JPH06265623A - Satellite navigation receiver - Google Patents

Abstract

PURPOSE:To prevent the occurrence of positioning errors to be caused by the individual difference of the internal delay amount of each receiving circuit and the changes in temperature and frequency of the circuit. CONSTITUTION:The carrier wave having the same frequency as each satellite is generated by a carrier-wave oscillator 26. Meanwhile, the same PN code as each satellite is generated with a code generator 28. A modulating part 30 performs the phase modulation for the output of the carrier wave oscillator 26 based on the output of the code generator 28. The result is supplied into a switch 14 as the reference signal. A delay-amount measuring and controling part 32 imparts the switching signal into the switch 14 and inputs the signal into a receiving circuit 10. The phase of the reference signal, which is internally delayed in the receiving circuit 10, is compared with the output phase of the code generator 28 in a delay-amount measuring part 24. The internal delay amount of each receiving circuit 10 is measured. A positioning computing part 23 selects and uses the delay amount in correspondence with the satellite and channel in reception, and the receiving time used in the positioning computation is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, GLONASS.
And the like, and particularly to a signal delay correction device in the receiver thereof.

[0002]

2. Description of the Related Art Conventionally, satellite navigation systems such as GPS and GLONASS have been operated and tried. All of these systems receive signals from artificial satellites that have been launched into the orbit around the earth by a predetermined number (target: 24), and the pseudo range between the satellite and the user (receiver) and the position of the satellite. Is a system for measuring (positioning) the current position of the user based on the above. The satellites that make up these systems transmit predetermined navigation data to a receiver mounted on a moving body on the earth, and the receiver receives and demodulates this to transmit the time and position of the satellite signal. Ask for. The signal transmitted from the satellite is phase-modulated by a pseudo noise (PN) signal, and the receiver obtains the reception time of the signal from the satellite by capturing the PN signal and obtaining the phase thereof. The receiver subtracts the transmission time from the obtained reception time, thereby obtaining the radio wave propagation time from the satellite to the receiver, and multiplying this time by the speed of light,
Find the distance between the satellite and the receiver. However, since the receiver clock has an error with respect to the satellite clock that is synchronized with the system clock, the calculated distance includes an error. If the distance including such an error, that is, the pseudorange and the above-mentioned satellite position are obtained for a predetermined number of satellites (4 in the case of three-dimensional positioning, and three in the case of two-dimensional positioning). The receiver's current position can be calculated by the receiver. That is, by substituting the obtained pseudorange and satellite position and the user's initial position or previous position into the simultaneous equations showing the relationship between the current position of the user and the clock error and the pseudorange, the present position and the clock error are solved. As a result, the current position of the user can be obtained.

Both GPS in the United States and GLONASS in CIS (former Soviet Union) are systems for performing positioning based on such a principle. But,
The design of each system is different. For example, GP
In S, the frequency of the carrier wave of the signal transmitted from the satellite is the same for all satellites, but GLONA
In SS, they are different from each other by 562.5 kHz. Therefore, the design of the receiver that receives and demodulates the signal from the satellite must also be changed accordingly.
That is, in the GPS in which the frequencies of the carrier waves of the signals from the respective satellites are the same, only one reception circuit is required to receive and down-convert the signals transmitted from the GPS satellites. On the other hand, in the GLONASS in which the frequencies of the carrier waves of the signals from the respective satellites are different, it is necessary to provide at least the number of satellites required for the positioning calculation to receive the signals from the GLONASS satellites and down-convert them.

