The present invention sets out to overcome the hearability problem in CDMA communications networks in which positioning services are provided, by using a separate sampling device (204, 205, 206) for each transmitter (201, 202, 203), which sends to the computing device (208) a representation of the s
The present invention sets out to overcome the hearability problem in CDMA communications networks in which positioning services are provided, by using a separate sampling device (204, 205, 206) for each transmitter (201, 202, 203), which sends to the computing device (208) a representation of the signals transmitted only by that transmitter. A cross-correlation of the representation sent back by the mobile terminal (207) with the representation sent back by the sampling device in the brightest transmitter is performed in the computing device (208), and an estimate of that brightest signal is subtracted from the representation sent back by the mobile terminal (207) in order to reduce its effect on the remaining signals as far as possible. The cross-correlation and subtraction steps are iterated until no useful signals remain to be extracted.
대표청구항▼
1. A method of finding the position or state of motion of a terminal in a communications network having a plurality of transmitters, the terminal having a radio receiver, the method comprising the steps of(a) creating at the terminal a section of a representation of the signals from the transmitters
1. A method of finding the position or state of motion of a terminal in a communications network having a plurality of transmitters, the terminal having a radio receiver, the method comprising the steps of(a) creating at the terminal a section of a representation of the signals from the transmitters received by the radio receiver; (b) creating a first section of a representation of the signal transmitted by a first of said transmitters, and creating a second section of a representation of the signals transmitted by a second of said transmitters, each of which sections overlaps in time with the section created at the terminal; (c) calculating an estimate of the signal received at the terminal from said first transmitter using said first section, and subtracting said estimate from the section created at the terminal, to produce a residual representation; (d) performing a calculation using said residual representation and said second section, and estimating the time offset between them; and (e) calculating the position of the terminal using said time offset. 2. A method of finding the position or state of motion of a terminal in a communications network having a plurality of transmitters, the terminal having a radio receiver, the method comprising the steps of(a) creating at the terminal a section of a representation of the signals from the transmitters received by the radio receiver; (b) creating a section of a representation of the signal transmitted by one of said transmitters, which overlaps in time with the section created at the terminal; (c) calculating an estimate of the signal received at the terminal from said transmitter using said section of the representation of the signal transmitted by said transmitter, and subtracting said estimate from the section created at the terminal, to produce a residual representation; (d) performing one or more calculations using said residual representation and one or more known components of the signals transmitted by the communications network in order to estimate the time offset of the respective component; and (e) calculating the position of the terminal using any of said time offsets. 3. A method of finding the time offset between at least one of the signals received from a plurality of the transmitters of a communications network by a receiver attached to a fixed terminal and a reference generated in the fixed terminal, the method comprising the steps of(a) creating at the fixed terminal a section of a representation of the signals from the transmitters received by the radio receiver; (b) creating a section of a representation of the signal transmitted by one of said transmitters, which section overlaps in time with the section created at the fixed terminal; (c) calculating an estimate of the signal received at the fixed terminal from said transmitter using said section of a representation of the signal transmitted by said transmitter, and subtracting said estimate from the section created at the fixed terminal, to produce a residual representation; and (d) performing a calculation using said residual representation and said reference in order to estimate the time offset between the at least one signal and said reference. 4. A method according to any of claims 1, 2 or 3, wherein the or each section of a representation of the signal transmitted by a respective transmitter is created at a respective transmitter.5. A method according to any of claims 1, 2 or 3, wherein the or each section of a representation of the signal transmitted by a respective transmitter is created in a sampling device associated with the respective transmitter.6. A method according to any of claims 1, 2 or 3, in which the signal representation sections are sent to one or more computing devices in which said estimates and time offsets are calculated.7. A method according to claim 6, in which the terminal location is calculated in said one or more computing devices.8. A method according to claim 1, in which the time offset between said section of a representation of the signals received by the receiver and said first section is first calculated, and then used in the calculation of said estimate.9. A method according to any of claims 1, 2 or 3, in which the section of the representation of the signals received by the receiver at the terminal is recorded in the terminal before being sent to one or more computing devices.10. A method according to any of claims 1, 2 or 3, in which the section of the representation of the signals received by the receiver at the terminal is transferred in real time to one or more computing devices and a recording or recordings made there.11. A method according to claim 6, in which the computing device is in the handset.12. A method according to claim 6, in which one or more of the computing devices each comprise a processor connected to the network.13. A method according to any of claims 1, 2 or 3, in which the representation of the signals received by the receiver is a digitised version of the received signals converted first to baseband in the receiver.14. A method according to any of claims 1, 2 or 3, in which the representation of the signals transmitted by a transmitter is a digitised version of the transmitted signals converted first to baseband.15. A method according to any of claims 1, 2 or 3, in which, in order to ensure an overlap of the respective sections, a known component of the transmitted signals is used to indicate the start of sampling.16. A method according to any of claims 1, 2 or 3, in which the calculations performed include cross-correlations.17. A method according to claim 2, in which the known components of the transmitted signals are the pilot codes.18. A communications network comprising(a) a computing device or devices; (b) a terminal having a radio receiver attached to the terminal, means for creating a section of a representation of the signals, received by the radio receiver, from the transmitters of the communications network, and means for sending the section to the computing device or devices; (c) sampling devices associated with respective first and second of said transmitters for creating respective first and second sections of representations of the signal transmitted by the respective transmitter which overlap in time with the section created at the terminal, and for sending the sections of the representations created at said transmitters to said computing device or devices; the computing device or devices being adapted to perform 1. a calculation of an estimate of the signals received at the terminal from said first transmitter using said first section; 2. a subtraction of said estimate from the section sent by the terminal, to produce a residual representation; 3. a calculation using said residual representation and said second section to produce an estimate of the time offset between them; and 4. a calculation of the position of the terminal using said time offset. 