Patent Document ID: 5508707
Application ID: 08314486
Patent Status: 1

Claim One:
1. For use in a wireless communication system including a plurality of Spatial Division Multiple Access (SDMA)-equipped base stations each having a smart antenna with a predetermined number of fixed lobes, each of the lobes oriented in a predetermined direction and operative to communicate with a mobile unit on a corresponding communication channel within a known coverage area, a method for determining the position of a mobile unit, comprising: for each of the base stations, determining in cooperation with a receiver, a plurality of RF measurements for the base station, for a predetermined plurality of distances and directions; for each of the base stations, modeling its determined RF measurements as a scaled contour shape having minimum and maximum boundaries; determining where the contour shapes of the neighboring base stations intersect so as to define a first bounding polygon area that describes the relative position of the mobile unit; determining which lobes of the neighboring base stations are in communication with the mobile unit; determining the orientations of the communicating lobes of the neighboring base stations in terms of azimuth angles so as to define a second bounding polygon area that describes the relative position of the mobile unit; and determining where the first and second bounding polygon areas intersect so as to define a location polygon that describes the position of the mobile unit in terms of minimum and maximum error estimate.