Due to such a difference, GLONAS
The S receiver has a problem that does not occur in the GPS receiver. Generally, various filters are used in the receiving circuit. Since the filter has a group delay characteristic, this group delay acts as an internal delay of the receiving circuit. A demodulation unit is provided at the subsequent stage of the reception circuit, and the reception time of the signal from each satellite is obtained by this demodulation unit. The reception time of this signal is delayed by the internal delay of the receiving circuit in the previous stage. In a receiver such as a GPS receiver that uses a common receiving circuit for each satellite, the reception time obtained by the demodulation unit in the subsequent stage is a time delayed by the same amount for all satellites, so that an error may occur. There is no problem. On the other hand, in the case of a receiver such as a GLONASS receiver that uses a different receiving circuit for each satellite, the reception times obtained by the corresponding demodulating units are tens of nanoseconds from each other due to individual differences in the receiving circuits. The reception time is delayed by a different amount. If the reception time is different for each satellite in this way, an error will occur in the positioning calculation executed using this reception time.

The internal delay amount of the receiving circuit generally differs depending on individual differences among the receiving circuits, and also changes depending on the frequency and temperature of the received signal. That is, even if the same receiving circuit receives signals from different GLONASS satellites, the amount of internal delay differs. Further, even when signals from the same satellite are received by the same receiving circuit, if the temperature changes, the internal delay amount changes.
It is known that the change in the internal delay amount of the receiving circuit due to the frequency and temperature of the received signal is about several tens of nsec at the maximum.

In order to perform the positioning calculation more accurately in the GLONASS receiver, it is necessary to take measures against such an internal delay amount of the receiving circuit. For example, “Digital Ho
pping GPS / GLONASS Receiver ”, James Danaher and Ro
nald R. Geriach, ProceedingS of ION GPS-91, Fourth
International Technical Meeting of the Satellite
The Division of The Institute of Navigation, pp. 69 to 76, shows an example of a countermeasure against changes in the internal delay amount of the receiving circuit due to the received signal frequency and temperature. In this document, precise filter design is carried out so that the group delay amount does not change with the frequency of the received signal, and the phase characteristics of the various filters forming the receiving circuit are flat with respect to the frequency. Further, this document discloses a method of executing temperature control of a receiving circuit so that the internal delay amount does not depend on temperature. Therefore, by using the method disclosed in this document, it is possible to take measures against the frequency dependence and temperature dependence of the internal delay amount of the receiving circuit.

[0007]

However, even if such a filter characteristic design and temperature control are performed, the difference in the internal delay amount due to the individual difference of the plurality of receiving circuits still remains. Further, in order to make the phase characteristic of the filter that constitutes the receiving circuit flat with respect to the frequency, it is necessary to precisely design the filter, which limits the degree of freedom in development design. However, the cost of development and design increases significantly. Further, when the temperature of the receiving circuit is to be controlled, it is necessary to provide a structure for insulating the receiving circuit from the surroundings, a heater for heating the receiving circuit, a means for controlling the heater, and the like. Bloat will occur.

The present invention has been made to solve the above problems, and prevents the occurrence of positioning errors due to individual differences in the internal delay amount of a plurality of receiving circuits used. At the same time, it is an object of the present invention to eliminate the influence of the change of the internal delay amount due to the frequency and the temperature without performing the precise design of the filter characteristic and the temperature control of the receiving circuit.

[0009]

In order to achieve such an object, the satellite navigation receiver of the present invention is provided with at least the number of satellites required for positioning calculation (for example, four) or more, and each has an internal delay. Satellite navigation system (eg GL
ONASS), which receives a phase-modulated signal from any of a plurality of satellites that phase-modulate carriers of different frequencies, and demodulates the satellite orbit information from the signal received by the corresponding receiving circuit. A plurality of demodulation units for obtaining the phase of the signal, a reference signal generating means for generating a reference signal relating to the same carrier and the same modulation content as the signal transmitted from each satellite, and a signal from the satellite for each receiving circuit Instead, the switching means for switching and supplying the reference signal at a predetermined timing, and the phase of the reference signal at the time of supply to each receiving circuit and the demodulating section in the state where the reference signal is supplied to each receiving circuit by the switching means By comparing the phase of the reference signal after passing through the received circuit,
The delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite, and the transmission time of the signal from the satellite based on the orbit information of each satellite, and the internal delay of the receiving circuit from the phase obtained by each demodulation unit. , The reception time of the signal containing
Of the internal delay amount measured by the delay amount measuring means, the reception time is corrected using the values corresponding to the satellite and the receiving circuit related to the reception, and the predetermined positioning calculation is performed based on the calculated transmission time and the corrected reception time. And a positioning calculation unit that obtains the current position of the user by performing the calculation.

