Silicon Laboratories Inc.
One way ranging measurement using sounding sequence

Abstract:

A system and method for one-way ranging is disclosed. The system comprises a transmitter, also referred to as a tag, transmitting a packet having a sounding sequence. The receiver, also referred to as the locator, receives the sounding sequence. The receiver measures and saves the phase at a plurality of points in time. The sounding sequence has two frequencies, which are additive inverses of one another. A discrete Fourier transform is performed on the plurality of phase measurements to determine the phase of each of the two frequencies. The difference between these two frequencies is related to the time that the packet traveled. Additionally, a calibration of the transmit path and/or receive path may be performed to improve the accuracy of the results.