JP2006119062A - Mobile terminal and positioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal capable of positioning the current position, in a short time and of reducing the power consumption. <P>SOLUTION: The mobile terminal is equipped with a positioning section 12 which positions the current position based on positioning signals Sg1, Sg2 from satellites for positioning; and a control section 16 which controls the positioning section 12. The positioning section 12 is constituted operable in both of a first positioning mode, in which an integration process is applied to the positioning signals Sg1, Sg2 in order to position the current position, and a second positioning mode in which the current position is positioned, without applying the integration process on the positioning signals Sg1, Sg2. The control section 16 brings the positioning section 12 to operate in the first positioning mode, when the received intensity of the positioning signal Sg1 from a semi-zenith satellite serving as the satellite for positioning is not higher than a prescribed threshold, and brings the positioning section 12 to operate in the second positioning mode, when the received intensity of the positioning signal Sg1 from the semi-zenith satellite exceeds the prescribed threshold. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile terminal that measures a current position based on a positioning signal from a positioning satellite, and a positioning system including the mobile terminal.

Conventionally, a GPS (Global Positioning System) device has been used as a positioning system for positioning using an artificial satellite. In positioning by a GPS device, it is necessary to receive radio waves transmitted from GPS satellites. Generally, in a mobile terminal, a high sensitivity mode using a control device that operates at high speed and a normal mode using a control device that operates at low speed are used. Can be switched. As a method for switching between high-speed operation and low-speed operation, a GPS receiver disclosed in Japanese Patent Laid-Open No. 7-209405 is known. In this GPS receiver, when tracking a GPS satellite with a low elevation angle, the control device operates at a high speed based on a high-speed operation clock, and when tracking a GPS satellite with a high elevation angle, a low-speed operation clock is used. Based on this, the control device operates at a low speed. Therefore, it is possible to reduce power consumption compared to a configuration in which the control device always operates at high speed.
Japanese Patent Laid-Open No. 7-209405 (page 3, FIG. 1)

  However, the conventional GPS receiver has the following problems. That is, in this GPS receiver, the position of the satellite is known from the orbit information table of the GPS satellite, and the high-speed operation and low-speed operation of the control device are switched according to the elevation angle of the satellite used for positioning. In this case, for example, when there is a high structure around the GPS signal reception intensity may be weak due to the influence of the high structure even when the elevation angle of the GPS satellite is high. However, in the conventional GPS receiver, even if the reception intensity is weak, when the elevation angle of the GPS satellite is high, the control apparatus operates at a low speed regardless of the intensity of the GPS signal. On the other hand, when there is no obstacle around or above (the zenith), the GPS signal may be received with sufficient intensity even when the elevation angle of the GPS satellite is low. When the current position is measured based on such a sufficiently strong GPS signal, it is not necessary to perform special processing on the GPS signal. Even if the speed is relatively low, the current position can be measured in a short time. However, even if the conventional GPS receiver can receive the GPS signal with sufficient intensity, the controller operates at high speed regardless of the intensity of the GPS signal when the elevation angle of the GPS satellite is low. Therefore, in general, switching between the normal mode used for outdoor positioning and the high sensitivity mode used for indoor positioning is performed using the signal strength, elevation angle, etc. from the satellite used for positioning. As described above, switching between the normal mode by the low speed operation and the high sensitivity mode by the high speed operation cannot be performed with clear judgment. For this reason, there is a problem that wasteful power is consumed, such as positioning in a high sensitivity mode by high-speed operation, even though the normal mode by low-speed operation is sufficient.

  The present invention has been made in view of such problems, and can select a high-sensitivity mode and a normal mode satisfactorily, and realizes both positioning in a short time and reduction in power consumption. The main object is to provide a mobile terminal and a positioning system.

  In order to achieve the above object, a mobile terminal according to the present invention includes a positioning unit that measures a current position based on a positioning signal from a positioning satellite, and a control unit that controls the positioning unit, and the positioning unit includes: A first positioning mode for positioning the current position by executing an integration process on the positioning signal, and a second positioning for positioning the current position without executing the integration process on the positioning signal. The control unit is configured to be operable in both modes of the mode, and the control unit is configured to operate in the first positioning mode when a reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite is equal to or lower than a predetermined threshold value. The positioning unit is operated, and the positioning unit is operated in the second positioning mode when the reception intensity of the positioning signal from the quasi-zenith satellite exceeds the predetermined threshold value.