In the satellite navigation receiver according to claim 2 of the present invention, the command means for causing the switching means to perform switching in response to a command from the user and supplying the reference signal to each receiving circuit for a predetermined time. It is characterized by including.

Further, the satellite navigation receiver according to claim 3 of the present invention comprises a time division control means for controlling switching by the switching means so that the reference signal is supplied to each reception circuit in a time division manner. Characterize.

According to a fourth aspect of the present invention, the satellite navigation receiver is characterized in that the time-division control means executes the time-division supply every predetermined time when it can be considered that the temperature of the receiving circuit changes.

The signal delay correction apparatus according to the present invention is a reference for generating a reference signal for a carrier having the same frequency as a signal transmitted from a plurality of satellites constituting a satellite navigation system (for example, GLONASS) and the same modulation content. The signal generating means, the switching means for switching the signal from the satellite to the plurality of receiving circuits each having an internal delay and switching the signal from the satellite at a predetermined timing, and the reference signal is supplied to each receiving circuit by the switching means. In this state, by comparing the phase at the time of supply to each receiving circuit with the phase of the reference signal output from each receiving circuit, the delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite. A reception time correction means for correcting the reception time using a value corresponding to the satellite and the receiving circuit related to the reception among the measured internal delay amounts. To.

[0014]

The operation of the satellite navigation receiver of the present invention is different depending on whether a signal from the satellite is supplied to each receiving circuit or a reference signal. First,
When the reference signal relating to the carrier having the same frequency as the signal transmitted from each satellite and the same modulation content is generated by the reference signal generating means and the reference signal is supplied to each receiving circuit by the switching means, the delay amount is measured. An internal delay amount measurement by means is performed. That is, the reference signal supplied to each receiving circuit undergoes an internal delay in the receiving circuit, and the phase of the reference signal subjected to the internal delay is obtained by the corresponding demodulator. The delay amount measuring means measures the internal delay amount of each receiving circuit for each satellite by comparing the phase of the reference signal thus subjected to the internal delay with the phase when it is supplied to each receiving circuit.

Next, in the state where the signal from the satellite is supplied to each receiving circuit by the operation of the switching means, the signal from each satellite is supplied to the corresponding demodulating section after undergoing an internal delay in the receiving circuit. Then, the phase is obtained in the demodulation section, and the orbit information of the satellite is demodulated from the signal. In the positioning calculation means, the transmission time of the signal from the satellite based on the orbit information demodulated by the demodulator,
Further, the reception time of the signal is obtained from the phase obtained by each demodulation unit. The calculated reception time includes the influence of the internal delay of the reception time. The positioning calculation means selectively corrects the reception time by selectively using the internal delay amount calculated by the delay amount measurement means, and executes the positioning calculation by using the transmission time and the corrected reception time.

By such an operation, in the satellite navigation receiver of the present invention, the influence of the individual difference in the internal delay amount of the receiving circuits used in plural is eliminated during the positioning calculation. Also, when the satellite that receives the signal is switched, the change in the internal delay amount due to this switching is corrected. Further, even when the internal delay amount of the receiving circuit changes due to the temperature change, it is possible to preferably eliminate the influence of this change by executing the delay amount measurement at an appropriate frequency.

In the satellite navigation receiver according to the second aspect of the present invention, the above-mentioned delay amount measurement is executed in response to the user's instruction via the instruction means. That is, when the user commands the delay amount measurement by the command means, the switching means operates in response to this, and the reference signal generated by the reference signal generating means is supplied to each receiving circuit for a predetermined time. In this way, the user can perform the delay amount measurement as needed.

