MOBILE TERMINAL DEVICE AND POSITIONING METHOD

• US 20130035112A1
• Filed: 04/11/2011
• Published: 02/07/2013
• Est. Priority Date: 04/14/2010
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takahashi, Makoto
• Granted Patent: US 9,026,135 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 5/01 Determining conditions which influence positioning, e.g. radio environment, state of motion or energy consumption

Abstract

There are provided a mobile terminal device and a positioning method, in which power saving is enabled. When an environment estimating unit determines that the mobile terminal device is currently located in an indoor environment, an autonomous GPS positioning regulating unit thereof regulates implementation of an autonomous positioning operation by an autonomous GPS positioning unit to enable the suppression of wasteful power consumption caused by the implementation of the autonomous GPS positioning operation that has no possibility of being successful at a current time. In the meanwhile, an assist information acquiring processing unit of an A-GPS positioning unit is made to perform an assist information acquiring process that is a former process of the A-GPS positioning operation. When the location accuracy of outline location information acquired has a good result of a level 3 or higher, the outline location information is provided as a positioning result.

Claims

1. A mobile terminal device capable of selectively performing a plurality of different positioning methods for acquiring location information of the mobile terminal device in a repeated manner,

the mobile terminal device comprising:

a positioning timing base unit for giving a positioning timing base signal to be a basis for specifying a timing of performing each positioning operation, when the positioning operation is performed in the repeated manner;

a positioning result holding unit for at least temporarily holding positioning data corresponding to a result of the each positioning operation;

an A-GPS positioning unit for performing an A-GPS positioning operation at the timing in synchronization with the positioning timing base signal given by the positioning timing base unit, the A-GPS positioning operation including an assist information acquiring process for acquiring GPS assist information including outline location information of the mobile terminal device in communication with a base transceiver station, and a positioning operation process by use of the GPS assist information acquired by the assist information acquiring process;

an autonomous GPS positioning unit for performing an autonomous GPS positioning operation without using the GPS assist information at the timing in synchronization with the positioning timing base signal given by the positioning timing base unit;

an environment estimating unit for estimating whether or not the mobile terminal device is currently located in an indoor environment or in an outdoor environment; and

an autonomous GPS positioning regulating unit for regulating implementation of the autonomous GPS positioning operation by the autonomous GPS positioning unit to cause the A-GPS positioning unit to perform the assist information acquiring process of the A-GPS positioning operation, when the environment estimating unit estimates that the mobile terminal device is currently located in the indoor environment, and at a time after the estimation, when the positioning timing base unit gives the positioning timing base signal.

2. The mobile terminal device according to claim 1, further comprising:

an assist information holding unit for holding the GPS assist information acquired by the assist information acquiring process by the A-GPS positioning unit;

an outline location information accuracy determining unit for determining whether or not accuracy of a location of the outline location information of the mobile terminal device included in the GPS assist information held by the assist information holding unit satisfies a predefined level; and

a positioning operation process regulating unit for regulating implementation of the positioning operation process by the A-GPS positioning unit and causing the positioning result holding unit to hold as the positioning data the outline location information on which a positive determination is made by the outline location information accuracy determining unit, when the outline location information accuracy determining unit makes the positive determination, and at a time after the determination, when the positioning timing base unit gives the positioning timing base signal.

3. The mobile terminal device according to claim 1, wherein the environment estimating unit estimates that the mobile terminal device is currently located in the indoor environment, when already acquired positioning data held at a most recent time in the past out of the positioning data held by the positioning result holding unit is one of the positioning data acquired by the A GPS positioning operation and the positioning data acquired by the autonomous GPS positioning operation, and when accuracy of a location of the already acquired positioning data does not satisfy a predefined level.

4. The mobile terminal device according to claim 2, wherein the positioning operation process regulating unit permits the A-GPS positioning unit to perform the positioning operation process, when the outline location information accuracy determining unit makes a negative determination, and at a time after the determination, when the positioning timing base unit gives the positioning timing base signal.

5. A positioning method for selectively performing a plurality of different positioning methods for acquiring location information of a mobile terminal device in a repeated manner to acquire positioning data corresponding to a result of each positioning operation, the positioning method comprising the steps of:

generating a positioning timing base signal to be a basis for specifying a timing of performing the each positioning operation, when the positioning operation is performed in the repeated manner;

performing an A-GPS positioning operation including an assist information acquiring process for acquiring GPS assist information including outline location information of the mobile terminal device in communication with a base transceiver station, and a positioning operation process by use of the GPS assist information acquired by the assist information acquiring process;

performing an autonomous GPS positioning operation without using the GPS assist information at the timing in synchronization with the positioning timing base signal generated;

estimating whether or not the mobile terminal device is currently located in an indoor environment or in an outdoor environment; and

regulating implementation of the step of performing the autonomous GPS positioning operation, while performing the A-GPS positioning operation at the timing in synchronization with the positioning timing base signal, when the step of estimating estimates that the mobile terminal device is currently located in the indoor environment, and at a time after the step of estimating, when the positioning timing base signal is given.