JP2008196896A - Location positioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem caused by stop of a power supply to be supplied to a receiving circuit when positioning is impossible or when it is not used so that a using time is elongated, in a conventional portable terminal for performing location positioning by utilizing GPS. <P>SOLUTION: This device is provided with a receivable satellite determination circuit 8 for determining the number of receiving circuits 4 to be operated, based on the number of receivable satellites and necessary location positioning accuracy among a plurality of receiving circuits 4, and stopping operation of each receiving circuit unnecessary to be operated among the plurality of receiving circuits. Hereby, operation of unnecessary receiving circuits is stopped even during location positioning, and power consumption during location positioning is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a position positioning device that measures a position using GPS (Global Positioning System) signals transmitted from a plurality of artificial satellites, and more particularly to a portable position positioning device using a battery as a power source.

  Currently, position positioning is performed using a position positioning system called GPS (Global Positioning System Global Positioning System). This system is configured by arranging a plurality of GPS satellites in an orbit at an altitude of about 20,000 km. GPS positioning determines the current position based on the distance from the orbit by measuring how long it takes for the radio wave emitted from the satellite to reach the receiving point. Two-dimensional positioning with a known altitude is possible by receiving radio waves from three GPS satellites. Further, by receiving four GPS satellites, it is possible to correct the error between the clock on the satellite side and the clock on the receiver side and execute more accurate positioning.

  As described above, since positioning using GPS requires receiving signals from a plurality of GPS satellites, the positioning device must be provided with a plurality of receiving circuits for receiving signals from GPS satellites. I must. In Patent Document 1, in order to reduce power consumption by the plurality of receiving circuits, when the reception state deteriorates or reception becomes impossible, power supply to all the receiving circuits is stopped as necessary. It was.

JP-A-11-352206

  By the way, since the conventional positioning device operates all receiving circuits when performing positioning, there is a problem that the usable time is shortened in a portable positioning device using a battery as a power source. is there. If the number of receiving circuits that receive satellite signals for positioning is reduced, it is possible to reduce power consumption during positioning. However, if the number of receiving circuits for position positioning is reduced, the number of satellites that can be received simultaneously decreases, which causes a problem that position positioning accuracy and positioning time deteriorate.

  The present invention has been made in order to solve the above-mentioned problems, and by stopping a part of the receiving circuit during position positioning and reducing power consumption during position positioning, the usage time of the portable position positioning device can be reduced. The purpose is to lengthen.

  The present invention uses a reception satellite signal including a satellite signal transmitted from at least one artificial satellite to receive a predetermined satellite signal from a predetermined artificial satellite specified by the identification code using an identification code unique to the artificial satellite. A receiving unit that separates from the signal, a positioning operation based on a predetermined satellite signal separated by the receiving unit, a position calculating unit that obtains a positioning result, and a reference clock input from the outside, A plurality of reference clock separating means to be distributed to each of the plurality of receiving means, and the number of receiving means to be operated is determined based on the number of receivable satellites or the required positioning accuracy among the plurality of receiving means. The control means for stopping the reception means that does not need to be operated among the plurality of reception means is provided.

  The present invention uses a reception satellite signal including a satellite signal transmitted from at least one artificial satellite to receive a predetermined satellite signal from a predetermined artificial satellite specified by the identification code using an identification code unique to the artificial satellite. A receiving unit that separates from the signal, a positioning operation based on a predetermined satellite signal separated by the receiving unit, a position calculating unit that obtains a positioning result, and a reference clock input from the outside, A plurality of reference clock separating means to be distributed to each of the plurality of receiving means, and the number of receiving means to be operated is determined based on the number of receivable satellites or the required positioning accuracy among the plurality of receiving means. The control means for stopping the reception means that does not need to be operated among the plurality of reception means is provided. It is possible to reduce the power consumption during positioning.

