JP3302432B2 - Satellite navigation receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, GLONASS
In particular, the present invention relates to a signal delay correction device in a receiver thereof.

[0002]

2. Description of the Related Art Conventionally, satellite navigation systems such as GPS and GLONASS have been operated and tested. Each of these systems receives signals from a predetermined number of satellites (target: 24) orbited in orbit around the earth, and generates a pseudorange between the satellite and a user (receiver) and the position of the satellite. And measures (positions) the current position of the user based on these. The satellites constituting these systems transmit predetermined navigation data to a receiver mounted on a moving object on the earth, and the receiver receives and demodulates the data to transmit the satellite's signal transmission time and satellite position. Ask for. A signal transmitted from a satellite is phase-modulated by a pseudo-noise (PN) signal, and a receiver obtains the time of reception of a signal from the satellite by acquiring the PN signal and obtaining the phase. 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 clock of the receiver has an error with respect to the satellite clock synchronized with the system clock, the obtained distance includes an error. If a distance including such an error, that is, a pseudorange and the above-described satellite position can be obtained for a predetermined number of satellites (four for three-dimensional positioning and three for two-dimensional positioning) The current position of the user can be obtained by calculation in the receiver. That is, the obtained pseudorange, satellite position, and user's initial position or previous position are substituted into the simultaneous equations indicating the relationship between the user's current position and clock error and the pseudorange, and the current position and clock error are solved. Thus, the current position of the user can be obtained.

[0003] Both GPS in the United States and GLONASS in the CIS (former Soviet Union) are systems for performing positioning based on such a principle. But,
The design of each system is different from each other. For example, GP
In S, the frequency of the carrier of the signal transmitted from the satellite is the same for all the satellites.
The SSs are different from each other by 562.5 kHz. Therefore, the design of the receiver for receiving and demodulating the signal from the satellite must be different accordingly.
That is, in a GPS in which the carrier wave frequency of the signal from each satellite is the same, only one receiving circuit for receiving and down-converting the signal transmitted from the GPS satellite is sufficient. On the other hand, in GLONASS in which the carrier frequency of the signal from each satellite is different, a receiving circuit for receiving and down-converting the signal from the GLONASS satellite must be provided at least for the number of satellites necessary for positioning calculation.

[0004] 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 inside the receiving circuit. Since the filter has a group delay characteristic, the group delay acts as an internal delay of the receiving circuit. A demodulation unit is provided at a subsequent stage of the receiving circuit, and the demodulation unit obtains a reception time of a signal from each satellite. The reception time of this signal is delayed due to the internal delay of the preceding receiving circuit. In a receiver such as a GPS receiver that uses a common receiving circuit for each satellite, the reception time obtained in the subsequent demodulation unit is a time delayed by the same amount for all satellites, so that errors such as errors may occur. 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 receiving times obtained by the corresponding demodulators are several tens of nsec due to individual differences of the receiving circuits. The reception times are delayed by different amounts. If the reception time is different for each satellite as described above, an error occurs in the position calculation performed using the reception time.

In general, the amount of internal delay of a receiving circuit differs depending on individual differences among the receiving circuits, and also changes depending on the frequency and temperature of a received signal. That is, even if the same receiving circuit is receiving signals from different GLONASS satellites, the internal delay amounts are different. 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 nsec at the maximum.

In order to execute the positioning calculation more accurately in the GLONASS receiver, it is necessary to take measures against the internal delay amount of such a 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. 69-76, shows an example of a countermeasure against a change in the internal delay amount of the receiving circuit due to the received signal frequency and temperature. In this document, precise filter design is performed so that the amount of group delay due to the frequency of a received signal does not occur, and the phase characteristics of various filters constituting the receiving circuit are flat with respect to frequency. This document also discloses a method of performing temperature control of a receiving circuit so that the amount of internal delay 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 the temperature dependence of the internal delay amount of the receiving circuit.

