JP3925075B2 - Communication terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication terminal that notifies position information.
[0002]
[Prior art]
Conventionally, for example, when four or more GPS artificial satellites are observed in a mobile phone, position information corresponding to the satellite signal from each GPS artificial satellite is displayed on the display panel, while less than four GPS artificial satellites are displayed. Various types have been proposed in which position information corresponding to the satellite signal from each GPS satellite and the reference signal from the reference station is displayed on the display panel. In this manner, even when four or more GPS artificial satellites are not observed and position information cannot be obtained only by the satellite signals from the GPS artificial satellites, the reference signal from the reference station is added to the satellite signals from the GPS artificial satellites. By adopting a signal, position information can be obtained.
[0003]
[Problems to be solved by the invention]
By the way, in obtaining the position information, the distance between the mobile phone and the GPS artificial satellite is calculated according to the satellite signal, and the distance between the mobile phone and the reference station is calculated according to the reference signal. For this reason, when the reference signal or the satellite signal is reflected by the reflector and reaches the mobile phone, the calculation accuracy of the distance, and hence the accuracy of the position information, deteriorates.
[0004]
Here, since the reference station is installed on the ground, the reference signal from the reference station is not reflected by a reflecting object (for example, a building) as compared with a satellite signal from a GPS artificial satellite, and directly is a mobile phone. The probability of reaching For this reason, in the mobile phone described above, the accuracy of the position information deteriorates as the number of reference signals used in the reference station increases. Therefore, although the accuracy of the position information varies depending on the number of observations of the GPS artificial satellite, there is a problem that the user cannot grasp the accuracy of the position information.
[0005]
An object of this invention is to provide the communication terminal which notifies a user of the precision of the positional information with positional information in view of the said point.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a satellite receiving means (120) for receiving a satellite signal from each artificial satellite (30) and each reference station (20) are provided. ) For receiving a reference signal from each of them, and transmitting the received satellite signal and the reference signal to the outside and observing the received satellite signal according to the transmitted satellite signal. The number of observations of the artificial satellite is obtained, and when the number of observations is a predetermined number or more, the position information of the communication terminal is obtained only according to the transmitted satellite signal, while the number of observations of the artificial satellite is less than the predetermined number when the can to obtain the location information of the communication terminal the transmitted satellite signal and by said transmitted reference signal, the information about the accuracy of the obtained positional information and the position information from the external A signal to means (140, 150), and a display unit that performs display (14), control means for the received location information to control the display unit so as to display on the map information (180), the receiving And accuracy notification means (170) for notifying the accuracy of the position information set based on the information regarding the accuracy of the position information . Thereby, the accuracy of the position information can be notified to the user by the accuracy notification means. Specifically, as in the invention described in claim 2, the accuracy notification means controls the display unit to display the accuracy of the position information so that the display unit displays the accuracy of the position information. May be. Further, as in the invention described in claim 3, it has a colored light generating section (19) for generating colored light, and the accuracy notification means is colored so as to notify the user of the accuracy of the position information by the colored light. By controlling the light generation unit, the accuracy of the position information may be notified to the user by the colored light of the colored light generation unit.
[0007]
Further, the accuracy of the position information may be set according to the number of observations of the artificial satellite as in the invention described in claim 4 . Here, as described above, when the number of observable artificial satellites is equal to or larger than a predetermined number, the position information is determined according to the number of observations of the artificial satellites in order to obtain the positional information only in accordance with the satellite signals. As a result, it is possible to obtain highly accurate position information.
[0008]
Furthermore, as in the invention of claim 5, the accuracy of the position information may also be set according to both the number of observations observations number and the reference station for the satellite. Here, when the number of observations of the artificial satellite is less than the predetermined number, the position information is obtained from the satellite signal and the reference signal received by the reference receiving means. By setting according to both the number, it is possible to obtain more accurate position information.
[0009]
Here, in obtaining the position information, the satellite signal from the artificial satellite is more reliable than when the reference signal from the reference station is adopted. Therefore, as in the invention according to claim 6 , the position information The accuracy is set such that the number of observations of the artificial satellite is larger than the number of observations of the reference station, so that highly accurate accuracy in the position information can be notified.
