Simulator
 Includes the Transfer Function of the
Transmit antenna & the receive antenna.
 Utilize IEEE802.15 model (temporal)
39
Antennas and Radiated Measurements
-35
0.05
3
4050A
4100
HP 8510 Network Analayzer
Received
Time-gated
0.04
-40
2
Amplitude (V)
0.01
0
-0.01
-0.02
-0.03
Phase for Antenna#1 (radians)
Transfer Function Amplitude (dB)
0.03
0.02
4050A
4100
-45
-50
-55
1
0
-1
-2
-60
-0.04
-0.05
-65
0
0.5
1
1.5
2
2.5
Time (ns)
3
3.5
4
Stripline
Feed
5
10
15
0
5
Frequency (GHz)
Received boresight signal
Antenna#1 TEM Horn
-3
0
10
15
Frequency (GHz)
Boresight Spectrum Magnitude
Boresight Spectrum phase
0.15
0.1
0.1
0.0
8
∑
∆
Amplitude (V)
Amplitude (V)
0.05
0
0.0
4
0.0
2
-0.05
0
-0.1
0
Lower
Antenna
0.0
6
0.5
1
1.5
2
2.5
Time (ns)
3
3.5
4
4.5
0
1
2
3
4
5
6
Time (ns)
7
8
9
10
Phase Shifter
Antenna#2 TEM Horn Array
Received boresight signal
Antenna#3 Bicone
Received boresight signal
40
Multipath Angle and Pulse Shape
60o
60o
Side Wall
ceiling
Rx
45o
Tx
Rx
45o
Tx
30o
Side Wall
30o
floor
15o
15o

Sources and Antennas Characterization:
0
Compare and test the measurement
setups
0o
receiving
receiving antenna
Maximum
and average power measurements
and
dynamic range.
z
antenna
-15
-15
Evaluate the ringing and mismatch.
y
Understand the effect of the antenna on the radiated pulse shape. -30
-30
x
Characterization bandwidth.
-45
The effect of the angle-45of transmission and angle of arrival on the captured
-60
pulse shape.
-60
H-Scan (Azimuth Angle)
E-Scan (Elevation Angle)
o
o
o
o
o
o
o
o
o
41
Acquired Signals
Sent Impulse
Monocycle
250
50
40
200
30
20
Amplitude (mV)
Amplitude (mV)
150
100
10
0
-10
0.0
0.2
0.4
0.6
0.8
1.0
-20
50
-30
-40
0
0.0
0.2
0.4
0.6
0.8
1.0
-50
-60
-50
time (nano-seconds)
time (nano-seconds)
•The transmitted signal could get differentiated before it is decoded
•Multiple reflection cannot be avoided
42
Measurements in Hand (or through web)
Photo for location 4C with cubical partitions
Hallways in Durham Hall, location 2B
Blueprint for the fourth floor of Durham Hall
43
Multipath Scenarios
close to ground
Amplitude in V
0.02
0.01
0
-0.01
Amplitude in V
2
4
6
8
12
10
Time ns
14
16
18
20
Higher
0.02
0
-0.02
0
2
4
6
8
12
10
Time ns
14
16
18
20
44
Models
 “System” models
 path loss estimation
 appropriate for link budget analysis and
interference prediction
 perhaps similar to Hata model for cellular
 “Receiver” models
 multipath statistical characterization
 appropriate for receiver design
 perhaps similar to Hashemi model or
Saleh/Valenzuela model for wideband indoor
45
Path Loss Model
 The commonly used Friis transmission formula may
give misleading or incorrect results when applied to
UWB systems.
 Friis, or "path loss," formulas predict that the received
signal power will decrease with the square of
increasing frequency.
 UWB signals span a very large bandwidth such that
change in received power over the bandwidth cannot
be ignored as in narrowband systems.

