GB2330716A - Position determination using a reference transmitter - Google Patents

Position determination using a reference transmitter Download PDF

Info

Publication number
GB2330716A
GB2330716A GB9722510A GB9722510A GB2330716A GB 2330716 A GB2330716 A GB 2330716A GB 9722510 A GB9722510 A GB 9722510A GB 9722510 A GB9722510 A GB 9722510A GB 2330716 A GB2330716 A GB 2330716A
Authority
GB
United Kingdom
Prior art keywords
mobile unit
mobile
signal
determining
fixed receivers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9722510A
Other versions
GB9722510D0 (en
Inventor
Luis Lopes
Howard John Thomas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Motorola Solutions UK Ltd
Original Assignee
Motorola Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Ltd filed Critical Motorola Ltd
Priority to GB9722510A priority Critical patent/GB2330716A/en
Publication of GB9722510D0 publication Critical patent/GB9722510D0/en
Publication of GB2330716A publication Critical patent/GB2330716A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/06—Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

Three or more fixed base stations 10, 12 and 14 receive signals from a mobile unit 18 and a reference transmitter 16. The time differences of arrival (TDOA) of both the mobile and reference signals at the base stations are measured, and from the known locations of the base stations and the reference transmitter, the absolute position of the mobile unit can be determined without the need for synchronising the base stations.

Description

MOBILE COMMUNICATIONS SYSTEM Field of the Invention The present invention relates to a system and method of determining the position of a mobile unit in a mobile communications system.
Background of the Invention In cellular communication systems, for example, there is at present no standard method of determining the actual location of a mobile unit in communication with a fixed base unit of the system. With the growth in mobile communication systems, certain national authorities are asking for methods to be developed which are able to locate a mobile unit for use, for example, by emergency services, for navigation and the like.
Summary of the Invention The present invention seeks to provide a system for determining the position of a mobile unit of a mobile communications system.
According to an aspect of the present invention, there is provided a system for determining the position of a mobile unit of a mobile communications system including three or more fixed receivers spaced from one another; a reference transmitter spaced from the fixed receivers and operable to transmit a reference signal to the receivers; and processing means operable to determine on the basis of a signal from a mobile unit in communication with the fixed receivers and of the reference transmitter the position of the mobile unit.
Locating the mobile unit in this manner can be useful for emergency services, navigational systems and the like.
Preferably, the reference transmitter is a reference mobile unit.
The processing means is preferably operable to determine the differences in times of arrival of the signals from the mobile unit and the reference transmitter and to determine therefrom the position of the mobile unit.
The fixed receivers may be separate base stations, separate antennae, or antenna elements of an adaptive antenna array.
According to another aspect of the present invention, there is provided a method of determining the position of a mobile unit of a mobile communications system including the steps of transmitting a reference signal from a fixed transmitter to at least three fixed receivers which are spaced from one another; transmitting a signal from a mobile unit to the fixed receivers; and determining on the basis of the signal from the mobile unit and of the reference transmitter the position of the mobile unit.
Preferably, the step of determining the position of the mobile unit includes the step of determining the differences in times of arrival of the signals from the mobile unit and the reference transmitter.
Brief Description of the Drawing An embodiment of the present invention is described below, by way of example only, with reference to the accompanying drawing, in which the sole figure is a schematic view of a preferred embodiment of a system for determining the position of a mobile unit.
Description of a Preferred Embodiment Referring to the figure, the preferred embodiment of mobile unit location system is designed for use in a mobile communications system, for example a GSM network.
In each cell of the mobile communications system 100 there is provided a plurality of fixed receivers 10, 12, 14, which in this example are shown as base stations BTS1-BTS3. In other examples, the base stations BTS1-BTS3 may be individual antenna elements of an adaptive antenna array.
The system 100 also includes a reference transmitter, which in this example is shown as a reference mobile 16.
Mobile unit 18 is a user unit of conventional type and which it is desired to locate relative to the base stations 10-14. The position ofthe mobile unit 18 could be used, for example, by emergency services or for the purposes of offering position related navigation or other information.
In use, the mobile unit 18 transmits uplink signals as and when required, which are received at each base station 10-14. As the distance D1-D3 from the mobile unit 18 to each base station 10-14 is different, the time of arrival of the uplink signal to the base stations 10-14 will differ. In practice, the uplink signal used for positioning purposes may be the RACH burst or any other known data signal.
As the base stations 10-14 are not time synchronised, the differences in times of arrival of the uplink signal alone cannot be used to determine the position of the mobile unit 18. Even if the base stations are nominally synchronised there may typically be small but significant time offsets between them.
A reference transmitter 16, in the preferred embodiment of a reference mobile, sends a reference uplink signal which also arrives at the base stations 10-14 at different times as a result the difference in distances D,' D3, the reference mobile 16 to the base stations 10-14. As the position of the reference mobile 16 is known, the time differences of the reference uplink signal can be used to determine the position of the mobile unit 18.
The reference uplink signal could in practice be the same as the known signal used for the mobile unit 18 or any other known signal.
More specifically, six signal waveforms are produced, from which the following time differences can be determined: AT2 = Dl-D2 + AT'12 = D'1-D'2 + 1- 2 AT13=D1-D3 + AT', =D'1-D\ + O,-O3 AT23-D-D3 + 2- 3 AT'23 = D'2-D'3 + O2-O3 where AT, 2 is the time difference of the mobile unit 18 uplink signal reaching the first and second base stations 10, 12; AT'12 is the time difference of the reference mobile 16 uplink signal reaching the first and second base stations 10, 12; O" 2 and O3 are random but fixed offsets representative of the synchronisation errors between the base stations 10, 12 and 14.
For the above equations, given that D'1, D'2 and D'3 are known, the differences D,-D2, D,-DJ and D2-D3 can be calculated and the position of the mobile unit 18 relative to the base stations 10-14 determined. Given that the positions of the base stations 10-14 are known, the absolute position of the mobile unit 18 can thus be established.
Processing means operable to calculate the position of the mobile according to the described method is preferably implemented by a software program running on processing hardware as apparent to the skilled person. The processing means may be disposed in the mobile unit the reference mobile, the basestation or in a separate processor.
The example given above provides a solution in two dimensions for the location of the mobile unit, assuming that the height differences between the base stations, the reference unit and the mobile unit are negligible. The skilled person may apply the method to a solution in more dimensions without detracting from the current invention.
The reference mobile 16 may be a standard mobile unit located at a known position and may be permanently registered with the base stations 10-14.
The reference mobile 16 may also be located very close to and even with the base stations 10-14. As the purpose of the reference mobile is merely to provide the reference signal, a call to the reference mobile 16 need not be set up, the RACH bursts could be ignored.
In principle, the BCCH channel receiver system could be used for serving cell measurements. However, transmission from other cells could not be received in this way, so a separate receiver system would be required, which could readily be provided by an omni antenna.
The communication link between the base stations 10-14 will be readily envisaged by the skilled person, in dependence in particular upon the actual implementation of the base stations 10-14.

