JP2001042023A - Intermittent positioning method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermittent positioning-type positioning device which requires a shorter positioning time than before. SOLUTION: In this positioning device, base clocks generated at a base clock generating part 22A are enumerated by a timer 16A during a quiescent period. At the time of detecting the completion of the quiescent period as the result of the enumeration, power supply from a power source 10 to a frequency converting part 12A is started, and the supply of base clocks from the base clock generating part 22A to the frequency converting part 12A and a signal processing part 14A is started. Electric power is supplied for the signal processing part 14A from the power source 10 also during a quiescent period. A processor 40A predicts a synchronous state that a frequency phase synchronous loop 42A should take at the time of starting a next positioning period prior to the transition from a positioning period to a quiescent period and sets the synchronous state at a carrier generating part 34A and code generating part 36A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent positioning method and a positioning apparatus for executing a positioning operation intermittently.

[0002]

2. Description of the Related Art A GPS (Global Positioning System) transmits a satellite signal from a GPS satellite in an orbit around the earth to a receiver on the earth, and the receiver determines a current position, a moving speed, and the like based on the satellite signal. This is a system having a configuration of deriving. Various small and relatively inexpensive GPS receivers have already been developed and are common. On the other hand, terrestrial radio systems such as mobile phones and PHSs have also become widespread, and the miniaturization and cost reduction of their terminals have already been extremely advanced. That is, the positioning device including the GPS receiver and the terrestrial radio terminal including the mobile phone are both of a portable size and weight. Therefore, there has been an increasing motivation to combine them to form a complex system, thereby providing more diverse and convenient services.

[0003] For example, a GPS receiver and a mobile phone are carried by a person who is likely to be lost, such as a wandering elderly person or a mountain climber. These GPS receivers and mobile phones are
Each time the predetermined time elapses, the GPS receiver is functionally linked so that the positioning result is transmitted from the mobile phone. As a result, it becomes possible for relatives to know the current position of these persons, etc., to prevent the occurrence of missing situations, and to find missing persons early. In the academic field, a similar device is carried by an animal to be investigated in order to investigate the behavior of a wild animal. As a result, information on the behavior of wild animals, such as the position, the moving speed, the degree of crowding, and changes thereof, can be automatically and efficiently collected.

In the applications listed above, it is of course possible to keep the GPS receiver operating at all times, but this is not preferred in terms of power consumption. That is, in a GPS receiver carried by a human or an animal, it is necessary to supply power from a battery, which is as light as possible, and if the positioning operation is continuously performed, the battery is consumed. . For this reason, in the above-mentioned applications, the positioning operation is performed intermittently, and a period during which the positioning operation is performed (positioning period) and a period during which the positioning operation is not performed (pause period) are set between the next positioning period. It is desirable to reduce the consumption of the battery. In addition,
The intermittent positioning can be executed and adopted other than the above-mentioned applications and systems.

[0005] JP-A-8-146115, JP-A-1
Conventionally, as described in Japanese Patent Application Laid-Open No. 0-170626 and Japanese Patent Application Laid-Open No. H11-23690, a power supply for most of GPS receivers (in more general terms, “positioning device”) is provided during a rest period. By interrupting the supply,
The battery consumption during the suspension period was suppressed. In FIG.
“SiRFstarI / LX Low Power GPS Architecture”, Turetz
An example in which an intermittent operation type GPS receiver is configured based on the suggestion in ky, Knight and Norman, ION-97, pp. 75-79 is shown. The GPS receiver shown in this figure is provided with a timer 16 and a power switch 18 for periodically turning on / off the power supply from the power supply 10, for example, a battery, to the frequency conversion unit 12 and the signal processing unit 14.

First, the frequency converter 12 converts a satellite signal transmitted from a GPS satellite and received by the antenna 20 into
Frequency conversion is performed from a radio frequency (RF) to an intermediate frequency (IF). The local oscillation signal for that purpose is
2 is generated by multiplying a base clock generated by a base clock generation unit 22 provided in 2 to a predetermined frequency by a multiplier 24. The frequency conversion is performed by mixing the local oscillation signal with the satellite signal by the mixer 26. In the figure, 28 and 30 are R
F and IF amplifiers 32 are A / D converters for converting IF satellite signals after frequency conversion into digital data.

