1. Ultra-wideband (UWB) Signals for Communications and Localization
Sinan Gezici
Assistant Professor
Dept. of Electrical and Electronics Eng.
Bilkent University

2. Ultra-wideband (UWB) Definition (Absolute) bandwidth ≥ 500 MHz
Babs = fH– fL
Fractional bandwidth ≥ 0.2
Bfrac = (fH– fL) / fC ≥ 0.2

3. Regulations for UWB
FCC in the US allows transmission in GHz band
Coexists with incumbent systems
Low power spectral density (-41.3 dBm/MHz)
Large spreading factors
UWB

4. UWB Signals 3 common signaling formats: OFDM UWB DS-CDMA UWB
Impulse radio (IR) UWB
A train of short duration (sub-nanosecond) pulses with a low
duty cycle
One information symbol

5. Advantages of UWB (1/2)
High data rate: Large bandwidth increases capacity
For AWGN channels
Low power/cost: Simple transceiver architectures with low power consumption are possible

6. Advantages of UWB (2/2)
Precise position estimation (localization): High time resolution
Radar Transceiver
Object
Time=T1
Transmitted Signal
Time=T2
Reflected Signal
Device
Object
15 m
Range = 0.5(T2-T1)c c : Speed of light
Penetration through obstacles: Large frequency band facilitates penetration through objects
Low probability of detection: Similar to white noise for other systems

7. Applications (1/2) Communications
High data rate: e.g. wireless USB, WPAN
Low data rate: IEEE a, wireless sensor networks

8. Applications (2/2) Radar and localization Other applications:
[E. M. Staderini 2002]
Other applications:
e.g., thru-wall monitoring, rescue operations after an earthquake.
Medical applications:
e.g., non-invasive patient monitoring, respiration and heartbeat rate estimation