JP5338708B2 - Satellite signal receiver - Google Patents

Description

  The present invention relates to a satellite signal receiving apparatus that receives a signal from a positioning satellite such as a GPS satellite.

  A satellite signal transmitted from a GPS (Global Positioning System) satellite is spectrum-spread by a predetermined spreading code, and its signal level is lower than the noise level. Further, since the satellite signal operates at a high speed, the frequency of the signal at the reception point is shifted, and a delay occurs in the satellite signal reaching the reception point due to the distance from the GPS satellite. Therefore, in order to demodulate the satellite signal, it is first necessary to perform acquisition processing for searching for the frequency of the satellite signal and the synchronization point of the spread spectrum.

  In addition, as a prior art related to the present application, Patent Document 1 discloses a technique of a GPS receiving terminal of a method in which a signal output from a GPS receiving unit is once taken into a memory and used repeatedly several times. Yes.

JP 2000-266834 A

  Satellite signals cannot be received in places where radio waves do not reach, such as in buildings or underground. For this reason, if the receiving device executes the receiving process in such a place, it cannot be distinguished whether the radio wave has not arrived or the satellite signal has not been captured. For a second). Furthermore, the conventional satellite signal receiving apparatus has a problem that wasteful power consumption occurs because the receiving unit that receives the satellite signal continuously operates during the acquisition process.

  An object of the present invention is to provide a sanitary signal receiving apparatus that can prevent a large amount of power from being consumed unnecessarily due to a satellite signal capturing process when radio waves of a satellite signal do not reach.

In order to achieve the above object, the present invention provides:
In the satellite signal receiving device that receives the satellite signal sent from the positioning satellite,
A receiver for receiving signals in the frequency band of the satellite signal;
A storage unit capable of partially storing the signal received by the receiving unit as time-series data;
A capturing unit that captures the satellite signal from signals received by the receiving unit;
A tracking unit that tracks and demodulates the satellite signal captured by the capturing unit;
The received signal is temporarily stored in the storage unit, and the received signal is stored in the storage unit.Then, the reception unit is set in a non-operating state, and the time-series data stored in the storage unit is read and the First control means for repeatedly outputting to the capturing unit;
Second control means for determining whether or not the satellite signal is captured by the capturing unit by executing a control operation by the first control means when receiving a satellite signal from the positioning satellite;
When it is determined that the satellite signal has been captured by the second control means, the reception unit is operated to track and demodulate the satellite signal, while the satellite signal is not captured by the second control means. A third control unit that does not execute reception of the satellite signal while the reception unit is in a non-operating state,
It is characterized by having.

  According to the present invention, when receiving a satellite signal, the signal received by the receiving unit is stored in the storage unit as time series data, and the time series data in the storage unit is repeatedly sent to the capturing unit to include the satellite signal. It is determined whether or not If the satellite signal is not included, the reception process is interrupted, and if it is included, the reception process is executed. Therefore, it is possible to avoid the reception operation of the receiving unit from being continued unnecessarily for a long time in a place where the radio wave of the satellite signal does not reach, and to reduce power consumption.

1 is a block diagram showing an overall configuration of an electronic timepiece equipped with a satellite signal receiving device according to an embodiment of the present invention. It is a timing chart explaining an example of receiving operation of a satellite signal. It is a timing chart explaining an example of detailed receiving operation at the receiving time. It is a flowchart which shows the procedure of the reception control process performed by CPU. It is a flowchart which shows the procedure of the preliminary | backup acquisition process performed by step S5 of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an overall configuration of an electronic timepiece 1 equipped with a satellite signal receiving apparatus according to an embodiment of the present invention.

  The electronic timepiece 1 of this embodiment is, for example, a wristwatch that can receive a satellite signal transmitted from a GPS satellite to acquire time information and can correct a time measurement based on the time information. The electronic timepiece 1 includes an antenna 11 that receives radio waves in the frequency band of satellite signals, and a reception that converts a signal received by the antenna 11 into a signal of an intermediate frequency such as 4 MHz, and performs analog / digital conversion and outputs the signal. An RF (radio wave) receiving unit 12 as a unit, a memory unit (storage unit) 13 capable of storing or reading out digital signals output from the RF receiving unit 12 as time-series data, and a memory unit 13 A selector (switching unit) 14 that selectively sends one of the output and the output of the RF receiving unit 12 to the signal processing circuit 15, and signal processing for capturing, tracking, and demodulating a satellite signal from the output of the RF receiving unit 12 A circuit 15, a decoder 18 for decoding various information from the demodulated satellite signal, a clock for supplying or stopping an operation clock to the memory unit 13 and the signal processing circuit 15. The CPU supply circuit 19, a CPU (Central Processing Unit) 20 that controls the operation of each unit, a RAM (Random Access Memory) 21 that provides a working memory space to the CPU 20, and a control program and control executed by the CPU 20 A ROM (Read Only Memory) 22 for storing data, a display unit 23 such as a liquid crystal display for displaying time, a time measuring unit (time measuring means) 24 for measuring time, and the like are provided.

  In the present embodiment, a satellite signal receiving device is configured by the antenna 11, the RF receiving unit 12, the memory unit 13, the selector 14, the signal processing circuit 15, the decoder 18, the clock supply circuit 19, and the CPU 20 among the above configurations. . The CPU 20 constitutes first control means, second control means, third control means, intermittent reception control means, and time correction means.

