JP2008298790A - Positioning system, device, and method, and control program of positioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning system and the like in an inter-base-station asynchronous system communication network capable of executing, without needing a significant system change of each base station, positioning even when signals from three or more base stations can not be received. <P>SOLUTION: A communication base station 20A or the like includes: a base station positional information storage means storing base station positional information 152; a time difference information generation means generating time difference information 160 representing a time difference between a transmission time and a satellite time at the transmission time; and the like. A terminal device 50 includes: a base station information acquisition means acquiring the bast station positional information 152 and the time difference information 160 from the communication base station 20A or the like; a sky satellite number determination means determining the number of sky satellites being positioning satellites 12a or the like located above the terminal device 50; a positioning means selection means selecting any of a satellite signal positioning means, a signal radio wave positioning means for communication and a complex positioning means based on the number of sky satellites; and the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a positioning system, a terminal device, a terminal device control method, a terminal device control program, and a terminal device in an asynchronous communication network between base stations that do not have a common reference timing such as the same clock between communication base stations. The present invention relates to a computer-readable recording medium on which the control program is recorded.

Conventionally, for example, in a so-called digital mobile communication system of a CDMA (Code Division Multiple Access) system, a reception signal between a plurality of base stations and mobile radio terminal apparatuses is premised on ensuring time synchronization between the plurality of base stations. There is known a method for detecting a position based on a difference in arrival times (for example, JP-A-7-181242).
However, there is a problem that the economic burden is large for the construction of a system for synchronizing the time between base stations existing in large numbers throughout the country.
On the other hand, in the asynchronous communication network between base stations, a technology has been proposed in which a location management station that manages time difference information between a plurality of base stations is provided and the location management station measures the location of the mobile terminal. (For example, Patent Document 1).

Japanese Patent Laid-Open No. 11-252632 (FIG. 1 etc.)

However, in the prior art, a system for obtaining the difference in arrival time between the timing signal transmitted from each base station and the timing signal received from another base station requires a significant system change of the base station, and the construction is economical. The burden is heavy.
In addition, when signals from three or more base stations cannot be received, there is a problem that the position of the mobile terminal cannot be measured.

  Therefore, the present invention provides an asynchronous inter-base station system that can perform positioning even when signals from three or more communication base stations cannot be received without requiring a significant system change of the communication base stations. It is an object of the present invention to provide a positioning system, a terminal device, a control method for the terminal device, a control program for the terminal device, and a computer-readable recording medium on which the control program for the terminal device is recorded.

  The object is, according to the first invention, an asynchronous positioning system between communication base stations having a plurality of communication base stations and a terminal device capable of communicating with the communication base station, wherein the communication base station Base station position information storage means for storing base station position information indicating the position of the communication base station, and communication with transmission time information for transmitting transmission time information indicating a transmission time on a communication signal radio wave transmitted from the communication base station Signal radio wave generating means, satellite time information generating means for generating satellite time information indicating the satellite time which is the time of the positioning satellite based on a satellite signal which is a signal from the positioning satellite, and the transmission at the transmission time A time difference information generating means for generating time difference information indicating a time difference between a time and the satellite time, a communication signal radio wave transmitting means for transmitting the communication signal radio wave carrying the transmission time information, and the base Base station information transmitting means for transmitting position information and time difference information, and the terminal device indicates a satellite time which is a time of the positioning satellite based on the satellite signal from the positioning satellite Terminal-side satellite time information generating means for generating satellite time information; base station information acquiring means for acquiring the base station position information and the time difference information from the communication base station; and the positioning located above the terminal device. The number of sky satellites as satellites, satellite signal positioning means for positioning the position of the terminal device based on the satellite signal, and the communication signal radio wave from the communication base station. A communication signal radio wave reception means for receiving; a reception time information generation means for generating reception time information indicating a time at which the communication signal radio wave is received; the base station position information; the time difference information; Communication signal radio wave positioning means for positioning the terminal device based on the time information and the reception time information, the satellite signal, the base station position information, the time difference information, the transmission time information, and the reception time Based on the information, any one of the composite positioning means for positioning the terminal device and the satellite signal positioning means, the communication signal radio wave positioning means, or the composite positioning means based on the number of the sky satellites And positioning means selection means for selecting the communication means. This is achieved by an asynchronous positioning system between communication base stations.

According to the configuration of the first invention, the communication base station can generate the satellite time information by the satellite time information generating means. It is well known that the current position is measured based on the plurality of satellite signals, and as a result, the accurate satellite time can be obtained together with the positioning position information.
And the said communication base station can produce | generate the said time difference information by the said time difference information generation means.
That is, since the communication base station does not synchronize the transmission time with the satellite time, but only generates the time difference information, the configuration is simple, and the system change of the communication base station is significant. Do not need.

On the other hand, the terminal device can acquire the base station position information and the time difference information from the communication base station by the base station information acquisition means.
In addition, the terminal device can receive the communication signal radio wave from the communication base station by the communication signal radio wave receiving means.
The reception time information can be generated by the reception time information generation means. Here, since the terminal device can generate the satellite time information by the terminal-side satellite time information generation means, the reception time information can be in a state that is not different from the satellite time.
When the base station position information and the time difference information can be received from three or more communication base stations, and the communication signal radio wave can be received from the three or more communication base stations. In addition, since it is possible to accurately calculate the propagation time from each communication base station until the communication signal radio wave reaches the terminal device, positioning by the communication signal radio wave positioning means is possible.

However, when the communication signal radio wave can be received only from 0 to 2 communication base stations, positioning by the communication signal radio wave positioning means cannot be performed.
In this regard, since the terminal device includes the composite positioning means and the satellite positioning means, when the communication signal radio wave can be received only from 0 to 2 communication base stations, the communication Positioning can be performed based on the signal radio wave and the satellite signal or based only on the plurality of satellite signals.
For this reason, the terminal device can perform positioning even when signals from three or more communication base stations cannot be received.
As a result, according to the configuration of the present invention, positioning can be performed even when signals from three or more communication base stations cannot be received without requiring a significant system change of the communication base stations.

