T2 - UWB Radio Technology
| • | Kazimierz Siwiak, TimeDerivative, Inc |
Based on their new book, Ultra-wideband Radio Technology, Wiley: UK, 2004, authors Siwiak and McKeown trace UWB technology through history, regulations, standards, system implementations and commercial applications. They strike a judicious balance between sufficient technical detail for the seasoned practitioner, and practical and strategic observations to benefit technology managers, marketers and potential investors in the technology. There has been a recent surge of invention and commercialization interest following the FCC’s “Report and Order” which legalizes an unprecedented access to more than 7.5 GHz of unlicensed UWB spectrum in the US. Methods of generating and modulating UWB signals are described and set in the context of UWB proposals for IEEE802 Standards. Interesting UWB antenna, radiation, and propagation phenomena, including unique behavior in multipath, are presented in contrast with narrow band radio. Examples of UWB link margins including data throughput versus range and system data capacity (up to 2 Gb/s) are compared with conventional and much higher power 802.11a/b systems. The future of UWB is a judicious mix of wireless communications, precision positioning and radar. UWB can enable an accurate indoor adjunct to GPS with centimeter accuracy. Discussions of applications show that UWB capabilities make possible delivery of location-specific content and information, tracking of high value assets, security systems and various automotive and interesting home based “location awareness” systems.
Descriptions of topics:
| 1. | History of Wireless and UWB - The earliest wireless was “UWB” but spectrum sharing technology evolved around narrow band techniques. The development of wireless shows a trend back towards UWB as new techniques make the technology more attractive. |
| 2. | Regulatory Climate - Summary of Regulatory Activities – By 2002 US FCC regulations are written to permit the deployment of UWB under the unlicensed provisions of the regulations. Both European and Asian regulators are considering permitting the technology along a path similar to what happened in the USA. |
| 3. | Standards: UWB in IEEE802 - Ultra-high data rate standard is evolving under IEEE 802.15.3a, and a lower data rate version including positioning is growing in IEEE 802.15.4a. Standards for UWB deployment are under review in Europe. |
| 4. | Generating and Modulating UWB Signals - Methods of generating UWB signals are discussed: “time” signal designs and how they fill the spectrum; modulating UWB signals with data. |
| 5. | Radiating UWB Signals – UWB signal shapes change in the radiation and reception process. The process is followed from currents supplied to the antenna, to fields in space and finally to terminal voltages at the receiving antenna. |
| 6. | Propagating UWB Signals – Once launched as propagating wavelets, UWB signals are affected by multipath differently than conventional narrow band radio signals. |
| 7. | Receiving UWB Signals – UWB became practical with the advent of efficient recovery techniques for the UWB wavelet energy. |
| 8. | UWB Link Budgets and System Capacity – The link budget for UWB is constrained by regulations, bandwidth, and device technology. Samples of link designs are discussed. With 7.5 GHz of spectrum available (in the USA), UWB offers some unique challenges and capabilities in system design. Huge aggregate and shared capacities are available. Capacities in comparison to existing 802.11a/b systems will be seen. |
| 9. | Location Awareness and Positioning in UWB-RT - UWB bandwidth and some modulation techniques allow for a high degree of positioning accuracy making the concept of location awareness a part of future wireless systems. The value of knowing “where” a device is will take on an economic value on par with the value of the actual data transferred on UWB data links. |
| 10. | Applications and Future Considerations - Systems will begin to be deployed under the UWB standards; special applications systems will also begin to appear. The R&D trends and directions will fin UWB appearing as a participant in late 3G and early 4G scenarios. |
Kazimierz “Kai” Siwiak is an author, inventor, engineer and Founder of TimeDerivative, Inc., a wireless technology consulting firm. He was Vice President of Strategic Development at Time Domain Corp., and recently received the Dan Noble Fellow Award and the Silver Quill Award from Motorola Corporation where he served as Member of the Technical Staff. He is a Registered Professional Engineer in Florida, Senior Member of the IEEE, and has lectured internationally on ultra-wideband radio technology, wireless systems, antennas and propagation. He received his B.S.E.E. and M.S.E.E. degrees from the Polytechnic Institute of Brooklyn, Brooklyn, NY, and his Ph.D. from Florida Atlantic University, Boca Raton, FL. Dr. Siwiak holds more than 70 patents world-wide, including 31 issued in the US. He has published extensively, including the text book, Radiowave Propagation and Antennas for Personal Communications, Artech House, now in Second Edition, and has contributed chapters to five other books and encyclopedias. Dr. Siwiak was Technical editor for the IEEE 802.15.3 Study Group 3a, and is active in UBW standards development. He is a contributing member to FCC and ARRL RF Safety Committees and Electromagnetic Exposure committees. Kai is an Extra-class amateur radio operator and a commercial airplane pilot holding instrument and multi-engine ratings.
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