Distributed method and system for determining the position of a mobile device using long-range signals and calibrating the position using short-range signals

摘要

A method and system is described where a plurality of position reference devices use short-range wireless communication protocols to transmit positioning assistance data to nearby mobile devices, and the mobile devices use the assistance data to model errors and re-calibrate their positioning systems. The short-range communication methods include NFC, RFID, Bluetooth®, short-range 802.11, Wi-Fi Direct, and high frequency focused beams such as 60 GHz. The position reference devices are passive or active NFC tags, passive or active RFID tags, other devices that include such tags as their components, Bluetooth®-enabled devices, 60 GHz-enabled devices, and 802.11 access points that can lower their transmit power. The reference devices are located at various indoor and outdoor locations such as smart posters, kiosks, ATM machines, malls, store checkout counters, store security gates, wireless access points, cellular base-stations, tollbooths, traffic lights, and street lamp posts.

主权项

1. A method of determining a position of a mobile device and calibrating a positioning system of the mobile device, the method comprising:
receiving a plurality of signals from a plurality of transmitting devices; using the positioning system of the mobile device, setting the position of the mobile device to a position calculated based on the received signals; receiving a position of a position reference device using near field communication (NFC) electromagnetic coupling in an NFC mode, wherein the mobile device provides an electromagnetic field and the position reference device responds by modulating and backscattering the position of the position reference device; setting the position of the mobile device from said calculated position to the position of the position reference device; and calibrating the positioning system of the mobile device such that the calculated position of the mobile device using the positioning system coincides with the received position of the position reference device.