tailieunhanh - Báo cáo hóa học: " Research Article On the Geolocation Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article On the Geolocation Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 584670 10 pages doi 2008 584670 Research Article On the Geolocation Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels Laurence Mailaender Alcatel-Lucent Bell Labs Holmdel NJ 07733 USA Correspondence should be addressed to Laurence Mailaender lm@ Received 20 February 2007 Revised 31 July 2007 Accepted 28 October 2007 Recommended by Richard J. Barton The development of future geolocation systems requires a fundamental understanding of the importance of various system parameters such as the number of sensors the SNR bandwidth and channel conditions. We consider the bounds on time-based geolocation accuracy when all sensors experience non-line-of-sight NLOS conditions. While location accuracy generally improves with additional bandwidth we find that NLOS effects place a limit on these gains. Our evaluation focuses on indoor geolocation where Rayleigh fading is present different average SNR conditions occur on each link and the sensors may not fully encircle the user. We introduce a new bound for round-trip time-of-arrival RT-TOA systems. We find that time-of-arrival TOA outperforms time-difference-of-arrival TDOA and RT-TOA but the relative ordering of the latter two depends on the sensor geometry. Copyright 2008 Laurence Mailaender. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The success of the global positioning system GPS has sparked great interest in locating mobile wireless users. Applications include locating E-911 callers in the cellular telephone network tracking emergency responder personnel in indoor environments personal navigation using maps and turn-by-turn driving directions or tracking vehicles and other valuable property. .