Methods and apparatus for locationing in a wireless network using statistical weighting
US7873367B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2007 |
| Grant date | Jan 18, 2011 |
| Priority date | — |
| Expiry date | Jun 27, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W64/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and systems are provided for determining the location of a first wireless device (e.g., a mobile unit) within a wireless network comprising a plurality of second wireless devices (e.g., access points). The method includes identifying an overlap area corresponding to the intersection of RF ranges for the one or more second wireless devices then computing a set of signal strength values, each associated with a measure of RF signal strength (e.g., RSSI) received by the plurality of second wireless devices from the first wireless device. A decision metric is evaluated for a plurality of locations within the overlap area based on the set of signal strength values. The location of the first wireless device is determined by selecting, from the plurality of locations, a location having the optimum value of the decision metric within the overlap area. The decision metric may utilize a minimum mean square error (MMSE) calculation. A weighting function may be used to remove redundant or weak signal strength values. The systems and methods are applicable, for example, to networks operating in accordance with 802.11, RFID, WiMax, WAN, Bluetooth, Zigbee, UWB, and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.