In the satellite navigation receiver according to the third aspect, the delay amount measuring operation is time-division controlled by the time-division control means. That is, the switching means operates so that the reference signal is supplied to each receiving circuit in a time division manner. As a result, it becomes possible to execute the delay amount measurement without interrupting the reception of the signal from the satellite and the positioning calculation, and the operation related to the delay amount measurement is automatically performed regardless of the instruction from the user. It becomes possible to execute.

In the satellite navigation receiver according to the fourth aspect, the time division control means causes the divided supply to be executed at every predetermined time when the temperature of the receiving circuit is considered to change. As a result, the frequency of delay amount measurement can be suppressed to the necessary minimum frequency.

The signal delay compensating device according to the present invention realizes a device that can be used for delay amount measurement in the satellite navigation receiver according to the present invention. That is, the above-mentioned reference signal generation means, switching means, delay amount correction means, and reception time correction means in positioning calculation are provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a GL according to the first embodiment of the present invention.
The configuration of the ONASS receiver is shown. As shown in this figure, the GLONASS receiver has n receive channels. n is at least 4 in the case of three-dimensional positioning and at least 3 in the case of being limited to two-dimensional positioning.
And need to.

Each reception channel is provided with a reception circuit 10. The receiving circuit 10 receives each GLON received by the antenna 12 and supplied through the switch 14.
The signal from the ASS satellite is down-converted using the local oscillation signal supplied from the local oscillator 16, and the demodulation unit 1
Supply to 8.

In each receiving channel, the demodulation unit 1
8, the signal tracking unit 20 and the code generator 22 form a phase locked loop (PLL). First, the code generator 22 generates a PN code according to the phase control signal supplied from the signal tracking unit 20. The demodulation unit 18 determines whether there is a correlation between the PN code included in the signal supplied from the receiving circuit 10 and the PN code supplied from the code generator 22. When the demodulator 18 determines that there is a correlation, it can be considered that the phase of the PN code generated by the code generator represents the reception time of the signal from the GLONASS satellite. In addition to the reception time thus obtained, the demodulation unit 18 uses the navigation data obtained by demodulating the signal supplied from the reception circuit 10 as a demodulation signal via the signal tracking unit 20 as a loop filter to perform positioning calculation. It is output to the unit 23.

The positioning calculation unit 23 executes positioning calculation based on a predetermined algorithm. That is, the positioning calculation unit 23 obtains the satellite position and the transmission time of the GLONASS satellite based on the orbit information included in the navigation data supplied from each channel, and based on the obtained transmission time and the reception time obtained by the above-described PLL operation. Calculate the pseudo distance. When the pseudo range and the satellite position are obtained from the number of GLONASS satellites or more required for the positioning calculation, the positioning calculation unit 23 can execute the positioning calculation based on these. At that time, the positioning calculation unit 23 determines, based on the delay amount obtained for each channel and for each satellite (for each reception frequency) in the delay amount measuring unit 24 for each channel,
Correct the reception time. For example, when the signal from the first satellite is received on channel 1, the positioning calculation unit 2
In correcting the reception time obtained from channel 1, 3 uses the delay amount obtained from the delay amount measuring unit 24 of channel 1 for the first satellite.

The feature of this embodiment is that the internal delay amount in each receiving circuit 10 is measured in advance by the delay amount measuring unit 24 for each satellite, and this is measured by the positioning calculation unit 23.
This is a point used for correction of the reception time.

Next, the configuration and operation relating to the measurement of the delay amount will be described.

In this embodiment, a carrier oscillator 26, a code generator 28 and a modulator 30 are provided as means for generating a reference signal used when measuring the delay amount. The carrier wave oscillator 26 generates a carrier wave having a frequency according to the frequency setting signal supplied from the delay amount measurement control unit 32, and outputs the carrier wave to the modulation unit 30 in the subsequent stage. The modulator 30 phase-modulates the carrier wave supplied from the carrier wave oscillator 26 with the PN code generated by the code generator 28, and supplies the carrier wave to the switcher 14. The switching unit 14 is switched at a predetermined timing by a switching signal supplied from the delay amount measurement control unit 32.

