Terminal apparatus, positioning method, control program for terminal apparatus, and computer readable recording medium having recorded therein control program for terminal apparatus
First Claim
1. A terminal apparatus configured to receive position related information signals from a plurality of SPS satellites, the terminal apparatus comprising:
- a control unit determining a first satellite-to-be-acquired from among the plurality of SPS satellites, and generating a first initial search frequency for the first satellite-to-be- acquired; and
a positioning device having a plurality of search units, the positioning device acquiring the first satellite-to-be-acquired by using the plurality of search units,the control unit determining first drift information, the first drift information being a difference between the first initial search frequency and the frequency acquiring the first satellite-to-be-acquired,the control unit determining a second satellite-to-be-acquired from among the plurality of SPS satellites excluding the first satellite-to-be-acquired,the control unit generating a second initial search frequency for the second satellite- to-be-acquired,the positioning device acquiring the second satellite-to-be-acquired by using some of the plurality of search units,the control unit determining second drift information, the second drift information being difference between the second initial search frequency and the frequency acquiring the second satellite-to-be-acquired,the control unit verifying the first drift information by comparing the first and second drift information,when the first and second drift information is substantially equal, the control unit generating corrected search frequency by using one of the first and second drift information for at least some of the plurality of SPS satellites excluding the first and second satellites-to- be-acquired,the positioning device acquiring at least another position information satellite by using the corresponding corrected search frequency.
1 Assignment
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Accused Products
Abstract
A terminal apparatus includes a control unit and a positioning device. The control unit determines a first satellite-to-be-acquired from among a plurality of SPS satellites, and generates an initial search frequency for the first satellite-to-be-acquired. The positioning device has a plurality of search units, and is configured to acquire the first satellite-to-be-acquired using the plurality of search units. The control unit determines first difference information, which is a difference between the initial search frequency and the frequency at which the first satellite-to-be-acquired is acquired. The control unit generates corrected search frequencies for other SPS satellites, using the first difference information. The positioning device acquires other necessary SPS satellites using the corresponding corrected search frequencies. The terminal apparatus can acquire SPS satellites accurately even when there has been a frequency shift in the terminal apparatus since the last positioning.
40 Citations
19 Claims
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1. A terminal apparatus configured to receive position related information signals from a plurality of SPS satellites, the terminal apparatus comprising:
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a control unit determining a first satellite-to-be-acquired from among the plurality of SPS satellites, and generating a first initial search frequency for the first satellite-to-be- acquired; and a positioning device having a plurality of search units, the positioning device acquiring the first satellite-to-be-acquired by using the plurality of search units, the control unit determining first drift information, the first drift information being a difference between the first initial search frequency and the frequency acquiring the first satellite-to-be-acquired, the control unit determining a second satellite-to-be-acquired from among the plurality of SPS satellites excluding the first satellite-to-be-acquired, the control unit generating a second initial search frequency for the second satellite- to-be-acquired, the positioning device acquiring the second satellite-to-be-acquired by using some of the plurality of search units, the control unit determining second drift information, the second drift information being difference between the second initial search frequency and the frequency acquiring the second satellite-to-be-acquired, the control unit verifying the first drift information by comparing the first and second drift information, when the first and second drift information is substantially equal, the control unit generating corrected search frequency by using one of the first and second drift information for at least some of the plurality of SPS satellites excluding the first and second satellites-to- be-acquired, the positioning device acquiring at least another position information satellite by using the corresponding corrected search frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A terminal apparatus configured to receive position related information signals from a plurality of SPS satellites, the terminal apparatus comprising:
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search means for searching SPS satellites with a predetermined search power; synchronizing frequency information means for determining initial search frequencies of the terminal for each of the plurality of SPS satellites; first satellite-to-be-acquired determining means for determining a first satellite-to-be- acquired from among the plurality of SPS satellites; first satellite-to-be-acquired acquiring means for acquiring the first satellite-to-be- acquired by using the search means with the predetermined search power; first drift information obtaining means for obtaining first drift information indicating a difference between the initial search frequency of the first satellite-to-be-acquired and a first acquisition frequency at which the first satellite-to-be-acquired is acquired; second satellite-to-be-acquired determining means for determining a second satellite- to-be-acciuired from among the plurality of SPS satellites excluding the first satellite-to-be- acquired, second satellite-to-be-acquired acquiring means for acquiring the second satellite-to- be-acquired, second drift information obtaining means for obtaining second drift information indicating a difference between the initial search frequency of the second satellite-to-be- acquired and a second acquisition frequency at which the second satellite-to-be-acquired is acquired, the first drift information being verified by comparing the first and second drift information, and means for acquiring sufficient satellites acquiring a sufficient number of SPS satellites required for positioning the terminal apparatus by using at least one of the first drift information and the second drift information, when the first and second drift information are substantially equal, and positioning means for obtaining position related information from the SPS satellites that have been acquired, and locating a present position of the terminal apparatus. - View Dependent Claims (10, 11, 12)
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13. A positioning method for use in a terminal apparatus configured to receive position related information signals from a plurality of SPS satellites, the positioning method comprising:
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determining a first satellite-to-be-acquired by the terminal apparatus from among the plurality of SPS satellites; acquiring a first satellite-to-be-acquired by the terminal apparatus by using a first initial search frequency of the first satellite-to-be-acquired; obtaining first drift information by the terminal apparatus, the first drift information indicating a difference between the first initial search frequency of the first satellite-to-be- acquired and a first acquisition frequency acquiring the first satellite-to-be-acquired; determining a second satellite-to-be-acquired by the terminal apparatus from among the plurality of SPS satellites excluding the first satellite-to-be-acquired; acquiring a second satellite-to-be-acquired by the terminal apparatus by using a second initial search frequency of the second satellite-to-be-acquired; obtaining second drift information by the terminal apparatus indicating a difference between the second initial search frequency of the second satellite-to-be-acquired and a second acquisition frequency at which the second satellite-to-be-acquired is acquired; acquiring the sufficient number of SPS satellites by the terminal apparatus by using at least one of the first drift information and second drift information to acquire the sufficient number of SPS satellites required for positioning the terminal apparatus, when the first and second drift information are substantially equal; positioning via the terminal apparatus obtaining position related information from the acquired SPS satellites, and locating a present position of the terminal apparatus; and displaying the present position by the terminal apparatus. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification