24-01-2013, 02:23 PM
Ultra Wide Band (UWB) Technology and Applications
[attachment=48310]
So why is UWB so Interesting?
7.5 Ghz of “free spectrum” in the U.S.
FCC recently legalized UWB for commercial use
Spectrum allocation overlays existing users, but its allowed power level is very low to minimize interference
Very high data rates possible
500 Mbps can be achieved at distances of 10 feet under current regulations
“Moore’s Law Radio”
Data rate scales with the shorter pulse widths made possible with ever faster CMOS circuits
Simple CMOS transmitters at very low power
Suitable for battery-operated devices
Low power is CMOS friendly
Ultra Wideband Characteristics
Extremely low transmission energy ( less than 1mW)
Very high bandwidth within short range (200Mbps within 10m)
Extremely difficult to intercept
– Short pulse excitation generates wideband spectra – low energy densities
– Low energy density also minimizes interference to other services
Multipath immunity
Commonality of signal generation and processing architectures
Radar
– Inherent high precision – sub-centimeter ranging
– Wideband excitation for detection of complex, low RCS targets
Geolocation/Positioning
– Sub-centimeter resolution using pulse leading edge detection
– passes through building blocks, walls, etc. (LOS not required)
Low Cost
– Nearly “all-digital” architecture
– ideal for microminiaturization into a chipset
Frequency diversity with minimal hardware modifications
UWB Advantages
Capacity
possibility of achieving high throughput
Low power & Low cost
Can directly modulate a baseband pulse
Can be made nearly all digital
High capacity with lower Tx power levels
Fading robustness
Wideband nature of the signal reduces time varying amplitude fluctuations (?)
Relatively immune to multipath cancellation effects
Path delay ~ 1ns > pulse duration
But don’t we build RAKE just to rebuild the multipath thing ?
What about ISI ?
Position location capability
Developed first as radar technology (!)
Flexibility
Can dynamically trade-off throughput for distance
Possible Research Topics for UWB
UWB as WPAN (IEEE 802.15.3a)
currently, debating with PHY layer and MAC layer
- optimal MAC vs. 802.15.3 MAC vs. 802.11a MAC
- QOS scheduling algorithm for multimedia stream
- Interoperability with 802.11, Bluetooth, wired LAN, sensor network(?)
- security policy
UWB as Localization device (in sensor network or other mobile node)
- optimal localization protocol in ad hoc network
(task dispatching between UWB and RF unit)
- security issue
UWB as alternate RF component (in sensor network or other mobile node)
- optimal MAC
- routing algorithm
- QOS scheduling
[attachment=48310]
So why is UWB so Interesting?
7.5 Ghz of “free spectrum” in the U.S.
FCC recently legalized UWB for commercial use
Spectrum allocation overlays existing users, but its allowed power level is very low to minimize interference
Very high data rates possible
500 Mbps can be achieved at distances of 10 feet under current regulations
“Moore’s Law Radio”
Data rate scales with the shorter pulse widths made possible with ever faster CMOS circuits
Simple CMOS transmitters at very low power
Suitable for battery-operated devices
Low power is CMOS friendly
Ultra Wideband Characteristics
Extremely low transmission energy ( less than 1mW)
Very high bandwidth within short range (200Mbps within 10m)
Extremely difficult to intercept
– Short pulse excitation generates wideband spectra – low energy densities
– Low energy density also minimizes interference to other services
Multipath immunity
Commonality of signal generation and processing architectures
Radar
– Inherent high precision – sub-centimeter ranging
– Wideband excitation for detection of complex, low RCS targets
Geolocation/Positioning
– Sub-centimeter resolution using pulse leading edge detection
– passes through building blocks, walls, etc. (LOS not required)
Low Cost
– Nearly “all-digital” architecture
– ideal for microminiaturization into a chipset
Frequency diversity with minimal hardware modifications
UWB Advantages
Capacity
possibility of achieving high throughput
Low power & Low cost
Can directly modulate a baseband pulse
Can be made nearly all digital
High capacity with lower Tx power levels
Fading robustness
Wideband nature of the signal reduces time varying amplitude fluctuations (?)
Relatively immune to multipath cancellation effects
Path delay ~ 1ns > pulse duration
But don’t we build RAKE just to rebuild the multipath thing ?
What about ISI ?
Position location capability
Developed first as radar technology (!)
Flexibility
Can dynamically trade-off throughput for distance
Possible Research Topics for UWB
UWB as WPAN (IEEE 802.15.3a)
currently, debating with PHY layer and MAC layer
- optimal MAC vs. 802.15.3 MAC vs. 802.11a MAC
- QOS scheduling algorithm for multimedia stream
- Interoperability with 802.11, Bluetooth, wired LAN, sensor network(?)
- security policy
UWB as Localization device (in sensor network or other mobile node)
- optimal localization protocol in ad hoc network
(task dispatching between UWB and RF unit)
- security issue
UWB as alternate RF component (in sensor network or other mobile node)
- optimal MAC
- routing algorithm
- QOS scheduling