  According to the second aspect of the present invention, there is provided a terminal device capable of receiving communication signal radio waves carrying transmission time information indicating transmission times from a plurality of communication base stations in an asynchronous communication network between communication base stations. From the communication base station, terminal-side satellite time information generating means for generating terminal-side satellite time information indicating the satellite time that is the time of the positioning satellite based on a satellite signal that is a signal from a positioning satellite, Base station position information indicating the position of a communication base station, base station information acquisition means for acquiring time difference information indicating a time difference between the transmission time and the satellite time at the transmission time, and the terminal device located above the terminal device From the satellite base station, a satellite signal positioning unit that determines the position of the terminal device based on the satellite signal, a satellite signal positioning unit that determines the number of satellites that are positioning satellites, and the communication base station Signal radio signal receiving means for receiving a signal radio wave, reception time information generating means for generating reception time information indicating a time when the signal radio wave for communication is received, the base station position information, the time difference information, and the transmission time Communication signal radio wave positioning means for positioning the terminal device based on the information and the reception time information, the satellite signal, the base station position information, the time difference information, the transmission time information, and the reception time information. Based on the above, the composite positioning means for positioning the position of the terminal device, and the satellite signal positioning means, the communication signal radio wave positioning means, or the composite positioning means based on the number of the sky satellites It is achieved by a terminal device comprising positioning means selecting means for selecting.

  According to the configuration of the second invention, similar to the configuration of the first invention, it is possible to receive signals from three or more base stations without requiring a significant system change of the base station. Can also be measured.

  According to a third aspect, in the configuration of the second aspect, the positioning means selection means selects the satellite signal positioning means when the number of the sky satellites is three or more, and the number of the sky satellites is The composite positioning means is selected when the number is one or two, and the communication signal radio wave positioning means is selected when the number of the sky satellites is zero. Is a terminal device.

In general, the positioning accuracy based on the satellite signal is higher than the positioning accuracy based on the communication signal radio wave.
In this regard, the positioning means selection means of the terminal device selects the satellite signal positioning means when the number of the above-mentioned satellites is three or more, and the number of the above-mentioned satellites is one or two. In this case, the composite positioning means is selected, and when the number of the sky satellites is 0, the communication signal radio wave positioning means is selected, so that the satellite signal is received from the positioning satellite. As long as it can, positioning can be performed based only on the satellite signal or based on both the satellite signal and the communication signal radio wave.
Therefore, the terminal device can perform positioning with the highest positioning accuracy according to the number of the sky satellites.

  According to a fourth aspect of the present invention, there is provided the base station switching determination means for determining whether or not all or a part of the communication base stations capable of communication are switched in the configuration of the second aspect or the third aspect of the invention. The base station information acquisition unit is a terminal device configured to acquire the base station position information and the time difference information based on a determination result of the base station switching determination unit.

When all or a part of the communication base stations capable of communication is switched, all or a part of the base station position information and the time difference information held before the switching is the signal radio wave positioning means for communication. And cannot be used for positioning by the combined positioning means.
In this regard, according to the configuration of the fourth aspect of the invention, since the terminal device has the base station switching determination means, it can determine whether or not all or a part of the communication base stations capable of communication have switched. it can.
And since the said base station information acquisition means becomes the structure which acquires the said base station position information and the said time difference information based on the determination result of the said base station switching determination means, it is the structure of the said communication base station which can communicate After the switching, the base station position information and the time difference information can be newly acquired, and positioning can be performed by the communication signal radio wave positioning means and the composite positioning means.

  According to the fifth aspect, the object is that a terminal device capable of communicating with a plurality of communication base stations indicates a satellite time that is a time of the positioning satellite based on a satellite signal that is a signal from the positioning satellite. A terminal-side satellite time information generation step for generating time information; the terminal device transmits base station position information indicating a position of the communication base station; and the communication base station transmits a communication signal radio wave from the communication base station. A base station information receiving step for receiving time difference information indicating a time difference between the transmission time and the satellite time at the transmission time, and the number of sky satellites that are the positioning satellites located above the terminal device. A satellite signal for determining the position of the terminal device based on the satellite signal based on a determination result in the sky satellite number determination step. And communication signal radio wave positioning means for positioning the terminal device based on the base station position information, the time difference information, the transmission time information, and the reception time information indicating the time when the communication signal radio wave is received. A positioning means selection step for selecting one of the satellite signal, the base station position information, the time difference information, the transmission time information, and the composite positioning means for positioning the terminal device based on the reception time information; It is achieved by a method for controlling a terminal device, comprising:

  According to the configuration of the fifth invention, as in the configuration of the first invention, when signals from three or more communication base stations cannot be received without requiring a significant system change of the communication base station. Even if there is, it can be measured.

  According to the sixth aspect, the object is that a terminal device capable of communicating with a plurality of communication base stations is connected to a computer based on a satellite signal that is a signal from a positioning satellite, and is a satellite time that is the time of the positioning satellite. A terminal-side satellite time information generation step for generating satellite time information indicating the base station position information indicating the position of the communication base station from the communication base station, and the communication base station is a communication signal. A base station information receiving step for receiving time difference information indicating a time difference between the transmission time and the satellite time at a transmission time at which radio waves are transmitted; and the terminal device is the positioning satellite located above the terminal device. An aerial satellite number determining step for determining the number of satellites; Satellite signal positioning means for performing positioning of the terminal device based on the base station position information, the time difference information, the transmission time information, and the reception time information indicating the time when the communication signal radio wave is received Positioning for selecting one of radio positioning means and composite positioning means for positioning the terminal device based on the satellite signal, the base station position information, the time difference information, the transmission time information, and the reception time information And a means selection step. This is achieved by a control program for a terminal device.

