System and Method of Implementing Asynchronously-Clocked Fixed-Location Devices for a Distance Determination by a Roaming Client Device

摘要

A system of asynchronously-clocked fixed-location devices and a roaming client device can be used for a distance determination of the roaming client device. The system includes a master device, at least one slave device, and any number of roaming client devices. The master device transmits a series of pulses. Once those pulses reach the client device, the client device will begin to count the number of pulses. Once those pulses reach the slave device, the slave device will transmit an acknowledgement pulse. After the client device receives the acknowledgement pulse, the client device will stop counting the pulses from the master device. The total number of pulses counted by the client device will then be used in the distance determination of the client device.

主权项

1. A method of implementing asynchronously-clocked fixed-location devices for a distance determination by a roaming client device, the method comprises the steps of:
(A) providing a master device and an at least one slave device, wherein said slave device is separated from said master device by a constant distance; (B) providing an at least one client device located in between or around said master device and said slave device; (C) transmitting a series of pulses from said master device, wherein said series of pulses is transmitted at a predetermined interval; (D) initiating a counter for said client device, once said client device receives a first pulse from said master device; (E) incrementing said counter as said client device receives each subsequent pulse from said master device; (F) transmitting an acknowledgement pulse from said slave device, once said first pulse is received by said slave device; (G) recording an actual value of said counter, once said client device receives said acknowledgement pulse from said slave device; and (H) calculating a time difference of arrival (TDOA) at said client device, wherein said TDOA is for said master device and said slave device.