  In this mobile terminal, the control unit operates the positioning unit in the first positioning mode when the reception intensity of the positioning signal from the quasi-zenith satellite is equal to or less than a predetermined threshold value. For this reason, for example, in a use environment where the reception strength of the positioning signal is weak and the integration processing is required for the positioning signal at a high speed, the current position is determined by operating the positioning unit in the first positioning mode. Positioning can be done in a short time. In this mobile terminal, the control unit operates the positioning unit in the second positioning mode when the reception strength of the positioning signal from the quasi-zenith satellite exceeds a predetermined threshold value. For this reason, for example, in a use environment in which the positioning signal is strong and the current position can be measured without executing the integration process, the positioning unit is operated in the second positioning mode, thereby allowing the positioning unit to operate. The power consumption can be reliably reduced. Therefore, according to this mobile terminal, it is possible to satisfactorily select the first positioning mode which is the high sensitivity mode and the second positioning mode which is the normal mode, and the positioning of the current position and the power consumption in a short time. Reduction can be realized together.

  The mobile terminal according to the present invention includes a positioning unit that measures a current position based on a positioning signal from a positioning satellite, and a control unit that controls the positioning unit, and the positioning unit includes the positioning unit. Both a first positioning mode in which an integration process is performed on a signal to determine the current position, and a second positioning mode in which the current position is determined without executing the integration process on the positioning signal. And the control unit operates the positioning unit in the first positioning mode when the positioning signal from the quasi-zenith satellite as the positioning satellite cannot be received, and the quasi-zenith When the positioning signal from the satellite can be received, the positioning unit is operated in the second positioning mode.

  In this mobile terminal, the control unit operates the positioning unit in the first positioning mode when the positioning signal from the quasi-zenith satellite cannot be received, and the control unit operates when the positioning signal from the quasi-zenith satellite can be received. Operate the positioning unit in 2 positioning mode. For this reason, the first positioning mode that is the high sensitivity mode and the second positioning mode that is the normal mode can be satisfactorily selected, and both the positioning of the current position and the reduction of power consumption can be realized in a short time. be able to.

  Further, the mobile terminal according to the present invention includes a wireless communication unit configured to be able to perform wireless communication with an information output device that outputs orbit information of the positioning satellite in the above mobile terminal, and the positioning unit includes: The positioning satellite to be received is selected using the orbit information acquired from the information output device via the wireless communication unit.

  In addition, the positioning system according to the present invention executes a first positioning mode in which a current position is determined by executing an integration process on a positioning signal from a positioning satellite, and an execution of the integration process on the positioning signal. A positioning unit configured to be able to operate in both modes of the second positioning mode for positioning the current position without performing the operation, and the reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite is a predetermined threshold. The positioning unit is operated in the first positioning mode when the value is less than or equal to a value, and the positioning is performed in the second positioning mode when the reception intensity of the positioning signal from the quasi-zenith satellite exceeds the predetermined threshold value. A mobile terminal having a control unit for operating the unit, and an information output device configured to be capable of wireless communication with the mobile terminal and outputting orbit information of the positioning satellite to the mobile terminal.

  In this mobile terminal and this positioning system, the positioning unit selects a positioning-purpose positioning satellite using the orbit information acquired from the information output device via the wireless communication unit. For this reason, for example, as compared with the configuration in which the positioning unit calculates the orbit of the positioning satellite, the current position can be measured in a shorter time and the mobile terminal can be simply configured.

  In addition, the positioning system according to the present invention executes a first positioning mode in which a current position is determined by executing an integration process on a positioning signal from a positioning satellite, and an execution of the integration process on the positioning signal. A positioning unit configured to be able to operate in both modes of the second positioning mode for positioning the current position without performing wireless transmission, and wirelessly transmitting the reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite A mobile terminal having a communication unit and a control signal for operating the positioning unit in the first positioning mode when the reception intensity wirelessly transmitted from the wireless communication unit is a predetermined threshold value or less is sent to the wireless communication unit And transmits a control signal for operating the positioning unit in the second positioning mode to the wireless communication unit when the reception intensity wirelessly transmitted from the wireless communication unit exceeds the predetermined threshold value. And a control unit.

