Method for performing measurements and positioning in a network based WLAN positioning system

摘要

A network based positioning (NBP) system that improves the accuracy of wireless positioning systems by concurrently performing RTT ranging operations and associated TDOA operations to generate a number of difference measurement values from which the position of a station device (STA) can be determined using, for example, multilateration techniques. Because the RTT values and their corresponding TDOA values both include the turn-around time (TAT) of the STA, subtracting TDOA values from their corresponding RTT values generates difference measurement values that do not include such TAT values of the STA. In this manner, the STA position can be determined without estimating the STA's TAT.

主权项

1. A method of determining a position of a wireless station (STA), the method comprising:
exchanging a request (REQ) frame and an acknowledgement (ACK) frame between a first access point (AP) and the STA; determining, in the first AP, a round trip time (RTT) value in response to exchanging the REQ frame and the ACK frame between the first AP and the STA; determining a time of arrival (TOA) of the REQ frame at a second AP and a TOA of the ACK frame at the second AP; determining a time difference of arrival (TDOA) value indicative of the difference between the TOA of the ACK frame and the TOA of the REQ frame; and determining a difference measurement value indicative of a difference between the RTT value and the TDOA value, wherein the first AP and the STA are separated by a first distance, the second AP and the STA are separated by a second distance, and the difference measurement value indicates a difference between the first and the second distances.