JP5337966B2 - Position search method, information processing system, and information management apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To locate a location of a mobile communication terminal with high accuracy, using the electric field strength of a signal received from a fixed base station or an access point. <P>SOLUTION: A method for searching the location includes the steps of: measuring, by a mobile communication terminal, the electric field strength of a radio signal received from a base station which can communicate; detecting, by the mobile communication terminal, identification information for identifying the base station etc.; controlling, by the mobile communication terminal, to associate the electric field strength with the identification information from a plurality of base station etc. and to transmit them to an information management device; creating, by the information management device, an isopleth-curve map showing an isopleth-curve of the electric field strength about each base station etc.; superimposing, by the information management device, a plurality of isopleth-curve maps related with a plurality of base stations identified by the identification information; using, by the information management device, the superimposed plurality of isopleth-curve maps to extract an intersection of each isopleth-curve as a measuring point candidate, based on the electric field strength of the radio signal from the plurality of base stations which can communicate with the mobile communication terminal; and determining, by the information management device, the location of the mobile communication terminal based on a plurality of measuring point candidates. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention is position search method, an information processing system relates to your and information management system, in particular, so that can be identified using the field intensity of the signal receiving location of the mobile communication terminal from a fixed base station or access point position search method was, an information processing system, a contact and information management device.

  A mobile communication terminal represented by a PHS (Personal Handy-phone system) or a mobile phone is connected to an existing public line network through a base station that covers the position of the mobile communication terminal. The area covered by each base station is called a cell, and a base station is installed in each area that is divided in advance. The base station to which the mobile communication terminal is connected is a base station that covers the area where the mobile communication terminal is located. In other words, the base station to which the mobile communication terminal is connected is the base station closest to the mobile communication terminal.

In recent years, a location information providing service by detecting the location of a mobile communication terminal has been rapidly spread. As a technique for detecting the position of the mobile communication terminal, the following technique is known (see, for example, Patent Document 1). According to the technique proposed in Patent Document 1, the mobile communication terminal, a base station stores the received level of a radio wave from the mobile base station near the communication terminal, connected to the standby state, when that communicates The mobile management station that selects the base station with the maximum reception level that can be used and detects the current position of the mobile communication terminal is provided with an identification code of the base station transmitted from the mobile communication terminal via the base station, and Based on the location information with the received electric field value as a data pair, refer to the database that accumulates the geographical location information of the base station and select the appropriate location information to accurately identify the location of the mobile communication terminal Then, the mobile communication terminal uses at least one of the first trajectory obtained from the received electric field value of the selected position information by the calculation formula and the second trajectory obtained from the isoelectric field generated by the selected base station. Identify the current location of It is possible. Thereby, it is possible to improve the position accuracy of the mobile communication terminal.

  The position detection method of the mobile communication terminal using the relationship between the base station and the mobile communication terminal is more accurate in position information than the position detection method of the mobile communication terminal using position information based on GPS positioning. However, the position of the mobile communication terminal can be detected even in a building where a GPS wave (GPS information) does not reach or in a subway premises. Furthermore, the position detection method of the mobile communication terminal using the relationship between the base station and the mobile communication terminal can reduce power consumption and is useful for narrowing down the approximate position of the mobile communication terminal. is there.

  In particular, when the mobile communication terminal is a PHS, the area covered by each base station of the PHS is several hundred meters at most, so that the mobile communication terminal using the relationship between the base station and the mobile communication terminal With the position detection method, the position of the mobile communication terminal that is a PHS can be detected with higher accuracy than when the mobile communication terminal is other than the PHS.

Japanese Patent Laid-Open No. 11-252622

  However, in the case of a mobile communication terminal position detection method that uses the relationship between a base station and a mobile communication terminal, depending on the reception level of radio waves from the base station that the mobile communication terminal receives, the detected mobile communication An error in the position of the terminal may be several hundred meters to several kilometers, and various studies have been conducted to increase the calculation accuracy (detection accuracy) of the position of the mobile communication terminal.

  For example, even when the mobile communication terminal is a PHS, there are not a few regions where the detected error of the position of the mobile communication terminal is several hundred meters. That is, the propagation characteristics of radio waves transmitted by the base station differ depending on the environment of the area where the position of the mobile communication terminal is measured (detected). Must be measured (detected). In particular, measurement areas where radio wave propagation characteristics should be considered include areas where base stations are unevenly distributed, areas where buildings are unevenly distributed, areas where land undulations are large, and lakesides and gulf areas. In such an area, a large error may occur in the measurement (detection) of the position of the mobile communication terminal.

The present invention has been made in view of such a situation, and a position search that can specify the position of a mobile communication terminal with high accuracy using the electric field strength of a signal received from a fixed base station or an access point. method, an information processing system, and an object thereof is to provide a contact and information management device.

In order to solve the above-described problem, the position search method of the present invention is the position search method of an information processing system including a mobile communication terminal and an information management device that manages the position of the mobile communication terminal. The mobile communication terminal wirelessly communicates with a base station or an access point, measures the electric field strength of a radio signal received from the base station or access point with which the mobile communication terminal can communicate, and Detecting identification information for identifying a base station or an access point from among received radio signals, and the electric field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate, The identification information related to the plurality of base stations or the plurality of access points is associated with and transmitted to the information management apparatus And the information management device creates an isoline map indicating an isoline of the electric field strength related to each base station or each access point connected to the mobile communication terminal, and can communicate with the mobile communication terminal Receiving the field strength of radio signals from a plurality of base stations or a plurality of access points and the identification information of the plurality of base stations or the plurality of access points from the mobile communication terminal; The mobile communication terminal uses the plurality of isoline maps superimposed on the plurality of isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information. The intersection of each isoline based on the field strength of radio signals from multiple base stations or multiple access points that can communicate with A plurality of said measurement point candidate that, to determine the position of the mobile communication terminal by using two different base stations or access point measurement point candidate angle that isolines each other forming a field intensity equal to or larger than the reference value of It is characterized by that.

In order to solve the above-described problems, an information processing system according to the present invention is an information processing system including a mobile communication terminal and an information management device that manages the position of the mobile communication terminal. A communication means for wirelessly communicating with a station or an access point; a measuring means for measuring the electric field strength of a radio signal received from a base station or an access point with which a mobile communication terminal can communicate using the communication means; Detecting means for detecting identification information for identifying the base station or access point from radio signals received from the base station or access point, and a plurality of base stations or a plurality of mobile stations capable of communicating with the mobile communication terminal using the communication means The field strength of radio signals received from multiple access points and the identification information related to multiple base stations or multiple access points In addition, a communication control means for controlling the communication means to transmit to the information management apparatus, the information management apparatus is configured to provide an isoline of the electric field strength for each base station or each access point connected to the mobile communication terminal. An isoline map creating means for creating an isoline map to be shown, and electric field strengths of radio signals from a plurality of base stations or a plurality of access points capable of communicating with a mobile communication terminal, and a plurality of base stations or a plurality of access points A plurality of base stations or a plurality of access points identified by the identification information among the isoline map created by the receiving means for receiving the identification information from the mobile communication terminal and the isoline map creating means And a plurality of bases capable of communicating with the mobile communication terminal using the superimposing means for superimposing the isoline map and a plurality of isoline maps superimposed by the superimposing means Or an intersection of the isolines based on the field intensity of the radio signals from a plurality of access points and extracting means for extracting a measurement point candidate among the plurality of measurement point candidate extracted by the extraction means, two different base stations Alternatively, a determination unit that determines a position of the mobile communication terminal using a measurement point candidate whose angle between isolines relating to the electric field strength of the access point is equal to or greater than a reference value, and a position of the mobile communication terminal determined by the determination unit And a storage means for storing.

In order to solve the above-described problem, the information management apparatus of the present invention creates an isoline map that creates an isoline map indicating an isoline of electric field strength relating to each base station or each access point connected to a mobile communication terminal. Receives from the mobile communication terminal the field strength of radio signals from multiple base stations or multiple access points that can communicate with the map creation means and the mobile communication terminal, and identification information of the multiple base stations or multiple access points. And a superimposing unit that superimposes a plurality of isoline maps related to a plurality of base stations or a plurality of access points identified by the identification information among the isoline maps created by the isoline map creating unit. Wireless from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal using a plurality of isoline maps superimposed by the superimposing means Extraction means for extracting an intersection of the isolines based on the field strength of No. a measurement point candidate among the plurality of measurement point candidate extracted by the extraction means, such as a field strength of two different base stations or access point A determination unit that determines a position of the mobile communication terminal using a measurement point candidate whose angle formed between the value lines is equal to or greater than a reference value ; and a storage unit that stores the position of the mobile communication terminal determined by the determination unit. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the position of a mobile communication terminal can be pinpointed with high precision using the electric field strength of the signal received from a fixed base station.

