Wireless base station location estimation

• US 8,219,116 B1
• Filed: 11/26/2008
• Issued: 07/10/2012
• Est. Priority Date: 11/27/2007
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Ji, Zhengrong, Youssef, Adel Amin, Chu, Michael Jesse, Lee, Steven John, Jain, Ravi
• Primary Examiner(s): Balaoing, Ariel
• Application Number:
  US12/323,622
• Time in Patent Office: 1,322 Days
• Field of Search: 455/456.5, 455/456.6, 455/443
• US Class Current: 455/456.6
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

A wireless base station allows a mobile device to communicate with a wireless network. An estimate of the location of the wireless base station may allow a location based service to determine the location of a mobile device. In an embodiment, location may be estimated using a collection of data samples obtained from a mobile device. These data samples may contain carrier related timing information, for example GSM (Global System for Mobile Communications) timing information and received signal strength indication (RSSI). Data from the GSM timing information and RSSI may be analyzed to estimate a distance of a mobile device from a wireless base station. In another embodiment, a centroid of the data samples is computed. The centroid may then be used to estimate the direction of a cell phone tower relative to the centroid. In this way, using an estimate of distance and direction, location of wireless base station may be estimated.

Claims

1. A method for identifying a location of a wireless base station, comprising:

obtaining data samples from one or more mobile devices;

acquiring signal strength information in the data samples;

analyzing timing information in the data samples to determine at least one of a synchronization offset and a value of distance;

plotting one or more of the data samples on a multi-dimensional plane;

computing a centroid of the data samples;

computing a first curve based on a location of the wireless base station;

computing a second curve based on the data samples obtained from the one or more mobile devices;

determining a phase shift between the first curve and the second curve;

computing an angle between a location of the wireless base station and the centroid using at least the phase shift;

determining a direction of the wireless base station from one of the mobile devices using the phase shift and the angle; and

outputting a signal to the one or more mobile devices, the signal corresponding to the location of the wireless base station.

2. The method of claim 1, wherein the first curve and the second curve are sinusoidal curves.

3. The method of claim 1, wherein the first curve is based on a location of the wireless base station at a direction north of the centroid.

4. The method of claim 1, wherein the phase shift is determined based on at least a convolution between the first curve and the second curve.

5. The method of claim 1, wherein the phase shift is based on one or more signal propagation models.