Next, the signal processing unit 14 includes a carrier generation unit 34, a code generation unit 36, a correlator 38, and a processor 4
It has a frequency phase locked loop 42 composed of zeros. The carrier generator 34 generates a carrier at a frequency according to a command from the processor 40 and supplies the carrier to the correlator 38. The code generator 36 generates a spectrum despreading code at a phase according to a command from the processor 40 and supplies the generated code to the correlator 38. The correlator 38 calculates the correlation between the carrier and the spectrum despread code and the satellite signal, and supplies the result to the processor 40. The processor 40 gives an instruction to the carrier generator 34 and the code generator 36 so as to maximize the correlation, and controls the frequency of the carrier and the phase of the spectrum despreading code.

[0008] The satellite signal transmitted from the GPS satellite is L
Taking 1 as an example, the signal is transmitted by a carrier having a fixed frequency of 1575 MHz, but the carrier frequency of the satellite signal when receiving at the GPS receiver side is Doppler shifted due to the relative movement between the GPS satellite and the GPS receiver. . Further, when the local oscillation frequency changes due to the influence of the temperature characteristics of the base clock generation unit 22, etc., the frequency conversion unit 12
Changes the frequency of the IF satellite signal output from. Therefore, to demodulate navigation data from satellite signals,
Synchronization with the carrier frequency of the converted satellite signal must be established and maintained. Furthermore, when transmitted from a GPS satellite, the satellite signal is spread-spectrum-modulated with a spread-spectrum code of 1.023 MHz, for example, using a C / A code. Synchronization to the spread spectrum phase in the received satellite signal must be established and maintained. Therefore, in order to establish and maintain the synchronization with the carrier after the IF conversion and the spread spectrum phase, the above-mentioned frequency phase locked loop 42 is required. Note that the frequency and phase locked loops 42 are provided for a plurality of channels because the synchronization conditions are different for each GPS satellite, but the number of the frequency and phase locked loops is one, not shown, including the drawings appearing later.

[0009] Processor 40 further demodulates navigation data from the correlated detected and thereby despread spectrum modulated satellite signals. The navigation data includes ephemeris data indicating the detailed orbit of the source GPS satellite, each G
Various data such as almanac data indicating a general orbit (orbital calendar) of the PS satellite and data indicating a transmission time of a satellite signal are included. Processor 40, based on these,
Perform satellite selection and positioning calculations. That is, based on the demodulated and collected almanac data and the current position (approximate value), GPS satellites more than the number required for positioning are selected, and the frequency phase locked loop 42 can be synchronized with satellite signals from the selected GPS satellites. Based on the ephemeris data and transmission time data demodulated and transmitted as much as possible, the distance (pseudo distance) between the GPS satellite and the GPS receiver, the relative movement (Doppler shift) of the GPS receiver with respect to the GPS satellite, and The information on the behavior of the mobile body on which the GPS receiver is mounted, such as the current position of the GPS receiver and the moving speed over the ground, is derived and output as a positioning result.

The timer 16 has a positioning period length Ton and a pause period length Tof which are set in advance manually or the like.
The elapse of f is detected, and the timer signal as the output is turned on / off according to the result. As shown in FIG. 7, when the timer 16 detects that Ton has elapsed since the start of the positioning period, the power switch 18 is turned off in response to the turning off of the timer signal, and the frequency conversion from the power source 10 is performed. The supply of power to the unit 12 and the signal processing unit 14 is cut off. This initiates a pause. When the timer 16 detects that Toff has elapsed since the start of the suspension period, the power switch 18 is turned on in response to the turning on of the timer signal, and the frequency converter 12 and the signal processor 14 The supply of power to the power supply is started. During the positioning period, a frequency conversion operation including generation of a base clock is performed in the frequency conversion unit 12, and a positioning operation including initialization, satellite selection, and acquisition / tracking is performed in the signal processing unit 14. . Here, the initial setting is a process of setting predetermined or necessary information in various registers in the processor 40. In the acquisition and tracking, the synchronization with the satellite signal is established by the frequency phase lock loop 42.
That is, the positioning calculation is performed.