  According to the seventh aspect, the object is that a terminal device capable of communicating with a plurality of communication base stations is connected to a computer based on a satellite signal that is a signal from a positioning satellite, and a satellite time that is a time of the positioning satellite. A satellite time information generating step for generating satellite time information indicating the base station position information indicating the position of the communication base station from the communication base station, and the communication base station is a communication signal. A base station information receiving step for receiving time difference information indicating a time difference between the transmission time and the satellite time at a transmission time at which radio waves are transmitted; and the sky where the terminal device is the positioning satellite located above the terminal device An aerial satellite number determining step for determining the number of satellites; Satellite signal positioning means for performing positioning of the terminal device based on the base station position information, the time difference information, the transmission time information, and the reception time information indicating the time when the communication signal radio wave is received Positioning that selects one from radio positioning means and composite positioning means that performs positioning of the terminal device based on the satellite signal, the base station position information, the time difference information, the transmission time information, and the reception time information It is achieved by a computer-readable recording medium on which a control program for a terminal device is recorded.

Preferred embodiments of the present invention will be described below 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.

FIG. 1 is a schematic diagram showing a positioning system 10 according to an embodiment of the present invention.
As shown in FIG. 1, the positioning system 10 has base stations 20A, 20B, 20C, and 20D. The base station 20A and the like are an example of a plurality of communication base stations.
The positioning system 10 also includes a terminal 50 that can communicate with the base station 20A and the like. This terminal 50 is an example of a terminal device.
The base station 20A or the like has a base station GPS device 32, and receives satellite signals that are signals from positioning satellites such as GPS satellites 12a, 12b, 12c, and 12d, such as signals G1, G2, G3, and G4. Can be received.
The base station 20A and the like have a base station communication device 34, and for the terminal 50 having the terminal communication device 62, for example, signal radio waves S1 (hereinafter referred to as signal S1), S2, S3, S4 can be transmitted.
The base stations 20A and the like are not time synchronized with each other and constitute an asynchronous communication network between communication base stations.

  The terminal 50 has a terminal GPS device 60 and can receive a signal G1 and the like from the GPS satellite 12a and the like. The terminal 50 is, for example, a mobile phone, a PHS (Personal Handy-phone System), a PDA (Personal Digital Assistance), or the like, but is not limited thereto.

  Unlike the present embodiment, the number of GPS satellites 12a may be three, or five or more. Further, unlike the present embodiment, the number of base stations 20A and the like may be five or more, and the number of terminals 50 may be two or more.

(Main hardware configuration of base station 20A)
FIG. 2 is a schematic diagram showing the main hardware configuration of the base station 20A.
Note that the main hardware configuration of the base stations 20B, 20C, and 20D is the same as that of the base station 20A, and thus description thereof is omitted.
As shown in FIG. 2, the base station 20 </ b> A has a computer, and the computer has a bus 22.
The bus 22 is connected to a CPU (Central Processing Unit) 24, a storage device 26, an external storage device 28, and the like. The storage device 26 is, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory). The external storage device 28 is, for example, an HD (Hard Disk).

The bus 22 is connected to an input device 30 for inputting various information and the like, a base station GPS device 32, and a base station communication device 34. The base station communication device 34 is configured to transmit a signal S1 for communicating with the terminal 50.
The bus 22 is connected to a display device 36 for displaying various types of information and a base station clock 38. The base station clock 38 is not synchronized with the base station clock 38 of the other base station 20B or the like, and is not synchronized with the time of the GPS satellite 12a or the like (hereinafter referred to as GPS time).

Further, a base station second clock 40 is connected to the bus 22. As will be described later, the time measured by the base station second clock 40 can be maintained in a state that is not different from the GPS time.
Furthermore, a base station second communication device 42 is connected to the bus 22. As will be described later, the base station second communication device 42 is configured to transmit base station position information 162 and time difference information 160 (see FIG. 4).

(Main hardware configuration of terminal 50)
FIG. 3 is a schematic diagram showing a main hardware configuration of the terminal 50.
As illustrated in FIG. 3, the terminal 50 includes a computer, and the computer includes a bus 52.
A CPU 54, a storage device 56, an input device 58, a terminal GPS device 60, a terminal communication device 62, a display device 64, and a terminal clock 66 are connected to the bus 52. As will be described later, the time measured by the terminal clock 66 can be maintained in a state that is not different from the GPS time.

(Main software configuration of base station 20A)
FIG. 4 is a schematic diagram showing a main software configuration of the base station 20A.
The main software configuration of the base stations 20B, 20C, and 20D is the same as that of the base station 20A, and thus description thereof is omitted.
As shown in FIG. 4, the base station 20A corresponds to the base station control unit 100 that controls each unit, the base station GPS unit 102 corresponding to the base station GPS device 32 of FIG. 2, and the base station communication device 34 of FIG. A base station communication unit 104; The base station communication unit 104 is an example of a communication signal radio wave transmission unit that transmits the signal S1.
The base station 20A also includes a base station timer 106 corresponding to the base station clock 38 in FIG. 2, a base station second timer 108 corresponding to the base station second clock 40 in FIG. 2, and a base station second in FIG. The base station second communication unit 110 corresponding to the communication device 42 is included.
The base station 20A further includes a base station first storage unit 120 that stores various programs and a base station second storage unit 150 that stores various types of information.

  As illustrated in FIG. 4, the base station 20 </ b> A stores base station position information 152 in the base station second storage unit 150. The base station position information 152 is information indicating the position of the base station 20A. For example, the position of the base station 20A is indicated by latitude, longitude, and altitude. The base station position information 152 is an example of base station position information, and the base station second storage unit 150 is an example of base station position information storage means.

As shown in FIG. 4, the base station 20 </ b> A stores satellite orbit information 154 in the base station second storage unit 150. The satellite orbit information 154 includes, for example, almanac that is general orbit information of all GPS satellites 12a and the like and ephemeris that is precise orbit information of each GPS satellite 12a and the like. The satellite orbit information 154 is used for positioning based on the signal G1 from the GPS satellite 12a or the like.
The base station control unit 100 periodically receives a signal G1 or the like from the GPS satellite 12a or the like by the base station GPS unit 102, and extracts an almanac and an ephemeris from the signal G1 or the like. Almanac is updated every 7 days, for example, and ephemeris is updated every 4 hours, for example.