Embodiment 1 FIG.
FIG. 1 is a block diagram illustrating a received signal processing unit of the position measurement apparatus. In FIG. 1, a receiving antenna 1 receives a satellite signal such as a GPS signal transmitted from an artificial satellite. The received satellite signal received by the receiving antenna 1 is A / D converted by the RF block 2 and converted into sampling data 3. The receiving circuit 4 performs a correlation operation on the sampling data 3 with a C / A code (Clear and Acquisition or Coarse and Access), which is an identification code unique to the satellite, to obtain a predetermined value from the sampling data 3. The predetermined satellite signal from the artificial satellite is separated. The C / A code is pseudo-random data that differs for each artificial satellite. One receiving circuit 4 outputs a correlation calculation result 5 in which a signal of one artificial satellite is separated from a received satellite signal by performing a correlation operation on the satellite-specific C / A code and the sampling data 3. Therefore, in order to separate and extract the signals of a plurality of satellites from the received satellite signal, the position positioning device is provided with a plurality of receiving circuits 4 ₁ to 4 _N. The correlation calculation results 5 _{1 to} 5 _N calculated by the receiving circuits 4 ₁ to 4 _N are input to the central processing unit 6 which is position calculation means, and the position calculation is executed. Positioning data 7 which is a position positioning result obtained by the central processing unit 6 performing position calculation is stored in a storage device 7 such as a memory.

The flow of processing will be described with reference to the block diagram of FIG. Sampling data 3 is obtained by receiving satellite signals transmitted from a plurality of artificial satellites by the receiving antenna 1 and A / D converting the received satellite signals by the RF block 2. The reception circuits 4 ₁ to 4 _N perform correlation calculation between the C / A code and the sampling data 3 to obtain a correlation calculation result for separating a predetermined artificial satellite signal. In the correlation calculation results 5 _{1 to} 5 _N obtained by the receiving circuits 4 ₁ to 4 _N , a correlation peak is obtained at a point that matches the C / A code, and data is sent to the central processing unit 6 that performs position calculation. send. If the signal is attenuated due to a satellite that is not in the sky or a shield that cannot be received, a signal cannot be obtained by the correlation calculation in the receiving circuits 4 ₁ to 4 _N. Therefore, the C / A code for another satellite Calculate again using. When satellite signals can be received from the number of satellites necessary for position measurement, the central processing unit 6 calculates the position of the mobile terminal by calculating the distance between the satellite and the mobile terminal from the correlation calculation results 5 _{1 to} 5 _N. .

When the number of satellites that can be received by the positioning device is less than the number of receiving circuits 4 ₁ to 4 _{N that} the positioning device has, it is not necessary to operate all the receiving circuits for positioning, The receiving circuit 4 can be stopped. FIG. 2 is a block diagram showing a received signal processing unit of the position measurement apparatus according to Embodiment 1 of the present invention. In FIG. 2, the same reference numerals as those in FIG. The reception circuits 4 ₁ to 4 _N are assumed to be configured by circuits that can be controlled to operate and stop. Receivable satellite judging circuit 8, since the receiving circuit 4 ₁ to 4 _N number of satellites that can be received from the correlation calculation result 5 ₁ to 5 _N by is known, to calculate the number of reception circuits that need to be operated for positioning . Receivable satellite judging circuit 8, the results of calculating the number of receiver circuit that needs to operate for positioning, generates a reception circuit control signal 12 for controlling the operation and stoppage of the reception circuit 4 ₁ 4 _N, Output to the clock gate circuit 11. The clock gate circuit 11 separates the reference clock 9 input from the outside into reference clocks 10 ₁ to 10 _N for receiving circuits that are supplied for the receiving circuits 4 ₁ to 4 _N , respectively. The clock gate circuit 11 stops the supply of the reception circuit reference clock 10 to the reception circuit 4 to be stopped in response to the reception circuit control signal 12 from the receivable satellite determination circuit 8. Since the receiving circuit 4 to which the receiving circuit reference clock 10 is not supplied stops its operation, there is an effect that power consumption during the positioning is saved.

  As described above, the receivable satellite determination circuit 8 calculates the number of reception circuits that need to be operated for position measurement, and stops supplying the reference clock to the reception circuits that do not need to operate. This makes it possible to stop the operation of the receiver circuit and reduce the power consumption during positioning. In particular, mobile terminals that use dry batteries or rechargeable secondary batteries as power sources are limited in the power that can be supplied. There is an effect that it can be extended. Instead of stopping the reference clock to the reception circuit that does not require operation, the power supply may be separated for each reception circuit, and the power supply for the reception circuit that does not require operation may be stopped. The receivable satellite determination circuit 8 may be replaced with software processing by the central processing unit 6, and the generation of the reception circuit control signal 12 may be controlled by the central processing unit 6.