Here, the carrier wave oscillator 26 is an oscillator capable of generating a carrier wave of the same frequency as a carrier wave of a signal from all GLONASS satellites launched into an orbit around the earth. When measuring the delay amount, the delay amount measurement control unit 32 instructs the carrier wave oscillator 26 which GLONASS satellite is to be oscillated at the carrier frequency using a frequency setting signal. The carrier wave oscillator 26 oscillates in response to this. On the other hand, the PN code generated by the code generator 28 is the same code as the PN code used in the GLONASS satellite. Therefore, the phase modulation signal output from the modulator 30 is GLO
The signal has the same carrier frequency and the same modulation content as the signal transmitted from the NASS satellite. However, the carrier frequency is under the control of the delay amount measurement controller 32 as described above. Hereinafter, the phase modulation signal output from the modulator 30 will be referred to as a reference signal.

The delay amount measurement control unit 32 controls the operation of generating the reference signal and the operation of supplying the reference signal to the receiving circuit 10 as described above, as well as the operation of receiving and demodulating the reference signal. That is, when performing the delay amount measurement, the delay amount measurement control unit 32 gives a frequency setting signal to the carrier wave oscillator 26 and a switching signal to the switch 14 to receive the reference signal for a predetermined carrier wave frequency on all channels. While being supplied to the circuit 10, a delay amount measurement instruction signal is supplied to the reception control unit 34 of each channel. The reception controller 34 controls the operations of the local oscillator 16 and the code generator 22 according to the delay amount measurement instruction signal supplied from the delay amount measurement controller 32.
That is, the local oscillation frequency used in the local oscillator 16 is controlled according to the frequency of the carrier wave generated in the carrier wave oscillator 26, and the code generator 22 is also used.
Controls the phase of the PN code generated in. At that time, the reception control unit 34 monitors the demodulated signal output from the demodulation unit 18 via the signal control unit 20.

The delay amount measuring section 24 compares the phase of the PN code output from the code generator 22 with the phase of the PN code generated by the code generator 28. That is, the phase of the reference signal affected by the internal delay of the receiving circuit 10 is compared with the phase of the reference signal before being supplied to the receiving circuit 10. The delay amount measuring unit 24 measures the internal delay amount of the corresponding receiving circuit 10 by this comparison. The measured internal delay amount is supplied to the positioning calculation unit 23.

The delay amount measurement control unit 32 executes such a delay amount measuring operation for all GLONASS satellites launched into the orbit around the earth. That is,
Delay amount measuring unit 2 for a certain carrier frequency (a certain satellite)
When the delay amount measuring operation in 4 is completed, the delay amount measuring operation for another carrier frequency (other satellite) is started. When the delay amount measurement is completed for all the satellites by such an operation, the delay amount measurement control unit 32 gives a switching signal to the switch 14 to supply the reception signal obtained by the antenna 12 to each receiving circuit 10. .

FIG. 2 shows the flow of the delay amount measuring operation in this embodiment. As shown in this figure,
The delay amount measuring operation in this embodiment is executed according to the operation of the button 36. That is, when the user presses the button 36 (100), the delay amount measurement control unit 32 is correspondingly pressed.
Generates a switching signal, a frequency setting signal and a delay amount measurement instruction signal, and starts a measurement operation by generation of a reference signal and reception demodulation (102). When the delay amount measurement operation is completed for a certain carrier frequency (104), the delay amount measurement control unit 32 changes the carrier frequency generated by the carrier oscillator 26 and the local oscillation frequency generated by the local oscillator 16 to those of other satellites ( 106) Then, the delay amount measuring operation is continuously executed. When such an operation ends for all frequencies, that is, for all satellites (10
8) The delay amount measuring operation ends. Specifically, a switching signal is given from the delay amount measurement control unit 32 to the switching device 14,
The received signal from the satellite used for positioning is supplied to the receiving circuit 10 of the corresponding channel.