In the base station 20A, the base station timing unit 106 generates transmission time information 156 indicating the transmission time of the signal S1. The base station control unit 100 stores the transmission time information 156 in the base station second storage unit 150.
As illustrated in FIG. 4, the base station 20 </ b> A stores a transmission frame generation program 122 in the base station first storage unit 120. The transmission frame generation program 122 is a program for the base station control unit 100 to place the transmission time information 156 on the signal S1. That is, the transmission frame generation program 122 and the base station control unit 100 are an example of a communication signal radio wave generation unit with transmission time information.

FIG. 5 is a schematic diagram illustrating an example of a transmission frame FR that is placed on the signal S1 transmitted by the base station communication unit 104.
As shown in FIG. 5, the transmission frame FR is composed of, for example, subframes SF1 to SF7, and each subframe SF1 etc. includes information indicating transmission times t1 to t7 of each subframe SF1 etc. ing. The transmission time t1 and the like are measured by the base station time measuring unit 106.
The base station 20A continuously transmits the signal S1 including the timing signal TS1 by the base station communication unit 104.

As illustrated in FIG. 4, the base station 20 </ b> A stores a GPS time generation program 124 in the base station first storage unit 120. The GPS time generation program 124 is a program for the base station control unit 100 to generate GPS time information 158 indicating the GPS time based on a signal G1 or the like (see FIG. 1) from the GPS satellite 12a or the like. That is, the GPS time generation program 124 and the base station control unit 100 are examples of satellite time information generation means.
The base station control unit 100 uses the satellite orbit information 154 to determine the current position based on a plurality of signals G1 received by the base station GPS unit 102 and generate accurate GPS time information 158. And stored in the base station second storage unit 150.

As shown in FIG. 4, the base station 20 </ b> A stores a base station second clock correction program 126 in the base station first storage unit 120. The base station second clock correction program 126 is used for the base station control unit 100 to maintain the time of the base station second clock unit 108 in a state that is not different from the GPS time based on the GPS time information 158 described above. It is a program.
Accordingly, the base station 20A maintains the time in the base station second storage unit 108 in a state where there is no difference from the GPS time.

As illustrated in FIG. 4, the base station 20 </ b> A stores a time difference information generation program 128 in the base station first storage unit 120. The time difference information generation program 128 is used by the base station control unit 100 to indicate time difference between the transmission time indicated by the transmission time information 156 and the time generated by the base station second time counting unit 108 at the transmission time of the signal S1. Is a program for generating That is, the time difference information generation program 128 and the base station control unit 100 are examples of time difference information generation means.
Specifically, as shown in FIG. 5, the base station control unit 100 receives the transmission frame FR generated by the base station communication unit 104, and indicates the time difference td from the time t1a of the base station second time counting unit 108. Time difference information 160 is generated. Specifically, the time difference td is measured based on the timing difference between the timing signal TS1 generated by the base station timing unit 106 and included in the signal S1 and the timing signal TS2 generated by the base station second timing unit 108. Here, the propagation delay time of the transmission frame FR inside the base station 20A is considered to be absent because it is extremely short.
As described above, since the time of the base station second time measuring unit 108 is maintained in a state in which there is no difference from the GPS time, the time difference information 160 indicates the time difference between the transmission time t1 and the GPS time.
The base station control unit 100 stores the generated time difference information 160 in the base station second storage unit 150.

As shown in FIG. 4, the base station 20 </ b> A stores a time difference information transmission program 130 in the base station first storage unit 120. The time difference information transmission program 130 is a program for the base station control unit 100 to transmit the base station position information 152 and the time difference information 160 to the terminal 50 by the base station second communication unit 110. That is, the time difference information transmission program 130, the base station control unit 100, and the base station second communication unit 110 are examples of base station information transmission means.
Specifically, in response to a request from terminal 50, base station control unit 100 transmits base station position information 152 and time difference information 160 on a signal of a system different from that of signal S1 described above.

  As described above, the base station 20A does not synchronize the transmission time measured by the base station time measuring unit 106 with the GPS time, but generates the time difference information 160 and transmits the time difference information 160 according to the request of the terminal 50. Since the signal S1 is transmitted on a signal of a different system from the signal S1, the configuration is simple, and no significant system change is required for a general communication base station that is asynchronous between base stations.

(Main software configuration of terminal 50)
FIG. 6 is a schematic diagram illustrating a main software configuration of the terminal 50.
As shown in FIG. 6, the terminal 50 includes a terminal control unit 200 that controls each unit, a terminal GPS unit 202 corresponding to the terminal GPS device 60 in FIG. 3, a terminal communication unit 204 corresponding to the terminal communication device 62 in FIG. 3 has a terminal timing unit 206 corresponding to the terminal clock 66 of FIG.
The terminal 50 also includes a terminal first storage unit 210 that stores various programs and a terminal second storage unit 250 that stores various information.

As illustrated in FIG. 6, the terminal 50 stores terminal-side satellite orbit information 252 in the terminal second storage unit 250. The terminal-side satellite orbit information 252 is information including, for example, almanac and ephemeris.
The terminal control unit 200 periodically receives a signal G1 or the like from the GPS satellite 12a or the like by the terminal GPS unit 202, extracts the almanac from the signal G1 or the like, for example, every 7 days, and the ephemeris, for example, every 4 hours. It is designed to keep it valid.
Unlike the present embodiment, terminal control unit 200 may acquire satellite orbit information 154 (see FIG. 4) including almanac and ephemeris from base station 20A by terminal communication unit 204.

  As illustrated in FIG. 6, the terminal 50 stores a terminal-side GPS time information generation program 212 in the terminal first storage unit 210. The terminal-side GPS time information generation program 212 is a program for the terminal control unit 200 to generate terminal-side GPS time information 254 indicating the GPS time based on a signal G1 or the like (see FIG. 1) from the GPS satellite 12a or the like. It is. The terminal-side GPS time information 254 is an example of terminal-side satellite time information, and the terminal-side GPS time information generation program 212 and the terminal control unit 200 are examples of terminal-side satellite time information generation means.

As illustrated in FIG. 6, the terminal 50 stores a terminal clock correction program 214 in the terminal first storage unit 210. The terminal clock correction program 214 is a program for the terminal control unit 200 to correct the time of the terminal clock unit 206 based on the terminal-side GPS time information 254.
Thereby, the terminal 50 can make the time of the terminal time measuring unit 206 not different from the GPS time.