Embodiment 2.
The position positioning apparatus described in the first embodiment calculates the number of receiving circuits to be stopped during position positioning by calculating the number of receivable satellites. However, the number of receiving circuits to be stopped may be determined according to the required positioning accuracy, not the number of receivable satellites. FIG. 3 is a block diagram showing a received signal processing unit of the position measurement apparatus according to Embodiment 2 of the present invention. In FIG. 3, the same reference numerals as those in FIG. The resolution of the map to be displayed is known from the scale of the map displayed on the mobile terminal. Specifically, the required positioning accuracy is determined from the mobile terminal state information 13 indicating the state of the mobile terminal such as the scale of the map currently displayed on the mobile terminal. The central processing unit 6 calculates the number of satellites to be received in order to obtain the required positioning accuracy, and outputs the satellite information 14 to the reception circuit control signal generation circuit 15. The reception circuit control signal generation circuit 15 generates the reception circuit control signal 12 based on the satellite information 14, thereby stopping the reception circuit that does not require operation. When the map displayed by the mobile terminal is enlarged and higher positioning accuracy is required, the position is increased by supplying a reference clock or power to the receiving circuit to be newly operated in order to increase the number of satellites to be received. The accuracy of positioning can be increased.

Embodiment 3 FIG.
For example, in a situation where the mobile terminal is executing the navigation function, the position measurement result is displayed on the display unit. However, when the display unit is turned off, the user does not see the position positioning result of the display unit, so it can be determined that the necessity of performing the position positioning calculation is low. That is, the power consumption can be further reduced by stopping the receiving circuit 4 while the display unit of the portable terminal is turned off.

  By including information indicating whether the display unit is turned on / off in the mobile terminal state information 13 shown in FIG. 3, the central processing unit 6 can detect whether the display unit of the mobile terminal is turned off. When the display unit is turned off, the central processing unit 6 determines that positioning is not necessary, and outputs a control signal for stopping all the receiving circuits to the receiving circuit control signal generating circuit 15. On the other hand, when the user operates the mobile terminal, the display unit lights up, and when the positioning results are displayed on the display unit, the reference clock or power is supplied according to the number of receivable satellites, and the positioning calculation is resumed. Let

  As described above, when the display unit is turned off, the power consumption can be reduced by stopping the receiving circuit, and the central processing unit 6 itself does not perform the positioning calculation. Can be reduced. In the above description, the receiving circuit is stopped when the position positioning result is not displayed on the display unit. However, the position positioning result may be output from the speaker in the form of voice guidance. Therefore, the receiving circuit may be stopped by detecting that the speaker is turned off instead of turning off the display unit.

It is a block diagram which shows the received signal processing part of a position measuring apparatus. It is a block diagram which shows the received signal processing part of the positioning device which concerns on Embodiment 1 of this invention. It is a block diagram which shows the received signal processing part of the position positioning apparatus which concerns on Embodiment 2 of this invention.

Explanation of symbols

1 receiving antenna, 2 RF block, 3 A / D converted sampling data,
4 receiving circuit, 5 correlation calculation result, 6 central processing unit, 7 storage device,
8 Receivable satellite determination circuit, 9 reference clock, 10 reference clock for reception circuit,
11 clock gate circuit, 12 receiving circuit control signal, 13 mobile terminal status information,
14 Satellite information necessary for positioning, 15 Receiver circuit control signal generation circuit

Claims (5)

From a received satellite signal including a satellite signal transmitted from at least one artificial satellite, an identification code unique to the artificial satellite is used to obtain a predetermined satellite signal from a predetermined artificial satellite specified by the identification code from the received satellite signal. A receiving means for separating;
Position calculating means that performs position positioning calculation based on the predetermined satellite signal separated by the receiving means, and obtains a position positioning result;
A reference clock separating unit that separates a reference clock input from the outside and distributes the reference clock to each of the plurality of receiving units;
The number of receiving means to be operated is determined based on the number of receivable satellites or the required positioning accuracy among the plurality of receiving means, and reception that does not need to be operated among the plurality of receiving means. And a control means for stopping the means. 2. The position positioning apparatus according to claim 1, wherein the control means controls the reference clock separating means so as to stop the supply of the reference clock to the receiving means that does not need to be operated. 2. The position positioning apparatus according to claim 1, wherein the control unit performs control so as to stop the supply of power to the receiving unit that does not need to be operated. The control means determines the required positioning accuracy based on the scale of the map on which the position positioning result obtained by the position calculating means is displayed, operates the number of receiving circuits necessary to obtain this positioning accuracy, The position positioning device according to any one of claims 1 to 3, wherein control is performed to stop the reception circuit that does not require operation. The control means determines whether or not the position positioning result obtained by the position calculating means is displayed, and controls to stop the operating receiving means when the position positioning result is not displayed. The position positioning device according to any one of claims 1 to 4.

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