1 is a diagram showing an overall configuration of an information processing system according to an embodiment. The block diagram which shows the internal structure of the PHS communication terminal applicable to the mobile communication terminal which concerns on this embodiment. The block diagram which shows the internal structure of the position calculation server which concerns on this embodiment. FIG. 2 is a block diagram showing an internal configuration of a personal computer applicable to the information processing apparatus according to the embodiment. The conceptual diagram of the position detection method of a PHS communication terminal in this embodiment. The flowchart explaining the base station electric field strength transmission process in the PHS communication terminal of FIG. 2 located in one prior measurement point. The figure which shows the structural example of the correspondence table which shows the correspondence of the RSSI value from each base station of the periphery of the PHS communication terminal located in one prior measurement point, and base station ID memorize | stored in the memory | storage part of a PHS communication terminal. . The flowchart explaining the isoline map creation process in the position calculation server of FIG. The figure which shows the structural example of the latitude longitude table memorize | stored in the memory | storage part of a position calculation server. When the isoline map relating to the base station 12-2 shown in FIG. 5 is created, the RSSI value from the base station 12-2 measured at each of the pre-measurement points α-1 to α-14 is used as each pre-measurement point α. The figure plotted to -1 thru | or (alpha) -14. The figure which shows the isoline map regarding the base station produced by the control part of a position calculation server. The figure which shows the structural example of the base station position database stored in the memory | storage part of a position calculation server. The flowchart explaining the base station electric field strength transmission process in the PHS communication terminal of FIG. 2 located in a measurement point. The flowchart explaining the position detection process of the PHS communication terminal in the position calculation server of FIG. The figure which shows the map (superimposition isoline map) which superimposed each isoline map regarding the base station shown by each base station ID. The figure which shows the extraction method of the measurement point candidate based on the RSSI value from base station 12-1 thru | or 12-3. Explanatory drawing explaining the method (1st determination method) which determines the measurement point where a PHS communication terminal is located using a measurement point candidate. (A) and (B) are the points of intersection formed by the contour lines of two base stations, which are generated when the electric field strength relating to one of the base stations out of the electric field strength values from the two base stations is shifted. The figure which shows deviation | shift. Each base station 12 around the PHS communication terminal located at the measurement point includes base stations 12-1 to 12-3 indicated by base station ID1 to base station ID3, and base stations 12-1 to 12-12. The figure which shows the angle which the isoline which cross | intersects by measurement point candidate (gamma) -1 thru | or γ-4 makes when the RSSI value from -3 is "18", "22", and "21". A method of determining a measurement point where a PHS communication terminal is located using the remaining measurement point candidates after excluding measurement point candidates whose extracted lines are lower than the reference value among the extracted measurement point candidates Explanatory drawing explaining (2nd determination method). The figure which shows a mode that the intersections P, Q, and R which show the true position where a PHS communication terminal is located among the intersections (measurement point candidate) of a some isoline close. Explanatory drawing explaining the method (3rd determination method) which determines the measurement point in which a PHS communication terminal is located using two or more intersections (measurement point candidate) which adjoin within the predetermined distance mutually. The figure which shows the contrast of the measurement result by the position detection method of the conventional PHS communication terminal, and the measurement result by the position detection method which concerns on this embodiment. 5 is a flowchart for explaining a series of processing in the position calculation server in FIG. 3 and the personal computer in FIG. 4. 1 is a block diagram showing an internal configuration of a mobile phone that can be applied to a mobile communication terminal according to an embodiment. The flowchart explaining the other base station electric field strength transmission process in the PHS communication terminal of FIG. 2 located in one prior measurement point. The flowchart explaining the base station electric field strength transmission process in the PHS communication terminal of FIG. 2 located in a measurement point.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of an information processing system 1 according to the present embodiment. In the information processing system 1, base stations 12-1 to 12-n, which are fixed wireless stations, are installed in cells obtained by dividing a communication service providing area into a desired size. In the embodiment of the present invention, the case where there are n base stations 12 has been described, but the number n of base stations may be one or more. In addition, the base stations 12-1 to 12-n are collectively referred to as “base station 12” when it is not necessary to individually distinguish each of them in the following.

  A PHS communication terminal 11 applicable to the mobile communication terminal according to the present embodiment is wirelessly connected to these base stations 12-1 to 12-n. The PHS communication terminal 11 includes base station information (for identifying the base station 12) regarding a plurality of base stations 12 (for example, about 10 to 20 locations or 10 locations or less) that can be transmitted and received with the PHS communication terminal 11. Base station ID, etc.), information on the electric field strength of radio waves from a plurality of base stations 12 that can be transmitted to and received from the PHS communication terminal 11, and information on the stored base station information and electric field strength. It transmits to the PHS network 13 via the base station 12. The base stations 12-1 to 12-n are connected to a PHS network 13 as a public telephone line network via a wired line. A PHS line control server 14 for controlling the PHS line is connected to the PHS network 13. Connected to the PHS line control server 14 is a position calculation server 15 (information management apparatus according to this embodiment) that manages position information related to the PHS communication terminal 11 that is appropriately transmitted from the PHS communication terminal 11 via the PHS network 13. The The position calculation server 15 receives base station information and information on electric field strength from the PHS communication terminal 11 via the PHS network 13, and based on the received information, a base station position database (base station in FIG. 3). The base station ID is identified by referring to the position database 71) and the base station 12 around the PHS communication terminal 11 is specified, and a program related to the positioning algorithm (measurement algorithm) in the position calculation server 15 is executed and moved. The position of the PHS communication terminal 11 as the body communication terminal is calculated. The PHS line control server 14 and the position calculation server 15 constitute a position information center.

A network 16 (including the Internet (IP), a LAN (Local Area Network), a WAN (Wide Area Network), and other various networks) is connected to the position calculation server 15. Connected to the network 16 is a personal computer 17 (information processing apparatus according to the present embodiment) managed by a user who desires to detect the position of the PHS communication terminal 11. Position calculation server 15, for example, the acquisition request from the personal computer 17 (request) received via the network 16, via the network 16 the calculation results relating to the position of the PHS communication terminal 11 to the personal computer 17.

  FIG. 2 shows an internal configuration of the PHS communication terminal 11 applicable to the mobile communication terminal according to the present embodiment. As shown in FIG. 2, the PHS communication terminal 1 includes an antenna 31, a radio transmission / reception unit 32, a signal processing unit 33, an RSSI measurement unit 34, a control unit 35, a storage unit 36, a display unit 37, a phase sub 38, a battery 39, A power supply circuit 40 and a clock circuit 41 are provided.

  The antenna 31 receives from the space a radio signal transmitted from the base station 12 in the PHS communication frequency band (1.9 GHz band). Further, the antenna 31 radiates a radio signal in a PHS communication frequency band (1.9 GHz band) in a space so that radio communication with the base station 12 can be performed. The wireless transmission / reception unit 32 performs wireless communication with the base station 12 via the antenna 31. The radio transmission / reception unit 32 generates a radio signal having a carrier frequency instructed from the control unit 35 based on the modulation signal generated by the signal processing unit 33. Further, the radio transmission / reception unit 32 receives a radio signal having a carrier frequency instructed from the control unit 35, and performs demodulation processing on the received radio signal. Then, the wireless transmission / reception unit 32 outputs the reception result after the demodulation processing to the signal processing unit 33 and the control unit 35. The signal processing unit 33 is configured by a DSP (Digital Signal Processor) or the like, and performs predetermined signal processing on the signal from the wireless transmission / reception unit 32. The signal processing unit 33 detects a base station ID (base station identification information) for identifying the base stations 12 existing around the PHS communication terminal 11 from the reception result after the demodulation process, and detects the detected base The station ID is output to the control unit 35. The RSSI measurement unit 34 measures the electric field strength of the signal received by the wireless transmission / reception unit 32 from the base station 12, and sends information related to the measured RSSI value (value indicating the electric field strength of the received signal) to the control unit 35. Output.

  The control unit 35 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and the CPU is loaded from the program stored in the ROM or the storage unit 36 into the RAM. In addition to executing various processes according to various application programs and control programs including an operating system (OS), the mobile radio terminal 1 is comprehensively controlled by generating various control signals and supplying them to the respective units. Specifically, the control unit 35 has a control function for realizing data communication by various communication processing systems, controls the carrier frequency used by the wireless transmission / reception unit 32, and is based on the reception result at the wireless transmission / reception unit 32. Synchronization with the radio frame transmitted from the base station is established. The RAM appropriately stores data necessary for the CPU to execute various processes.