As illustrated in FIG. 6, the terminal 50 stores a handover determination program 216 in the terminal first storage unit 210. The handover determination program 216 is a program for the terminal control unit 200 to determine whether all or a part of the currently communicable base stations 20A and the like (see FIG. 1) have been switched to other base stations. . That is, the handover determination program 216 and the terminal control unit 200 are examples of base station switching determination means.
Handover means that a base station with which the terminal 50 can communicate is switched. For example, from a state where the terminal 50 can communicate with the base stations 20A, 20B and 20C (see FIG. 1) (referred to as an initial state), a state where the terminal 50 can communicate with the base stations 20B, 20C and 20D (a state after switching) In this case.

As illustrated in FIG. 6, the terminal 50 stores a base station information acquisition program 218 in the terminal first storage unit 210. The base station information acquisition program 218 is a program for the terminal control unit 200 to acquire the base station position information 152 and the time difference information 160 (see FIG. 4) from the base station 20A or the like. That is, the base station information acquisition program 218 and the terminal control unit 200 are examples of base station information acquisition means.
The terminal control unit 200 acquires the base station position information 152 and the time difference information 160 (see FIG. 4) when it is determined by the above-described handover determination program 216 that a handover has occurred. Thereby, when it switches from the state before the above-mentioned switching to the state after switching, it can measure based on signal S2 from base stations 20B, 20C, and 20D which can communicate after switching. The positioning method will be described later.
The terminal control unit 200 stores the acquired base station position information 152 in the terminal side second storage unit 250 as the terminal side base station position information 256 and the time difference information 160 as the terminal side base station time difference information 258.
Further, the terminal control unit 200 determines that the base station position information 152 and the time difference when the power source (not shown) of the terminal 50 is turned on other than when a handover occurs based on the base station information acquisition program 218. Information 160 is acquired. When the power of the terminal 50 is turned off, the current communicable base station 20A and the like cannot be determined. Therefore, the base station position information 152 from the communicable base station 20A and the like when the power is turned on again. And the time difference information 160 is acquired.
Furthermore, the terminal control unit 200 receives base station position information 152 and time difference information 160 (see FIG. 4) from the base station 20A or the like periodically, for example, every 30 minutes based on the base station information acquisition program 218. It is like that. In general, for example, a crystal oscillator that generates a reference frequency for measuring time changes in frequency due to temperature change, and therefore the time difference indicated in the time difference information 160 also changes due to temperature change. In this regard, by periodically receiving the time difference information 160, the time difference information 160 after being changed due to a temperature change can be acquired.

As illustrated in FIG. 6, the terminal 50 stores an aerial satellite number determination program 220 in the terminal first storage unit 210. The sky satellite number determination program 220 is a program for the terminal control unit 200 to determine the number of GPS satellites 12 a and the like located above the terminal 50. That is, the sky satellite number determination program 220 and the terminal control unit 200 are examples of the sky satellite number determination means.
Specifically, the terminal control unit 200 uses the almanac included in the terminal-side satellite orbit information 252 and is located above the terminal 50 and can be observed at the current time measured by the terminal timing unit 206. The number of satellites 12a etc. is determined. And the terminal control part 200 stores the sky satellite number information 260 which shows the number of the GPS satellites 12a etc. which are located in the sky in the terminal 2nd memory | storage part 250. FIG.

As illustrated in FIG. 6, the terminal 50 stores a satellite positioning program 222 in the terminal first storage unit 210. The satellite positioning program 222 is a program for the terminal control unit 200 to measure the position of the terminal 50 based on signals G1 and the like (see FIG. 1) from three or more GPS satellites 12a and the like. That is, the satellite positioning program 222 and the terminal control unit 200 are examples of satellite signal positioning means.
Specifically, the terminal control unit 200 calculates the difference between the time when the signal G1 or the like is transmitted from each GPS satellite 12a and the time when the signal G1 or the like is received, and the speed of the signal G1 or the like is the speed of light. Based on the fact, the distance between each GPS satellite 12a and the like and the terminal 50 (referred to as a pseudo distance) is calculated. On the other hand, the position of each GPS satellite 12a or the like on the satellite orbit at the current time measured by the terminal timer 206 is calculated by the ephemeris included in the terminal-side satellite orbit information 252.
Then, the current position is measured based on the above-described pseudo distance and the position of each GPS satellite 12a or the like on the satellite orbit.
The terminal control unit 200 stores the satellite positioning position information 262 generated by positioning in the terminal second storage unit 250.
Note that positioning performed by the terminal control unit 200 using the satellite positioning program 222 is referred to as satellite positioning.

As illustrated in FIG. 6, the terminal 50 stores a communication signal reception program 224 in the terminal first storage unit 210. The communication signal reception program 224 is a program for the terminal control unit 200 to receive the signal S1 and the like from the base station 20A and the like. That is, the communication signal reception program 224 and the terminal control unit 200 are examples of communication signal radio wave reception means.
The communication signal reception program 224 includes a transmission time information extraction program 224a. The transmission time information extraction program 224a is a program for the terminal control unit 200 to extract the transmission time information 156 (see FIG. 4) from the signal S1 and the like.
The terminal control unit 200 stores the extracted transmission time information 156 in the terminal second storage unit 250 as terminal-side transmission time information 264.

As illustrated in FIG. 6, the terminal 50 stores a reception time information generation program 226 in the terminal first storage unit 210. The reception time information generation program 226 is a program for generating reception time information 266 indicating the time at which the terminal control unit 200 received the signal S1 and the like. The reception time information 266 is an example of reception time information, and the reception time information generation program 226 and the terminal control unit 200 are examples of reception time information generation means.
Specifically, the terminal control unit 200 measures the time when the signal S1 is received by the terminal timing unit 206, and generates reception time information 266.
The terminal control unit 200 stores the generated reception time information 266 in the terminal second storage unit 250.

