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