[0011]

However, in such an apparatus configuration, every time the positioning period starts, the processing necessary for positioning, including the initial setting, must be performed again. First
In addition, it takes a considerable time to pull the frequency phase locked loop into a locked state. Second, it takes some time to set an initial value in a register in the processor. As described above, in the related art, strict restrictions have been imposed on preventing the power supply, for example, the battery from being consumed by shortening the length of the positioning period.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make it possible to end a positioning period in a shorter time than before, and to suppress power consumption of a power supply. And its purpose.

[0013]

In order to achieve the above object, an intermittent positioning method according to the present invention comprises the steps of: (1) receiving a satellite signal transmitted from a positioning satellite through spread spectrum modulation; By establishing the synchronization of the frequency phase locked loop with the carrier frequency and spread spectrum phase of the signal, the navigation data necessary for positioning calculation is demodulated from the satellite signal, the positioning calculation is executed based on the navigation data, and the movement of the loading destination is performed. Output positioning results related to body position,
A series of positioning operations are performed in a positioning period that intermittently arrives with a pause period interposed therebetween, and in the pause period, at least a part of circuits or devices necessary for the positioning operation is in an operation pause state in an intermittent positioning method. (2) Prior to the transition from the positioning period to the idle period, the carrier frequency and the spread spectrum phase after the elapse of the idle period are set to the state of the frequency phase locked loop and the length of the idle period before the transition. (3) In the pause period, while keeping the result of the prediction, a counting operation for detecting the end of the pause period is executed. (4) The pause operation is performed by the counting operation. When the end of is detected, the circuit or device that has been in the operation halt state is returned to the operation state in order to shift from the halt period to the positioning period. Together, wherein the operating frequency phase locked loop results of the prediction which has been held as an initial state.

Further, the positioning device according to the present invention is mounted on a moving body, executes a positioning operation during a positioning period, and suspends a positioning operation during a pause period between the positioning period and the next positioning period. (2) a frequency conversion unit that performs a process of frequency-converting a satellite signal transmitted from a positioning satellite through spread spectrum modulation to a lower frequency, and a positioning operation from the frequency-converted satellite signal A signal processing unit that performs a positioning operation based on the demodulated navigation data necessary for demodulation and performs a positioning operation based on the demodulated navigation data and outputs a result of the position of the moving object or information related thereto, a frequency conversion unit and a signal processing unit. Intermittent positioning management means for shifting to the operation halt state when shifting from the positioning period to the halt period, and for shifting to the operation state when shifting from the halt period to the positioning period; In the period, the signal processing unit obtains a correlation between the frequency-converted satellite signal obtained from the operating frequency conversion unit, a carrier generated in the signal processing unit, and a spectrum despreading code. The navigation data is demodulated from the satellite signal by controlling the frequency of the carrier and the phase of the spectrum despreading code accordingly. (4) When shifting from the positioning period to the pause period,
The signal processing unit predicts the frequency of the carrier and the phase of the spectrum despreading code to be adopted at the end of the pause period based on the operation state of the signal processing unit and the length of the pause period before the transition, and performs intermittent positioning management. Means for putting a portion of the frequency conversion unit and the signal processing unit relating to holding of information about the carrier frequency and the phase of the spectrum despreading code into an operation state, and shifting the other parts from the operation state to the operation pause state; 5) In the pause period, the signal processing unit holds information on the result of the prediction, and the intermittent positioning management unit manages the length of the pause period to be the length used for prediction in the signal processing unit; (6) When shifting from the suspension period to the positioning period, the intermittent positioning management unit returns the frequency conversion unit and the signal processing unit from the operation suspension state to the operation state, and performs the signal processing. Part is, the retained have information during the pause period, characterized in that to start the process for obtaining the correlation as an initial setting.