  In this positioning system, the control device transmits a control signal for operating the positioning unit in the first positioning mode to the wireless communication unit when the reception intensity of the positioning signal from the quasi-zenith satellite is equal to or lower than a predetermined threshold value, When the reception intensity of the positioning signal from the quasi-zenith satellite exceeds a predetermined threshold value, a control signal for operating the positioning unit in the second positioning mode is transmitted to the wireless communication unit. For this reason, it is not necessary to perform processing for mode switching on the mobile terminal side, and accordingly, the processing load on the mobile terminal can be reduced.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

(First embodiment)
Hereinafter, the best mode of a mobile terminal and a positioning system according to the present invention will be described with reference to the accompanying drawings. A positioning system 10 shown in FIG. 1 is an example of a positioning system according to the present invention, and includes a plurality of mobile terminals 1, 1..., A plurality of radio base stations 2, 2. The radio base stations 2, 2... And the management center facility 3 are connected to each other via a network N. In the figure, only one mobile terminal 1 and one radio base station 2 are shown.

  The mobile terminal 1 is an example of a mobile terminal according to the present invention, and includes a wireless communication unit 11, a positioning unit 12, a storage unit 13, a display unit 14, an operation unit 15, and a control unit 16, as shown in FIG. ing. The radio communication unit 11 transmits / receives a transmission request signal Sr, assist data Da described later, and the like to / from the radio base station 2 under the control of the control unit 16. Note that, in order to facilitate understanding of the present invention, description regarding transmission / reception of audio data during a call and illustration of a microphone, a speaker, and the like for a call are omitted.

  The positioning unit 12 includes a receiving unit and a calculation unit (both not shown), and outputs from the quasi-zenith satellite 9a shown in FIG. 1 using the assist data Da acquired via the wireless communication unit 11. Positioning signals Sg2 and GPS satellites 9b, 9b (hereinafter also referred to as “positioning satellite 9” when not distinguished from quasi-zenith satellite 9a and GPS satellite 9b). (Hereinafter, when the positioning signal Sg1 and the positioning signal Sg2 are not distinguished from each other, it is also referred to as “positioning signal Sg”), and the current position of the portable terminal 1 is measured based on the received positioning signal Sg. Here, the quasi-zenith satellite 9a actually has a plurality (for example, three), and its orbit is defined so that at least one is always located above Japan (near the zenith). Therefore, the positioning signal Sg1 from the quasi-zenith satellite 9a is less susceptible to the influence of buildings, mountains, and the like than the positioning signal Sg2 from the GPS satellite 9b that orbits the earth and the elevation angle changes with time. In addition, the positioning unit 12 performs a high-sensitivity mode (first positioning mode in the present invention) for performing positioning of the current position by executing integration processing on the positioning signal Sg at high speed according to the control of the control unit 16, and positioning. The operation is performed in any one of the normal mode (second positioning mode in the present invention) in which the current position is measured by omitting the integration process for the signal Sg. In this case, in this normal mode, since the integration process for the positioning signal Sg is omitted, the positioning unit 12 operates with power saving compared to the high sensitivity mode. In addition, about the positioning process of the present position by the positioning part 12, since arbitrary well-known methods are employable, the description is abbreviate | omitted. The storage unit 13 stores an operation program of the control unit 16 and assist data Da received via the wireless communication unit 11.

  The display unit 14 is configured by a color liquid crystal display as an example, and displays an image based on the image data Dg generated by the control unit 16 in color. The operation unit 15 is configured by arranging various operation buttons (not shown) such as a numeric button for inputting a telephone number and a positioning button for instructing the start of positioning at the current position. The corresponding operation signal is output. The control unit 16 controls the wireless communication unit 11, the positioning unit 12 and the display unit 14 according to the operation signal output from the operation unit 15. In addition, the control unit 16 stores the assist data Da received via the wireless communication unit 11 in the storage unit 13. Further, the control unit 16 controls the positioning unit 12 to measure the current position of the mobile terminal 1. In this case, the control unit 16 executes the mode switching process 50 shown in FIG. 5, and based on the reception strength (electric field strength) of the positioning signal Sg <b> 1, the control unit 16 performs either the high sensitivity mode or the normal mode. The positioning unit 12 is operated. Further, the control unit 16 causes the display unit 14 to display the positioning result of the positioning unit 12.