  The storage unit 36 includes, for example, a flash memory element that is an electrically rewritable and erasable nonvolatile memory, an HDD (Hard Disc Drive), and the like, and includes various application programs executed by the CPU of the control unit 35 and various types. , A control program and control data for the PHS communication terminal 11, and terminal identification information uniquely assigned to the PHS communication terminal 11 are stored. In addition, the storage unit 36 appropriately stores data acquired through data communication and downloaded data. The display unit 37 includes, for example, an LCD or an organic EL. The operation unit 38 includes operation keys and buttons. The power supply circuit 40 generates a predetermined operating power supply voltage Vcc based on the output of the battery 39 and supplies it to each circuit unit. The PHS communication terminal 11 includes a clock circuit (timer) 41 that measures the current time.

  The display unit 37 and the operation unit 38 in FIG. 2 may be omitted.

  FIG. 3 shows an internal configuration of the position calculation server 15 according to the present embodiment. As illustrated in FIG. 3, the position calculation server 15 includes a control unit 50, an input / output interface 55, an input unit 56, an output unit 57, a storage unit 58, a communication unit 59, and a drive 60. These are connected to each other via a bus 54. The control unit 50 includes a CPU 51, a ROM 52, and a RAM 53. The CPU 51 of the control unit 50 executes various processes according to a program stored in the ROM 52 or a program loaded from the storage unit 58 to the RAM 53. The RAM 53 also appropriately stores data necessary for the CPU 51 to execute various processes. The CPU 51, ROM 52, and RAM 53 are connected to each other via a bus 54. An input / output interface 55 is also connected to the bus 54. The input / output interface 55 includes an input unit 56 including a keyboard and a mouse, a display including a CRT (Cathode Ray Tube) and an LCD (Liquid Crystal Display), an output unit 57 including a speaker, and a storage including a hard disk. A communication unit 59 including a unit 58, a modem, a terminal adapter, and a network interface is connected. The communication unit 59 performs communication processing via the network 16 or the like. The storage unit 58 includes a base station position database 71 in which the position of the base station 12 indicated by the latitude and longitude is registered in association with the base station ID.

  A drive 60 is connected to the input / output interface 55 as necessary, and includes a magnetic disk 61 (including a floppy disk), an optical disk 62 (CD-ROM (Compact Disk-Read Only Memory)), and a DVD (Digital Versatile Disk). ), A magneto-optical disk 63 (including MD (Mini-Disk)), a semiconductor memory 64, or the like is appropriately mounted, and then a read computer program is installed in the storage unit 58 as necessary.

  FIG. 4 illustrates an internal configuration of the personal computer 17 applicable to the information processing apparatus according to the present embodiment. Note that the internal configuration of the personal computer 17 described with reference to FIG. 4 is basically the same as the internal configuration of the position calculation server 15 described with reference to FIG. To do.

  The information processing system 1 according to the present embodiment uses the radio wave level from the surrounding base station 12 acquired by the PHS communication terminal 11 applicable to the mobile communication terminal and the base station ID of the base station 12 to perform PHS communication. The position of the terminal 11 is specified. As a result, the information processing system 1 according to the present embodiment enables the PHS even in a measurement area (measurement area where radio wave propagation characteristics should be taken into account) where a large error may occur in the measurement (detection) of the position of the mobile communication terminal. It becomes possible to specify the position of the communication terminal 11 with high accuracy. FIG. 5 shows the concept of the position detection method of the PHS communication terminal 11 in this embodiment. As shown in FIG. 5, in the present embodiment, the radio field intensity (from a neighboring base station 12) is preliminarily measured at a plurality of points (preliminary measurement points) included in a measurement area where the position of the PHS communication terminal 11 is measured (detected). Electric field intensity) is measured, and the propagation characteristics of radio waves from the surrounding base station 12 in the measurement area are represented by isolines based on the measurement results. In the case of FIG. 5, in the measurement area where the three base stations 12 (base stations 12-1 to 12-3) are close to each other, the neighboring base stations 12-1 to 12- The electric field strengths from 3 are measured in advance, and the propagation characteristics of radio waves from the surrounding base stations 12-1 to 12-3 in the measurement area are represented by isolines based on the measurement results.

  Next, when the position of the PHS communication terminal 11 to be specified by the information processing system 1 is a measurement point (unknown measurement point) β, the information processing system 1 acquires the surrounding base station 12 acquired by the PHS communication terminal 11. -1 to 12-3 and the base station IDs of the base stations 12-1 to 12-3 are used to determine the propagation characteristics of radio waves from the surrounding base stations 12-1 to 12-3 in the measurement area. The current position (new measurement point β) of the PHS communication terminal 11 is specified with reference to the isoline shown. That is, the information processing system 1 determines the current position of the PHS communication terminal 11 using the intersection of the isolines indicating the electric field strengths from the surrounding base stations 12-1 to 12-3 acquired by the PHS communication terminal 11. Identify.

  As described above, the position detection method of the mobile communication terminal according to this embodiment includes the position of the base station 12, the electric field strength from the base station 12 assumed at the base station point, and the electric field from each base station 12 in advance. Mobile communication using an isoline diagram of the electric field strength from the base station 12 drawn for each base station 12 by interpolating the measured values using the positions of the pre-measurement points where the strengths are measured and the measured values. This is a terminal position detection method. The details of the process using the position detection method of the mobile communication terminal will be described below. First, PHS communication located at a pre-measurement point, which is performed as a premise of an isoline map creation process in which the location calculation server 15 creates an isoline map indicating the propagation characteristics of radio waves from surrounding base stations 12 in the measurement area. A base station field strength transmission process in the terminal 11 will be described. In addition, when the base station electric field intensity | strength transmission process in the PHS communication terminal 11 located in a prior measurement point is performed, the PHS communication terminal 11 shall be previously arrange | positioned beforehand at each prior measurement point in a measurement area, respectively.

  With reference to the flowchart of FIG. 6, the base station electric field strength transmission process in the PHS communication terminal 11 of FIG. 2 located in one prior measurement point is demonstrated. It is assumed that the PHS communication terminal 11 is waiting for one of the base stations 12. Moreover, the PHS communication terminal 11 is arrange | positioned in the any prior measurement point in a measurement area. The position calculation server 15 acquires in advance information related to the longitude and latitude indicating the pre-measurement point where the PHS communication terminal 11 executing the base station field strength transmission process is located together with the terminal identification information for identifying the PHS communication terminal 11. It shall be.

  In step S1, the control unit 35 of the PHS communication terminal 11 determines whether or not an instruction to start the base station field strength transmission process is accepted by the operator operating the operation unit 38, and the base station field strength transmission is performed. Wait until it is determined that an instruction to start processing has been accepted. When it is determined in step S1 that the PHS communication terminal 11 has received an instruction to start the base station field strength transmission process, the control unit 35 of the PHS communication terminal 11 performs the wireless transmission / reception unit 32 and the RSSI measurement unit 34 in step S2. The base station 12 in the vicinity of the PHS communication terminal 11 located at one pre-measurement point (the base station 12 to which the PHS communication terminal 11 can transmit and receive signals and other than the standby base station 12) The RSSI value of a predetermined frequency from a plurality of base stations 12 is included if the signal can be transmitted and received. That is, the control unit 35 sequentially assigns carrier frequencies existing in the PHS communication frequency band to the radio transmission / reception unit 32, and causes the radio transmission / reception unit 32 to sequentially receive signals having the assigned carrier frequency. The radio transmission / reception unit 32 sequentially receives a signal having a carrier frequency assigned by the control unit 35 and outputs the received signal to the RSSI measurement unit 34. The RSSI measurement unit 34 measures an RSSI value (a value indicating the electric field strength of the reception signal) regarding the reception signal of each frequency from the radio transmission / reception unit 32 and outputs information regarding the measured RSSI value to the control unit 35. At this time, when the radio transmission / reception unit 32 receives a signal having the assigned carrier frequency, the radio transmission / reception unit 32 receives a signal including control channel information from the base station 12 connected to the PHS network 13. Then, demodulation processing is performed on the received signal including the control channel information, and the reception result after the demodulation processing is output to the control unit 35. The control unit 35 recognizes that the received signal is a signal from the base station 12 connected to the PHS network 13 based on the control channel information included in the reception result.

In step S <b> 3, the signal processing unit 33 performs predetermined signal processing on the reception result after the demodulation processing according to the control of the control unit 35, and is positioned at one prior measurement point from the control channel information included in the reception result. The base station ID (base station identification information) for identifying the base stations 12 existing around the PHS communication terminal 11 to be detected is sequentially detected, and the detected base station ID is sequentially output to the control unit 35. Although the processing in step S2 and the step S3 is described in time series in the present embodiment, a parallel processing basically.