[0007]

However, even if such filter characteristics are designed and the temperature is controlled, the difference in the internal delay amount due to the individual difference of a plurality of receiving circuits still remains. Further, in order to make the phase characteristic of the filter constituting the receiving circuit flat with respect to the frequency, it is necessary to precisely execute the design of the filter. In addition, the cost of development and design is significantly increased. 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.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and prevents a positioning error from occurring due to an individual difference in an internal delay amount of a plurality of receiving circuits. It is another object of the present invention to be able to eliminate the influence of the change of the internal delay amount due to the frequency and temperature without performing precise design of filter characteristics and temperature control of a receiving circuit.

[0009]

In order to achieve the above object, the satellite navigation receiver according to the present invention is provided with at least the number of satellites (for example, four) required for positioning calculation, and each has an internal delay. And a satellite navigation system (eg, GL
ONASS), a receiving circuit for receiving a phase-modulated signal from any of a plurality of satellites that phase-modulate carriers of different frequencies, demodulates satellite orbit information from a signal received by a corresponding receiving circuit, and A plurality of demodulation units for determining the phase of the signal, a reference signal generating means for generating a carrier signal having the same frequency as the signal transmitted from each satellite and a reference signal relating to the same modulation content, and a signal from the satellite for each receiving circuit. A switching means for switching the reference signal at a predetermined timing; and a state where the reference signal is supplied to each receiving circuit by the switching means. By comparing with the phase of the reference signal after passing through the receiving circuit
A delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite, and a transmission time of a signal from the satellite based on the orbit information of each satellite, and an internal delay of the receiving circuit based on a phase obtained by each demodulation unit. The reception time of the signal containing
The reception time is corrected using the value corresponding to the satellite and the reception circuit related to reception among the internal delay amounts measured by the delay amount measurement means, and a predetermined positioning calculation is performed based on the obtained transmission time and the corrected reception time. by performing a positioning calculation means for calculating a current position of the user, so that the signal and the reference signal from the satellite by a predetermined time to Shi at every constant time each receiving circuit is <br/> time division supply , Time-division control means for controlling switching by the switching means.

The satellite navigation receiver according to a second aspect of the present invention is characterized in that the time division control means executes the time division supply every predetermined time.

According to a third aspect of the present invention, in the satellite navigation receiver, the time-division control means executes the time-division supply every predetermined time when the temperature of the receiving circuit is considered to change.

The signal delay correction apparatus according to the present invention provides a reference signal for generating a carrier signal having the same frequency as a signal transmitted from a plurality of satellites constituting a satellite navigation system (eg, GLONASS) and a reference signal relating to the same modulation content. Signal generating means, switching means for switching the reference signal at a predetermined timing instead of a signal from a satellite to a plurality of receiving circuits each having an internal delay, and a reference signal is supplied to each receiving circuit by the switching means. In the state, by comparing the phase at the time of supply to each receiving circuit and the phase of the reference signal output from each receiving circuit, a delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite. a receiving time correcting means for correcting the reception time using a value corresponding to the satellite and a receiving circuit according to the reception of the measured internal delay, Shi pairs to each receiver circuit It said every predetermined time every constant time Mamoru
So that the signal from the star and the reference signal are supplied in a time-sharing manner,
Time division control means for controlling switching by the switching means,
It is characterized by having.

[0013]

The operation of the satellite navigation receiver according to the present invention is different between a state where a signal from a satellite is supplied to each receiving circuit and a state where a reference signal is supplied to each receiving circuit. First,
In a state where a carrier signal having the same frequency as the signal transmitted from each satellite and a reference signal relating to the same modulation content are generated by the reference signal generating means, and the reference signal is supplied to each receiving circuit by the switching means, the delay amount measurement The internal delay amount measurement by the means is performed. That is, the reference signal supplied to each receiving circuit undergoes internal delay in the receiving circuit, and the phase of the internally delayed reference signal is obtained by the corresponding demodulation unit. 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 subjected to the internal delay in this way with the phase at the time of supply 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 demodulation section after receiving an internal delay in the receiving circuit. Then, the phase is obtained in the demodulation unit, 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 demodulation unit,
Further, the reception time of the signal is obtained from the phase obtained by each demodulation unit. The obtained reception time includes the influence of the internal delay of the reception time. The positioning calculation means corrects the reception time by selectively using the internal delay amount obtained by the above-described delay amount measurement means, and executes positioning calculation using the transmission time and the corrected reception time.