As illustrated in FIG. 6, the terminal 50 stores a base station positioning program 228 in the terminal first storage unit 210. In the base station positioning program 228, the terminal control unit 200 measures the position of the terminal 50 based on the terminal-side base station position information 256, the terminal-side base station time difference information 258, the terminal-side transmission time information 264, and the reception time information 266. It is a program to do. That is, the base station positioning program 228 and the terminal control unit 200 are examples of communication signal radio wave positioning means.
Hereinafter, the positioning performed by the terminal control unit 200 using the base station positioning program 228 is referred to as base station positioning.

FIG. 7 is an explanatory diagram of an example of a base station positioning method.
FIG. 7A shows the position of each base station 20A and the like. The position of the base station 20A or the like is known from the terminal-side base station position information 256.
FIG. 7B is a diagram illustrating the propagation time tb01 and the like of the signal S1 and the like from each base station 20A and the like. The propagation time tb01 and the like are unknown numbers.
FIG. 7C shows a transmission time t1 of each signal S1 and the like. The transmission time t1 and the like are known from the terminal-side transmission time information 264. Here, since the time is not synchronized between the base stations 20A and the like, t1, t2, and t3 are not necessarily the same time.
FIG. 7D is a diagram illustrating the time difference ta1 and the like of each base station 20A and the like. The time difference ta1 and the like are known from the terminal-side base station time difference information 258.
FIG. 7E shows the propagation speed of the signal S1 and the like. Since the signal S1 and the like are carried on radio waves, the propagation speed is the speed of light C.
FIG. 7F shows a time difference td01 between the transmission time t1 of the signal S1 and the like and the time when the terminal 50 receives the signal S1 and the like. As shown in FIG. 7G, the time when the terminal 50 receives the signal S1 and the like is assumed to be t0.
The position (X, Y, Z) of the terminal 50 shown in FIG. 7 (h) is an unknown number.

Based on the above, the equations (1) to (9) shown in FIGS. 7 (i) to 7 (k) will be described.
First, since the distance between each base station 20A and the terminal 50 and the terminal 50 is equal to the product of the propagation time of the signal S1 and the like and the velocity of the radio wave (the speed of light C), the equations (1) to ( 3) holds.
Next, since the transmission time t1 includes the time difference ta1 from the GPS time, the equations (4) to (6) in FIG.
Further, for the time difference td01 in FIG. 7F, the transmission time t1 in FIG. 7C, the propagation time tb01 in FIG. 7B, and the time t0 in FIG. Equations (7) to (9) of k) hold.
Here, since there are six unknowns indicating the position of the terminal 50, X, Y, Z, propagation times tb01, tb02, and tb03, equations (1), (2), (3), (7), ( All unknowns can be calculated by calculating 8) and 9) simultaneously.
The terminal control unit 200 stores the base station positioning position information 268 generated in this way in the terminal second storage unit 250.
Note that the above-described base station positioning is based on the premise that the terminal 50 can communicate with the base station 20A and the like, and thus is located within the communication range of the base station 20A and the like. For this reason, when the area where the terminal 50 is located is less undulating and the altitude components Z1 and the like (see FIG. 7A) at the positions of the base stations 20A and the like are substantially equal, for example, the average of the altitude components Z1, Z2 and Z3 It is also possible to perform the above-mentioned base station positioning using the value as the altitude component Z of the position of the terminal 50.

As illustrated in FIG. 6, the terminal 50 stores a hybrid positioning program 230 in the terminal first storage unit 210. The hybrid positioning program 230 allows the terminal control unit 200 to control the terminal 50 based on the signal G1 and the like, the terminal-side base station position information 256, the terminal-side base station time difference information 258, the terminal-side transmission time information 264, and the reception time information 266. It is a program for positioning. That is, the hybrid positioning program 230 and the terminal control unit 200 are examples of a composite positioning unit.
The positioning performed by the terminal control unit 200 based on the hybrid positioning program 230 is performed by positioning one or two base stations 20A in the positioning method performed based on the above-described base station positioning program 228 described with reference to FIG. This is performed in place of the satellite 12a.
In general, a positioning method combining two or more sensors such as positioning by artificial satellite, positioning by mobile communication information, acceleration sensor by gyroscope, vehicle speed pulse, etc. is called hybrid positioning. , Positioning performed by the terminal control unit 200 based on the hybrid positioning program 230, which combines information on the base station 20A and the like and information on the GPS satellites 12a and the like, is referred to as hybrid positioning.
The terminal control unit 200 stores the hybrid positioning position information 270 generated by the hybrid positioning in the terminal second storage unit 250.

As illustrated in FIG. 6, the terminal 50 stores a positioning method selection program 232 in the terminal first storage unit 210. The positioning method selection program 232 allows the terminal control unit 200 to select one of satellite positioning, base station positioning, or hybrid positioning based on the number of GPS satellites 12a and the like indicated in the number of satellites 260 above. It is a program. That is, the positioning method selection program 232 and the terminal control unit 200 are examples of positioning means selection means.
Specifically, the terminal control unit 200 selects satellite positioning when the number of GPS satellites 12a and the like indicated in the sky satellite number information 260 is three or more. And the terminal control part 200 selects hybrid positioning, when the number of the GPS satellites 12a etc. which are shown in the number information 260 of aerial satellites is one or two. And the terminal control part 200 selects base station positioning, when the number of the GPS satellites 12a etc. which are shown in the sky satellite number information 260 is zero.

In general, the positioning accuracy based on the signal G1 from the GPS satellite 12a or the like is higher than the positioning accuracy based on the communication signal S1 or the like. For example, in the case of satellite positioning, the positioning error is 0 meter (m) to 20 meters (m), whereas in the case of base station positioning, the positioning error is 5 meters (m) to 400 meters (m). ).
In this regard, the terminal 50 can perform positioning using only the signal G1 or the like or the signal G1 and the communication signal S1 or the like as long as the signal G1 or the like can be received from the GPS satellite 12a or the like. .
For this reason, the terminal 50 can perform positioning with the highest positioning accuracy according to the number of GPS satellites 12a and the like that can be observed.
On the other hand, for example, in an environment where three or more GPS satellites 12a or the like cannot be observed, such as indoors, it is possible to perform hybrid positioning or base station positioning using a communication signal S1 that can be received indoors.