  In step S4, the control unit 35 stores the RSSI value from each base station 12 around the PHS communication terminal 11 and the base station ID, which are sequentially acquired by the processing in step S2 and step S3, in association with each other in the storage unit 36. To do. FIG. 7 is a correspondence table showing the correspondence between the RSSI values from the base stations 12 around the PHS communication terminal 11 located at one prior measurement point and the base station ID stored in the storage unit 36. As shown in FIG. 7, “base station ID1” and the RSSI value “a” of the signal from the base station 12 identified by the base station ID1 are stored in association with each other. “Base station ID2” and the RSSI value “b” of the signal from the base station 12 identified by the base station ID1 are stored in association with each other. The same applies to other cases.

  In step S5, the control unit 35 reads the correspondence table stored in the storage unit 36, controls the wireless transmission / reception unit 32 and the signal processing unit 33, and uses the read correspondence table to perform one preliminary measurement. A PHS network 13 via the base station 12 waiting for the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 located at the point together with the terminal identification information for identifying the PHS communication terminal 11. To the position calculation server 15 via. Thereafter, the process ends.

In the case of the base station field strength transmission process of FIG. 6, when it is determined that the instruction that the PHS communication terminal 11 starts the base station field strength transmission process has been received, the PHS communication terminal 11 has one pre-measurement point. The RSSI value of the predetermined frequency from the base station 12 around the PHS communication terminal 11 located in the base station 12 is measured, and the RSSI value and the base from each base station 12 around the PHS communication terminal 11 located at one pre-measurement point The station ID is sequentially transmitted to the position calculation server 15 via the PHS network 13 via the base station 12 waiting along with the terminal identification information for identifying the PHS communication terminal 11, but in such a case Not limited to. For example, as shown in FIG. 26, the base station 12 around the PHS communication terminal 11 is located at one pre-measurement point at every predetermined time (for example, 1.2 seconds). While measuring the RSSI value of a predetermined frequency from the base station (steps S301 to S302), and then transmitting the RSSI value and the base station ID from each base station 12 around the previous PHS communication terminal 11 to the position calculation server 15 When a predetermined time (for example, 10 minutes to 1 day) has passed, the RSSI value from each base station 12 around the PHS communication terminal 11 and the data group of the base station ID are collectively transmitted to the position calculation server 15. (Steps S305 to S306). Thereby, power consumption due to transmission processing in the PHS communication terminal 11 can be suppressed, and an isoline map indicating an isoline of the base station 12 described later can be updated more efficiently. Further, the PHS communication terminal 11 may transmit the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 to the position calculation server 15 according to an acquisition request from the position calculation server 15, for example. Good.

  In the case of the base station field strength transmission process of FIG. 6, the position calculation server 15 uses the information about the longitude and latitude indicating the prior measurement point where the PHS communication terminal 11 executing the base station field strength transmission process is located as the PHS communication terminal. However, the present invention is not limited to such a case. For example, the PHS communication terminal 11 includes a GPS receiving unit, and the PHS communication terminal 11 is used by using the GPS receiving unit. Information on the longitude and latitude of the PHS communication terminal 11 is obtained, the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 located at one prior measurement point, And the terminal identification information for identifying the PHS communication terminal 11 may be transmitted to the position calculation server 15.

  In addition, each of a plurality of other PHS communication terminals 11 located in a plurality of other pre-measurement points provided in a certain measurement area also performs a similar base station field strength transmission process, The RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 are transmitted to the position calculation server 15. In addition, this embodiment uses the PHS communication terminal 11 located in each pre-measurement point in the measurement area, and calculates the RSSI value from each base station 12 around each PHS communication terminal 11 located in each pre-measurement point. The RSSI value at each pre-measurement point is measured and transmitted to the position calculation server 15. However, the present invention is not limited to such a case. For example, using a dedicated terminal other than the PHS communication terminal 11, each advance The RSSI value from each base station 12 around each PHS communication terminal 11 located at the measurement point may be measured, and each RSSI value at each prior measurement point may be transmitted to the position calculation server 15.

  With reference to the flowchart of FIG. 8, the isoline map creation process in the position calculation server 15 of FIG. 3 will be described. In addition, the position calculation server 15 identifies the information about the longitude and latitude indicating the prior measurement point where the PHS communication terminal 11 that executes the base station field strength transmission process is identified in the isoline map creation process. It is assumed that it is acquired in advance together with the terminal identification information for this purpose.

In step S <b> 21, the communication unit 59 of the position calculation server 15 uses the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 located at each prior measurement point, and the terminal identification information of the PHS communication terminal 11. At the same time, the received information is sequentially supplied to the control unit 50. In step S22, the control unit 50 preliminarily determines the terminal identification information of the PHS communication terminal 11 and the PHS communication terminal 11 based on the terminal identification information of each PHS communication terminal 11 that transmits the RSSI value and the base station ID from each base station. The longitude / latitude at the prior measurement point where the PHS communication terminal 11 is located is extracted with reference to the longitude / latitude table registered in association with the longitude / latitude at the previous measurement point where the PHS is located . FIG. 9 illustrates a configuration example of a latitude / longitude table stored in the storage unit 58 of the position calculation server 15. As shown in FIG. 9, the terminal identification information of the PHS communication terminal 11 located at each pre-measurement point and the longitude and latitude at each pre-measurement point are registered in association with each other. For example, “terminal identification information 1” of the PHS communication terminal 11 located at the prior measurement point α-1 and the longitude and latitude “longitude m1 latitude n1” at the prior measurement point α-1 are registered in association with each other. The same applies hereinafter.

  In step S23, the control unit 50 extracts the longitude / latitude at each pre-measurement point where each extracted PHS communication terminal 11 is located and the base stations 12 around each PHS communication terminal 11 located at each pre-measurement point. Based on the RSSI value and the base station ID, an isoline map for a specific base station is created. At this time, when creating an isoline map relating to a specific base station, the control unit 50 measures each RSSI value from each base station 12 around each PHS communication terminal 11 located at each prior measurement point. Plot to the point. FIG. 10 shows the RSSI values from the base station 12-2 measured at each of the pre-measurement points α-1 to α-14 when creating an isoline map related to the base station 12-2 shown in FIG. It is the figure plotted to the prior measurement points alpha-1 thru / or alpha-14. In the case of FIG. 10, the RSSI value measured in advance by the PHS communication terminal 11 (PHS communication terminal 11 identified by the terminal identification information 1) at the pre-measurement point α-1 is “21 (dBμV / m)”. Further, the RSSI value measured in advance by the PHS communication terminal 11 (PHS communication terminal 11 identified by the terminal identification information 2) at the pre-measurement point α-2 is “24 (dBμV / m)”. The same applies to other prior measurement points. In the case of FIG. 10, the RSSI value from the base station 12-2 cannot be measured at the pre-measurement point α-8.

  Since it is impossible to measure the electric field strength of the radio wave from the base station at the position of the base station 12, the control unit 50 determines the virtual RSSI value regarding the radio wave from the base station at the position of the base station 12 ( As the value indicating the electric field strength, the maximum value measurable in the PHS communication terminal 11 is set. In the case of FIG. 10, the virtual RSSI value regarding the radio wave from the base station at the position of the base station 12-2 is “40 (dBμV / m)”.

  Next, the control unit 50 relates to a specific base station 12 by using the RSSI value from each base station 12 around each PHS communication terminal 11 located at each pre-measurement point, which is plotted at each pre-measurement point. Create an isoline map. Specifically, the control unit 50 forms an RSSI value plotted at each pre-measurement point by a spline interpolation method or a relational expression E = k / D (k: charge, D: distance) between the distance and the electric field strength. Interpolation is performed between the pre-measurement points using a method of interpolation so as to have a gradient, an electric field intensity isoline for a specific base station 12 is created, and an isoline map for the specific base station 12 is created. FIG. 11 shows an isoline map relating to the base station 12-2 created by the control unit 50 of the position calculation server 15.

  In step S <b> 24, the control unit 50 stores the created isoline map relating to the specific base station 12 in the base station position database 71 of the storage unit 59 in association with the base station ID. Under the control of the control unit 50, the storage unit 59 stores the created isoline map relating to the specific base station 12 in the base station position database 71 in association with the base station ID. FIG. 12 illustrates a configuration example of the base station position database 71 stored in the storage unit 59 of the position calculation server 15. As shown in FIG. 12, “base station ID”, “latitude / longitude” indicating the position of the base station 12, and “isoline map” indicating the isolines of the electric field strength related to the base station 12 are registered in association with each other. Is done. In the case of FIG. 12, “base station ID”, “latitude / longitude” indicating the position of the base station 12, and “isoline map” indicating the isolines of the electric field strength related to the base station 12 are registered in association with each other. . For example, “base station ID 1”, “latitude ma longitude na” indicating the position of the base station 12 identified by the base station ID 1, and “etc.” indicating the isolines of the electric field strength relating to the base station 12 identified by the base station ID 1 "Value line map 1" is registered in association with each other. The same applies to other base stations. In step S25, the control unit 50 creates isoline maps for all base stations based on the RSSI values and base station IDs from the base stations 12 around the PHS communication terminal 11 located at each pre-measurement point. Determine whether or not. When the control unit 50 determines in step S25 that the isoline map for all base stations has been created, the isoline map creation process ends. On the other hand, when the control unit 50 determines in step S25 that the isoline map for all base stations has not been created, the process returns to step S23, and the isoline map for the other base station 12 is created. .