Claims (8)

  1. Claims 1. A system for determining a position of a mobile unit of a mobile communications system including at least three fixed receivers spaced from one another; a reference transmitter spaced from the at least three fixed receivers and operable to transmit a reference signal to the at least three fixed receivers; and processing means operable to determine the position of the mobile unit using at least a signal from the mobile unit and received at the at least three fixed receivers and a second signal of the reference transmitter.
  2. 2. A system according to claim 1, wherein the reference transmitter is a reference mobile.
  3. 3. A system according to claim 1 or 2, wherein the processing means is operable to determine differences in times of arrival at each of the at least three fixed receivers of the first signal from the mobile unit and the second signal from the reference transmitter and to determine therefrom the position of the mobile unit.
  4. 4. A system according to claim 1, 2 or 3, wherein the at least three fixed receivers are chosen from a group consisting of base stations, antennae, or antenna elements of an adaptive antenna array.
  5. 5. A method of determining a position of a mobile unit of a mobile communications system including the steps of transmitting a first reference signal from a reference transmitter to at least three fixed receivers which are spaced from one another; transmitting a second signal from the mobile unit to the at least three fixed receivers; and determining the position of the mobile unit using at least the second signal from the mobile unit and of the first reference signal of the reference transmitter.
  6. 6. A method according to claim 5, wherein the step of determining the position of the mobile unit includes the step of determining the differences in times of arrival of the first and second signals from the mobile unit and the reference transmitter at each of the at least three fixed receivers.
  7. 7. A system for determining a position of a mobile unit of a mobile communication system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.
  8. 8. A method of determining the position of a mobile unit of a mobile communication system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.
GB9722510A 1997-10-27 1997-10-27 Position determination using a reference transmitter Withdrawn GB2330716A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9722510A GB2330716A (en) 1997-10-27 1997-10-27 Position determination using a reference transmitter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9722510A GB2330716A (en) 1997-10-27 1997-10-27 Position determination using a reference transmitter

