US 8,026,850 B2Granted

Apparatus and method for computing location of a moving beacon using time difference of arrival and multi-frequencies

AssigneeElectronics and Telecommunications Research Institute

InventorsNak-Seon Seong, Choon-Sik Lim, Cheol-Sig Pyo, Jong-Suk Chae

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Abstract

Provided is an apparatus and method for computing the location of a radio beacon by using Time Difference Of Arrival (TDOA) and multiple frequencies. The apparatus and method of the present invention compute the location of a radio beacon without limitation in distance by using multiple frequencies and time difference of arrival to resolve the problem of phase ambiguity. A radio beacon location computing system includes a plurality of base stations configured to receive signals of multiple frequencies transmitted from the radio beacon, and detect and output phase differences and arrival time; and a location computing server configured to receive the phase differences and the arrival time outputted from the respective base stations, acquire calculation distances based on the phase differences, remove phase ambiguity from the calculation distances based on the arrival time, and compute the location of the radio beacon.

Claims9

Dependent claims

A method for computing a location of a radio beacon by using Time Difference Of Arrival (TDOA) and multiple frequencies, comprising the steps of:

a) receiving arrival time tj transmitted from each of a plurality of base stations, j (1<=j<=n, n is the number of the base stations), wherein each of the base stations, j receives first and second signals respectively having first and second frequencies from the radio beacon, and detects and transmits phase difference ΔΦj between the first and second signals and the arrival time tj of a predetermined one of the first and second signals;
b) receiving the phase difference ΔΦj from each of the base stations, j;
c) acquiring calculation distance Rj based on the phase difference ΔΦj with respect to each base station j, wherein the calculation distance Rj corresponds to a plurality of solution distances;
d) calculating a predicted location of the radio beacon based on Time Difference Of Arrival (TDOA) (Δt1, . . . , Δtn), wherein Δti is difference between one pair of arrival times among the arrival times (t1, . . . , tn);
e) removing phase ambiguity from the calculation distance Rj by selecting the closest solution distance to the predicted location of the radio beacon among the plurality of solution distances, with respect to each base station j;
and
f) determining the location of the radio beacon based on the calculation distances (R1, . . . , Rn) deprived of the phase ambiguity.

4 more elements

A system for computing a location of a radio beacon by using Time Difference Of Arrival (TDOA) and multiple frequencies, comprising:

a plurality of base stations, wherein each of the base stations, j (1<=j<=n, n is the number of the base stations) is configured to receive first and second signals respectively having first and second frequencies transmitted from the radio beacon, and detect and output phase difference ΔΦj between the first and second signals and arrival time tj of a predetermined one of the first and second signals;
and
a location computing server configured to:
receive the phase difference ΔΦj and the arrival time tj outputted from each base station j,
acquire calculation distance Rj based on the phase difference ΔΦj with respect to each base station j, wherein the calculation distance Rj corresponds to a plurality of solution distances,
calculate a predicted location of the radio beacon based on Time Difference Of Arrival (TDOA) (Δt1, . . . , Δtn), wherein Δti is difference between one pair of arrival times among the arrival times (t1, . . . , tn),
remove phase ambiguity from the calculation distance Rj by selecting the closest solution distance to the predicted location of the radio beacon among the plurality of solution distances, with respect to each base station j, and
compute the location of the radio beacon based on the calculation distances (R1, . . . , Rn) deprived of the phase ambiguity.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/096,777Filed 8 Dec 2006
Priority: KR 10-2005-01196238 Dec 2005
Published: US 2008/0291089 A127 Nov 2008
Granted: 27 Sep 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01S 5/06
Using radio waves: position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
G01S 5/14
Using radio waves: determining absolute distances from a plurality of spaced points of known location
H04W 64/00
Locating users or terminals or network equipment for network management purposes
G01S
Radio direction-finding