  Note that the isoline map once created by the isoline map creation process of FIG. 8 is the RSSI value newly measured at each pre-measurement point or the RSSI value measured at the pre-measurement point newly installed. It is updated as needed. Thereby, even when a new building or the like is built in the measurement area, the influence of the presence of the building on the isoline of the electric field strength related to the base station 12 in the measurement area is considered. The isoline map for the base station 12 can be updated.

  Further, the base station position database 71 in this embodiment includes a “base station ID”, a “latitude / longitude” indicating the position of the base station 12, a “longitude / latitude” at each pre-measurement point of the electric field strength for each base station 12, and The electric field strength value (RSSI value) regarding each pre-measurement point for each base station may be associated and registered.

  Next, the base station field strength transmission process in the PHS communication terminal 11 of FIG. 2 located at the measurement point will be described with reference to the flowchart of FIG. It is assumed that the PHS communication terminal 11 is waiting for one of the base stations 12. Further, it is assumed that the PHS communication terminal 11 is attached to a container or the like and is moved in a measurement area by a car or the like, or is stopped in a building or a subway yard in the measurement area. Note that the processing in steps S102 to S105 in FIG. 13 is basically the same as the processing in steps S2 to S5 in FIG. 6, and the description thereof will be omitted as appropriate.

  In step S101, the control unit 35 of the PHS communication terminal 11 uses the clock circuit 41 to transmit the RSSI value and the base station ID from each base station around the previous PHS communication terminal 11 to the position calculation server 15. It is determined whether or not a predetermined time (for example, 1.2 seconds) has elapsed from the time until it is determined that a predetermined time (for example, 1.2 seconds) has elapsed. . If the PHS communication terminal 11 determines in step S101 that a predetermined time set in advance (for example, 1.2 seconds) has elapsed, the process proceeds to step S102.

  In step S105, the control unit 35 reads the correspondence table stored in the storage unit 36, controls the wireless transmission / reception unit 32 and the signal processing unit 33, and uses the read correspondence table to read the PHS communication terminal 11. Location calculation server via the PHS network 13 via the base station 12 waiting for the RSSI value and the base station ID from each base station 12 around the base station 12 together with the terminal identification information for identifying the PHS communication terminal 11 15 to send. Thereafter, the process returns to step S101, and the processes after step S101 are repeatedly executed. Thereby, the position calculation server 15 can receive the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 transmitted from the PHS communication terminal 11 at predetermined time intervals.

  In the present embodiment, the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 are periodically transmitted to the position calculation server 15 using a timer. For example, the information may be transmitted to the position calculation server 15 according to an acquisition request from the position calculation server 15. In the case of the base station field strength transmission process of FIG. 13, the RSSI value and the base station ID from each base station 12 around the previous PHS communication terminal 11 are transmitted to the position calculation server 15 and then set in advance. When a time (for example, 1.2 seconds) elapses, the PHS communication terminal 11 measures the RSSI value of a predetermined frequency from the base station 12 around the PHS communication terminal 11 located at the measurement point, The PSI is received via the base station 12 waiting for the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 located at the pre-measurement point together with the terminal identification information for identifying the PHS communication terminal 11. Although the transmission is made to the position calculation server 15 via the network 13, it is not limited to such a case. For example, as shown in FIG. 27, the base station 12 around the PHS communication terminal 11 is located at one pre-measurement point at every predetermined time (for example, 1.2 seconds). While measuring the RSSI value of a predetermined frequency from the base station (steps S311 to S312), and then transmitting the RSSI value and the base station ID from each base station 12 around the previous PHS communication terminal 11 to the position calculation server 15 When a predetermined time (for example, 10 minutes to 1 day) has elapsed, the RSSI and the base station ID data group from the base stations 12 around the PHS communication terminal 11 are collectively transmitted to the position calculation server 15. (Steps S315 to S316). Thereby, the PHS communication terminal 11 can transmit the positional information of the PHS communication terminal 11 collectively to the position calculation server 15, and can suppress the power consumption by the transmission process in the PHS communication terminal 11.

  With reference to the flowchart of FIG. 14, the position detection process of the PHS communication terminal 11 in the position calculation server 15 of FIG. 3 is demonstrated.

  In step S121, the communication unit 59 of the location calculation server 15 receives the RSSI value and the base station ID from each base station 12 around the PHS communication terminal 11 located at the measurement point, together with the terminal identification information of the PHS communication terminal 11. The received information is supplied to the controller 50. For example, the communication unit 59 of the position calculation server 15 receives a data group in which the base station ID and the RSSI value are paired together with the terminal identification information of the PHS communication terminal 11 as shown in FIG. In step S <b> 122, the control unit 50 specifies the PHS communication terminal 11 that detects the position based on the terminal identification information of the PHS communication terminal 11 from the communication unit 59. In step S123, the control unit 50 receives each base station received from the base station location database 71 of the storage unit 58 based on the base station ID of each base station 12 around the PHS communication terminal 11 located at the measurement point. Each isoline map regarding ID is read. For example, when “base station ID1” to “base station ID3” are included in the base station ID of each base station 12 around the PHS communication terminal 11 located at the measurement point, the control unit 50 reads the base station position database 71 from The respective isoline maps relating to the base stations 12-1 to 12-3 indicated by “base station ID1” to “base station ID3” are read.

  In step S124, the control unit 50 superimposes each isoline map related to the base station 12 indicated by each read base station ID. FIG. 15 represents a map (superimposed isoline map) in which each isoline map related to the base station 12 indicated by each base station ID is superimposed. For example, when the base stations 12-1 to 12-3 indicated by the base station ID1 to the base station ID3 are included in the base stations 12 around the PHS communication terminal 11 located at the measurement point, the base stations 12-1 to 12-12 Each isoline map relating to -3 is superimposed. In the case of the present embodiment, in order to simplify the description, the case where the respective isoline maps related to the base stations 12-1 to 12-3 are superimposed will be described explicitly, but only in such a case. I can't. Of course, the position calculation server 15 has a base station 12 whose electric field intensity related to a radio signal from the base station 12 that can communicate with the PHS communication terminal 11 is equal to or higher than a reference value among the plurality of base stations 12 identified by the base station identification information. A plurality of isoline maps related to may be superimposed.

  In step S125, the control unit 50 uses the superimposed isoline map to extract intersection points of the isolines based on the RSSI values from the base stations 12 around the PHS communication terminal 11 as measurement point candidates. . Specifically, for example, each base station 12 around the PHS communication terminal 11 located at the measurement point includes base stations 12-1 to 12-3 indicated by the base station ID1 to base station ID3, and When the RSSI values from the base stations 12-1 to 12-3 are “18”, “22”, and “21”, the control unit 50 receives the RSSI values from the base stations 12-1 to 12-3 (“ 18 ”,“ 22 ”, and“ 21 ”) are extracted as measurement point candidates. FIG. 16 shows a method of extracting measurement point candidates based on the RSSI values from the base stations 12-1 to 12-3. As illustrated in FIG. 16, the control unit 50 determines four intersections of the isolines based on the RSSI values (“18”, “22”, and “21”) from the base stations 12-1 to 12-3. Extracted as measurement point candidates γ-1 to γ-4.

  In step S126, the control unit 50 determines a measurement point where the PHS communication terminal 11 is located by using the plurality of extracted measurement point candidates. FIG. 17 is an explanatory diagram for explaining a method (first determination method) for determining a measurement point where the PHS communication terminal 11 is located using a measurement point candidate. In the case of FIG. 17, the measurement point candidates where the PHS communication terminal 11 is located include measurement point candidates γ-1 to γ-4. In the case of FIG. 17, the control unit 50 determines the center of gravity of these four measurement point candidates as the measurement result of the measurement point where the PHS communication terminal 11 is located. At this time, the error between the measurement point where the PHS communication terminal 11 is actually located and the measurement result of the PHS communication terminal 11 determined in step S126 was 28.0 m. The control unit 50 may determine a point other than the center of gravity of these four measurement point candidates as the measurement result of the measurement point where the PHS communication terminal 11 is located. In addition, for example, the center of gravity may be calculated after weighting the measurement point candidates.

  In step S127, the control unit 50 causes the storage unit 58 to store the determined measurement result of the position of the PHS communication terminal 11 (position information represented by longitude and latitude) together with the terminal identification information of the PHS communication terminal 11. . Thereafter, the position detection process ends.

