INDOOR POSITIONING WITH RADIO FREQUENCY CHIRP SIGNAL PROPAGATION DELAY MEASUREMENT

摘要

A radio frequency locator system and method. First, second and third reference devices are operable to transmit a plurality of spread spectrum chirp signals frequency offset from one another. An object device is operable to receive the plurality of spread spectrum chirp signals, the object device is further operable to evaluate the received plurality of spread spectrum chirp signals for relative phase shifts between the plurality of spread spectrum chirp signals and derive a fine propagation time between the reference devices and the object device using the phase shifts between the spread spectrum chirp signals. The reference devices determine their location independent of the object device and determine the location of the object device as a function of each of their locations and of their range to the object device.

主权项

1. A method of determining the location of a device capable of receiving and transmitting a chirp spread spectrum signal, the method comprising:
determining a first position; transmitting a chirp spread spectrum signal from the first position and receiving a chirp spread spectrum range reply signal at the first position from the device; determining range between the first position and the device; determining a second position; transmitting a chirp spread spectrum signal from the second position and receiving a chirp spread spectrum range reply signal at the second position from the device; determining range between the second position and the device; determining a third position; transmitting a chirp spread spectrum signal from the third position and receiving a chirp spread spectrum range reply signal at the third position from the device; determining range between the third position and the device; and determining the location of the device based on the locations determined for the first, second and third positions and the range between the first position and the device, the range between the second position and the device, and the range between the third position and the device.