1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANS) Submission Title: [UWB System Design for Low Power, Precision Location TG4a] Date Submitted: [March 2004] Source: [Roberto Aiello] Company [Staccato Communications] E-mail [Roberto@StaccatoCommunications.com] Re: [Design Considerations for UWB low rate] Abstract: [This presentation introduces some fundamental concepts for UWB system design in preparation for evaluation of forthcoming PHY proposals] Purpose: [In anticipation of CFP for 802.15.4a] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual or organization. The material in this document is subject to change in form and content after further study. The contributor reserves the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 2 UWB System Design Considerations for Low Power + Precision Location Roberto Aiello Roberto@StaccatoCommunications.com Staccato Communications

3. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 3 Summary Applications of low power & location awareness Requirements Low duty cycle – long battery life Precision ranging – methods of location estimation Other relevant parameters

4. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 4 Application examples Building automation (ease of installation and maintenance) Home automation Inventory (hospital, warehouses, file tracking, etc.) People tracking (resource optimization in offices), optimize efficiency/security in factories, etc.)

5. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 5 Location relevant requirements No mobility or low speed requirement Relatively fast response time for tracking Centimeters to meters resolution and accuracy Low power (long battery lifetime) Low cost

6. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 6 Methods for location awareness Fixed infrastructure –Access points synchronization –Inverse GPS triangulation Ad hoc network –No engineered access points –Only relative distances between nodes are known Ad hoc network with fixed references –Some network nodes fix location and provide reference –2 references to fix in 2D, 3 references to fix in 3D

7. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 7 UWB advantages High accuracy (proportional to bandwidth) Robust to multipath and to interference Low power consumption Leads to low cost implementation

8. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 8 Battery characteristics Source: doc.: IEEE 802.15-01/231r2

9. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 9 Power sources’ characteristics 100  W is the threshold for energy scavenging

10. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 10 Practical means of energy scavenging

11. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 11 Example UWB link budget Negative RX antenna gain 500 MHz bandwidth 2 MHz chip rate (10 chips/bit) 200 kbps raw bit rate, ½ coding 30 dB link margin at 10m 300 m path loss d = 2 30 m path loss d = 3.5

12. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 12 Radio transmitter Minimum UWB bandwidth allowed: 500 MHz UWB transmit power –PSD = -41.3 dBm/MHz –Average power: -14.3dBm => 38  W Energy/bit (@100 kbps) = 0.38 nJ/bit

13. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 13 Radio receiver Analog section power typically dominated by oscillators and mixers Digital section power driven by clock rate Low power UWB radio: not a software radio! –Analog section No LNA: increase transmit power, allow higher noise figure No oscillator at the receiver: envelope detector Low power oscillator: low Q and relaxed phase noise requirement, low power reference oscillator –Digital section Circuits running at symbol rate (kHz or MHz), not at RF rate (GHz) Design compromise for very low power optimization will impact performance optimization

14. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 14 Transceiver architecture Fast wake-up –1ms acquisition time => 6.2  J per first bit acquired Transmit/receive accurate synchronization –Requires correct system architecture –Adaptive periodic polling (application dependent) Receiver power budget

15. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 15 Other issues relevant to TG4 Communication and location may not require processing different paths, but different clock resolution Communication and location are probably separate functions Most of location function is PHY related -> no MAC modifications required

16. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 16 Conclusions UWB is a natural technology for location awareness Provides additional feature beyond a “communications only” platform UWB works in multipath environments where narrow band approaches are challenged

17. doc.: IEEE 802.15-04/xxxr0 Submission March 2004 Roberto Aiello, Staccato CommunicationsSlide 17 References UWB: a solution for location awareness in TG4 applications –03050r1P802-15_TG4-UWB-a-solution-for-location-awareness Understanding UWB - Principles & Implications for Low-Power Communications –03157r1P802-15_WG-Understanding_UWB_For_Low- Power_Communications-A_Tutorial