  The radio base station 2 corresponds to the information output device in the present invention, and is installed in an available area of the positioning system 10 to execute radio communication with the mobile terminal 1. Specifically, the radio base station 2 includes a radio communication unit 21, a communication modem 22, a storage unit 23, and a control device 24 as shown in FIG. The wireless communication unit 21 transmits / receives a transmission request signal Sr, assist data Da, and the like to / from the portable terminal 1 under the control of the control device 24. In this case, the assist data Da includes various types of information such as orbit information (for example, navigation data such as ephemeris data) defined for each positioning satellite 9. The communication modem 22 transmits and receives assist data Da and the like to and from the management center facility 3 via the network N. The storage unit 23 stores an operation program of the control device 24, assist data Da, and the like. The control device 24 generally controls the radio base station 2. Specifically, the control device 24 controls the wireless communication unit 21 according to the transmission request signal Sr, thereby transmitting the assist data Da toward the mobile terminal 1. Further, the control device 24 controls the communication modem 22 to receive the latest assist data Da and the like from the management center facility 3.

  As shown in FIG. 4, the management center facility 3 includes a communication modem 31, an assist data generation unit 32, a storage unit 33, and a control device 34. The communication modem 31 transmits and receives assist data Da and the like to and from the radio base station 2 via the network N under the control of the control device 34. The assist data generating unit 32 receives the positioning signals Sg1 and Sg2 transmitted from the positioning satellite 9 that can be supplemented in the available area of the positioning system 10, and repeatedly executes the process of generating the assist data Da. . The storage unit 33 stores an operation program of the control device 34, assist data Da generated by the assist data generation unit 32, and the like. The control device 34 controls the operations of the communication modem 31 and the assist data generation unit 32. Further, the control device 34 causes the storage unit 33 to store the assist data Da generated by the assist data generation unit 32. Further, the control device 34 controls the communication modem 31 to transmit the latest assist data Da and the like stored in the storage unit 33 toward the radio base station 2.

  Next, the overall operation of the positioning system 10 will be described with reference to the drawings. In this positioning system 10, the assist data generation unit 32 of the management center facility 3 repeatedly executes a process of generating assist data Da to be transmitted to the mobile terminal 1 at predetermined time intervals. In this process, the assist data generation unit 32 receives, for example, the positioning signal Sg1 transmitted from the quasi-zenith satellite 9a and all the GPSs that can receive the positioning signal Sg2 within the usable area of the positioning system 10. For the satellites 9b, 9b,..., Positioning signals Sg2 transmitted from the respective GPS satellites 9b, 9b,. Next, the assist data generation unit 32 generates assist data Da including each orbit information about the quasi-zenith satellite 9a and the GPS satellites 9b, 9b,... Based on the received positioning signals Sg1, Sg2. Subsequently, the control device 34 overwrites and stores the assist data Da generated by the assist data generating unit 32 in the storage unit 33.

  On the other hand, for example, when positioning the current position using the portable terminal 1, the positioning button of the operation unit 15 in the portable terminal 1 is operated. In response to this, the control unit 16 acquires the assist data Da. Specifically, the control unit 16 controls the wireless communication unit 11 to transmit a transmission request signal Sr requesting transmission of the assist data Da to the wireless base station 2. At this time, in the radio base station 2 installed in the communication area (communication possible area) where the mobile terminal 1 exists, the radio communication unit 21 receives the transmission request signal Sr transmitted from the mobile terminal 1. . In response to this, the control device 24 of the radio base station 2 determines whether or not the latest assist data Da is stored in the storage unit 23, and the assist data Da stored in the storage unit 23 is the latest assist data Da. When the data is Da (relatively new assist data Da), the wireless communication unit 21 is controlled to transmit the assist data Da to the mobile terminal 1. In addition, when the assist data Da has passed a predetermined available time (not the latest assist data Da), the transmission that controls the communication modem 22 to request transmission of the latest assist data Da is performed. A request signal is transmitted to the management center facility 3 via the network N. At this time, the communication modem 31 of the management center facility 3 receives the transmission request signal and outputs it to the control device 34, and the control device 34 reads the latest assist data Da from the storage unit 33 according to the transmission request signal. At the same time, the communication modem 31 is controlled to transmit the assist data Da to the radio base station 2. Next, in the wireless base station 2, the control device 24 controls the wireless communication unit 21 to transmit the assist data Da transmitted from the management center facility 3 toward the mobile terminal 1.