As described above, according to the present embodiment, prior to executing the positioning calculation, the internal delay amount is measured for the combination of all GLONASS satellites and all receiving circuits 10, and the measured delay amount is selectively. Since the reception time is corrected by using this, it is possible to eliminate or prevent the error in the current position obtained by each positioning calculation due to the individual difference in the internal delay amount of the receiving circuit 10. In addition, since the delay amount measurement is executed for all GLONASS satellites and the delay amount related to the satellite currently being received is selected and used for the correction of the reception time, the error due to the frequency dependence of the internal delay amount of the receiving circuit 10 It is possible to prevent the occurrence of
Which satellite is currently being received may be given as information from a satellite selection unit (not shown). Further, the receiving circuit 10
Even if the internal delay amount of C changes depending on the temperature, if the delay amount is measured at an appropriate frequency, the positioning calculation can be accurately performed in response to the temperature change. FIG. 3 shows the GL according to the second and third embodiments of the present invention.
The configuration of the ONASS receiver is shown. In this embodiment, a timing management unit 38 is provided instead of the button 36 in the first embodiment.

FIG. 4 shows the flow of the delay amount measuring operation in the second embodiment. As shown in this figure,
In this embodiment, the delay amount measurement is time-division controlled. That is, the delay amount measurement control unit 32 generates a switching signal according to the timing supplied from the timing management unit 38, and outputs the signal from each GLONASS satellite for 6 msec.
In the meantime, each receiving circuit 10 is made to receive (110). The delay amount measurement controller 32 again generates a switching signal after 6 msec has elapsed, generates a reference signal for 4 msec, and supplies the reference signal to each receiving circuit 10 (112). At the same time, the delay amount measurement control unit 32 receives the delay amount measurement instruction signal from the reception control unit 34.
To control the reception demodulation operation of the reference signal.

As described above, in this embodiment, the GLO
1 chip of PN signal transmitted from NASS satellite = 10
6 msec out of msec is for receiving signals from satellites,
4 msec is used for measuring the amount of delay in each time division. When the delay amount measurement operation for a certain frequency (a certain satellite) ends (104), the measurement control unit 32 changes the oscillation frequencies of the carrier oscillator 26 and the local oscillator 16 (10
6) The delay amount measurement operation is executed again by time division for different frequencies (different satellites).

When the delay amount measuring operation executes time division in this way, unlike the above-described first embodiment, there is no need to interrupt the reception of the signal from the GLONASS satellite. That is, there is no need to interrupt the positioning calculation. Moreover, since the delay amount measurement is always continuously executed, the reliability of the delay amount used in the positioning calculation unit 23 becomes high. Further, the user does not need to operate the button 36, and the receiver is easier to handle than in the first embodiment.

FIG. 5 shows a GL according to the third embodiment of the present invention.
The flow of the delay amount measurement operation in the ONASS receiver is shown. The present embodiment can be implemented by the device configuration shown in FIG. 3, but the operations of the delay amount measurement control unit 32 and the timing management unit 38 are different.

As shown in this figure, in this embodiment, each time the timer built in the timing management unit 38 counts up (114), the delay amount measurement by time division is executed. The timer incorporated in the timing management unit 38 is set with a time period during which the temperature-dependent change in the internal delay amount of the receiving circuit 10 can be regarded as a significant value. When the timer counts up (11
4), reception of signal from GLONASS satellite is 6 mse
During c (110), the delay amount measurement using the reference signal is 4 m
When the delay amount measurement is finished for a certain frequency (104) during a period of sec (112), the frequency is changed (106), and the delay amount measurement is performed for another frequency (another satellite). All frequencies (all satellites)
When the delay amount measurement is completed for (108), the process returns to step 114. After that, when the timer counts up again (114), the delay amount measurement process by time division is restarted. By such processing, the frequency of execution of delay amount measurement by time division is suppressed.