  As illustrated in FIG. 6, the terminal 50 stores a positioning position information display program 234 in the terminal first storage unit 210. The positioning position information display program 234 is for the terminal control unit 200 to display any one of the satellite positioning position information 262, the base station positioning position information 268, or the hybrid positioning position information 270 on the display device 64 (see FIG. 3). It is a program.

The above is the configuration of the positioning system 10 according to the present embodiment. Hereinafter, an example of the operation will be mainly described with reference to FIG.
FIG. 8 is a schematic flowchart showing an operation example of the positioning system 10 according to the present embodiment.

The following description will be made on the assumption that the terminal 50 has switched from a state where communication with the base stations 20A, 20B and 20C is impossible to a state where communication is possible.
First, the terminal 50 generates terminal-side GPS time information 254 (see FIG. 6) (step ST1 in FIG. 8). This step ST1 is an example of a terminal side satellite time information generation step. By correcting the time of the terminal timekeeping unit 206 (see FIG. 6) with the terminal-side GPS time information 254, the GPS time can be made no different.

  On the other hand, the base station 20A and the like continuously generate time difference information 160 (see FIG. 4) (step ST1A in FIG. 8).

Subsequently, terminal 50 determines whether or not a handover has occurred (step ST2).
When the terminal 50 determines that a handover has occurred, the terminal 50 requests the base station position information 152 and the time difference information 160 (see FIG. 4) from the communicable base station 20A or the like (step ST3).

The base station 20A or the like that receives the request from the terminal 50 transmits the base station position information 152 and the time difference information 160 to the terminal 50 (step ST4).
Subsequently, terminal 50 receives base station position information 152 and time difference information 160 from base station 20A or the like (step ST5). This step ST5 is an example of a base station information receiving step.

Subsequently, the terminal 50 determines the number of GPS satellites 12a and the like that are located above the terminal 50 and can be observed (step ST6). This step ST6 is an example of a step for determining the number of sky satellites.
When the terminal 50 determines that the number of observable GPS satellites 12a and the like is three or more, the terminal 50 performs satellite positioning (step ST101) and generates satellite positioning position information 262 (see FIG. 6). . This step ST101 is an example of a positioning means selection step.
Then, the terminal 50 displays the satellite positioning position information 262 on the display device 64 (see FIG. 3) (step ST102).

In step ST6, if the terminal 50 determines that the number of observable GPS satellites 12a or the like is one or two, the terminal 50 performs hybrid positioning (step ST201), and hybrid positioning position information 270 (FIG. 6). This step ST201 is also an example of a positioning means selection step.
Then, terminal 50 displays hybrid positioning position information 270 on display device 64 (see FIG. 3) (step ST202).

In step ST6, if the terminal 50 determines that the number of observable GPS satellites 12a and the like is zero, the terminal 50 performs base station positioning (step ST301), and base station positioning position information 268 (FIG. 6). Reference). This step ST301 is also an example of a positioning means selection step.
Then, terminal 50 displays base station positioning position information 268 on display device 64 (see FIG. 3) (step ST302).

  As described above, according to the positioning system 10, it is possible to perform positioning even when signals from three or more base stations cannot be received without requiring a significant system change of the base station. .

(About programs and computer-readable recording media)
A terminal apparatus control program for causing a computer to execute a terminal side satellite time information generation step, a base station information reception step, an aerial satellite number determination step, a positioning means selection step, and the like in the above-described operation example. .
Moreover, it can also be set as the computer-readable recording medium etc. which recorded the control program etc. of such a terminal device.

  A program storage medium used for installing the control program of the terminal device in the computer and making it executable by the computer is, for example, a floppy disk such as a floppy (registered trademark), a CD-ROM (Compact Disc Read Only). Semiconductor memory in which programs are temporarily or permanently stored as well as package media such as Memory, CD-R (Compact Disc-Recordable), CD-RW (Compact Disc-Rewritable), DVD (Digital Versatile Disc), etc. It can be realized with a magnetic disk or a magneto-optical disk.

  The present invention is not limited to the embodiments described above. Furthermore, the above-described embodiments may be combined with each other.

It is the schematic which shows the positioning system which concerns on embodiment of this invention. It is the schematic which shows the main hardware constitutions of a base station. It is the schematic which shows the main hardware constitutions of a terminal. It is the schematic which shows the main software structures of a base station. It is the schematic which shows the transmission frame FR etc. It is the schematic which shows the main software structures of a terminal. It is explanatory drawing of an example of the base station positioning method. It is a schematic flowchart which shows the operation example of a positioning system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Positioning system, 12a, 12b, 12c, 12d ... GPS satellite, 20A, 20B, 20C, 20D ... Base station, 104 ... Base station communication part, 106 ... Base station time measuring part, 108 ... Base station second time measuring part, DESCRIPTION OF SYMBOLS 110 ... Base station 2nd communication part, 122 ... Transmission frame generation program, 124 ... GPS time generation program, 126 ... Base station 2nd clock correction program, 128 ... Time difference information generation program, 130 ... Time difference information transmission program, 212 ... Terminal Side GPS time information generation program, 214 ... terminal clock correction program, 216 ... handover determination program, 218 ... base station information acquisition program, 220 ... sky satellite number determination program, 222 ... satellite positioning program, 224 ... communication signal reception program, 226 ... Reception time information generation program, 228 ... Base station measurement Program, 230 ... hybrid positioning program 232 ... positioning method selection program, 234 ... positioning position information display program.

