DETERMINING A POSITION OF A MOBILE COMMUNICATION DEVICE

• US 20150373494A1
• Filed: 01/31/2014
• Published: 12/24/2015
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: K.Mizra LLC
• Original Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Inventors: Van Rijn, Martin, Elferink, Franciscus Hendrikus
• Granted Patent: US 10,812,933 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/02213 Receivers arranged in a network for determining the position of a transmitter
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

A method of determining a position of a mobile telecommunication device (10) which transmits a signal (S) to base stations (1, 2, 3, . . . ) connected by a data link (8) comprises the steps of: •correlating the received signal (S) and a reference signal (S′) so as to produce a correlation for each base station, •detecting a maximum in each correlation, which maximum is indicative of a time of arrival of the signal (S) at the respective base station, and •using the respective times of arrival and the distances (D1, D2, . . . ) derived therefrom to derive a location of the mobile telecommunication device. The method uses receivers (21, 22, . . . ) coupled to a data network (7), each receiver (21, 22, . . . ) deriving the reference signal (S′) from the received signal (S). Each base station may select, if it receives multiple reference signals, the reference signal (S′) having the highest quality.

Claims

1. A method of determining a position of a mobile telecommunication device which transmits a signal to base stations connected by a data link and having known locations, the method comprising the steps of:

receiving the signal at two or more base stations wirelessly,

providing a reference signal at the base stations,

correlating the signal and the reference signal so as to produce a correlation for each base station,

detecting a maximum in each correlation, which maximum is indicative of a time of arrival of the signal at the respective base station,

deriving from the times of arrival respective distances to the mobile communication device and,

using the respective distances and the respective known locations to derive a location of the mobile telecommunication device,

the method further comprising

providing a data network coupled to the data link,

providing receivers coupled to the data network,

deriving by using A/D conversion the reference signal from the signal as received by each receiver, and

forwarding the reference signal to the base stations through the data network and the data link.

2. The method according to claim 1, wherein the data network and the receivers are configured for WLAN access.

3. The method according to claim 1, wherein at least one of the receivers has a location which is distinct from the location of any of the base stations.

4. The method according to claim 1, wherein each base station selects, if it receives multiple reference signals, the reference signal having the highest quality.

5. The method according to claim 4, further comprising the step of determining the signal-to-noise ratio of the reference signal so as to select the reference signal having the highest quality.

6. The method according to claim 1, wherein the signal is a modulated digital communication signal.

7. The method according to claim 1, wherein the signal is a continuous signal.

8. The method according to claim 1, further comprising the steps of:

providing a local clock in each base station for determining the times of arrival of the signal,

exchanging timing messages between the base stations,

deriving from the timing messages any time deviations of the local clocks, and

determining the time of arrival of the signal at each base station using the respective local clock and the respective time deviation.

9. The method according to claim 8, further comprising the steps of:

each transmitting base station registering the time of transmission of each timing message, and

each receiving base station registering the time of receipt of each timing message,

determining the time deviation, ε

2, of a second base station relative to a first base station by according to ε

2=(tr1+tt1−

tt2−

tr2)/2, wherein tt1 and tt2 represent the times of transmission at the first base station and the second base station, respectively, and wherein tr1 and tr2 represent the times of receipt at the first base station and the second base station, respectively.

10. The method according to claim 8, wherein the timing messages contain the time of transmission at the transmitting base station.

11. The method according to claim 8, wherein the timing messages are constituted by pulse-shaped signals which are preferably transmitted wirelessly.

12. The method according to claim 8, wherein the timing messages are constituted by frequency modulated signals, preferably signals having a linear frequency sweep.

13. A non-transitory computer readable medium having a computer program embodied thereon, the computer program including instructions for carrying out method steps according to claim 1.

14. A base station for use in a mobile telecommunication system, the base station comprising:

a first signal reception unit for wirelessly receiving a signal from a mobile telecommunication device,

a second signal reception unit for receiving a reference signal,

a memory unit for storing the signal, and

a processor unit for processing the signal and the reference signal,

and being configured for;

correlating the signal and the reference signal so as to produce a correlation for each base station,

detecting a maximum in each correlation, which maximum is indicative of a time of arrival of the signal at the respective base station,

deriving from the times of arrival respective distances to the mobile telecommunication device and,

using the respective distances and the respective known locations to derive a location of the mobile telecommunication device,

wherein the second signal reception unit comprises a network interface unit for interfacing, preferably via a data link, with a data network to which signal receivers capable of forwarding reference signals are coupled.

15. A system for determining a position of a mobile telecommunication device which transmits a signal, the system comprising at least three base stations according to claim 14.