IP Library Granted Patent US 8,823,588
Granted Patent B2
US 8,823,588 · App. 12/795,101 · Granted Sep 2, 2014

Radio positioning and ranging system and positioning and ranging program

Inventors: Masafumi Asai (Kawasaki, JP); Hidenori Sekiguchi (Kawasaki, JP); Akira Fujii (Kawasaki, JP)
Assignee: Fujitsu Limited
G01S11/06G01S5/0221G01S5/06G01S5/14G01S11/08
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Quick Facts
Patent No.
US 8,823,588
App. No.
12/795,101
Granted
Sep 2, 2014
Kind
B2
Abstract

A positioning and ranging system includes a transmitter transmits a plurality of impulses; and a receiver receives the impulses; the receiver includes an initial detection unit records a sensing time of a first impulse among a plurality of impulses transmitted by the transmitter; a sensing margin detection unit for detecting a sensing margin being a difference between a field intensity of the first impulse and a reception limit field intensity of the receiver; a correction unit identifies a sensing error differential time based on a given relationship between the sensing margin and the sensing error differential time, and corrects the sensing time detected by the initial detection unit using the identified sensing error differential time; the system measures a distance between the transmitter and the receiver and a position of the transmitter based on a time the transmitter transmits the first impulse and a time the receiver receives the impulse.

Claims (47)

1. A positioning and ranging system comprising:

a transmitter that transmits a plurality of impulses; and

a receiver that receives the plurality of impulses;

wherein, the receiver includes:

a memory, and

a processor coupled to the memory and configured to:

record a sensing time of a first impulse among the plurality of impulses transmitted by the transmitter,

detect a sensing margin that is a difference between a field intensity of the first impulse received and a field intensity reception limit of the receiver,

identify a sensing error differential time being a timing corresponding with sensing of the first impulse based on the sensing margin detected, and

correct the sensing time of the first impulse using the identified sensing error differential time,

wherein the positioning and ranging system measures a distance between the transmitter and the receiver and a position of the transmitter based on a time when the transmitter transmits the first impulse and the corrected sensing time,

wherein the transmitter includes:

a memory, and

a processor coupled to the memory and configured to:

transmit a frame that includes a plurality of impulses with substantially the same intensity, and

wherein the processor of the receiver is configured to:

attenuate the field intensity of each of the plurality of impulses in the frame so that the field intensity of each of the plurality of impulses is different from attenuated intensities of other impulses included in the frame transmitted, and

detect the sensing margin based on the plurality of impulses attenuated within the frame.

2. The positioning and ranging system according to claim 1 , wherein

the first impulse is an impulse that is first detected from among the plurality of impulses.

3. The positioning and ranging system according to claim 1 , wherein

the given relationship between the sensing margin and the sensing error differential time is obtained by using the transmitter, the receiver, and a cable and an attenuator that are coupled between the transmitter and the receiver.

4. The positioning and ranging system according to claim 1 , comprising

an apparatus including:

a memory, and

a processor coupled to the memory and configured to:

correct a sensing time for each of a plurality of receivers based on a measured distance between a plurality of receivers and a position of the transmitter.

5. The positioning and ranging system according to claim 1 ,

wherein different sensing error differential times are identified and stored in the receiver based on changes to the sensing margin.

6. The positioning and ranging system according to claim 1 herein the field intensity reception limit set for the receiver indicates a threshold for detecting a field intensity of an impulse by the receiver.

7. A positioning and ranging system comprising:

a transmitter that transmits a plurality of impulses; and

a receiver that receives the plurality of impulses;

wherein, the receiver includes:

a memory, and

a processor coupled to the memory and configured to:

record a sensing time of a first impulse among the plurality of impulses transmitted by the transmitter,

detect a sensing margin that is a difference between a field intensity of the first impulse received and a field intensity reception limit of the receiver,

identify a sensing error differential time being a timing corresponding with sensing of the first impulse based on the sensing margin detected, and

correct the sensing time of the first impulse using the identified sensing error differential time,

wherein the positioning and ranging system measures a distance between the transmitter and the receiver and a position of the transmitter based on a time when the transmitter transmits the first impulse and the corrected sensing time,

wherein the transmitter includes:

a memory, and

a processor coupled to the memory and configured to:

transmit a plurality of frames that each include a plurality of impulses with substantially the same field intensity to the receiver,

wherein the processor of the receiver is configured to:

detect the sensing margin by attenuating impulses over the plurality of frames.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 8, 2010
From: ASAI, MASAFUMI; SEKIGUCHI, HIDENORI; FUJII, AKIRA
To: FUJITSU LIMITED
Reel/Frame 024498/0077 →
Priority Claims (1)
JP 2009-137631 · Jun 8, 2009 · national
Continuity (1)
Related Publication 20100309053A1 · Dec 9, 2010