[0011]
Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of a positioning system for a mobile phone according to the present invention. FIG. 1 is a diagram showing a schematic configuration of a mobile phone positioning system. As shown in FIG. 1, the mobile phone positioning system includes a mobile phone with GPS function 10, a plurality of reference stations 20, and a plurality of GPS artificial satellites 30. A mobile phone with a GPS function (hereinafter referred to as a mobile phone 10) includes an antenna 11, a radio unit 12, a data storage unit 13, a GPS antenna 14, a GPS receiver 15, a display 16, a control unit 17, and a key operation unit 18. , And an incoming call lamp 19.
[0013]
The antenna 11 receives each of the reference signal and the position information signal from the reference station 20 as radio waves and outputs each of the reference signal and the position information signal to the radio unit 13, while the request signal in the position information signal is transmitted as a radio wave medium. Send as. The radio unit 12 is controlled by the control unit 17 to output a request signal in the position information signal from the antenna 11 and receive each of the reference signal and the position information signal from the antenna 11. The data storage unit (memory) 13 holds a computer program, arrangement data of each GPS satellite 30, and an accuracy determination table described later.
[0014]
The GPS antenna 14 receives satellite signals from each of the GPS artificial satellites 30 using radio waves as a medium, and the GPS receiver 15 receives each satellite signal received by the GPS antenna 14. The display (for example, a liquid crystal panel) 16 is controlled by the control unit 17 to display position information and position error information. The control unit 17 includes a microcomputer or the like, and performs various processes during execution of the computer program. Do. However, in the mobile phone 10, the configuration for wireless communication and the description thereof are omitted.
[0015]
Each of the plurality of reference stations 20 includes an antenna 21, a radio unit 22, a GPS antenna 23, a GPS receiver 24, and a control unit 25. The antenna 21 transmits a reference signal using radio waves as a medium, and the wireless unit 22 is controlled by the control unit 25 to output the reference signal to the antenna 21 at regular intervals. However, the reference signal includes an identification code for each reference station 30.
[0016]
The GPS antenna 23 receives satellite signals from each of the GPS artificial satellites 30 using radio waves as media, and the GPS receiver 24 is controlled by the control unit 25 to receive each satellite signal received by the GPS antenna 23. To do. The control unit 25 performs various processes during execution of the computer program. However, as the plurality of reference stations 20, substantially the same one is employed, and only two reference stations are shown in FIG.
[0017]
Further, each GPS artificial satellite 30 periodically rotates around the earth in a predetermined orbit and transmits satellite signals using radio waves as a medium. However, each satellite signal includes an identification code. Further, substantially the same GPS satellites 30 are employed for each of the plurality of GPS artificial satellites 30. In FIG. 1, only three GPS artificial satellites are shown as the GPS artificial satellites 30.
[0018]
Hereinafter, the operation of the present embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing the operation of the control unit 17 of the mobile phone 10 and the control unit 25 of the reference station 20. The control unit 17 of the mobile phone 10 and the control unit 25 of one reference station 20 perform processing according to the flowchart shown in FIG. However, as the reference station 20, the one that can obtain the largest received power from the mobile phone 10 among the plurality of reference stations 20 is selected. Hereinafter, the reference station 20 is referred to as a selected reference station 20.
[0019]
First, when a predetermined operation of the key operation unit 18 (for example, pressing of the function “F” and the numeric keypad “1”) is performed on the mobile phone 10, the control unit 17 performs a request signal transmission process (step 100). ). Thereby, the wireless unit 12 is controlled by the control unit 17 to cause the antenna 11 to transmit a request signal.
[0020]
Next, in the selection reference station 20, when the antenna 21 receives a request signal using radio waves as a medium, the antenna 21 outputs the request signal to the radio unit 22. When the control unit 25 receives the request signal at the wireless unit 22, the control unit 25 performs observation processing of the GPS artificial satellite 30 (step 200). That is, each identification code of each satellite signal received by the GPS receiver 24 is decoded.