By the above operation, in the satellite navigation receiver of the present invention, the influence of the individual difference of the internal delay amount of the plurality of receiving circuits is eliminated at the time of positioning calculation. Further, even when the satellite for receiving the signal is switched, the change in the internal delay amount accompanying this switching is corrected. Further, even when the internal delay amount of the receiving circuit changes due to a temperature change, the effect of this change can be preferably eliminated by executing the delay amount measurement at an appropriate frequency.

In the satellite navigation receiver according to the present invention,
The delay amount measuring operation is time-divisionally 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, consequently, the positioning calculation, and to automatically perform the operation related to the delay amount measurement without a command from the user. It is possible to execute.

In the satellite navigation receiver according to the second and third aspects, the time division control means executes the division supply every predetermined time, for example, 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 minimum necessary frequency.

In the signal delay compensating device according to the present invention, a device that can be used for delay amount measurement in the satellite navigation receiver according to the present invention is realized. That is, the above-described reference signal generation unit, switching unit, delay amount correction unit, time division control unit, and reception time correction unit in positioning calculation are provided.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a GL inspired by the inventor of the present invention.
The configuration of the ONASS receiver is shown. As shown in this figure, the GLONASS receiver has n reception channels. n is at least 4 for three-dimensional positioning and at least 3 for limiting to two-dimensional positioning.
It is necessary to

Each receiving channel has a receiving 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
8

In each reception channel, the demodulation unit 1
8. A phase locked loop (PLL) is formed by the signal tracking unit 20 and the code generator 22. 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. If the demodulation unit 18 determines that there is a correlation, it can be considered that the phase of the PN code generated by the code generator indicates the reception time of the signal from the GLONASS satellite. The demodulation unit 18 calculates the navigation data obtained by demodulating the signal supplied from the reception circuit 10 in addition to the reception time obtained in this way, as a demodulated signal via a signal tracking unit 20 as a loop filter. Output to the unit 23.

In the positioning calculation unit 23, positioning calculation based on a predetermined algorithm is executed. That is, the positioning calculation unit 23 obtains the satellite position and transmission time of the GLONASS satellite based on the orbit information included in the navigation data supplied from each channel, and calculates the transmission time and the reception time obtained by the above-described PLL operation. Find the pseudorange. When the pseudorange and the satellite position are obtained from GLONASS satellites that are equal to or more than the number required for the positioning calculation, the positioning calculation unit 23 can execute the positioning calculation based on these. At this time, the positioning calculation unit 23 calculates the delay amount based on the delay amount obtained for each channel and for each satellite (for each reception frequency) by the delay amount measurement unit 24 for each channel.
Correct the reception time. For example, when a signal from the first satellite is received on channel 1, the positioning calculation unit 2
3 corrects the reception time obtained from the channel 1 by using the delay amount obtained from the delay amount measurement unit 24 of the channel 1 for the first satellite.

The feature of this configuration 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 used by the positioning calculating unit 23 to correct the reception time. Is a point.

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

In this configuration, the carrier wave oscillator 2 is used as a means for generating a reference signal used for measuring the amount of delay.
6, a code generator 28 and a modulation unit 30 are provided. The carrier oscillator 26 generates a carrier having a frequency corresponding to the frequency setting signal supplied from the delay amount measurement controller 32, and outputs the carrier to the modulator 30 at the subsequent stage. The modulator 30 modulates the phase of the carrier supplied from the carrier oscillator 26 with the PN code generated by the code generator 28, and supplies the carrier to the switch 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 oscillator 26 is an oscillator capable of generating a carrier having the same frequency as a carrier of a signal from all GLONASS satellites launched in orbit around the earth. When measuring the delay amount, the delay amount measurement control unit 32 instructs the carrier oscillator 26 using the frequency setting signal to determine which GLONASS satellite will oscillate at the carrier frequency. The carrier oscillator 26 oscillates accordingly. 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 control unit 32 as described above. Hereinafter, the phase modulation signal output from the modulation unit 30 is 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 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 supplies the frequency setting signal to the carrier oscillator 26 and the switching signal to the switch 14 to receive the reference signal related to the predetermined carrier frequency on all channels. While supplying the signal to the circuit 10, it supplies a delay amount measurement instruction signal to the reception control unit 34 of each channel. The reception control unit 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 control unit 32.
That is, the local oscillation frequency used in the local oscillator 16 is controlled according to the frequency of the carrier generated in the carrier oscillator 26, and the code generator 22
Controls the phase of the generated PN code. At this 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 by 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 section 32 executes such a delay amount measurement operation for all GLONASS satellites launched in orbit around the earth. That is,
Delay amount measuring unit 2 for a certain carrier frequency (a certain satellite)
When the delay amount measurement operation in 4 is completed, the delay amount measurement 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 supplies a switching signal to the switch 14 to supply the reception signal obtained by the antenna 12 to each reception circuit 10. .