  Next, the wireless communication unit 11 of the mobile terminal 1 receives the assist data Da according to the control of the control unit 16, and the control unit 16 stores the assist data Da in the storage unit 13 and transfers it to the positioning unit 12. Subsequently, the control unit 16 executes a mode switching process 50 shown in FIG. In the mode switching process 50, the control unit 16 first outputs an instruction signal for starting the search for the positioning satellite 9 (reception process of the positioning signals Sg1 and Sg2) in, for example, the normal mode to the positioning unit 12. In response to this, the positioning unit 12 uses the orbit information included in the assist data Da to identify a positioning satellite 9 that can be captured, and starts searching for the specified positioning satellite 9 in the normal mode. (Step 51). Next, the control unit 16 determines whether or not the orbit information of the quasi-zenith satellite 9a is included in the assist data Da (step 52). At this time, when the orbit information of the quasi-zenith satellite 9a is not included, the control unit 16 continues the operation of the positioning unit 12 in the current mode (in this case, the normal mode) (step 53).

  On the other hand, when the orbit information of the quasi-zenith satellite 9a is included in the assist data Da, the control unit 16 acquires the search status of the quasi-zenith satellite 9a from the positioning unit 12 (step 54), and performs the search shown in FIG. A mode determination process 60 is executed (step 55). In the search mode determination process 60, the control unit 16 determines whether or not the positioning unit 12 has received (can receive) the positioning signal Sg1 from the quasi-zenith satellite 9a (step 61). At this time, when the positioning unit 12 can receive the positioning signal Sg1 from the quasi-zenith satellite 9a, the control unit 16 determines that the reception intensity of the positioning signal Sg1 from the quasi-zenith satellite 9a is a predetermined threshold value (an example). It is determined whether it exceeds -140 dBm) (step 62). In this case, when the reception strength of the positioning signal Sg1 exceeds the threshold value, it means that the mobile terminal 1 is located outdoors, for example, without any obstacles or few, and in this case, the GPS satellite 9b. Positioning signal Sg2 from can also be received with strong reception strength. Therefore, even in the normal mode in which special processing such as integration processing for positioning signals Sg1 and Sg2 is omitted, the current position can be measured in a short time. Therefore, when it is determined in step 62 that the reception intensity exceeds the threshold value, the control unit 16 determines that the normal mode is preferable as the search mode for the positioning satellite 9 (step 63).

  Next, as shown in FIG. 5, the control unit 16 determines whether or not the determination result of the search mode determination process 60 is the high sensitivity mode (step 56 of the mode switching process 50). At this time, since the determination result of the search mode determination process 60 is the normal mode, the control unit 16 switches the search mode of the positioning satellite 9 to the normal mode (step 58 of the mode switching process 50). In this example, since the search has already been performed in the normal mode, the control unit 16 continues the normal mode. In response to this, the positioning unit 12 measures the current position in the normal mode. Subsequently, the control unit 16 causes the display unit 14 to display the current position based on the positioning result by the positioning unit 12.