Publications (2)

Publication Number Publication Date
GB9722510D0 GB9722510D0 (en) 1997-12-24
GB2330716A true GB2330716A (en) 1999-04-28

Family

ID=10821052

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9722510A Withdrawn GB2330716A (en) 1997-10-27 1997-10-27 Position determination using a reference transmitter

Country Status (1)

Country Link
GB (1) GB2330716A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2353671A (en) * 1999-08-24 2001-02-28 Roke Manor Research Base station synchronisation
GB2383708A (en) * 2001-12-31 2003-07-02 Systems Engineering & Assessme Position determination
GB2386801A (en) * 1999-08-24 2003-09-24 Roke Manor Research A method of locating a mobile station
EP1483902A1 (en) * 2002-03-12 2004-12-08 Menache, LLC Motion tracking system and method
WO2005047926A1 (en) * 2003-11-07 2005-05-26 Wherenet Corp Location system and method that achieves time synchronized network performance with nodes divided into separate networks
EP1666912A1 (en) * 2004-12-01 2006-06-07 Abatec Electronic AG Method and system for determining the position of an object
EP1672378A1 (en) * 2004-12-17 2006-06-21 Hitachi, Ltd. Node position measuring system
US7528776B2 (en) * 2007-03-22 2009-05-05 Nortel Networks Limited Beacon-assisted precision location of untethered client in packet networks
US9274207B2 (en) 2006-02-01 2016-03-01 Zih Corp. System and method for determining signal source location in wireless local area network
US9360547B2 (en) 2005-05-10 2016-06-07 Zih Corp. Extensible object location system and method using multiple references
CN108112070A (en) * 2017-12-25 2018-06-01 武汉大学 A kind of method of time synchronization in unidirectional alignment systems of UWB
EP3764121A1 (en) * 2019-07-09 2021-01-13 Rockwell Collins, Inc. System and method for blind differential time-of-arrival estimation

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1362343A (en) * 1971-07-28 1974-08-07 Siemens Ag Vehicle-position-determining systems
EP0006594A1 (en) * 1978-07-05 1980-01-09 Siemens Aktiengesellschaft Hyperbolic-phase method of comparison for determining the location of surface-bound vehicles and apparatus for carrying out this method
US4916455A (en) * 1987-02-20 1990-04-10 Scientific Development Inc. Locating system and method
WO1991016639A1 (en) * 1990-04-06 1991-10-31 Vick Russell Integral modulation
US5374936A (en) * 1994-02-28 1994-12-20 Feng; Jun Security system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1362343A (en) * 1971-07-28 1974-08-07 Siemens Ag Vehicle-position-determining systems
EP0006594A1 (en) * 1978-07-05 1980-01-09 Siemens Aktiengesellschaft Hyperbolic-phase method of comparison for determining the location of surface-bound vehicles and apparatus for carrying out this method
US4916455A (en) * 1987-02-20 1990-04-10 Scientific Development Inc. Locating system and method
WO1991016639A1 (en) * 1990-04-06 1991-10-31 Vick Russell Integral modulation
US5374936A (en) * 1994-02-28 1994-12-20 Feng; Jun Security system

