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UWB (Ultra Wideband) Communication System
長庚電機通訊組 碩一 張晉銓
指導教授 : 黃文傑博士
Outline
Introduction to UWB Application of UWB UWB Spectrum FCC UWB Emission Limit Avoiding Interfering With Other Users Conclusion
UWB and 60 GHz radios potentially extend the range of application of radio technology
Carrier Frequency (GHz)
Pea
k D
ata
Rat
e (b
ps)
1 G
100 M
10 M
1 M
100 k
10 k
HDTV motion picture,Pt.-to-Pt. links
NTSC video;rapid file transfer
MPEG video;PC file transfer
Voice,Data
Cellular
3G
802.11b
60 GHzPt.-to-Pt.
60 GHzWLAN
Bluetooth
0.1 1 10 100
802.11a
ZigBee
UWB
UWB
F
Introduction to UWB 1/4
Extremely short pulses in the time domain Large bandwidth in the frequency domain Fractional bandwidth=(fH-fL)/fC> 25% or total bandwidth > 1,5 GHz
time / s
Am
plitu
de
frequency / Hz
Am
plitu
de
S
B
- Technology -
Introduction to UWB 2/4
advantage High data rates Low transmission power
(Bluetooth:1Mbps,10m,1mW
UWB: 1Mbps,10m,10 ㎼ )
Multipath immunity Simple implementation, low cost High spatial capacity (bps/m2)
- Technology-
disadvantage
• Short operating ranges
• Interference with other licensed, ”narrowband” systems
Introduction to UWB 3/4
FCC(Federal Communication Commission) approved the sale of UWB products in the United States under certain limits in February 2002
UWB devices are allowed to work on very low power levels to avoid interference
- Regulations -
Introduction to UWB 4/4
Automotive collision-detection systems Medical imaging Through-wall imaging Ground-penetrating radar Communications devices
- Applications -
In-Building Backbone and/or LANHighway Applications
Ad Hoc Video Links
Last 100 meters
Building-to-Building
Communications Backbone
60 GHz Beams XBC
Application Scenarios
UWB Spectrum FCC ruling permits UWB spectrum overlay
1.6 1.9 2.4
Bluetooth,802.11bCordless PhonesMicrowave OvensG
PS
PC
S
5
802.11a
-41 dBm/Mhz“Part 15 Limit”
UWB Spectrum
Frequency (Ghz)
EmittedSignalPower
10.63.1
FCC ruling issued 2/14/2002 after ~4 years of study FCC ruling issued 2/14/2002 after ~4 years of study & public debate& public debate
FCC believes current ruling is conservative FCC believes current ruling is conservative
FCC UWB Emission Limit for Outdoor Handheld Systems
FCC UWB Emission LimitFor Indoor Systems
Information Modulation
Pulse Position Modulation (PPM)
Pulse Amplitude Modulation (PAM)
On-Off Keying (OOK)
Bi-Phase Modulation (BPSK)
Pulse length <1ns; Energy concentrated in 2-6GHz band; Power < 10uW
Main data modulation schemes used for UWB systems
Time hopping pulse position modulation (TH-PPM)
Direct spread code division multiple access (DS-CDMA)
Subband (SB) UWB (Intal)
Avoiding Interfering With Other Users
Co-existence through very low power transmission: Operate so that aggregate Interference from UWB Transmissions is “Undetectable” (or Has Minimal Impact) to Narrow-Band Receivers.
UWB
Thermal (kT) Noise Floor
Conclusion
1. High spatial capacity (bps/m2)
2. Low power
(Bluetooth:1Mbps,10m,1mW UWB: 1Mbps,10m,10 ㎼ )
3. Low cost, simple implementation
4. multi-user interference
5. multiple-access interference
6. Synchronization problems
7. The hardware problem of high frequency in unlicensed band EX:>5GHz
GAIN
TX
CLK
ADC
DIG
ITA
L
End
Thank you for your attention
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