  On the other hand, when the reception intensity of the positioning signal Sg1 from the quasi-zenith satellite 9a is equal to or lower than the threshold value in step 62 of the search mode determination process 60 shown in FIG. 6, the mobile terminal 1 is placed indoors or in a place with many obstacles. In this case, the reception intensity of the positioning signal Sg2 from the GPS satellite 9b is also weak. In this case, when the weak positioning signals Sg1 and Sg2 are used, it is necessary to measure the current position in a high sensitivity mode in which the integration processing for the positioning signals Sg1 and Sg2 is executed at a high speed operation. Therefore, when the control unit 16 determines in step 62 of the search mode determination process 60 that the reception strength of the positioning signal Sg1 is equal to or less than the threshold value, the control unit 16 determines that the high sensitivity mode is preferable as the search mode for the positioning satellite 9. (Step 64 of the search mode determination process 60). Next, as shown in FIG. 5, the control unit 16 determines whether or not the determination result of the search mode determination process 60 is the high sensitivity mode (step 56 of the mode switching process 50). At this time, since the determination result of the search mode determination process 60 is the high sensitivity mode, the control unit 16 switches the positioning satellite search mode to the high sensitivity mode (step 57 of the mode switching process 50). In response to this, the positioning unit 12 measures the current position in the high sensitivity mode. Next, the control unit 16 causes the display unit 14 to display the current position based on the positioning result by the positioning unit 12.

  In step 61 of the search mode determination process 60, when the positioning unit 12 has not received the positioning signal Sg1 from the quasi-zenith satellite 9a, that is, when the reception strength of the positioning signal Sg1 is 0 (or almost 0). The control unit 16 controls the positioning unit 12 to select four GPS satellites 9b, 9b,... Having the smallest PDOP value from the supplementable GPS satellites 9b, and each of these GPS satellites 9b. , 9b, 9b, the positioning signal Sg2 is received. Further, when the positioning unit 12 does not receive the positioning signal Sg1, it means that the mobile terminal 1 is located in a place where it is difficult to receive the positioning signal Sg1, for example, indoors. The positioning signal Sg2 from the GPS satellite 9b becomes weak. For this reason, it is necessary to measure the current position in the high sensitivity mode in which the integration process for the positioning signal Sg2 is executed. Therefore, even when the control unit 16 determines that the positioning unit 12 cannot receive the positioning signal Sg1 in step 61 of the search mode determination process 60, the high sensitivity mode is preferable as the search mode for the positioning satellite 9. Determination (step 64 of the search mode determination processing 60). Subsequently, the control unit 16 determines whether or not the determination result of the search mode determination process 60 is the high sensitivity mode (step 56 of the mode switching process 50). Also in this case, since the determination result of the search mode determination process 60 is the high sensitivity mode, the control unit 16 switches the search mode of the positioning satellite 9 to the high sensitivity mode (step 57 of the mode switching process 50). In response to this, the positioning unit 12 measures the current position in the high sensitivity mode. Next, the control unit 16 displays the current position on the display unit 14 based on the positioning result.

  Thus, according to the portable terminal 1, the positioning signal Sg1 is operated by operating the positioning unit 12 in the high sensitivity mode when the reception intensity of the positioning signal Sg1 from the quasi-zenith satellite 9a is equal to or lower than the threshold value. In the use environment where the reception intensity of the signal is weak and the integration processing in the high-speed operation is required for the positioning signals Sg1 and Sg2, the positioning unit 12 is operated in the high sensitivity mode, thereby positioning the current position in a short time. be able to. Further, by operating the positioning unit 12 in the normal mode when the reception intensity of the positioning signal Sg1 exceeds the threshold value, the reception intensity of the positioning signal Sg1 is strong, and the current position can be obtained without executing the integration process. Under the usage environment in which positioning is possible, the power consumption of the positioning unit 12 can be reliably reduced by operating the positioning unit 12 in the normal mode. Therefore, according to the portable terminal 1, it is possible to satisfactorily select the high sensitivity mode and the normal mode, and it is possible to realize both the positioning of the current position and the reduction of power consumption in a short time.

  Further, according to the portable terminal 1 and the positioning system 10, the positioning unit 12 selects the GPS satellite 9 b to be received using the orbit information included in the assist data Da acquired from the radio base station 2. Compared with the configuration in which the positioning unit 12 calculates the orbit of the GPS satellite 9b, the current position can be measured in a shorter time and the portable terminal 1 can be simply configured.