This will distort the frequency spectrum of UWB pulses
and thus distort the pulse shape.
Reference: Sweeney, D. “Towards a Link Budget for Ultra Wideband (UWB)
Systems”. Presented to VT UWB Working Group, June 2002.
46
Different Measurements
Source 1
Source 2
Network Analyzer (ifft)
-5
0.12
x 10
0.06
Free-Space Reference
Through
0.1
Free-Space Reference
Through
Free-Space Impulse Resopnse
Through Impulse Response
15
0.08
10
Amplitude V
0.04
0.02
Amplitude
0.02
0.06
Amplitude V
Antenna 1
0.04
0
-0.02
5
0
0
-0.04
-0.02
-0.04
-5
0
0.5
1
0.25
1.5
time ns
2
2.5
-0.06
3
0
0.5
1
0.1
1.5
time ns
Free-Space Reference
Through
2
2.5
3
0
-4
x 10
3
Free-Space Reference
Through
1
1.5
time ns
2
2.5
3
Free-Space Impulse Resopnse
Through Impulse Response
2.5
0.2
2
0.05
1.5
0.1
Amplitude
Amplitude V
0.15
Amplitude V
Antenna 2
0.5
0
0.05
1
0.5
0
-0.5
-0.05
-1
0
-1.5
0
0.5
1
1.5
time ns
2
2.5
3
-0.1
0
0.5
1
1.5
time ns
2
2.5
3
-2
0
0.5
1
1.5
time ns
2
2.5
3
47
Marital Pictures (Bricks, Blocks, Styrofoam)
a
d1
h
b
d2
w
l
w = 8.53542 cml = 19.8 cm
h = 5.82676 cma = 3.5179 cm
b = 4.15036 cmd1 = 1.905 cm
d2 = 2.159 cm
a
d
c
e
b
b
a = 12.2 cm
b = 12.5 cm
c = 4.8 cm
d = 3.7 cm
e = 3.2 cm
48
More Materials
Wall-board
Sample Door
TDL Reinforced Concrete Pillar
PlyWood
Glass
Structure Wood
Office Partition
Whittemore 3rd floor Reinforced Concrete Pillar
49
Transient Insight
Source 2 Antenna 1 through brick measurement
0.05
Free-Space Reference
Through
0.04
0.03
Reference
0.2
0.02
Amplitude (V)
Amplitude (V)
0.4
0
-0.2
-0.4
0
5
10
15
0.01
0
-0.01
time (ns)
Amplitude (V)
0.04
-0.02
Through
0.02
Bricks wall
-0.03
0
-0.04
-0.02
-0.04
0
5
10
15
0
1
2
3
time (ns)
4
5
0.2
time (ns)
Free-Space Reference
Through
0.04
Amplitude (V)
6
Through, Long Profile
0.15
0.02
0.1
0
-0.02
0.05
0
10
20
30
40
50
time (ns)
60
70
80
90
100
• Effect of multiple reflections inside the wall.
Amplitude (V)
• Applicability of matched filter receiver (LOS/NLOS).
-0.04
0
-0.05
-0.1
• Extended time-domain response.
Blocks wall
-0.15
-0.2
0
1
2
3
4
5
time (ns)
6
7
8
9
50
10
Model Deconvolution
 The impulse response of the NB propagation
channel is often modeled as
I
h(t )   ai  (t   i )
i
 Does not fit the UWB channel because the
delta function at the receiver implies a wide
channel bandwidth relative to the bandwidth
of the excitation pulse.
 Deconvolution is need!
51
Subtractive Deconvolution
0.05
0.4
0
0.3
-0.05
-0.1
0.2
0
1
2
3
Amplitude (V)
0.1
4
time (ns)
5
6
7
8
0.1
0
-0.1
-0.2
0.05
-0.3
0
-0.4
-0.5
-0.05
-0.1
0
0
1
2
3
4
time (ns)
5
6
7
8
0
1
2
3
4
time (ns)
5
6
7
8
0.1
Amplitude (V)
0
15
30
45
60
0.5
Amplitude V
Amplitude (V)
0.1
1
2
3
4
5
Time ns
0.05
0
-0.05
-0.1
(a) Received profile, (b)reconstructed with zero-insertion,
(c) reconstructed with subtractive deconvolution
52
Energy capture
Goal :"best" values for the amplitude, delay and
template shape (angles) such that the synthesized
waveform is well matched to the received waveform.
Energy capture, EC,

r (t )  rc (t )

EC (L p )  1 
2
r (t )


2


 100%


53
Energy capture using zero-insertion
and subtractive deconvolution
Energy Capture (%)
60
50
40
30
Zero Insertion
Subtractive
20
10
2
4
6
8
10
12
14
16
Number of Single-Path Correlators
18
20
54
Energy capture for different number of
reference templates
85
5 LOS
5 NLOS
1 LOS
1 NLOS
80
75
Energy Capture (%)
70
65
60
55
50
45
40
35
2
4
6
8
10
12
14
Number of Single-Path Correlators
16
18
20
55
Extracted angle distribution for LOS
and NLOS scenarios
45
5 LOS
5 NLOS
40
Occurrence (%)
35
30
25
20
15
10
5
0
10
40
30
20
Angle in Degrees
50
60
56
Current Conclusions on
Directional UWB Characterization
The captured energy increases by more than 10%
when using five directional correlators rather than
one.
The use of subtractive deconvolution rather than
zero-insertion used by previous authors allowed for
resolving overlapping components and increased
the captured energy.
Further extension of the work would include
optimizing the choices of reference templates
based on extensive antenna measurements.
57
Areas in UWB Research Communication







Interference Measurements
Measurements
Antenna Design
Spread Spectrum Techniques
Signal Processing
Models
&
Multiple Access Techniques
Receiver Design
Multi-user detection
Time Hopping Codes
System Performance Evaluation under different
channel conditions (Gaussian, Raleigh)
 Coding and Diversity Applications
 Pulse Shaping and Modulation
58
Working Towards UWB Wireless Communication
Dr. Ali Hussein Muqaibel
[email protected]
King Fahd University of Petroleum & Minerals
Electrical Engineering Department
59
Research Groups
 Ultra Wideband Working Group (UWBWG) www.uwb.org
 Ultra Lab Web ultra.usc.edu/ulab/

University of Texas, Center of Ultra Wideband Research and
Engineering sgl.arlut.utexas.edu/asd/Cure/impulse.html
 Time Domain Laboratory (VT) tdl.ece.vt.edu
 Time Domain www.time-domain.com
 Bibliography Of Ultra-wideband Technology
www.aetherwire.com/CDROM/General/biblio.html
 Presentations from the 1st European Ultra Wideband Workshop
www.cordis.lu/ist/ka4/mobile/uwb_workshop.htm

Ultra Wideband (UWB) Frequently Asked Questions (FAQ)
www.multispectral.com/UWBFAQ.html
60