In the case of FIG. 17, the control unit 50 determines the center of gravity of these four measurement point candidates as the measurement result of the measurement point where the PHS communication terminal 11 is located. However, the present invention is not limited to such a case. For example, as illustrated in FIG. 16, the control unit 50 determines four intersections of the isolines based on the RSSI values (“18”, “22”, and “21”) from the base stations 12-1 to 12-3. Although extracted as measurement point candidates γ-1 to γ-4, among the extracted measurement point candidates γ-1 to γ-4, measurement point candidates (equivalence values) where the angle formed by the contour lines is lower than the reference value. (Excluding measurement point candidates having an angle that is not close to a right angle between the lines), and using the remaining measurement point candidates, the measurement result of the measurement point where the PHS communication terminal 11 is located may be determined. Good. Here, the reason for excluding the measurement point candidates in which the angle between the isolines among the measurement point candidates that are the intersections of the isolines is lower than the reference value will be described. That is, the electric field strength from each base station 12 measured by the PHS communication terminal 11 includes a certain amount of error, and the isoline may be shifted due to the measured electric field strength. Therefore, as shown in FIGS. 18A and 18B, when the electric field strength relating to the base station B out of the electric field strength values from the two base stations 12 of the base station A and the base station B is shifted, The intersection formed by the isolines of A and B is also shifted. The size of the displacement of the intersection, than when the angle formed by the isolines each other as shown in FIG. 18 (B) low, if the angle formed by isolines each other as shown in FIG. 18 (A) higher Because is smaller.

  FIG. 19 shows that base stations 12-1 to 12-3 indicated by base station ID1 to base station ID3 are included in each base station 12 around the PHS communication terminal 11 located at the measurement point, and the base station When the RSSI values from 12-1 to 12-3 are “18”, “22”, and “21”, they represent angles formed by isolines intersecting at the measurement point candidates γ-1 to γ-4. ing. As shown in FIG. 19, the angle “71 °” formed by the isolines intersecting at the measurement point candidate γ−1 and the angle “62 °” formed by the isolines intersecting at the measurement point candidate γ-2. And an angle “68 °” formed by the isolines intersecting at the measurement point candidate γ-3 and an angle “13 °” formed by the isolines intersecting at the measurement point candidate γ-1. At this time, when the reference value regarding the angle formed by the isolines when excluding the measurement point candidates is 60 °, in the case of FIG. 19, the measurement point candidate γ− from among the measurement point candidates γ−1 to γ-4. 4 is excluded. This reference value can be set and may be changed as appropriate. For example, when the interval between the base stations 12 is sufficiently small, the reference value regarding the angle formed by the isolines when excluding the measurement point candidates is lowered so that the measurement point candidates are not substantially excluded. Good. FIG. 20 shows a measurement in which the PHS communication terminal 11 is located using the remaining measurement point candidates after excluding the measurement point candidates whose angle between isolines is lower than the reference value among the extracted measurement point candidates. It is explanatory drawing explaining the method (2nd determination method) which determines a point. In the case of FIG. 20, the measurement point candidates where the PHS communication terminal 11 is located include measurement point candidates γ-1 to γ-4. The point candidate γ-4 is excluded. Then, the control unit 50 determines the center of gravity of the remaining three measurement point candidates γ-1 to γ-3 as the measurement result of the measurement point where the PHS communication terminal 11 is located. At this time, the error between the measurement point where the PHS communication terminal 11 is actually located and the measurement result of the PHS communication terminal 11 determined in step S126 was 74.8 m.

  Further, an isoline based on the RSSI value of the electric field intensity from the two base stations 12 basically has two intersections. Here, as shown in FIG. 21, among the intersections (measurement point candidates) of a plurality of isolines, the intersections P, Q, and R indicating the true position where the PHS communication terminal 11 is located approach each other. Other than that, it is far away. At this time, at the intersections (measurement points) P, Q, and R, the angle formed by the intersecting isolines is close to a right angle. Therefore, when there are a plurality of intersections (measurement point candidates) whose angles formed by the isolines are equal to or greater than the reference value, exclude intersections other than two or more intersections (measurement point candidates) that are close to each other within a predetermined distance. However, the measurement result of the measurement point where the PHS communication terminal 11 is located may be determined using two or more intersections (measurement point candidates) that are close to each other within a predetermined distance. FIG. 22 is an explanatory diagram illustrating a method (third determination method) for determining a measurement point where the PHS communication terminal 11 is located using two or more intersections (measurement point candidates) that are close to each other within a predetermined distance. It is. In the case of FIG. 22, the measurement point candidates where the PHS communication terminal 11 is located include measurement point candidates γ-1 to γ-4. Measurement point candidates γ-1 and γ-4 are excluded. Then, the control unit 50 determines the center of gravity of the remaining two measurement point candidates γ-2 to γ-3 that are close to each other within a predetermined distance as the measurement result of the measurement point where the PHS communication terminal 11 is located. At this time, the error between the measurement point where the PHS communication terminal 11 is actually located and the measurement result of the PHS communication terminal 11 determined in step S126 was 17.3 m. In the case of FIG. 22, the measurement point candidates excluded except for the measurement point candidates γ-1 to γ-4 are not shown in FIG.

  FIG. 23 shows a comparison between a measurement result obtained by the position detection method of the conventional PHS communication terminal and a measurement result obtained by the position detection method according to the present embodiment. As shown in FIG. 23, the positioning result by the first determination method using a plurality of measurement point candidates is the point indicated by δ-1, and the positioning result by the second determination method using the plurality of measurement point candidates. Is a point indicated by δ-2, and a positioning result by the third determination method using a plurality of measurement point candidates is a point indicated by δ-3. As described above, the error in the positioning result from the actual measurement point by the first determination method is 28.0 m, and the error in the positioning result from the actual measurement point by the second determination method is 74.8 m. The error of the positioning result from the actual measurement point according to the third determination method is 17.3 m. On the other hand, in the conventional method in which the position (latitude and longitude) of the base station 12-2 on which the PHS communication terminal 11 located at the measurement point is waiting is used as the measurement result of the position of the PHS communication terminal 11, the actual measurement point and The error of the positioning result is 224 m, and even in the conventional method in which the center of gravity of the positions of the base stations 12-1 to 12-3 that can be transmitted and received is the measurement result of the position of the PHS communication terminal 11, The error is 216m. Therefore, in the case of position detection by the first to third determination methods according to the present embodiment, the position of the PHS communication terminal 11 can be detected with higher accuracy than in the past.

  Further, when the measurement point where the PHS communication terminal 11 is located is determined using the second determination method, the intersection (the measurement point candidate γ-1 in the case of FIG. 20) having the highest angle between the isolines is determined. The position of the PHS communication terminal 11 may be used.

  A series of processing in the position calculation server 15 in FIG. 3 and the personal computer 17 in FIG. 4 will be described with reference to the flowchart in FIG.

  In step S211, when the control unit 90 of the personal computer 17 receives an instruction to acquire the position information of the PHS communication terminal 11 from the user, the control unit 90 controls the communication unit 99 and acquires the terminal identification information of the PHS communication terminal 11 that acquires the position. At the same time, a position information acquisition request is transmitted to the position calculation server 15 via the network 16. The communication unit 99 transmits a position information acquisition request to the position calculation server 15 via the network 16 together with the terminal identification information of the PHS communication terminal 11 that acquires the position, under the control of the control unit 90. In step S201, the communication unit 59 of the position calculation server 15 receives the position information acquisition request together with the terminal identification information of the PHS communication terminal 11 for acquiring the position via the network 15, and the received terminal identification of the PHS communication terminal 11 is received. A position information acquisition request is supplied to the control unit 50 together with the information. In step S <b> 202, the control unit 50 of the position calculation server 15 specifies the PHS communication terminal 11 for which acquisition of position information is requested based on the terminal identification information of the PHS communication terminal 11. In step S <b> 203, the control unit 50 of the position calculation server 15 reads out the specified position information of the PHS communication terminal 11 from the storage unit 58. In step S <b> 204, the control unit 50 of the position calculation server 15 controls the communication unit 59 and transmits the position information of the PHS communication terminal to the personal computer 17 via the network 15. In step S212, the communication unit 99 of the personal computer 17 receives the position information of the PHS communication terminal 11 (position information represented by longitude and latitude) and supplies the received position information of the PHS communication terminal 11 to the control unit 90. To do. In step S213, the control unit 90 causes the output unit 97 to output the position information of the PHS communication terminal 11. Thereby, the user can grasp | ascertain the present highly accurate position of the PHS communication terminal 11. FIG.