FIG. 6 shows the timing of the delay amount measurement in each of the embodiments described above. First, the timing in the first embodiment depends on the operation of the button 36, as shown in FIG. That is, when the user operates the button 36, the delay amount measurement control unit 32 starts the delay amount measurement operation in response to this. In detail,
All the receiving circuits 1 receive the reference signals related to the same carrier frequency.
The operation of simultaneously supplying 0 to measure the delay amount is executed for all frequencies. Reception of the signal from the GLONASS satellite is interrupted until the delay amount measurement is completed for all frequencies.

FIG. 6B shows the measurement timing in the second embodiment. As shown in this figure,
In the present embodiment, the signal reception from the GLONASS satellite and the delay amount measurement are executed in a time division manner, so that the signal reception from the satellite is not interrupted unlike the first embodiment. As in this embodiment, the delay amount is measured by 1 chip of PN code = 10 m.
When it is executed at 4 msec in sec, the steps 110 and 112 described above need to be executed several tens of times for one satellite, so the time required to measure the delay amount for 24 GLONASS satellites is , About 30
It will be about sec. When the time is about 30 seconds, the temperature change in the receiving circuit 10 can be almost ignored.

FIG. 6C shows the measurement timing in the third embodiment. This embodiment is different from the second embodiment in that the delay amount measurement stops the time division control every time the delay amount measurement is executed for all frequencies, and after a suitable time elapses, the delay amount measurement is again performed by the time division control. Is at the point of starting.

In the second and third embodiments, since the reception and the delay amount measurement are performed in a time division manner, the phase of the signal related to the reception is measured during the delay amount measurement and the delay amount is measured during the reception amount. It is necessary to extrapolate the phase of the signal related to the measurement.
Also, compared to the signal received from the GLONASS satellite,
Since the reference signal output from the modulator 30 can be a good S / N, it is possible to execute a suitable delay amount measurement by only allocating a small time of about 4 msec. Conversely, by improving the S / N of the reference signal, 4 ms is allocated for the delay amount measurement.
It is also possible to make ec a shorter time.

Although the above description has been made on the assumption that GLONASS is used as the satellite navigation system, it may be another type of satellite navigation system. However,
At least a plurality of receiving circuits must be provided.

[0045]

As explained above, according to the satellite navigation receiver of the present invention, a carrier signal having the same frequency as that of a signal transmitted from each satellite and a reference signal relating to the same modulation content are generated, and are supplied to the respective receiving circuits. By supplying and comparing the phase of this reference signal with the phase obtained by each demodulation unit, the internal delay amount of each receiving circuit is measured for each satellite, and the measured internal delay amount is selectively used for reception. Since the time is corrected, the positioning error caused by the internal delay of each receiving circuit can be suppressed and the positioning can be performed with higher accuracy.
At that time, since the internal delay amount is measured and used for each receiving circuit, not only the temperature change and the frequency change of the internal delay amount but also the individual difference between the receiving circuits can be corrected. In addition, since the internal delay amount is measured and used for each satellite, the influence of changes in the internal delay amount depending on the frequency is eliminated without setting the phase characteristics of the filters that make up each receiving circuit precisely. Therefore, the degree of freedom in designing the receiving circuit can be improved and the development cost can be reduced.
In addition, by measuring the internal delay amount at an appropriate frequency, it is possible to eliminate the influence of the temperature-dependent change in the internal delay amount without providing a heat retaining structure or the like in each receiving circuit. Simple and small.

Further, according to the satellite navigation receiver of the second aspect of the present invention, since the command means for giving the command to supply the reference signal to each receiving circuit is provided, the measurement of the internal delay amount is used. It is possible to execute according to a person's command.

Further, according to the satellite navigation receiver of the third aspect, since the delay amount measuring operation is executed in a time division manner, the delay amount is not interrupted without receiving and demodulating the signal from the satellite and by extension the positioning calculation. Measurement can be performed. That is, it becomes possible to perform real-time and automatic delay amount measurement, and it is possible to obtain the effects of improving the reliability of the measured internal delay amount and improving the usability of the receiver.