(Second Embodiment)
Next, a system configuration of a positioning system 10A (see FIG. 1) including the mobile terminal 1A according to the second embodiment will be described. In the following description, the same components as those of the positioning system 10 in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted. In the positioning system 10A, when the current position is measured using the mobile terminal 1A, the control unit 16 of the mobile terminal 1A executes the mode switching process 70 shown in FIG. 7 instead of the mode switching process 50 described above. In this mode switching process 70, the control unit 16 first acquires the assist data Da, and determines whether or not the orbit information of the quasi-zenith satellite 9a is included in the assist data Da (step 71). At this time, when the orbit information of the quasi-zenith satellite 9a is included, the quasi-zenith satellite is set as the search mode determination satellite, and when the orbit information of the quasi-zenith satellite 9a is not included, the control unit 16 The positioning unit 12 is operated by setting one satellite having the highest elevation angle as the search mode determination satellite (step 72).

  Next, the control unit 16 controls the positioning unit 12 to start a search for only the search mode determined satellite (step 73). Next, the control unit 16 acquires the search status of the search mode determination satellite from the positioning unit 12 (step 74), and executes the search mode determination process 60 (see FIG. 6) described above (step 75). A detailed description of the search mode determination processing unit 60 is omitted here. Next, the control unit 16 determines whether or not the result of the search mode determination process 60 is the high sensitivity mode (step 76). In this case, when the determination result of the search mode determination processing 60 is the high sensitivity mode, the control unit 16 designates the search mode of the GPS satellite 9b as the high sensitivity mode (step 77), and the determination result of the search mode determination processing 60 is In the normal mode, the search mode of the GPS satellite 9b is designated as the normal mode (step 78), and the positioning unit 12 is controlled to start searching for another GPS satellite 9b (step 79).

  Subsequently, the control unit 16 acquires the search status of the search mode determination satellite from the positioning unit 12 (step 80), and executes the search mode determination process 60 again (step 81). Next, the control unit 16 determines whether or not the result of the search mode determination process 60 is the high sensitivity mode (step 82), and switches the search mode of the positioning satellite 9. In this case, when the determination result of the search mode determination processing 60 is the high sensitivity mode, the control unit 16 switches the search mode of the positioning satellite 9 to the high sensitivity mode (step 83), and the determination result of the search mode determination processing 60 is In the normal mode, the search mode of the positioning satellite 9 is switched to the normal mode (step 84). In response to this, the positioning unit 12 searches the positioning satellite 9 in the switched mode to determine the current position. Next, the control unit 16 causes the display unit 14 to display the current position based on the positioning result by the positioning unit 12. According to the portable terminal 1A and the positioning system 10A, the satellite having the highest elevation angle is determined as the search mode satellite before the search for the positioning satellite 9 is started, and the reception intensity of the signal of the search mode satellite is determined. Since the satellite signal status can be grasped in advance, the high sensitivity mode and the normal mode can be switched well, and the positioning satellite 9 is positioned after switching to the reception mode suitable for the signal strength. Compared with the configuration in which the search for all the positioning satellites 9 is started simultaneously in a predetermined mode, positioning of the current position and reduction of power consumption can be realized in a shorter time.

  In addition, this invention is not limited to said structure. For example, although the example in which the GPS satellite 9b to be received is selected using the assist data Da has been described above, for example, the positioning unit 12 or the control unit 16 calculates the route of the GPS satellite 9b based on the positioning signals Sg1 and Sg2. The positioning unit 12 may select a GPS satellite 9b to be received based on the calculated route. Furthermore, the mobile terminal 1 can be applied to various mobile terminals such as a mobile phone type terminal, a PHS type terminal, and a PDA (Personal Digital Assistant) type terminal.

