Method for determining position by obtaining directional information from spatial division multiple access (SDMA)-equipped and non-SDMA-equipped base stations

• US 5,508,707 A
• Filed: 09/28/1994
• Issued: 04/16/1996
• Est. Priority Date: 09/28/1994
• Status: Expired due to Term

• Current Assignee: Qwest Communications International Incorporated (Lumen Technologies, Inc.)
• Original Assignee: US West Technologies, Inc.
• Inventors: LeBlanc, Frederick W., Uysal, Alparslan M.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/314,486
• Time in Patent Office: 566 Days
• Field of Search: 342/457, 342/357, 379/59, 379/60, 455/33.1, 455/33.4, 455/56.1
• US Class Current: 342/457
• CPC Class Codes: G01S 2205/06 Emergency
• CPC Class Codes: G01S 5/0269 Inferred or constrained positioning, e.g. employing knowledge of the physical or electromagnetic environment, state of motion or other contextual information to infer or constrain a position
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method for determining position by obtaining directional information from spatial division multiple access (SDMA)-equipped and non-SDMA-equipped base stations. The method is directed for use in a wireless communication system which includes a plurality of base stations each having a corresponding coverage area. For each of the base stations, a plurality of RF measurements are determined in cooperation with a receiver, including a link budget of the base station, for a predetermined plurality of distances and directions. Determined RF measurements for each of the base stations are modeled as a scaled contour shape having minimum and maximum boundaries. Base stations which neighbor the mobile unit are determined so as to define a first bounding polygon area by their intersecting contours. The first bounding polygon area generally describes the relative position of the mobile unit. A second bounding polygon area is determined in accordance with the lobes of neighboring base stations as described in terms of azimuth angles. The intersection of the first and second bounding polygon areas are determined so as to define a location polygon which more precisely describes the position of the mobile unit in terms of minimum and maximum error estimate.

Claims

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.

2. 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 floating lobes, each of the lobes operative to track and communicate with a mobile unit on a corresponding communication channel by changing its orientation within a predetermined direction range, 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 orientation ranges 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.

3. For use in a wireless communication system including a plurality of Spatial Division Multiple Access (SDMA)-equipped and non-SDMA-equipped base stations each having an antenna with a corresponding coverage area, a method for determining the position of a mobile unit, comprising:

for each of the non-SDMA-equipped base stations, providing a plurality of bandpass filters in electrical communication with the corresponding antenna, each of the band-pass filters having a corresponding waveguide and operative to receive mobile unit signals from predetermined directions in predetermined frequency slots;

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 the communication frequencies of the neighboring base stations and the corresponding directions of their received mobile unit signals 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.