As described above, in the present invention, a state to be taken at the start of the next positioning period is predicted based on the synchronization state and the length of the pause period before the start of the pause period, and the result is held over the pause period. At the start of the positioning period, the positioning device is synchronized with the satellite signal in accordance with the result, so that the synchronization pull-in time at the start of the positioning period is shortened, and the positioning period is shortened, and power consumption is reduced. Furthermore,
The above prediction is performed by (1) the frequency of the carrier and the phase of the spectrum despreading code before the transition to the idle period,
(2) Among the information obtained as a result of the positioning calculation, at least one of the position of the moving body, the pseudo distance from the moving body to the positioning satellite, the ground speed of the moving body, and the relative speed of the moving body to the positioning satellite, (3) By making the prediction based on the information such as the length of the suspension period, it is possible to perform an accurate prediction reflecting the movement of the positioning satellite and the moving object.

Further, in the positioning device according to the present invention,
More preferably, the intermittent positioning management means generates a base clock throughout the positioning period and the pause period, the length of the pause period is managed by counting the base clock, and the frequency conversion unit is supplied from the intermittent positioning management unit. The frequency conversion is executed using the base clock as the local oscillation signal, and the signal processing unit executes the positioning calculation in synchronization with the base clock supplied from the intermittent positioning management unit. As described above, the base clock is generated through the positioning period and the pause period by the intermittent positioning management means independent of the frequency conversion unit and the signal processing unit, and the frequency conversion operation, the positioning operation, and the management of the pause period length are also performed by the base clock. If the calculation is performed on the clock basis, the continuity of the phase of the base clock is guaranteed, so that the pause period length used in the prediction in the signal processing unit is correctly realized, and the prediction result is accurate. Furthermore, by using the temperature characteristics of the frequency of the base clock and the ambient temperature in the prediction, it is possible to reflect the frequency fluctuation of the local oscillation signal in the frequency conversion unit, and thus it is possible to improve the accuracy of the prediction.

In the present invention, the signal processing unit is in a state where it does not substantially consume the power of the power supply during the idle period but can hold the result of the prediction. This is an operation halt state in that the power supply is hardly consumed, but is in a state different from a state in which the supply of the power supply is cut off, that is, a state in which the operation is completely stopped as in the related art. is there.

As a method of realizing this kind of state, first, there is a method of not supplying the base clock to the signal processing unit during the idle period. That is, in the intermittent positioning management means, a base clock generating unit that generates a base clock, when the counting operation of the base clock is started from the transition from the positioning period to the pause period, and when the counted value reaches a given value, A timer that outputs a signal indicating that the end of the pause period has arrived, and when the signal that indicates the end of the pause period has been output from the timer, starts power supply from the power supply to the frequency conversion unit. A power switch that ends when the clock counting operation is started, and
A clock switch is provided to start supplying the base clock to the signal processing unit when a signal indicating the end of the pause period is output from the timer, and to terminate the supply when the timer starts counting operation of the base clock. The information processing unit keeps the signal processing unit in the operation halt state during the halt period due to the stop of the supply of the base clock and supplies power to the signal processing unit during the positioning period and the halt period, thereby retaining information regarding the prediction result in the signal processing unit even during the halt period. I will make it. In particular, when the signal processing unit includes a switching element formed by a CMOS process or the like, the switching operation of the element stops with the stop of the base clock, so that power consumption is reliably reduced.

Second, there is a method in which power supply to parts not related to holding of the prediction result is cut off during the idle period. That is, in the intermittent positioning management means, a base clock generating unit that generates a base clock, when the counting operation of the base clock is started from the transition from the positioning period to the pause period, and when the counted value reaches a given value, A timer that outputs a signal indicating that the end of the pause period has arrived, and a prediction result of the frequency conversion unit and the signal processing unit that is output from the power supply when a signal that indicates the end of the pause period has been output from the timer. A power switch is provided to start power supply to a part (eg, a processor for positioning calculation) that is not related to holding of information related to information, and to terminate when a timer starts counting operation of a base clock. Power related to the retention of information on the results (eg, carrier generation unit and code generation unit) should be supplied throughout the positioning period and the idle period. Also to be held with information on the prediction result by the signal processing portion in the rest period by.