FIG. 2 shows a flow of the delay amount measuring operation in this configuration. As shown in this figure, the delay amount measurement operation in the present embodiment is executed in response to the operation of the button 36. That is, when the user presses the button 36 (100), the delay amount measurement control unit 32 generates a switching signal, a frequency setting signal, and a delay amount measurement instruction signal in response to the button 36, and generates a reference signal and performs measurement by reception demodulation. The operation is started (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 another satellite ( 106) Then, the delay amount measurement operation is executed. Such operation is performed at all frequencies,
That is, when the processing is completed for all the satellites (108), the delay amount measuring operation is completed. Specifically, a switching signal is provided from the delay amount measurement control unit 32 to the switch 14, and a signal received from a satellite used for positioning is supplied to the receiving circuit 10 of the corresponding channel.

As described above, according to this configuration, before executing the positioning calculation, the internal delay amount is measured for the combination of all the GLONASS satellites and all the receiving circuits 10, and the measured delay amount is selectively used. Since the reception time is corrected in this way, errors due to individual differences in the internal delay amount of the reception circuit 10 can be eliminated or prevented from occurring in the current position obtained by each positioning calculation. Further, since the delay amount measurement is performed for all the GLONASS satellites and the delay amount related to the satellite currently being received is selected and used for correcting the reception time, the error due to the frequency dependence of the internal delay amount of the receiving circuit 10 is obtained. Can be prevented. Which satellite is currently being received may be given as information from a satellite selector (not shown). Furthermore, even when the internal delay amount of the receiving circuit 10 changes depending on the temperature,
If the delay amount measurement is executed at an appropriate frequency, the positioning calculation can be executed accurately in response to the temperature change.
FIG. 3 shows a GLON according to the first and second embodiments of the present invention.
The configuration of the ASS receiver is shown. In this embodiment, a timing management unit 38 is provided instead of the button 36 in FIG.

FIG. 4 shows a flow of the delay amount measuring operation in the first embodiment. As shown in this figure,
In the present embodiment, the delay amount measurement is time-divisionally controlled. That is, the delay amount measurement control unit 32 generates a switching signal in accordance with the timing supplied from the timing management unit 38, and outputs a signal from each GLONASS satellite for 6 msec.
During this period, each receiving circuit 10 receives (110). After a lapse of 6 msec, the delay amount measurement control unit 32 generates a switching signal again, generates a reference signal for 4 msec, and supplies it to each receiving circuit 10 (112). At the same time, the delay amount measurement control unit 32 sends the delay amount measurement instruction signal to the reception control unit 34.
To control the demodulation operation of the reference signal.

As described above, in this embodiment, the GLO
One chip of PN signal transmitted from NASS satellite = 10
6 msec out of msec for receiving signals from satellites,
4 msec is used for delay measurement in a time-division manner. When the delay amount measurement operation is completed for a certain frequency (a certain satellite) (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 performed again on a different frequency (different satellite) by time division.

When the delay amount measurement operation is performed in a time-sharing manner, there is no need to interrupt reception of a signal from the GLONASS satellite, unlike the above-described configuration. That is, there is no need to interrupt the positioning calculation. In addition, since the delay amount measurement is always performed continuously, the reliability of the delay amount used in the positioning calculation unit 23 increases. In addition, the user presses button 3
6 does not need to be performed, and the receiver is easier to handle than the above-described configuration.

