Radio communication terminal and position specifying system

• US 20030100313A1
• Filed: 08/09/2002
• Published: 05/29/2003
• Est. Priority Date: 11/28/2001
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Takeuchi, Toshihiro, Ogino, Hiroyasu, Shamoto, Michio
• Granted Patent: US 6,941,145 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/12 wherein the cooperating elements are telecommunication base stations
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A radio communication terminal is used in a position specifying system, in which both retrieval timing and retrieval time of each of GPS satellites are received via a communication base station from a position information server. The position information server specifies a position of the radio communication terminal based upon at least GPS satellite information received from the radio communication terminal. The radio communication terminal corrects at least any one of both retrieval timing and retrieval time so that the retrieval timing is moved, or the retrieval time is prolonged. The radio communication terminal retrieves the GPS satellites based upon the corrected retrieval timing and the corrected retrieval time.

Claims

1. A radio communication terminal for a position specifying system including a base station, a position information server and GPS satellites, the radio communication terminal comprising:

means for receiving, from the position information server through one communication base station, both retrieval timing and retrieval time that have been set with respect to each of the GPS satellites by the position information server; and

means for transmitting at least GPS satellite information to the position information server so that the position information server specifies a position of the radio communication terminal based upon the received information,

the radio communication terminal being characterized by further comprising;

means for correcting at least any one of the retrieval timing and the retrieval time, which are related to the GPS satellites notified from the position information server, in such a manner that the retrieval timing is moved or the retrieval time is prolonged, and

means for retrieving the GPS satellites based upon the corrected retrieval timing and retrieval time to acquire the GPS satellite information so that the acquired GPS satellite information is transmitted to the position information'"'"'server via the communication base station.

2. A radio communication terminal as in claim 1, wherein the correcting means corrects the retrieval timing related to the GPS satellite notified from the position information server so that the retrieval time related to the GPS satellite is time-sequentially prolonged only in one direction.

3. A radio communication terminal as in claim 1, wherein the correcting means sorts the GPS satellites notified from the position information server in the order of higher elevation angles, and corrects at least any one of the retrieval timing and the retrieval time, which are related to the GPS satellites notified from the position information server, in the order of the higher elevation angles of the GPS satellites.

4. A radio communication terminal as in claim 1, wherein the correcting means calculates a total retrieval time required to retrieve all of the GPS satellites based upon the retrieval time set with respect to the respective GPS satellites, and sets both the retrieval timing and the retrieval time, which are related to other GPS satellites notified from the position information server without any correction thereof after the calculated total retrieval time reaches a defined retrieval time.

5. A radio communication terminal as in claim 1, wherein the correcting means sets the retrieval timing and the retrieval time, which are related to other GPS satellites notified from the position information server without any correction thereof, after a total number of the GPS satellites in which at least any one of the retrieval timing and the retrieval time has been corrected reaches a defined correction number.

6. A radio communication terminal as in claim 1, wherein the retrieving means ceases retrieving of other GPS satellites after a total number of GPS satellites which could be successfully retrieved reaches a defined retrieval success number.

7. A radio communication terminal as in claim 6, wherein the correcting means corrects at least any one of the corrected retrieval timing and the corrected retrieval time after a total number of GPS satellites which could be successfully retrieved does not reach the defined retrieval success number.

8. A radio communication terminal as in claim 1, further comprising:

means for displaying the position specified by and received from the position information server.

9. A position specifying system comprising:

the radio communication terminal in claim 1;

and

a position information server for transmitting both retrieval timing and retrieval time, which have been set with respect to each of GPS satellites, via a communication base station to the radio communication terminal, and specifying a position of the radio communication terminal based upon at least GPS satellite information received from the radio communication terminal.

10. A computer program for causing a radio communication terminal to execute steps of:

receiving both retrieval timing and retrieval time, which have been set with respect to each of GPS satellites by a position information server, from the position information server;

correcting at least any one of the retrieval timing and the retrieval time, which are notified from the position information server, so that that the retrieval timing is moved, or the retrieval time is prolonged, and then for setting the corrected retrieval timing, or the corrected retrieval time;

retrieving the GPS satellites based upon the retrieval timing and the retrieval time, which have been corrected to be set, so as to acquire GPS satellite information; and

transmitting the acquired GPS satellite information via a communication base station to the position information server.