Third, there is a method in which the frequency of the base clock supplied to the signal processing unit is reduced during the idle period. That is, in the intermittent positioning management means, a base clock generating unit that generates a base clock, when the counting operation of the base clock is started from the transition from the positioning period to the pause period, and when the counted value reaches a given value, A timer that outputs a signal indicating that the end of the pause period has arrived, and when the signal that indicates the end of the pause period has been output from the timer, starts power supply from the power supply to the frequency conversion unit. A power switch for terminating when the clock counting operation is started, and from the base clock generating unit until the timer outputs the signal indicating the end of the pause period from when the timer starts counting operation for the base clock. A clock conversion unit that lowers the frequency of the base clock supplied to the frequency conversion unit from the other periods is provided. Place the operating hibernate signal processing section during the idle period with a reduced, also to retain the information about the prediction result by the signal processing portion in the rest period by supplying electric power to the signal processing section through a positioning period and rest period. Generally, as the clock frequency decreases, the power consumption of the electronic circuit decreases. In particular, CMOS in the signal processing unit
When there is an element manufactured by the process, the power consumption is reduced by reducing the through current, which accounts for most of the current consumption. Here, the clock converter is used as a component of the intermittent positioning processing means by focusing on its function, but since the clock converter is a circuit that is always used together with the signal processing unit, a circuit or device is actually created. In doing so, a clock conversion unit may be provided in the signal processing unit or its processor.

In order to ensure that the actual length and the length used for the prediction match with each other, the signal processing unit performs the intermittent positioning during the transition from the positioning period to the pause period. It is desirable to set the length of the suspension period in the management means.

[0022]

Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same or corresponding components as those of the related art shown in FIGS. 6 and 7 are denoted by the same reference numerals and description thereof is omitted.

FIG. 1 shows a GP according to a first embodiment of the present invention.
2 shows a configuration of an S receiver. In this embodiment, a base clock generation unit 22A corresponding to the base clock generation unit 22 conventionally provided in the frequency conversion unit 12 includes:
It is provided outside the frequency conversion unit 12A. The base clock generated by the base clock generator 22A is supplied to the timer 16A and the clock switch 44.
The clock switch 44 is connected to the base clock generator 22A.
A switch for turning on / off the supply of the base clock to the multiplier 24 and the signal processing unit 14A from
It turns on while the timer signal output from the timer 16A is on, and turns off while it is off. Timer 16A
Performs the counting of the idle period length according to the signal supplied from the processor 40A in the signal processing unit 14A. The pause period length Toff to be counted may be set manually, or may be set from the processor 40A as shown.

The power supplied from the power supply 10 is supplied to the frequency conversion unit 12A via the power switch 18, while it is always supplied to the signal processing unit 14A. That is, while the timer signal output from the timer 16A is on, power is supplied to both the frequency conversion unit 12A and the signal processing unit 14A.
When the timer signal is off, power supply to the frequency conversion unit 12A is interrupted by the operation of the power switch 18, and power supply to the signal processing unit 14A is continued.

Further, the processor 40A instructs the carrier generation unit 34A and the code generation unit 36A constituting the frequency phase locked loop 42A to transmit the signal to the carrier generation unit 34 and the code generation unit 36 during the positioning period. And the same frequency and phase control as performed for In addition, the processor 40A determines the frequency of the carrier to be generated by the carrier generator 34A and the spectrum despreading code to be generated by the code generator 36A when the pause period ends and the next positioning period starts. Is calculated at the time of transition from the positioning period to the pause period, and the carrier generation unit 3 is operated in accordance with the result.
The carrier frequency and the phase of the spectrum despreading code are set in 4A and the code generator 36A.

FIG. 2 shows the operation of this embodiment.

