Method and apparatus for determining a location of a communication unit in a wireless communication system
First Claim
1. A method for locating a mobile communication unit in a communication system, the method comprising the steps of:
- receiving, at a first base site and at least a second base site, an information signal transmitted by a first communication unit and a calibration signal transmitted by a second communication unit, the second communication unit being located at a known location;
determining, by the first base site, first timing information based at least on the information signal received at the first base site;
determining, by the first base site, first calibration information based on the calibration signal received at the first base site;
determining, by the at least a second base site, at least second timing information based at least on the information signal received at the at least a second base site;
determining, by the at least a second base site, at least second calibration information based on the calibration signal received at the at least s second base site; and
determining a location of the first communication unit based on the first timing information, the at least second timing information, the first calibration information, and the at least second calibration information.
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Accused Products
Abstract
A wireless communication system (100) that includes a plurality of base sites (101-103) employs a method and apparatus for determining a location of a communication unit (107) in the system. Upon transmission of an information signal (109) by the communication unit, each of the base sites receives the transmitted information signal. A serving base site (e.g., 103) determines a stream of information symbols from the information signal, derives timing information based on the information signal and the stream of information symbols, and conveys the stream of information symbols preferably to at least two non-serving base sites (101-102). The non-serving base sites determine respective timing information based on the information signal received from the communication unit and the stream of information symbols received from the serving base site. The location of the communication unit is then determined by either a base site or a stand-alone processing device (105) based on the serving base site'"'"'s and non-serving base site'"'"'s timing information.
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Citations
24 Claims
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1. A method for locating a mobile communication unit in a communication system, the method comprising the steps of:
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receiving, at a first base site and at least a second base site, an information signal transmitted by a first communication unit and a calibration signal transmitted by a second communication unit, the second communication unit being located at a known location; determining, by the first base site, first timing information based at least on the information signal received at the first base site; determining, by the first base site, first calibration information based on the calibration signal received at the first base site; determining, by the at least a second base site, at least second timing information based at least on the information signal received at the at least a second base site; determining, by the at least a second base site, at least second calibration information based on the calibration signal received at the at least s second base site; and determining a location of the first communication unit based on the first timing information, the at least second timing information, the first calibration information, and the at least second calibration information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 24)
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9. A method for locating a communication unit in a communication system, the method comprising the steps of:
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receiving, at each base site of a plurality of base sites, an information signal that conveys a stream of information symbols from the communication unit, wherein the stream of information symbols is unknown to the receiving base site since the stream of information symbols is not a pre-determined stream of information symbols; determining, at a first base site of the plurality of base sites, the stream of information symbols conveyed by the information signal received at the first base site, deriving the stream of information symbols from the information signal received at the first base site, thereby making the stream of information symbols known to the first base site; conveying, by each base site, the information signal received to a processing device; conveying, by the first base site, the stream of information symbols to the processing device; determining, by the processing device, timing information with respect to each base site based on the stream of information symbols and the information signal received by each base site; and determining, by the processing device, a location of the communication unit based at least on the timing information. - View Dependent Claims (10, 11, 12)
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13. A method for a processing device to locate a communication unit in a communication system, the method comprising the steps of:
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receiving a plurality of information signals from a plurality of base sites, a first information signal of the plurality of information signals being received from the communication unit by a first base site of the plurality of base sites; receiving a stream of information symbols from the first base site, the stream of information symbols being derived from the first information signal, wherein the stream of information symbols was unknown to the first base site prior to being derived from the first information signal since the stream of information symbols was not a pre-determined stream of information symbols; determining first timing information based on the stream of information symbols and the information signal received from the first base site; determining at least second timing information based on the stream of information symbols and the information signal received from at least a second base site of the plurality of base sites; and determining a location of the communication unit based on the first timing information and the at least second timing information. - View Dependent Claims (14, 15)
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16. A method for a processing device to determine location of a communication unit in a communication system, the method comprising the steps of:
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receiving, from a plurality of base sites, timing information, wherein the timing information is based on an information signal received from the communication unit by each of the plurality of base sites and a stream of information symbols, the stream of information symbols being unknown until derived from the information signal received at a base site of the plurality of base sites that is presently providing communication service to the communication unit since the stream of information symbols was not a pre-determined stream of information symbols; and determining a location of the communication unit based at least on the timing information. - View Dependent Claims (17, 18)
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19. An apparatus for use in determining a location of a communication unit in a communication system, the apparatus comprising:
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an information signal receiver, coupled to a plurality of base sites, that receives an information signal from each base site of the plurality of base sites, the information signal being originally transmitted to the plurality of base sites from the communication unit; a symbol stream receiver, coupled to a first base site of the plurality of base sites, that receives a symbol stream from the first base site, the symbol stream being unknown until derived from the information signal received by the first base site since the stream of information symbols is not a pre-determined stream of information symbols; and a time of arrival estimator, coupled to the information signal receiver and the symbol stream receiver, that determines timing information of the information signal with respect to each base site. - View Dependent Claims (20, 21, 22, 23)
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Specification