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7110781B1 (en) 1999-08-24 2006-09-19 Roke Manor Research Ltd. Mobile telecommunications systems
GB2386801A (en) * 1999-08-24 2003-09-24 Roke Manor Research A method of locating a mobile station
GB2386801B (en) * 1999-08-24 2004-03-24 Roke Manor Research A method of locating a mobile station within a telecommunications cell forming part of a telecommunications system
GB2353671B (en) * 1999-08-24 2004-04-28 Roke Manor Research Improvements in or relating to mobile telecommunications systems
GB2353671A (en) * 1999-08-24 2001-02-28 Roke Manor Research Base station synchronisation
GB2383708A (en) * 2001-12-31 2003-07-02 Systems Engineering & Assessme Position determination
EP1483902A1 (en) * 2002-03-12 2004-12-08 Menache, LLC Motion tracking system and method
EP1483902A4 (en) * 2002-03-12 2007-07-18 Menache Llc Motion tracking system and method
US7218229B2 (en) 2003-11-07 2007-05-15 Wherenet Corp Location system and method that achieves time synchronized network performance with nodes divided into separate networks
WO2005047926A1 (en) * 2003-11-07 2005-05-26 Wherenet Corp Location system and method that achieves time synchronized network performance with nodes divided into separate networks
EP1666912A1 (en) * 2004-12-01 2006-06-07 Abatec Electronic AG Method and system for determining the position of an object
US7321575B2 (en) 2004-12-17 2008-01-22 Hitachi, Ltd. Node position measuring system
CN1790049B (en) * 2004-12-17 2011-06-08 株式会社日立制作所 Node position measuring system, wireless base station and position measuring method
EP1672378A1 (en) * 2004-12-17 2006-06-21 Hitachi, Ltd. Node position measuring system
US9360547B2 (en) 2005-05-10 2016-06-07 Zih Corp. Extensible object location system and method using multiple references
US10139472B2 (en) 2005-05-10 2018-11-27 Zih Corp. Extensible object location system and method using multiple references
US9274207B2 (en) 2006-02-01 2016-03-01 Zih Corp. System and method for determining signal source location in wireless local area network
US9519046B2 (en) 2006-02-01 2016-12-13 Zih Corp. System and method for determining signal source location in wireless local area network
US7528776B2 (en) * 2007-03-22 2009-05-05 Nortel Networks Limited Beacon-assisted precision location of untethered client in packet networks
CN108112070A (en) * 2017-12-25 2018-06-01 武汉大学 A kind of method of time synchronization in unidirectional alignment systems of UWB
CN108112070B (en) * 2017-12-25 2020-08-25 武汉大学 Time synchronization method in UWB (ultra wide band) unidirectional positioning system
EP3764121A1 (en) * 2019-07-09 2021-01-13 Rockwell Collins, Inc. System and method for blind differential time-of-arrival estimation
US11378645B2 (en) 2019-07-09 2022-07-05 Rockwell Collins, Inc. System and method for blind differential time-of-arrival estimation

Also Published As

Publication number Publication date
GB9722510D0 (en) 1997-12-24

Similar Documents

Publication Publication Date Title
EP2167987B1 (en) Facilitating mobile station location using a ground-based cellular network
CA2299351C (en) Method and system for determining the position of mobile radio terminals
US5952969A (en) Method and system for determining the position of mobile radio terminals
US8050687B2 (en) Location systems and methods
US5943014A (en) Using a signal with increased power for determining the position of a mobile subscriber in a CDMA cellular telephone system
EP1415174B1 (en) Method for determining the position of a mobile communications device and corresponding device
US6539229B1 (en) System and method for mobile location detection in synchronous wireless systems
US5970413A (en) Using a frequency that is unavailable for carrying telephone voice information traffic for determining the position of a mobile subscriber in a CDMA cellular telephone system
US6195046B1 (en) Base station with slave antenna for determining the position of a mobile subscriber in a CDMA cellular telephone system
US8280412B2 (en) Method for enhanced mobile assisted positioning
AU756930B2 (en) Method and system for locating a mobile subscriber in a CDMA communication system
US7277712B2 (en) Method and system for providing location information for emergency services
EP1014103A2 (en) Local positioning system
US6654362B1 (en) Use of location in handoff in wireless communication systems
AU733935B2 (en) Using a signal with increased power for determining the position of a mobile subscriber in a CDMA cellular telephone system
JP2002507106A (en) Location Determination Method for Mobile Phones Using Short Repeated Bursts
CA2350518A1 (en) System and method for time of arrival positioning measurements based upon network characteristics
GB2330716A (en) Position determination using a reference transmitter
GB2359699A (en) locating a mobile station in a cellular telephone network
JP2828046B2 (en) Positioning Method of Mobile in Code Division Multiple Access System
KR100676171B1 (en) An uplink timing synchronization method in OFDMA system
GB2316823A (en) Loxcating cellular radio transmitter
GB2357013A (en) Locating a mobile station using a rotating beam antenna
KR101855378B1 (en) Method for positioning using heterogenous mobile communication systems
Romdhani et al. Mobile Location Estimation Approaches

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)