First, in this embodiment, unlike the prior art in which the base clock generator 22 is provided in the frequency converter 12, the base clock generator 2
2A is provided outside the frequency conversion unit 12A, and therefore, the base clock is constantly generated throughout the positioning period and the pause period. The timer 16A counts the idle period length Toff by counting the base clock. The timer 16A detects the end point of the pause period by this counting operation, and turns on the timer signal which is the output thereof. When the timer signal is turned on, power supply from the power supply 10 to the frequency conversion unit 12A is started by the power switch 18, and at the same time, the base clock generation unit 22A transmits the frequency conversion unit 12A and the signal processing unit 1A.
The supply of the base clock to the 4A via the clock switch 44 is started. The frequency conversion unit 12A starts the frequency conversion operation using the local oscillation signal obtained by multiplying the base clock at the same time as starting to receive the power supply. The signal processing unit 14A is always supplied with power from the power supply 10 irrespective of the state of the power switch 18. However, during the idle period, the supply of the base clock is interrupted and the power consumption is suppressed. Has become. When the supply of the base clock is restarted with the start of the positioning period, the signal processing unit 14A executes operations related to positioning, including satellite selection and acquisition / tracking of satellite signals. When a necessary positioning result is obtained, the processor 40A in the signal processing unit 14A supplies the obtained positioning result to a device such as a mobile phone, for example, and based on the current synchronization state of the frequency phase locked loop 42A and the idle period length Toff. Then, the carrier frequency and the spread spectrum phase at the next start of the positioning period are predicted and set to the carrier generator 34A and the code generator 36A, respectively, and the idle period length Toff is set to the timer 16A. After that, the counting of the pause period length Toff by the timer 16A is started. As a result, the positioning period ends, and the pause period starts.

Here, in the present embodiment, the base clock generator 22A independent of the frequency converter 12A and the like.
The base clock is generated by the timer 16A
The idle period length Tof is calculated by counting the base clock.
Since f is realized as set, the synchronization of the frequency phase locked loop 42A at the start of the positioning period
It will be achieved in a short time. Further, since power is supplied from the power supply 10 to the signal processing unit 14A even during the suspension period, not only the prediction result is held in the signal processing unit 14A, but also the information in various registers in the processor 40A is stored. Is held. Therefore, at the start of the positioning period, the time required for setting necessary information in various registers in the processor 40A is not required. In addition, although the power supply is supplied from the power supply 10 to the signal processing unit 14A even during the suspension period, the supply of the base clock is cut off by the operation of the clock switch 44, so that the signal processing unit 14A performs the signal processing. The state of the unit 14A is in a so-called suspend state, and the power consumption of the power supply is suppressed.
In particular, when the processor 40A or the like is realized by a CMOS process or the like, the switching operation of the transistors and the like in the processor 40A is stopped by shutting off the base clock, so that the power consumption of the signal processing unit 14A during the idle period is reduced. Will be suppressed.

Further, in this embodiment, the base clock generated by the base clock generator 22A is multiplied and used as a local oscillation signal in the frequency converter 12A. Therefore, since the continuity of the base clock is guaranteed during the positioning period and during the positioning suspension, the frequency and phase of the spread spectrum signal of the IF signal and the carrier can be accurately predicted. If the temperature characteristics of the oscillator constituting the base clock generation unit 22A, for example, TCXO, are known in advance and if the current temperature can be detected or estimated, the carrier and spectrum spread of the IF satellite signal at the start of the positioning period are provided. The frequency and phase of the signal can be more accurately predicted.

FIG. 3 shows a functional configuration of the processor 40A, particularly, a portion related to the prediction described above. As shown in this figure, the result of demodulation and positioning,
According to the state of the base clock generation unit 22A, a prediction unit 46 for predicting an initial state to be taken by the carrier generation unit 34A and the code generation unit 36A when the next positioning period starts is provided. In the figure, a temperature sensor 48 is a temperature detecting means of the base clock generator 22A. Acceleration calculation unit 5
Numeral 0 is a member that calculates the acceleration of the moving object with respect to the satellite or the earth from the relative speed of the GPS receiver with respect to the GPS satellite or the facing speed of the moving object and supplies the calculated acceleration to the prediction unit 46.

FIG. 4 shows a GP according to a second embodiment of the present invention.
2 shows a configuration of an S receiver. In this embodiment, the power supply from the power supply 10 to the processor 40A in the signal processing unit 14A is managed by the power switch 18. Therefore, in this embodiment, the power supply to the processor 40A during the idle period is cut off. Therefore, in the present embodiment, power consumption by the processor 40A is suppressed.