[0021]
As a result, the observed GPS satellites 30 can be identified in the selection reference station 20. That is, the number of observations of each GPS satellite (hereinafter referred to as observation number K) at the selection reference station 20 is obtained. And the control part 25 performs the transmission process of each identification code (step 210). For this reason, the radio | wireless part 22 is controlled by the control part 25, and makes the antenna 21 transmit the identification signal which shows each identification code.
[0022]
Next, in the mobile phone 10, when the antenna 11 receives an identification signal using radio waves as a medium, the identification signal is output from the antenna 11 to the control unit 17 through the wireless unit 12 (step 110). Then, the control unit 17 performs reception processing of satellite signals from each of the GPS artificial satellites 30 (hereinafter referred to as observation GPS artificial satellites 30) observed by the selection reference station 20 based on the identification signal (step 120). . Accordingly, the control unit 17 receives the satellite signal from the observation GPS artificial satellite 30 through the GPS receiver 15 through the GPS antenna 16. That is, the control unit 17 selects each GPS artificial satellite 30 based on a command from the selection reference station 20, and receives a satellite signal from each selected GPS artificial satellite 30.
[0023]
Next, in the mobile phone 10, the control unit 17 performs a process of receiving a reference signal from each of the plurality of reference stations 20 (step 130). That is, the control unit 17 receives each reference signal through the antenna 11 and the radio unit 12. However, the plurality of reference stations 20 are not limited to the selected reference station 20 and mean a plurality of reference stations including other reference stations 20. Then, a process for transmitting a measurement signal indicating the respective reference signal and the satellite signal (step 140). That is, the wireless unit 12 is controlled by the control unit 17 to transmit the measurement signal from the antenna 11 using radio waves as a medium.
[0024]
Next, in the selection reference station 20, when the control unit 25 receives the measurement signal through the antenna 21 via the radio unit 22 (step 220), the control unit 25 recognizes each identification data of each satellite signal based on the measurement signal. Decipher. Thereby, the number of observations of the GPS artificial satellite of the mobile phone 10 (hereinafter referred to as observation number D) is obtained. However, since the mobile phone 10 and the reference station 20 have different satellite signal reception environments, the number of observations D of the mobile phone 10 and the number of observations K of the reference station 20 do not necessarily match, and the number of observations D is the number of observations K. It may be smaller than Thereafter, the control unit 25 decodes each identification data of each reference signal based on the measurement signal. Thereby, the number of reference stations 20 of the mobile phone 10 (hereinafter referred to as reference station number S) is obtained.
[0025]
Next, in the selected reference station 20, the control unit 25 decodes each phase data of each satellite signal based on the measurement signal, and also decodes each phase data of each reference signal based on the measurement signal. Then, the position information (latitude, longitude, altitude) is obtained by positioning the current location of the mobile phone 10 as described below (step 230).
[0026]
That is, {circle over (1)}: When the number of observations D is “4” or more (D ≧ 4), the current location is measured based on the phase data of each satellite signal of each GPS satellite. (2): When the number of observations D is “3” and the number of reference stations S is equal to or greater than “1” (D = 3, S ≧ 1), one reference signal having a large received power is selected from each reference signal. The current position is determined from the phase data of the one reference signal and the phase data of the satellite signals of each of the three GPS satellites.
[0027]
(3): When the number of observations D is “3” and the reference station number S is “0” (D = 3, S = 0), from the phase data of each satellite signal of each of the three GPS satellites Performs positioning processing for the current location. (4): When the number of observations D is “2” and the number of reference stations S is “2” or more (D = 2, S ≧ 2), two reference signals with large received power are selected from the reference signals. The current location is determined from the phase data of these two reference signals and the phase data of each satellite signal of each of the two GPS satellites.
