SYSTEMS AND METHODS OF ASSISTED GPS
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Accused Products
Abstract
Embodiments of an improved assisted global positioning system (GPS) method and system are described. Wireless access points send assistance data to GPS receivers that are integrated into cellular chipsets and other chipsets. The access points may also act as fixed location references for differential GPS (DGPS) mobile stations. Errors caused by multipath travel of the GPS signals are reduced by using fixed location reference receivers.
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Citations
74 Claims
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1-54. -54. (canceled)
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55. A method of determining a position of a mobile device using global positioning system (GPS) signals, the method comprising:
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receiving, at the mobile device, GPS information from a plurality of GPS satellites, the mobile device experiencing multipath interference from signals received from at least one satellite of said plurality of GPS satellites; selecting a particular access point from a plurality of short range access points comprising WLAN, Bluetooth, UWB, RFID, and ZigBee access points, the particular access point near the mobile device and experiencing a same multipath interference as the mobile device; receiving GPS differential data from the particular short range access point, the GPS differential data from the particular access point comprising a difference between a known distance to said at least one satellite and a distance to said at least one satellite calculated based on GPS information received at the particular access point from said at least one satellite; computing a distance from the mobile device to each of said plurality of satellites based on the GPS information received from said plurality of GPS satellites, the computed distance to said at least one satellite affected by said multipath interference; compensating the effect of the multipath interference in the computed distance from the mobile device to said at least one satellite using said GPS differential data received from the particular access point experiencing the same multipath interference as the mobile station; and computing the position of the mobile device based on said distance from the mobile device to each of said plurality of satellites. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73)
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74. An apparatus for performing position determination using global positioning system (GPS) signals and compensating for effects of multipath signal interference, the apparatus comprising:
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a GPS receiver for receiving GPS information from a plurality of GPS satellites; a wireless communication module, communicatively coupled to said GPS receiver, the wireless communication module for receiving a plurality of GPS differential data from a plurality of short range access points comprising WLAN, Bluetooth, UWB, RFID, and ZigBee access points, the GPS differential data received from each access point comprising a difference between a known distance to said at least one satellite and a distance to said at least one satellite calculated based on GPS information received at the access point from said at least one satellite; and a navigation processor, communicatively coupled to said GPS receiver and said wireless communication module, the navigation processor for; selecting a particular access point from the plurality of access points, the selected particular access point near said apparatus and experiencing a same multipath signal interference as said apparatus; computing a distance from the apparatus to each of said plurality of GPS satellites based on the GPS information received from said plurality of GPS satellites, the computed distance to at least one satellite in said plurality of satellites affected by said multipath signal interference; compensating the effect of the multipath signal interference in the computed distance from the apparatus to said at least one satellite using said GPS differential data received from the particular access point experiencing the same multipath interference as the mobile station; and computing a position of the apparatus based on said distance from the apparatus to each of said plurality of satellites.
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Specification