Patent ID: 9594170
Date: 2017-03-14
CPC Classifications: G01S

Claim:
1. A method of determining the location of a mobile device: (a) receiving a first signal of opportunity (SoOP) at a mobile device, wherein the SoOP is an ambient radio frequency (RF) transmission that is not intended for navigation, position or timing for positioning purposes and the mobile device does not include a timing reference having precision to determine the latitude and longitude location of the mobile device and wherein the first signal does not contain a timing reference, and wherein the first SoOP is transmitted from a system different than the communication system of the mobile device; (b) receiving a second signal at the mobile device, wherein the second signal includes a timing reference that provides a first time stamp for receipt of the second signal; (c) sampling the first SoOP and digitizing a portion of it; (d) deriving a second time stamp for the first SoOP based on the first time stamp of the second signal; and (e) using the digitized portion of the first SoOP with the derived second time stamp for the first signal to determine the location of the mobile device.