[0028]
Further, (5): When the number of observations D is “2” and the number of reference stations S is “1” (D = 2, S = 1), one reference signal having a large received power is selected from each reference signal. Thus, the positioning process of the current location is performed from the phase data of this one reference signal and the phase data of each satellite signal of each of the two GPS artificial satellites. (6): When the number of observations D is “0” and the number of reference stations S is “4” or more (D = 0, S ≧ 4), four reference signals with large received power are selected from the reference signals. Then, the positioning processing of the current location is performed from the phase data of these four reference signals. {Circle around (7)} When the number of observations D is “0” and the number of reference stations S is “3” (D = 0, S = 3), the current location is determined from the phase data of the three reference signals. As described in (2) to (7) above, in order to perform the positioning process only for the satellite signal from the observation GPS artificial satellite 30, when the observation number D is insufficient, the satellite signal is appropriately set as a reference signal. To compensate and perform the positioning process.
[0029]
Next, the control unit 25 of the reference station 20 searches for map information (hereinafter referred to as search map information) corresponding to the position information (longitude, latitude, and altitude) based on the map database 270 (step 240). And the process which transmits the reply signal which has search map information, position information, the observation number D, the observation number K, the reference station number S, each identification data in each reference station 20, and each identification data in the mobile telephone 10 is performed ( Step 260). Thereby, the radio | wireless part 22 transmits a positioning signal from the antenna 21 by using electromagnetic waves as a medium. However, each identification data at the reference station 20 is identification data of each satellite signal received by the reference station 20, and each identification data at the mobile phone 10 is identification data of the satellite signal received by the mobile phone 10.
[0030]
Next, when the control unit 17 of the mobile phone 10 receives a reply signal through the antenna 11 through the wireless unit 12 (step 150), the accuracy of the position information is obtained according to the number of observations D and the number of reference stations S in the reply signal. (Step 160). Here, the observation number D is the sum of the direct observation number Da that can directly observe the GPS artificial satellite 30 for the mobile phone 10 and the indirect observation number Db that can indirectly observe the GPS artificial satellite 30 for the mobile phone 10. (D = Da + Db).
[0031]
However, as shown in FIG. 3, the direct observation number Da means that there are no buildings or the like around the mobile phone 10, as shown by arrows 301 to 306, from each of the six GPS satellites 30. When satellite signals are directly received, the number of the six GPS artificial satellites 30 is referred to as a direct observation number Da. Hereinafter, as the GPS artificial satellite 30, a satellite signal whose satellite signal is directly received by the mobile phone 10 without being reflected by a building or the like is referred to as a direct GPS artificial satellite.
[0032]
On the other hand, as shown in FIG. 4, the mobile phone 10 exists between the two buildings 400 and 401, and as indicated by an arrow 311, the satellite signal from the GPS artificial satellite 30 is reflected by the building 401 to the mobile phone 10. When received, the number of the GPS artificial satellites 30 is referred to as an indirect observation number Db. Hereinafter, the GPS satellite 30 that is received by the mobile phone 10 after the satellite signal is reflected by a building or the like is referred to as a reflected GPS satellite.
[0033]
Here, in obtaining the position information by the positioning process, when the satellite signal from the reflective GPS artificial satellite is adopted, the reliability is lower than when the satellite signal from the direct GPS artificial satellite is adopted. Therefore, when the satellite signal from the reflective GPS artificial satellite is adopted in obtaining the position information, the calculated position and the actual position are different as the position information of the mobile phone 10. Therefore, the control unit 17 of the mobile phone 10 determines whether the satellite signal is a signal from a reflected GPS artificial satellite or a signal from a direct GPS artificial satellite. This determination will be described with reference to FIGS.
[0034]
FIG. 5 shows an example in which the mobile phone 10 exists in the space portion of the U-shaped building 402 and six GPS artificial satellites 30 exist. In FIG. 5, the mobile phone 10 directly receives satellite signals from each of the two GPS artificial satellites 30 as indicated by arrows 321 and 322, but the satellite signal from the GPS artificial satellite 30 is indicated by an arrow 325. Is reflected by the building 402 and received by the mobile phone 10. As indicated by arrows 323324, 326, and 327, satellite signals from each of the four GPS artificial satellites 30 are reflected by the building 402 and have not reached the mobile phone 10. Hereinafter, the GPS artificial satellite 30 in which the satellite signal has not reached the mobile phone 10 is referred to as an unobservable GPS artificial satellite.