FIG. 5 shows a GP according to a third embodiment of the present invention.
2 shows a configuration of an S receiver. In this embodiment, the clock converter 52 provided in the signal processor 14B performs an operation of converting the frequency of the clock to be supplied to the processor 40A. That is, during the positioning period, while the base clock generated by the base clock generation unit 22A is supplied to the processor 40A as the operation clock, while the timer signal output from the timer 16A is off. That is, during the idle period, the clock converted to a lower frequency by the clock converter 52 is supplied to the processor 40A. In the case where a processor having elements formed by, for example, a CMOS process is used as the processor 40A, the power consumption of the power supply due to the through current is reduced as the operating clock frequency is reduced. The power consumption of the power supply of the unit 14B is suppressed.

[Brief description of the drawings]

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

FIG. 2 is a timing chart showing the operation of the embodiment.

FIG. 3 is a block diagram showing a part related to prediction among functions in the processor.

FIG. 4 is a block diagram illustrating a configuration of a GPS receiver according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a GPS receiver according to a third embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a GPS receiver according to the related art.

FIG. 7 is a timing chart showing the operation of the conventional technique.

[Explanation of symbols]

10 power supply, 12A frequency converter, 14A, 14B
Signal processing unit, 16A timer, 18 power switch, 22
A base clock generator, 34A carrier generator,
36A code generator, 38 correlator, 40A processor, 42A frequency phase locked loop, 44 clock switch, 46 predictor, 52 clock converter.

Claims (9)

