Patent Number: 7,042,868

Title: Method and system for performing ranging functions in an ultrawide bandwidth system

Abstract: A process is provided for determining the distance between two devices by sending ranging packets between them. The local device sends a first ranging packet, which the remote device sends holds for a first hold time before sending a second ranging packet in return. The local device also sends a third ranging packet, which the remote device sends holds for a second hold time before sending a fourth ranging packet in return. If the second hold time is twice the first hold time, then the propagation time for signals between the two devices can be determined solely by time measurements made by the local device. For received signals, these time measurements can be adjusted to provide accurate time estimates for a direct line of sight signal, which corresponds to a shortest transmission distance between the two devices. The propagation time can then be used to determine distance between the devices.

Inventors: Runkle; Paul R. (Durham, NC), Roberts; Richard D. (Vienna, VA)

Assignee: Freescale Semiconductor Inc.

International Classification: H04B 7/212 (20060101)

Expiration Date: 5/09/02018