Claims (7)

A plurality of communication base stations;
A terminal device capable of communicating with the communication base station;
An asynchronous positioning system between communication base stations having
The communication base station is
Base station position information storage means for storing base station position information indicating the position of the communication base station;
A communication signal radio wave generation means with transmission time information for putting transmission time information indicating a transmission time on the communication signal radio wave transmitted from the communication base station;
Satellite time information generating means for generating satellite time information indicating a satellite time which is a time of the positioning satellite based on a satellite signal which is a signal from a positioning satellite;
Time difference information generating means for generating time difference information indicating a time difference between the transmission time and the satellite time at the transmission time;
A communication signal radio wave transmission means for transmitting the communication signal radio wave carrying the transmission time information;
Base station information transmitting means for transmitting the base station position information and the time difference information;
Have
The terminal device
Terminal-side satellite time information generating means for generating terminal-side satellite time information indicating the satellite time, which is the time of the positioning satellite, based on the satellite signal from the positioning satellite;
Base station information acquisition means for acquiring the base station position information and the time difference information from the communication base station,
Sky satellite number determination means for determining the number of sky satellites which are the positioning satellites located above the terminal device;
Satellite signal positioning means for positioning the terminal device based on the satellite signal;
A communication signal radio wave receiving means for receiving the communication signal radio wave from the communication base station;
Reception time information generating means for generating reception time information indicating the time when the communication signal radio wave is received;
Based on the base station position information, the time difference information, the transmission time information and the reception time information, communication signal radio wave positioning means for positioning the position of the terminal device,
Based on the satellite signal, the base station position information, the time difference information, the transmission time information, and the reception time information, composite positioning means for measuring the position of the terminal device;
Positioning means selecting means for selecting one of the satellite signal positioning means, the communication signal radio wave positioning means, or the composite positioning means based on the number of the above-mentioned satellites;
An asynchronous positioning system between communication base stations, comprising: A terminal device capable of receiving communication signal radio waves carrying transmission time information indicating transmission times from a plurality of communication base stations in an asynchronous communication network between communication base stations,
Terminal-side satellite time information generating means for generating terminal-side satellite time information indicating a satellite time that is a time of the positioning satellite based on a satellite signal that is a signal from a positioning satellite;
Base station information acquisition means for acquiring, from the communication base station, base station position information indicating the position of the communication base station, and time difference information indicating a time difference between the transmission time and the satellite time at the transmission time;
Sky satellite number determination means for determining the number of sky satellites which are the positioning satellites located above the terminal device;
Satellite signal positioning means for positioning the terminal device based on the satellite signal;
A communication signal radio wave receiving means for receiving the communication signal radio wave from the communication base station;
Reception time information generating means for generating reception time information indicating the time when the communication signal radio wave is received;
Based on the base station position information, the time difference information, the transmission time information and the reception time information, a communication signal radio wave positioning means for positioning the position of the terminal device,
Based on the satellite signal, the base station position information, the time difference information, the transmission time information and the reception time information, composite positioning means for positioning the position of the terminal device;
Positioning means selecting means for selecting one of the satellite signal positioning means, the communication signal radio wave positioning means, or the combined positioning means based on the number of the above-mentioned satellites;
The terminal device characterized by having.   The positioning means selecting means selects the satellite signal positioning means when the number of the above-mentioned satellites is 3 or more, and the composite positioning means when the number of the above-mentioned satellites is one or two. The terminal device according to claim 2, wherein the communication signal radio wave positioning means is selected when the number of the above-mentioned satellites is zero. Comprising base station switching determining means for determining whether or not all or part of the communication base stations capable of communication have switched,
The base station information acquisition unit is configured to acquire the base station position information and the time difference information based on a determination result of the base station switching determination unit. The terminal device in any one of. A terminal side satellite time information generation step in which a terminal device capable of communicating with a plurality of communication base stations generates satellite time information indicating a satellite time which is a time of the positioning satellite based on a satellite signal which is a signal from a positioning satellite. When,
Base station position information indicating the position of the communication base station from the communication base station, and the time difference between the transmission time and the satellite time at the transmission time at which the communication base station transmits the communication signal radio wave. A base station information receiving step for receiving time difference information indicating:
The terminal device determines the number of sky satellites that determine the number of sky satellites that are the positioning satellites located above the terminal device; and
Satellite signal positioning means for positioning the terminal device based on the satellite signal, the base station position information, the time difference information, and the transmission time Communication signal radio wave positioning means for positioning the terminal device based on information and reception time information indicating a time when the communication signal radio wave is received, the satellite signal, the base station position information, the time difference information, the transmission Compound positioning means for positioning the terminal device based on time information and the reception time information, and positioning means selecting step for selecting one from
A control method for a terminal device, comprising: On the computer,
A terminal side satellite time information generation step in which a terminal device capable of communicating with a plurality of communication base stations generates satellite time information indicating a satellite time which is a time of the positioning satellite based on a satellite signal which is a signal from a positioning satellite. When,
Base station position information indicating the position of the communication base station from the communication base station, and the time difference between the transmission time and the satellite time at the transmission time at which the communication base station transmits the communication signal radio wave. A base station information receiving step for receiving time difference information indicating:
The terminal device determines the number of sky satellites that determine the number of sky satellites that are the positioning satellites located above the terminal device; and
Satellite signal positioning means for positioning the terminal device based on the satellite signal, the base station position information, the time difference information, and the transmission time Communication signal radio wave positioning means for positioning the terminal device based on information and reception time information indicating a time when the communication signal radio wave is received, the satellite signal, the base station position information, the time difference information, the transmission Compound positioning means for positioning the terminal device based on time information and the reception time information, and positioning means selecting step for selecting one from
A control program for a terminal device, characterized in that On the computer,
A terminal side satellite time information generation step in which a terminal device capable of communicating with a plurality of communication base stations generates satellite time information indicating a satellite time which is a time of the positioning satellite based on a satellite signal which is a signal from a positioning satellite. When,
Base station position information indicating the position of the communication base station from the communication base station, and the time difference between the transmission time and the satellite time at the transmission time at which the communication base station transmits the communication signal radio wave. A base station information receiving step for receiving time difference information indicating:
The terminal device determines the number of sky satellites that determine the number of sky satellites that are the positioning satellites located above the terminal device; and
Satellite signal positioning means for positioning the terminal device based on the satellite signal, the base station position information, the time difference information, and the transmission time Communication signal radio wave positioning means for positioning the terminal device based on information and reception time information indicating a time when the communication signal radio wave is received, the satellite signal, the base station position information, the time difference information, the transmission Compound positioning means for positioning the terminal device based on time information and the reception time information, and positioning means selecting step for selecting one from
A computer-readable recording medium on which a control program for a terminal device is recorded.

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