Further, according to the satellite navigation receiver of the fourth aspect, since the delay amount measurement is executed every time when the temperature of the receiving circuit is considered to change, the frequency of the delay amount measurement can be suppressed. .

According to the fifth aspect of the present invention, it is possible to realize a device that can be used for measuring the internal delay amount and correcting the reception time in the satellite navigation receiver described above.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a GLONASS receiver according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of a delay amount measuring operation in this embodiment.

FIG. 3 is a GLONA according to second and third embodiments of the present invention.
It is a block diagram which shows the structure of SS receiver.

FIG. 4 is a flowchart showing a flow of a delay amount measuring operation in the second embodiment.

FIG. 5 is a flowchart showing a flow of a delay amount measuring operation in the third embodiment.

FIG. 6 is a timing chart showing the timing of the delay amount measurement in each embodiment of the present invention, FIG. 6 (a) shows the first embodiment, FIG. 6 (b) shows the second embodiment, and FIG. FIG. 7C is a diagram showing the measurement timing of the third embodiment.

[Explanation of symbols]

 10 Receiver Circuit 12 Antenna 14 Switcher 16 Local Oscillator 18 Demodulator 20 Signal Tracker 22, 28 Code Generator 23 Positioning Calculator 24 Delay Amount Measuring Unit 26 Carrier Oscillator 30 Modulator 32 Delay Amount Measuring Controller 34 Reception Controller 36 Button 38 Timing management section

Claims (5)

[Claims] 1. Phase modulation of a carrier wave from any one of a plurality of satellites provided at least as many as the number of satellites required for positioning calculation, each having an internal delay, constituting a satellite navigation system, and phase-modulating carrier waves of different frequencies. A receiving circuit that receives a signal, a plurality of demodulation units that demodulate the satellite orbit information from the signal received by the corresponding receiving circuit and that obtains the phase related to the modulation, and a signal from the satellite based on the orbit information of each satellite The transmission time is obtained from the phase obtained by each demodulation unit, the reception time of the signal including the internal delay of the receiving circuit is obtained, and a predetermined positioning calculation is performed based on the obtained transmission time and reception time, thereby In a satellite navigation receiver equipped with a positioning calculation means for determining the current position, a carrier wave of the same frequency as the signal transmitted from each satellite and the same modulation content Reference signal generating means for generating a reference signal, switching means for switching the signal from the satellite to each receiving circuit and switching the reference signal at a predetermined timing, and switching means for supplying the reference signal to each receiving circuit. In this state, by comparing the phase of the reference signal at the time of supply to each receiving circuit with the phase of the reference signal after passing through the receiving circuit obtained by each demodulator, the internal delay amount of each receiving circuit The positioning calculation means corrects the reception time by using the value corresponding to the satellite and the receiving circuit related to the reception among the measured internal delay quantity, and the corrected reception time. A satellite navigation receiver characterized by performing positioning calculation using. 2. The satellite navigation receiver according to claim 1, further comprising command means for executing switching by the switching means in response to a command from a user and supplying the reference signal to each receiving circuit for a predetermined time. A satellite navigation receiver characterized by: 3. The satellite navigation receiver according to claim 1, further comprising a time division control means for controlling switching by the switching means so that the reference signal is supplied to each reception circuit in a time division manner. Satellite navigation receiver. 4. The satellite navigation receiver according to claim 3, wherein the time-division control means executes the time-division supply at every predetermined time when the temperature of the receiving circuit is considered to change. . 5. A reference signal generating means for generating a reference signal relating to a carrier having the same frequency as a signal transmitted from a plurality of satellites constituting a satellite navigation system and the same modulation content, and a plurality of receiving circuits each having an internal delay. On the other hand, switching means for switching and supplying the reference signal at a predetermined timing instead of the signal from the satellite, and the reference signal at the time of supply to each receiving circuit while the reference signal is being supplied to each receiving circuit by the switching means. By comparing the phase and the phase of the reference signal output from each receiving circuit, the delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite, and And a reception time correction means for correcting the reception time using values corresponding to the satellite and the receiving circuit.