Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
2007-08-01
2009-08-11
Taylor, Barry W (Department: 2617)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S456200, C455S456500, C455S404200
Reexamination Certificate
active
07574221
ABSTRACT:
A method that estimates jointly and iteratively the first arriving path of a received signal and a mobile terminal location uses a residual location error. The method may include setting a ranging threshold to reduce residual location error. The method iteratively estimates the first arriving path of the received signals and mobile terminal location, with the estimate of mobile terminal location improving the estimate of the first arriving path, and vice versa. Initially, a peak selection method determines a rough time-of-arrival (TOA) for a signal received at each of a number of different fixed terminals. An estimate of the location of the mobile unit is then provided (e.g., based on a least-squares (LS) triangulation). If the residual error is unsatisfactory, the TOAs are refined, using a search-back algorithm, which searches back from the strongest paths of the received signals. The new TOAs are used to refine the estimate of the location of the mobile terminal. In addition, the parameters of the search-back algorithm (e.g., a search-back threshold, timing windows) may be modified for greater accuracy in the estimated first path. The first arriving path estimate and the location estimate are iterated until convergence (e.g., the residuals are within a tolerance) or until a termination condition is reached, usually controlled by the thresholds setting.
REFERENCES:
patent: 6054950 (2000-04-01), Fontana
patent: 6266014 (2001-07-01), Fattouche et al.
patent: 2003/0025631 (2003-02-01), Kim
patent: 2003/0086512 (2003-05-01), Rick et al.
patent: 2003/0174086 (2003-09-01), Hirt
patent: 2004/0127228 (2004-07-01), You
patent: 2005/0235499 (2005-10-01), Van Deursen
patent: 2006/0104387 (2006-05-01), Sahinoglu
patent: 2006/0125695 (2006-06-01), Kennedy
patent: 2006/0160545 (2006-07-01), Goren et al.
patent: 1 469 685 (2004-10-01), None
I. Guvenc, Z. Sahinoglu, A. F. Molisch, and P. Orlik, “Non-coherent TOA estimation in IR-UWB systems with different signal waveforms,” inin Proc. IEEE Int. Workshop on Ultrawideband Networks(UWBNETS), Boston, MA, Oct. 2005, pp. 245-251, (invited paper).
P. C. Chen, “A non-line-of-sight error mitigation algorithm in location estimation,” inProc. IEEE Int. Conf. Wireless Commun. Networking(WCNC), vol. 1, New Orleans, LA, Sep. 1999, pp. 316-320.
PCT International Search Report for Int'l App. No. PCT/US 2007/075082, dated Mar. 11, 2008, 3 pages.
PCT Written Opinion of the International Searching Authority for Int'l App. No. PCT/US 2007/075082, dated Mar. 11, 2008, 3 pages.
Chong Chia-Chin
Guvenc Ismail
Haynes and Boone LLP
NTT DoCoMo Inc.
Taylor Barry W
LandOfFree
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