  The PHS communication terminal 11 is applied as the mobile communication terminal according to the present embodiment. However, the present invention is not limited to such a case. For example, a position calculation server is used via a mobile phone base station using a mobile phone. 15 may be communicated. In addition, as a mobile communication terminal according to the present embodiment, a terminal capable of communicating by a wireless communication method such as WLAN (Wireless Local Area Network) or WiMAX is used, and the mobile communication terminal uses an access point by these wireless communication methods. It is also possible to communicate with the position calculation server 15 via, for example. At this time, as in the case of the base station, an isoline map is created for each access point.

  FIG. 25 illustrates an internal configuration of the mobile phone 130 applicable to the mobile communication terminal according to the present embodiment. In the case of FIG. 25, for example, the internal configuration of the cellular phone is shown assuming wireless connection by a code division multiple access method called W-CDMA. Of course, other wireless connection methods are used. May be. For example, when a GSM connection method is used, GMSK (Gaussian Filtered Minimum Shift Keying) is used as a digital modulation method. In addition, processing by any connection method such as W-CDMA wireless connection method or GSM wireless connection method can be performed, and as appropriate, W-CDMA wireless connection method, GSM wireless connection method, etc. Several wireless connection methods may be selectively used.

  As shown in FIG. 25, the radio signal transmitted from the base station is received by the antenna 131 and then input to the receiving circuit (RX) 133 via the antenna duplexer (DUP) 132. The receiving circuit 133 mixes the received radio signal with the local oscillation signal output from the frequency synthesizer (SYN) 134 and converts the frequency into an intermediate frequency signal (down-conversion). Then, the reception circuit 133 orthogonally demodulates the down-converted intermediate frequency signal and outputs a reception baseband signal. Note that the frequency of the local oscillation signal generated from the frequency synthesizer 134 is indicated by a control signal SYC output from the control unit 138.

  The reception baseband signal from the reception circuit 133 is input to the signal processing unit 136. The signal processing unit 136 includes a RAKE receiver (not shown). In this RAKE receiver, a plurality of paths included in the received baseband signal are despread with each spreading code (that is, the same spreading code as that of the spread received signal). Then, the signals of the respective paths subjected to the despreading process are subjected to coherent Rake synthesis after the phase is adjusted. The data sequence after Rake combining is subjected to deinterleaving and channel decoding (error correction decoding), and then binary data determination is performed. Thereby, received packet data of a predetermined transmission format is obtained. This received packet data is input to the compression / decompression processing unit 137.

  The compression / decompression processing unit 137 is configured by a DSP (Digital Signal Processor) or the like, and the received packet data output from the signal processing unit 136 is separated for each medium by a demultiplexing unit (not shown), and the separated data for each medium Each is decrypted.

  The compression / decompression processing unit 137 multiplexes data including position information based on GPS positioning from the control unit 138 according to a predetermined transmission format by a demultiplexing unit (not shown) and then packetizes the data, and transmits the packetized transmission packet data as a signal. The data is output to the processing unit 136.

  The signal processing unit 136 performs spread spectrum processing on the transmission packet data output from the compression / decompression processing unit 137 using the spread code assigned to the transmission channel, and outputs the output signal after the spread spectrum processing to the transmission circuit (TX ) 135. The transmission circuit 135 modulates the signal after the spread spectrum processing using a digital modulation method such as a QPSK (Quadrature Phase Shift Keying) method according to the control of the control unit 138. The transmission circuit 135 combines the digitally modulated transmission signal with a local oscillation signal generated from the frequency synthesizer 34 and frequency-converts (up-converts) it into a radio signal. Then, the transmission circuit 135 amplifies the radio signal generated by this up-conversion at high frequency so that the transmission power level instructed by the control unit 138 is obtained. The radio signal amplified by the high frequency is supplied to the antenna 131 via the antenna duplexer 132 and transmitted from the antenna 131 to the base station.

  The control unit 138 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU is loaded from the program stored in the ROM or the storage unit 139 into the RAM. In addition, various processes are executed in accordance with various application programs including an operating system (OS), and various control signals are generated and supplied to the respective units to centrally control the communication terminal 2. The RAM appropriately stores data necessary for the CPU to execute various processes.

  The storage unit 139 includes, for example, a flash memory element or HDD (Hard Disc Drive), which is an electrically rewritable and erasable nonvolatile memory, and various application programs executed by the CPU of the control unit 138 and various types. The data group is stored. The storage unit 139 stores a command program composed of commands, various firmware, and the like in each memory area. In addition, the storage unit 139 stores identification information (for example, an identification number) uniquely assigned to each mobile phone 130. Further, the mobile phone 130 is provided with a clock circuit (timer) 144 that measures the current accurate current time. The display unit 140 includes, for example, an LCD or an organic EL. The operation unit 141 includes operation keys and buttons. The power supply circuit 143 generates a predetermined operating power supply voltage Vcc based on the output of the battery 142 and supplies it to each circuit unit. Note that the display unit 140 and the operation unit 141 in FIG. 2 may be omitted.

  Note that the concepts and processes described in FIGS. 5 to 24 are basically the same even if the mobile communication terminal according to the present embodiment is the mobile phone 130, and the description thereof is omitted because it is repeated. .

  An information processing system 1 according to the present embodiment includes an information processing apparatus (position calculation server 15) that manages a mobile communication terminal (PHS communication terminal 11 or mobile phone 130) and a position of the mobile communication terminal. In the system 1, the mobile communication terminal wirelessly communicates with the base station 12, measures the electric field strength of the radio signal received from the base station 12 with which the mobile communication terminal can communicate, and receives from the base station 12. Base station identification information for identifying a base station is detected from among the radio signals, and field strengths of radio signals received from a plurality of base stations 12 with which the mobile communication terminal can communicate, and base station identifications regarding the plurality of base stations 12 The information management device associates the information with the information management device and transmits the information to the information management device. An isoline generated by receiving, from the mobile communication terminal, the electric field strengths of the radio signals from the plurality of base stations 12 communicable with the mobile communication terminal and the base station identification information of the plurality of base stations 12 Among the maps, a plurality of isoline maps related to a plurality of base stations 12 identified by the base station identification information are superposed, and a plurality of communicable with a mobile communication terminal using the superposed isoline maps The intersection of each isoline based on the electric field strength of the radio signal from the base station 12 is extracted as a measurement point candidate, and the position of the mobile communication terminal is determined based on the extracted plurality of measurement point candidates. The position of the mobile communication terminal to be played can be stored. This makes it possible to measure the position of the mobile communication terminal with high accuracy regardless of the type and characteristics of the mobile communication terminal and the base station 12 and the change in the propagation characteristics of radio waves from the base station due to buildings and the like. The position of the mobile communication terminal can be specified with high accuracy using the electric field strength of the signal received from the fixed base station.

  The series of processes described in the embodiments of the present invention can be executed by software, but can also be executed by hardware.

  In the embodiment of the present invention, the steps of the flowchart show an example of processing that is performed in time series in the order described. However, even if they are not necessarily processed in time series, they are executed in parallel or individually. The processing to be performed is also included.

  DESCRIPTION OF SYMBOLS 1 ... Information processing system, 11 ... PHS communication terminal, 12 (12-1 thru | or 12-n) ... Base station, 13 ... PHS network, 14 ... PHS line control server, 15 ... Location calculation server, 16 ... Network, 17 ... Personal computer, 31 ... antenna, 32 ... radio transmission / reception unit, 33 ... signal processing unit, 34 ... RSSI measurement unit, 35 ... control unit, 36 ... storage unit, 37 ... display unit, 38 ... operation unit, 39 ... battery, 40 DESCRIPTION OF SYMBOLS ... Power supply circuit, 41 ... Clock circuit, 50 ... Control part, 51 ... CPU, 52 ... ROM, 53 ... RAM, 54 ... Bus, 55 ... Input / output interface, 56 ... Input part, 57 ... Output part, 58 ... Storage part , 59 ... communication unit, 60 ... drive, 61 ... magnetic disk, 62 ... optical disk, 63 ... magneto-optical disk, 64 ... semiconductor memory, 71 ... base station position database, 90 ... control 91 ... CPU, 92 ... ROM, 93 ... RAM, 94 ... bus, 95 ... input / output interface, 96 ... input unit, 97 ... output unit, 98 ... storage unit, 99 ... communication unit, 100 ... drive, 101 ... magnetic Disc 102, optical disc 103 ... magneto-optical disc 104 ... semiconductor memory 131 ... antenna 132 ... antenna duplexer (DUP) 133 ... reception circuit (RX) 134 ... frequency synthesizer (SYN) 135 ... transmission circuit (TX), 136: signal processing unit, 137: compression / decompression processing unit, 138 ... control unit, 139 ... storage unit, 140 ... display unit, 141 ... operation unit, 142 ... battery, 143 ... power supply circuit, 144 ... clock circuit 145 ... RSSI measurement part.