[0035]
Here, in the mobile phone 10, since the data storage unit 13 holds the arrangement data of each GPS satellite 30 as described above, the control unit 25 performs the arrangement data, the identification data of the reference station 20, And the arrangement | positioning relationship of the six GPS artificial satellites 30 on the basis of mobile phone 10 itself is calculated | required based on each identification data of the mobile phone 10. FIG. FIG. 6 shows an example in which two GPS artificial satellites 30 (# 1, # 3) are unobservable GPS artificial satellites and one GPS artificial satellite 30 (# 2) is an observable GPS artificial satellite. In this case, since there are two unobservable GPS artificial satellites (# 1, # 3) on both sides of the GPS artificial satellite 30 (# 2), the GPS artificial satellite 30 (# 2) itself directly transmits a satellite signal. Instead, it is determined that the satellite signal is received by the mobile phone 10 after being reflected by a building or the like.
[0036]
Specifically, the angle α formed by the unobservable GPS artificial satellite (# 1) and the observable GPS artificial satellite (# 2) centered on the mobile phone 10 is equal to or less than a predetermined angle θ, and the unobservable GPS artificial satellite When the angle β formed by (# 3) and the observable GPS artificial satellite (# 2) is equal to or smaller than the predetermined angle θ, the observable GPS artificial satellite is determined as a reflective GPS artificial satellite.
[0037]
Here, in obtaining the position information, it is assumed that the satellite signal from the reflective GPS artificial satellite and the reference signal from the reference station 20 have the same reliability. Then, the control unit 17 of the mobile phone 10 uses the sum of the indirect observation number Db and the reference station number S (hereinafter referred to as the determination reference station number DS) and the direct observation number Da in FIG. The accuracy of the position information is obtained with reference to the accuracy determination table shown.
[0038]
The accuracy determination table shown in FIG. 7A is set so that the accuracy of the position information is improved as the direct observation number Da is increased, and the accuracy of the position information is increased as the determination reference station number DS is increased. Set to degrade. That is, in the accuracy determination table shown in FIG. 7A, the accuracy of the position information is set so that the direct observation number Da has a greater specific gravity than the determination reference station number DS (Db + S). For example, as shown in FIG. 5, the number of observations Da = 2 (see arrows 321 and 322) and the number of determination reference stations DS (= number of indirect observations Db) = 1 (see arrow 325). In the example shown in FIG. 8, the number of observations Da = 4 (see arrows 331 to 334).
[0039]
Next, the control unit 17 of the mobile phone 10 displays the accuracy of the position information set as described above on the display 16 together with the position information and the map information (Steps 170 and 180). As shown in FIGS. 9A to 9D, the display 16 displays position information with black dots 16b on a rectangular map image 16a, and the accuracy of the position information is determined on the side of the map image 16a. It is displayed in a line. As an indication of the accuracy of the position information, the linear colored light emitting portion 16d becomes longer as the accuracy increases. 9A is a display of accuracy “5”, FIG. 9B is a display of accuracy “2”, FIG. 9C is a display of accuracy “7”, and FIG. 9D is a display of accuracy. “0” is displayed.
[0040]
The features of the embodiment will be described below. In the mobile phone 10, the accuracy of the position information is displayed on the display 16 together with the position information and the map information. Therefore, the accuracy of the position information can be notified together with the position information. And since the accuracy of position information, map information, and position information is displayed on the same indicator 16, it is not necessary to employ a new member for notifying the accuracy of position information.
[0041]
Here, when the position information is obtained using both the satellite signal from the GPS artificial satellite 30 and the reference signal from the reference station 20, when the satellite signal from the GPS artificial satellite 30 is adopted, the reference signal from the reference station 20 is used. The reliability is higher than when it is adopted, and further, when the satellite signal from the observable GPS artificial satellite is adopted, the reliability is higher than when the satellite signal from the reflective GPS artificial satellite is adopted. Therefore, in the accuracy determination table, the accuracy of the position information is set so that the direct observation number Da has a greater specific gravity than the determination reference station number DS (Db + S). Since accuracy is required using such an accuracy determination table, it is possible to notify highly reliable accuracy.
