Invention Grant
- Patent Title: Indoor positioning with radio frequency chirp signal propagation delay measurement
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Application No.: US13830291Application Date: 2013-03-14
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Publication No.: US09766321B2Publication Date: 2017-09-19
- Inventor: John Robert Schwartz , Terry Michael Schaffner
- Applicant: Digi International Inc.
- Applicant Address: US MN Minnetonka
- Assignee: Digi International Inc.
- Current Assignee: Digi International Inc.
- Current Assignee Address: US MN Minnetonka
- Agency: Fogg & Powers LLC
- Main IPC: G01S3/02
- IPC: G01S3/02 ; G01S5/06 ; G01S5/14 ; G01S13/87 ; G01S5/02

Abstract:
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.
Public/Granted literature
- US20140266914A1 INDOOR POSITIONING WITH RADIO FREQUENCY CHIRP SIGNAL PROPAGATION DELAY MEASUREMENT Public/Granted day:2014-09-18
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