Claims (13)

In a position search method for an information processing system comprising a mobile communication terminal and an information management device for managing the position of the mobile communication terminal,
The mobile communication terminal is
Wireless communication with the base station or access point,
Measure the electric field strength of a radio signal received from a base station or access point with which the mobile communication terminal can communicate,
Detecting identification information identifying the base station or access point from the radio signal received from the base station or access point,
Associating the electric field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate with the identification information relating to the plurality of base stations or a plurality of access points, Control to send to the information management device,
The information management device includes:
Create an isoline map showing isolines of electric field strength for each base station or each access point connected to the mobile communication terminal,
Receive from the mobile communication terminal the field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points. And
Of the isoline maps, superimpose a plurality of isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information,
Using the plurality of isoline maps to be superimposed, the intersection of each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal is measured. Extracted as a candidate,
Among the plurality of extracted measurement point candidates , the position of the mobile communication terminal is determined using a measurement point candidate whose angle formed by isolines relating to the electric field strengths of two different base stations or access points is equal to or greater than a reference value. A position search method characterized by determining.   In a position search method for an information processing system comprising a mobile communication terminal and an information management device for managing the position of the mobile communication terminal,
  The mobile communication terminal is
  Wireless communication with the base station or access point,
  Measure the electric field strength of a radio signal received from a base station or access point with which the mobile communication terminal can communicate,
  Detecting identification information identifying the base station or access point from the radio signal received from the base station or access point,
  Associating the electric field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate with the identification information relating to the plurality of base stations or a plurality of access points, Control to send to the information management device,
  The information management device includes:
  Create an isoline map showing isolines of electric field strength for each base station or each access point connected to the mobile communication terminal,
  Receive from the mobile communication terminal the field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points. And
  Of the isoline maps, superimpose a plurality of isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information,
  Using the plurality of isoline maps to be superimposed, the intersection of each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal is measured. Extracted as a candidate,
  When a plurality of measurement point candidates to be extracted include a plurality of measurement point candidates whose angle formed by isolines relating to the electric field strengths of two different base stations or access points is equal to or greater than a reference value, they are within a predetermined distance from each other. A position search method, wherein the position of the mobile communication terminal is determined using two or more candidate measurement points that are close to each other. In an information processing system comprising a mobile communication terminal and an information management device that manages the position of the mobile communication terminal,
The mobile communication terminal is
Means for wireless communication with a base station or access point;
Measuring means for measuring electric field strength of a radio signal received from a base station or an access point with which the mobile communication terminal can communicate using the communication means;
Detecting means for detecting identification information for identifying the base station or access point from among radio signals received by the communication means from the base station or access point;
The field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate using the communication means, and the identification information relating to the plurality of base stations or a plurality of access points; And communication control means for controlling the communication means so as to transmit the information to the information management device.
The information management device includes:
An isoline map creating means for creating an isoline map indicating an isoline of the electric field strength relating to each base station or each access point connected to the mobile communication terminal;
Receive from the mobile communication terminal the field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points. Receiving means for
Superimposing means for superimposing a plurality of the isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information among the isoline maps created by the isoline map creating means. When,
Using the plurality of isoline maps superimposed by the superimposing means, each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal Extraction means for extracting the intersection as a measurement point candidate;
Of the plurality of measurement point candidates extracted by the extraction means, the mobile communication using a measurement point candidate whose angle formed by isolines relating to the electric field strengths of two different base stations or access points is a reference value or more A determination means for determining a position of the terminal;
An information processing system comprising storage means for storing the position of the mobile communication terminal determined by the determination means.   In an information processing system comprising a mobile communication terminal and an information management device that manages the position of the mobile communication terminal,
  The mobile communication terminal is
  Means for wireless communication with a base station or access point;
  Measuring means for measuring electric field strength of a radio signal received from a base station or an access point with which the mobile communication terminal can communicate using the communication means;
  Detecting means for detecting identification information for identifying the base station or access point from among radio signals received by the communication means from the base station or access point;
  The field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate using the communication means, and the identification information relating to the plurality of base stations or a plurality of access points; And a communication control means for controlling the communication means to transmit to the information management device in association with each other
With
  The information management device includes:
  An isoline map creating means for creating an isoline map indicating an isoline of the electric field strength relating to each base station or each access point connected to the mobile communication terminal;
  Receive from the mobile communication terminal the field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points. Receiving means for
  Superimposing means for superimposing a plurality of the isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information among the isoline maps created by the isoline map creating means. When,
  Using the plurality of isoline maps superimposed by the superimposing means, each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal Extraction means for extracting the intersection as a measurement point candidate;
  When the plurality of measurement point candidates extracted by the extraction means include a plurality of measurement point candidates whose angle formed by the isolines relating to the electric field strengths of two different base stations or access points is equal to or greater than a reference value, Determining means for determining the position of the mobile communication terminal using two or more candidate measurement points that are close to each other within a predetermined distance;
  An information processing system comprising storage means for storing the position of the mobile communication terminal determined by the determination means. The communication control means includes the electric field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate using the communication means at predetermined time intervals set in advance. , information according to claim 3 or 4, wherein the controller controls the communication unit to transmit in association with the identification information on said plurality of base stations or the plurality of access points to the information management device Processing system . The communication control means, in accordance with an acquisition request from the information management device, the electric field strength of radio signals received from a plurality of base stations or a plurality of access points with which the mobile communication terminal can communicate using the communication means. any one of claims 3 to 5, wherein the controller controls the communication unit to transmit in association with the identification information on said plurality of base stations or the plurality of access points to the information management device Information processing system according to item . An isoline map creating means for creating an isoline map indicating an isoline of the electric field intensity relating to each base station or each access point connected to the mobile communication terminal;
Receiving from the mobile communication terminal the electric field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points; Receiving means;
Superimposing means for superimposing a plurality of the isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information among the isoline maps created by the isoline map creating means. When,
Using the plurality of isoline maps superimposed by the superimposing means, each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal Extraction means for extracting the intersection as a measurement point candidate;
Of the plurality of measurement point candidates extracted by the extraction means, the mobile communication using a measurement point candidate whose angle formed by isolines relating to the electric field strengths of two different base stations or access points is a reference value or more A determination means for determining a position of the terminal;
An information management apparatus comprising storage means for storing the position of the mobile communication terminal determined by the determination means.   An isoline map creating means for creating an isoline map indicating an isoline of the electric field intensity relating to each base station or each access point connected to the mobile communication terminal;
  Receiving from the mobile communication terminal the electric field strength of radio signals from a plurality of base stations or access points capable of communicating with the mobile communication terminal and the identification information of the plurality of base stations or access points; Receiving means;
  Superimposing means for superimposing a plurality of the isoline maps related to the plurality of base stations or the plurality of access points identified by the identification information among the isoline maps created by the isoline map creating means. When,
  Using the plurality of isoline maps superimposed by the superimposing means, each isoline based on the electric field strength of radio signals from a plurality of base stations or a plurality of access points that can communicate with the mobile communication terminal Extraction means for extracting the intersection as a measurement point candidate;
  The plurality of measurement point candidates extracted by the extraction means include a plurality of measurement point candidates whose angle formed by the isolines relating to the electric field strengths of two different base stations or access points is equal to or greater than the reference value. Determining means for determining the position of the mobile communication terminal using two or more measurement point candidates close to each other within a predetermined distance;
  An information management apparatus comprising storage means for storing the position of the mobile communication terminal determined by the determination means. The determining means includes
  Among the plurality of measurement point candidates extracted by the extraction means, for two different base stations or access points existing within a predetermined interval, the angle formed by the contour lines regarding the electric field strength is greater than the reference value. Use measurement point candidates with a small predetermined angle or more,
  The information management device according to claim 7 or 8. The isoline map creating means creates the isoline map based on the electric field strength of a radio signal from a base station or access point measured at a plurality of measurement points indicated by latitude and longitude. The information management device according to any one of claims 7 to 9 . The said determination means determines the gravity center of the said some measurement point candidate extracted by the said extraction means as a position of the said mobile communication terminal, The one of Claim 7 thru | or 10 characterized by the above-mentioned. Information management device. 12. The transmission device according to claim 7 , further comprising a transmission unit configured to transmit the position of the mobile communication terminal stored in the storage unit to an information processing apparatus connected to the information management apparatus via a network . The information management apparatus according to any one of the above. The superimposing means is configured such that, among the plurality of base stations or the plurality of access points identified by the identification information, an electric field strength relating to a radio signal from the base station or the access point that can communicate with the mobile communication terminal is a reference value. The information management apparatus according to any one of claims 7 to 12, wherein the plurality of isoline maps relating to the base station or the access point are superimposed.

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