FIG. 5 shows a GL according to a second embodiment of the present invention.
The flow of the delay amount measurement operation in the ONASS receiver is shown. The present embodiment can be realized by the configuration shown in FIG. 3 as the device configuration, except that 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, every time the timer built in the timing management section 38 counts up (114), the delay amount is measured by time division. In the timer built in the timing management unit 38, a time during which the temperature-dependent change of the internal delay amount of the receiving circuit 10 is considered to be a significant value is set. When the timer counts up (11
4) 、 Receive signal from GLONASS satellite for 6mse
During c (110), the delay amount measurement using the reference signal is 4 m
The delay time is measured for a certain frequency (104), 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 has been completed for (108), the process returns to step 114. Thereafter, when the timer counts up again (114), the delay amount measurement processing by time division is restarted. By such processing, the execution frequency of the delay amount measurement by the time division is suppressed.

FIG. 6 shows the timing of the delay amount measurement in the configuration of FIG. 1 and each of the embodiments described above. First, the timing in the configuration of FIG.
As shown in (a), it depends on the operation of the button 36. 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 the operation. More specifically, the operation of simultaneously supplying the reference signal relating to the same carrier frequency to all the receiving circuits 10 and measuring the delay amount is executed for all the frequencies. Until the delay measurement is completed for all frequencies, GLO
Reception of signals from NASS satellites is interrupted.

FIG. 6B shows the measurement timing in the first 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 as in the configuration of FIG. As in this embodiment, the delay amount is measured by one chip of the PN code = 10 m
In the case of executing at 4 msec during the sec, it is necessary to execute the above steps 110 and 112 several tens of times for one satellite. Therefore, the time required to measure the delay amount for 24 GLONASS satellites is , About 30
sec. In the time of about 30 sec, the temperature change in the receiving circuit 10 can be almost ignored.

FIG. 6C shows the measurement timing in the second embodiment. This embodiment is different from the first embodiment in that the delay amount measurement stops the time division control every time the delay amount measurement is performed for all the frequencies, and the delay amount measurement by the time division control is resumed after an appropriate time has elapsed. The point is to start.

In the first and second embodiments, the reception and the delay amount measurement are executed in a time-division manner, so that 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. It is necessary to extrapolate the phase of each signal involved in the measurement.
Also, compared to signals received from GLONASS satellites,
Since the reference signal output from the modulation section 30 can have a good S / N ratio, a suitable delay amount measurement can be performed even by allocating such a short time of about 4 msec. Conversely, by improving the S / N of the reference signal, 4 ms allocated to the delay amount measurement
ec can be shorter.

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

[0043]

As described above, according to the satellite navigation receiver of the present invention, a carrier signal having the same frequency as a signal transmitted from each satellite and a reference signal relating to the same modulation content are generated and transmitted to each receiving circuit. The internal delay of each receiving circuit is measured for each satellite by comparing the phase of the reference signal with the phase obtained by each demodulation section, and the measured internal delay is selectively used for reception. Since the time is corrected, it is possible to suppress a positioning error due to an internal delay of each receiving circuit, and to execute more accurate positioning.
At this time, since the internal delay amount is measured and used for each receiving circuit, not only a temperature change and a frequency change of the internal delay amount but also an individual difference between the receiving circuits can be corrected. Furthermore, since the internal delay amount is measured and used for each satellite, the effects of frequency-dependent changes in the internal delay amount are eliminated without precisely setting the phase characteristics of the filters and other components that constitute each receiving circuit. Therefore, the design flexibility of the receiving circuit can be improved and the development cost can be reduced.
In addition, by performing the measurement of the internal delay amount at an appropriate frequency, it is possible to eliminate the influence of the temperature-dependent change of the internal delay amount without providing a heat insulation structure or the like in each receiving circuit, and the device configuration can be reduced. Simple and compact.

Furthermore, according to the satellite navigation receiver of the second aspect, since the delay amount measuring operation is executed in a time division manner, the reception and demodulation of the signal from the satellite and, consequently, the positioning calculation can be performed without interruption. Measurement can be performed. That is, real-time and automatic delay amount measurement can be performed, and the effect of improving the reliability of the measured internal delay amount and improving the usability of the receiver can be obtained.