  In addition, the example in which the control unit 16 of the mobile terminal 1 or 1A executes the mode switching processing 50 or 70 or the search mode determination processing 60 has been described above. For example, the control device 34 of the management center facility 3 executes these processes. It is also possible to adopt a configuration that does this. In this configuration, the mobile terminals 1 and 1 </ b> A transmit, for example, intensity data indicating the intensity of the positioning signal Sg <b> 1 via the wireless communication unit 11. In addition, the control device 34 of the management center facility 3 acquires the intensity data from the portable terminals 1 and 1A via the radio base station 2, and based on the intensity data, mode switching processing 50 and 70 and search mode determination processing 60 are performed. The control signal for operating the positioning unit 12 of the mobile terminals 1 and 1A in the search mode is determined via the radio base station 2 and the search mode is determined by executing the same process as in FIG. 11 to send. According to this configuration, since it is not necessary to perform the mode switching processing 50, 70 and the search mode determination processing 60 on the portable terminal 1, 1A side, the processing load on the portable terminal 1, 1A can be reduced accordingly.

1 is a block diagram showing a configuration of a positioning system 10. FIG. 2 is a block diagram showing a configuration of a mobile terminal 1. FIG. 2 is a block diagram showing a configuration of a radio base station 2. FIG. 3 is a block diagram showing a configuration of a management center facility 3. FIG. 5 is a flowchart of a mode switching process 50. 7 is a flowchart of a search mode determination process 60. 5 is a flowchart of a mode switching process 70.

Explanation of symbols

  1, 1A mobile terminal, 2 radio base station, 9a quasi-zenith satellite, 9b GPS satellite, 10, 10A positioning system, 12 positioning unit, 16 control unit, Da assist data, Sg1, Sg2 positioning signal

Claims (5)

A positioning unit that measures the current position based on a positioning signal from a positioning satellite; and a control unit that controls the positioning unit,
The positioning unit performs a first positioning mode in which an integration process is performed on the positioning signal to determine the current position, and the current position is determined without performing the integration process on the positioning signal. Configured to be operable in both modes of the second positioning mode,
The control unit operates the positioning unit in the first positioning mode when reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite is equal to or lower than a predetermined threshold value, and the quasi-zenith satellite A mobile terminal that causes the positioning unit to operate in the second positioning mode when the received signal strength of the positioning signal from exceeds a predetermined threshold value. A positioning unit that measures the current position based on a positioning signal from a positioning satellite, and a control unit that controls the positioning unit,
The positioning unit performs a first positioning mode in which an integration process is performed on the positioning signal to determine the current position, and the current position is determined without performing the integration process on the positioning signal. Configured to be operable in both modes of the second positioning mode,
The control unit operates the positioning unit in the first positioning mode when the positioning signal from the quasi-zenith satellite as the positioning satellite cannot be received, and the positioning signal from the quasi-zenith satellite A mobile terminal that operates the positioning unit in the second positioning mode when a signal can be received. A wireless communication unit configured to be capable of wireless communication with an information output device that outputs orbit information of the positioning satellite;
The mobile terminal according to claim 1 or 2, wherein the positioning unit selects the positioning satellite to be received using the orbit information acquired from the information output device via the wireless communication unit. A first positioning mode in which integration processing is performed on a positioning signal from a positioning satellite to determine a current position, and a first positioning mode in which the current position is measured without executing the integration processing on the positioning signal. A positioning unit configured to be operable in both two positioning modes, and the first positioning mode when a reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite is equal to or less than a predetermined threshold value; And a mobile terminal having a control unit that operates the positioning unit in the second positioning mode when the positioning unit operates and the reception strength of the positioning signal from the quasi-zenith satellite exceeds the predetermined threshold value. When,
A positioning system configured to be capable of wireless communication with the mobile terminal and including an information output device that outputs orbit information of the positioning satellite to the mobile terminal. A first positioning mode in which integration processing is performed on a positioning signal from a positioning satellite to determine a current position, and a first positioning mode in which the current position is measured without executing the integration processing on the positioning signal. A mobile terminal having a positioning unit configured to be operable in both modes of two positioning modes, and a wireless communication unit that wirelessly transmits the reception intensity of the positioning signal from the quasi-zenith satellite as the positioning satellite;
When the reception intensity wirelessly transmitted from the wireless communication unit is equal to or lower than a predetermined threshold, a control signal for operating the positioning unit in the first positioning mode is transmitted to the wireless communication unit, and the wireless communication unit A positioning system comprising: a control device that transmits a control signal for operating the positioning unit in the second positioning mode to the wireless communication unit when the reception intensity transmitted by radio exceeds the predetermined threshold value.

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