[Claims] 1. A satellite signal transmitted from a positioning satellite after being subjected to spread spectrum modulation is received, and synchronization of a frequency phase locked loop is established with respect to a carrier frequency and a spread spectrum phase of the received satellite signal so that the satellite signal is transmitted from the satellite signal. A series of positioning operations of demodulating the navigation data required for positioning calculation, executing positioning calculation based on the navigation data, and outputting positioning results related to the position of the moving object on which the device is mounted, takes a period of time between pauses. In the intermittent positioning method which is performed during the intermittent positioning period and in which at least a part of the circuits or devices necessary for the positioning operation is in the operation halt state during the halt period, prior to the transition from the positioning period to the halt period, , The carrier frequency and the spread spectrum phase after the elapse of the pause period are determined by the state of the frequency phase locked loop before the transition. And a prediction based on the length of the suspension period. During the suspension period, while keeping the result of the prediction, a counting operation for detecting the end of the suspension period is executed. When the end of the suspension period is detected, the circuit or device that has been in the operation suspension state is returned to the operation state in order to shift from the suspension period to the positioning period, and the held prediction result is initialized. Intermittent positioning method characterized by operating a frequency phase locked loop. 2. A positioning device that is mounted on a mobile body, performs a positioning operation during a positioning period, and suspends a positioning operation during a pause period between the positioning period and the next positioning period. A frequency conversion unit that performs a process of frequency-converting a satellite signal transmitted after spreading modulation to a lower frequency, and demodulates navigation data necessary for positioning calculation from the frequency-converted satellite signal and based on the demodulated navigation data. A signal processing unit that executes a positioning calculation and outputs the result of the position of the moving object or information related thereto, and the frequency conversion unit and the signal processing unit are set to an operation halt state when shifting from the positioning period to the halt period. Intermittent positioning management means for shifting to the operating state when shifting from the suspension period to the positioning period, and the signal processing unit is in the operating state during the positioning period. And the frequency-converted satellite signals obtained from the wave number conversion unit,
The correlation between the carrier generated in the signal processing unit and the spectrum despreading code is obtained, and the navigation data is demodulated from the satellite signal by controlling the frequency of the carrier and the phase of the spectrum despreading code in accordance with the obtained correlation. In the transition from the period to the idle period, the signal processing unit determines the frequency of the carrier and the phase of the spectrum despreading code to be adopted at the end of the idle period, the operating state of the signal processing unit before the transition and the length of the idle period. The intermittent positioning management means puts a part related to holding of information on the frequency of the carrier and the phase of the spectrum despreading code in the frequency conversion unit and the signal processing unit into an operation state, and other parts in the operation state. In the pause period, the signal processing unit holds information on the result of the prediction and intermittently The position management means manages the length of the pause period so as to be the length used for prediction in the signal processing unit. When shifting from the pause period to the positioning period, the intermittent positioning management means uses the frequency conversion unit and the signal processing unit. A positioning unit that returns the operation unit from the operation pause state to the operation state, and the signal processing unit starts a process of obtaining a correlation with the information held during the suspension period as an initial setting. 3. The positioning device according to claim 2, wherein the intermittent positioning management means generates a base clock throughout the positioning period and the idle period, and manages the length of the idle period by counting the base clock. The unit performs frequency conversion using the base clock supplied from the intermittent positioning management unit as a local oscillation signal, and the signal processing unit executes the positioning calculation in synchronization with the base clock supplied from the intermittent positioning management unit A positioning device, characterized in that: 4. The positioning device according to claim 2, wherein the signal processing unit determines the frequency of the carrier and the phase of the spectrum despreading code to be adopted at the end of the idle period, by changing the phase of the carrier before shifting to the idle period. The frequency and phase of the spectrum despreading code, at least the position of the moving object among the information obtained as a result of the positioning operation, the pseudorange from the moving object to the positioning satellite, the ground speed of the moving object, and the relative speed of the moving object to the positioning satellite A positioning device for making a prediction based on any one of them and the length of the pause period. 5. The positioning device according to claim 3, wherein the signal processing unit determines the frequency of the carrier and the phase of the spectrum despreading code to be adopted at the end of the idle period and the frequency and the carrier of the carrier before the transition to the idle period. A positioning device that performs prediction based on a phase of a spectrum despreading code, a temperature characteristic and an ambient temperature of a frequency of a base clock, and a length of the pause period. 6. The positioning device according to claim 3, wherein the intermittent positioning management means includes a base clock generating unit that generates a base clock, and starts counting operation of the base clock from a transition from the positioning period to the suspension period. A timer that outputs a signal indicating that the end of the idle period has arrived when the numerical value reaches a given value; and a frequency output from the power supply when the signal that indicates the end of the idle period has been output from the timer. A power switch for starting power supply to the conversion unit and terminating when the timer starts counting the base clock; and a power switch for terminating the end of the pause period from the timer to the signal processing unit. And a clock switch for starting supply of the base clock and terminating when the timer starts counting operation of the base clock. The signal processing unit is put into an operation halt state during the halt period with the halt, and information about the prediction result is held in the signal processing unit even during the halt period by supplying power to the signal processing unit throughout the positioning period and the halt period. Positioning device. 7. The positioning device according to claim 3, wherein the intermittent positioning management means includes: a base clock generation unit that generates a base clock; and a base clock counting operation that starts a base clock counting operation from a transition from a positioning period to a pause period. A timer that outputs a signal indicating that the end of the idle period has arrived when the numerical value reaches a given value; and a frequency output from the power supply when the signal that indicates the end of the idle period has been output from the timer. A power switch that starts power supply to a part of the conversion unit and the signal processing unit that is not related to holding of information on the prediction result and ends when the timer starts counting operation of the base clock. The part related to the maintenance of the information on the prediction result is supplied with power throughout the positioning period and the suspension period, so that the Positioning device characterized in that to hold that information in the signal processing section. 8. The positioning device according to claim 3, wherein the intermittent positioning management means includes a base clock generating unit that generates a base clock, and starts counting operation of the base clock from a transition point from a positioning period to a pause period. A timer that outputs a signal indicating that the end of the idle period has arrived when the numerical value reaches a given value; and a frequency output from the power supply when the signal that indicates the end of the idle period has been output from the timer. A power switch that starts power supply to the converter and ends when the timer starts counting the base clock, and a signal indicating the end of the idle period after the timer starts counting the base clock. Until output,
A clock conversion unit that lowers the frequency of the base clock supplied from the base clock generation unit to the frequency conversion unit compared to other periods, and sets the signal processing unit to the operation halt state during the halt period by reducing the frequency of the base clock. A positioning device that supplies information to the signal processing unit during the pause period by supplying power to the signal processing unit throughout the positioning period and the pause period. 9. The positioning device according to claim 2, wherein the signal processing unit sets the length of the pause period in the intermittent positioning management means when shifting from the positioning period to the pause period. Characteristic positioning device.