Further, according to the satellite navigation receiver of the third and fourth aspects, the delay amount measurement is executed at every predetermined time, for example, at each time when the temperature of the receiving circuit can be considered to be changed. Frequency can be suppressed.

According to the fourth aspect of the present invention, it is possible to realize an apparatus which can be used for measuring the internal delay amount and correcting the reception time in the above-mentioned satellite navigation receiver.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a flow of a delay amount measurement operation in this configuration.

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

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

FIG. 5 is a flowchart illustrating a flow of a delay amount measurement operation in the second embodiment.

6A and 6B are timing charts showing timings of delay amount measurement in each embodiment of the present invention. FIG. 6A shows the configuration of FIG. 1, FIG. 6B shows the first embodiment, and FIG. (c) is a diagram showing the measurement timing of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Receiving circuit 12 Antenna 14 Switcher 16 Local oscillator 18 Demodulation part 20 Signal tracking part 22, 28 Code generator 23 Positioning calculation part 24 Delay amount measurement part 26 Carrier oscillator 30 Modulation part 32 Delay amount measurement control part 34 Reception control part 36 Button 38 Timing management unit

Continuation of the front page (56) References JP-A-61-294382 (JP, A) JP-A-3-48540 (JP, A) Raymond A. Eastwood, An Integrated GPS / GLONASS Receiver, Proceedings of the National Technical Meeting, United States, Institute of Navigation, p. 37-43, 1990 (58) Fields investigated (Int.Cl. ⁷ , DB name) G01S 5/00-5/14 G01C 21/00-21/24 G01C 23/00-25/00 H04B 1/69- 1/713 H04B 7/24-7/29 H04L 7/00-7/10 H04Q 7/00-7/38 JICST file (JOIS)

Claims (4)

(57) [Claims] 1. A phase modulation of a carrier from any one of a plurality of satellites provided at least as many as satellites necessary for positioning calculation, each having an internal delay, constituting a satellite navigation system, and phase modulating a carrier having a different frequency. A receiving circuit for receiving a signal, a plurality of demodulating units for demodulating satellite orbit information from the signal received by the corresponding receiving circuit and obtaining a phase related to 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 demodulator, 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 the reception time, so that the user's And a positioning calculation means for obtaining the current position, the carrier transmitted at the same frequency and the same modulation content as the signal transmitted from each satellite. Reference signal generating means for generating a reference signal, switching means for switching the reference signal at a predetermined timing instead of a signal from a satellite to each receiving circuit, and a reference signal supplied to each receiving circuit by the switching means. In this state, the internal delay amount of each receiving circuit is compared for each satellite 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 demodulation unit. a delay amount measuring means for measuring the above or satellite by a predetermined time to Shi at every constant time to each receiver circuit
Time-division control means for controlling the switching by the switching means so that the signals and the reference signal are supplied in a time-division manner, wherein the positioning calculation means comprises: A satellite navigation receiver, wherein a reception time is corrected using a value corresponding to a circuit, and a positioning calculation is performed using the corrected reception time. 2. The satellite navigation receiver according to claim 1, wherein said time division control means executes said time division supply at predetermined time intervals. 3. A satellite navigation receiver according to claim 2, wherein said time division control means executes said time division supply at predetermined time intervals at which the temperature of the receiving circuit is considered to change. . 4. A reference signal generating means for generating a carrier signal having the same frequency as a signal transmitted from a plurality of satellites constituting a satellite navigation system and a reference signal having the same modulation content, and a plurality of receiving circuits each having an internal delay. Switching means for switching the reference signal at a predetermined timing in place of a signal from a satellite, and when the reference signal is supplied to each receiving circuit by the switching means, By comparing the phase with the phase of the reference signal output from each receiving circuit, a delay amount measuring means for measuring the internal delay amount of each receiving circuit for each satellite, said one satellite by a predetermined time and receiving time correcting means for correcting the reception time, vs. Shi at every constant time to each receiver circuit using a value corresponding to the satellite and a receiving circuit according
A time division control unit for controlling switching by the switching unit so that the signals and the reference signal are supplied in a time division manner.