[0042]
Note that the practice of the present invention is not limited to the precise determination table shown in FIG. 7 (a), may be employed precision determination table shown in FIG. 7 (b). In precision determination table shown in FIG. 7 (b), as the accuracy of the position information, only the number of observations D, and determines the accuracy of the position information.
[0043]
Furthermore, in the implementation of the present invention, the notification of the positional information accuracy is not limited to the case where the display 16 is employed, but an incoming call lamp 19 may be employed as shown in FIGS. 10 (a) to 10 (e). . In this case, the incoming lamp 19 is a two-color light emitting diode of red light and green light. The accuracy “4” indicates that the incoming lamp 19 emits green light as shown in FIG. To do. For accuracy “3”, as shown in FIG. 10B, the incoming light 19 blinks green light. For accuracy “2”, as shown in FIG. 10C, green light and red light are alternately lit as the incoming lamp 19. The accuracy “1” indicates that the incoming light 19 blinks red light as shown in FIG. With accuracy “0”, red light is lit as the incoming call lamp 19 as shown in FIG.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a positioning system for a mobile phone according to the present invention.
2 is a flowchart showing operations of the mobile phone and the reference station shown in FIG.
FIG. 3 is a diagram showing an arrangement of GPS artificial satellites and mobile phones for obtaining accuracy of position information.
FIG. 4 is a diagram showing an example in which a satellite signal from a GPS artificial satellite is reflected by a building and received by a mobile phone.
FIG. 5 is a diagram showing an example of an arrangement of each GPS artificial satellite and a mobile phone.
FIG. 6 is a diagram for explaining determination of a GPS artificial satellite that is indirectly observed.
FIGS. 7A and 7B are tables showing an accuracy determination table for determining the accuracy of position information. FIGS.
FIG. 8 is a diagram showing an example of an arrangement of each GPS artificial satellite and a mobile phone.
FIG. 9 is a diagram showing an example of displaying position information on a map image 16a and displaying the accuracy of position information on the display device 16;
FIG. 10 is a diagram illustrating an example in which the accuracy of position information is notified by an incoming call lamp.
[Explanation of symbols]
16 ... Display, 16a ... Map image, 16b ... Black spot (longitude, latitude),
16d: colored light emitting part.

Claims (6)

Satellite receiving means (120) for receiving satellite signals from each of the artificial satellites (30);
Reference receiving means (130) for receiving a reference signal from each of the reference stations (20);
Transmitting the received satellite signal and the reference signal to the outside, and obtaining the number of observations of the artificial satellite that can be observed according to the transmitted satellite signal outside, and when the number of observations is a predetermined number or more, the one for obtaining positional information of the communication terminal in response only to the transmitted satellite signals, the when the number of observations satellites is less than the predetermined number, the communication the transmitted satellite signal and by said transmitted reference signal Means (140, 150) for obtaining the position information of the terminal, and receiving the obtained position information and information on the accuracy of the position information from the outside;
A display unit (14) for performing display;
Control means (180) for controlling the display unit to display the received position information on map information;
A communication terminal comprising: an accuracy notifying unit (170) for notifying the accuracy of the position information set based on information on the accuracy of the received position information .   The communication terminal according to claim 1, wherein the accuracy notifying unit controls the display unit to display the accuracy of the position information. A colored light generating part (19) for generating colored light;
The communication terminal according to claim 1, wherein the accuracy notifying unit controls the colored light generating unit so as to notify the accuracy of the position information by the colored light. The information regarding the accuracy of the position information includes the number of observations of the artificial satellite, and the accuracy of the position information is set according to the number of observations of the artificial satellite. 4. The communication terminal according to any one of 3. The number of observations of the reference station that can be observed in accordance with the transmitted reference signal is obtained outside, and the information on the accuracy of the position information includes the number of observations of the reference station in addition to the number of observations of the artificial satellite a is the accuracy of the position information, the communication terminal according to claim 4, characterized in that it is set according to both the number of observations observations number and the reference station of the satellite.   The communication terminal according to claim 5, wherein the accuracy of the position information is set such that the number of observations of the artificial satellite is greater than the number of observations of the reference station.

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