19. A communications network comprising(a) a computing device or devices; (b) a terminal having a radio receiver attached to the terminal, means for creating a section of a representation of the signals, received by the radio receiver, from the transmitters of the communications network, and means for sending the section to a computing device; (c) devices associated with the transmitters for creating sections of representations, of the signal transmitted by the respective transmitter, which overlap in time with the section created at the terminal, and for sending said sections to the computing device or devices; the computing device or devices being adapted to perform 1. generation of a reference signal; 2. calculation of an estimate of the signal received at the terminal from said transmitter using said section of a representation of the signal transmitted by the corresponding transmitter; 3. a subtraction of said estimate from the section sent by the terminal to produce a residual representation; 4. one or more calculations using said residual representation and said reference to estimate the time offset between a component of the residual representation and said reference; and 5. a calculation of the position of the terminal using the or any of the time offsets. 20. A communications network according to claim 18 or claim 19, in which the, section of the representation of the signals received by the receiver at the terminal is recorded in the terminal before being sent to a computing device.21. A communications network according to claim 18 or claim 19, in which the section of the representation of the signals received by the receiver at the terminal is transferred in real time to a computing device and a recording made there.22. A communications network according to claim 18 or claim 19, in which the section of the representation of the signal transmitted by a transmitter is obtained from a sampling device associated with the corresponding transmitter.23. A communications network according to claim 18 or claim 19, in which the computing device is in a handset.24. A communications network according to claim 18 or claim 19, in which the computing device comprises a processor connected to the network.25. A communications network according to claim 18 or claim 19, in which the representation received by the receiver is a digitised version of the received signals converted first to baseband in the receiver.26. A communications network according to claim 18 or claim 19, in which the representation of the signal transmitted by a transmitter is a digitised version of the transmitted signal converted first to baseband.27. A communications network according to claim 18 or claim 19, in which, in order to ensure an overlap of the respective sections, a known component of the transmitted signals is used to indicate the start of sampling.28. A communications network according to claim 18 or claim 19, in which the calculations performed in the computing device include cross-correlations.29. A communications network according to claim 19, in which the component of the residual representation is a pilot code.30. A computing device or devices for use in a communications network comprising a terminal having a radio receiver attached to the terminal, means for creating a section of a representation of the signals, received by the radio receiver, from the transmitters of the communications network, and means for sending the section to the computing device or devices; and sampling devices associated with respective first and second of said transmitters for creating respective first and second sections of representations of the signal transmitted by the respective transmitter which overlap in time with the section created at the terminal, and for sending the sections of the representations created at said transmitters to said computing device or devices;the computing device or devices being adapted to perform 1. a calculation of an estimate of the signals received at the terminal from said first transmitter using said first section; 2. a subtraction of said estimate from the section sent by the terminal, to produce a residual representation; 3. a calculation using said residual representation and said second section to produce an estimate of the time offset between them; and 4. a calculation of the position of the terminal using said time offset. 31. A computing device or devices for use in a communications network comprising a terminal having a radio receiver attached to the terminal, means for creating a section of a representation of the signals, received by the radio receiver, from the transmitters of the communications network, and means for sending the section to the computing device or devices; and devices associated with the transmitters for creating sections of representations, of the signal transmitted by the respective transmitter, which overlap in time with the section created at the terminal, and for sending said sections to the computing device or devices;the computing device or devices being adapted to perform 1. a generation of a reference signal; 2. a calculation of an estimate of the signal received at the terminal from said transmitter using said section of a representation of the signal transmitted by the corresponding transmitter; 3. a subtraction of said estimate from the section sent by the terminal to produce a residual representation; 4. one or more calculations using said residual representation and said reference to estimate the time offset between a component of the residual representation and said reference; and 5. a calculation of the position of the terminal using the or any of the time offsets. 32. A computer program or programs comprising computer program code means adapted to perform the steps of the computing device of claim 30.33. A computer program or programs comprising computer program code means adapted to perform the steps of the computing device of claim 31.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (6)
Drane Christopher R.,AUX ; MacNaughtan Malcolm D.,AUX ; Scott Craig A.,AUX, Location and tracking system.
Fischer, Sven; Amin, Muhammad Awais; Palanki, Ravi, Determination of positions of wireless transceivers to be added to a wireless communication network.
Strutt, Guenaell T.; Deoge, Peter B.; Goldberg, Keith J., Determining position of a node and representing the position as a position probability space.
Raghupathy, Arun; Pattabiraman, Ganesh; Kumar, Shubham; Clark, Henry; Sendonaris, Andrew; Willhoff, Steven J., Systems and methods for location positioning of user device.
Raghupathy, Arun; Meiyappan, Subramanian; Joseph, Deepak; Vajjhala, Varaprasad, Systems and methods for providing conditional access to transmitted information.
Raghupathy, Arun; Meiyappan, Subramanian; Joseph, Deepak; Vajjhala, Varaprasad, Systems and methods for providing conditional access to transmitted information.
Fischer, Sven; Amin, Muhammad Awais; Rowitch, Douglas Neal; Agrawal, Avneesh; Bachu, Raja S.; Sampath, Ashwin, Time of arrival (TOA) estimation for positioning in a wireless communication network.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.