  The RF receiver 12 is composed of, for example, one integrated circuit, an amplifier circuit that amplifies the signal received by the antenna 11, and a filter circuit that removes signal components other than the frequency band (1.5 GHz band) of the satellite signal. A mixer circuit that mixes local oscillation signals and converts a received signal into an intermediate frequency band signal, an AD (analog / digital) converter that analog-digital converts the intermediate frequency signal, and the like are provided. Since the RF receiver 12 includes an analog circuit, it consumes more current than a series of digital processing circuits in the subsequent stage.

  The RF receiving unit 12 can be controlled to execute a receiving operation when the power is turned on by the power control signal from the CPU 20 or to stop the receiving operation when the power is turned off. While the power is turned off by the power control signal, the current consumption can be kept very small.

  The memory unit 13 includes a RAM 13a that stores data, a memory controller 13b that performs data write control and data read control on the RAM 13a, and the like. The memory controller 13b receives an operation control signal (command) from the CPU 20, receives the digital signal output from the RF receiver 12 and writes it in the RAM 13a in time series, or reads this data in time series to read the selector 14 side. Or output to

  The RAM 13a temporarily accumulates time-series data representing a signal to be captured when performing a preliminary capture process to determine whether or not a satellite signal is included in the received signal. The digital signal output from the RF receiver 12 has a capacity capable of storing, for example, 10 milliseconds.

  In addition, since the GPS satellite signal is configured such that the spread code of the spread spectrum is repeated at a cycle of 1 msec, if the signal for 1 msec can be stored, it can be used for the acquisition process of the satellite signal. However, in order to stably perform the capturing process, it is preferable to store at least signals for 3 milliseconds, and for the purpose of reducing the current consumption by shortening the operation time of the RF receiver 12, it may be long. It is good to keep the memory of the signal for 50 milliseconds.

  The memory unit 13 operates by receiving an operation clock from the clock supply circuit 19 and stops the operation when the operation clock is stopped.

  Based on the selection control signal from the CPU 20, the selector 14 switches the input to the capture circuit 16 to the RF receiver 12 side or the memory unit 13 side.

  The signal processing circuit 15 includes a capturing circuit (capturing unit) 16 that captures a satellite signal, and a tracking circuit (tracking unit) 17 that demodulates the captured satellite signal while tracking it. The acquisition circuit 16 obtains a cross-correlation value between a signal waveform generated using a predetermined spreading code and an input signal while appropriately changing the shift amount of the satellite signal frequency and the shift amount of the synchronization point of the satellite signal. Thus, a setting that obtains a correlation value greater than a certain value is obtained. The tracking circuit 17 demodulates the satellite signal by performing despreading processing on the satellite signal acquired by the acquisition circuit 16 while appropriately adjusting the frequency and the shift amount of the synchronization point.

  The capture circuit 16 and the tracking circuit 17 operate by receiving operation clocks independently from the clock supply circuit 19 and stop the operation when these operation clocks are stopped.

  The clock supply circuit 19 supplies an operation clock to the memory unit 13 and the signal processing circuit 15, and can individually stop or re-supply these operation clocks according to a switching control signal from the CPU 20. It has become.

  In the ROM 22, as a control program executed by the CPU 20, a time display process for causing the display unit 23 to display the time corresponding to the time measurement data by updating the display content of the display unit 23 in synchronization with the time measurement data of the time measurement unit 24. And a program for reception control & time correction processing for acquiring time information by receiving a satellite signal from a GPS satellite at a predetermined timing and correcting the time measured by the time measuring unit 24 based on this time information. ing.

  Next, a satellite signal reception operation in the electronic timepiece 1 having the above-described configuration will be described.

  In the electronic timepiece 1 of this embodiment, satellite signals are received at intermittent timings in order to acquire time information from GPS satellites. When receiving a satellite signal, there is a possibility that the radio wave of the satellite signal has not arrived in the building or the like. First, a preliminary acquisition process is performed to determine whether or not the satellite signal is included in the received signal. Run.

  In the preliminary acquisition process, the reception signal from the RF reception unit 12 is temporarily accumulated in the memory unit 13, and the reception signal of the memory unit 13 is repeatedly sent to the acquisition circuit 16 to perform the acquisition process, whereby the received signal is a satellite signal. Whether or not is included.

  Immediately before the preliminary acquisition process, the RF receiving unit 12 is operated for a short time, and the reception signal of the RF receiving unit 12 is temporarily stored in the memory unit 13. The time length for accumulating the received signal is about 10 milliseconds. After accumulating the received signals, the power of the RF receiving unit 12 is turned off during the preliminary acquisition process. Therefore, even if it takes about several seconds for the acquisition circuit 16 to acquire the satellite signal in the preliminary acquisition process, the operation time of the RF receiver 12 that consumes a large amount of current is less than 1/100 of that. Can be reduced.

  If the satellite signal can be confirmed by the preliminary acquisition process, the RF reception unit 12 is operated again to acquire the time information, and the actual reception process of the satellite signal is performed. On the other hand, if the reception of the satellite signal cannot be confirmed by the preliminary acquisition process, it is determined that the radio wave of the satellite signal has not arrived and the satellite signal is not received. By the satellite signal reception process accompanied by such a preliminary acquisition process, it is avoided that the RF receiver 12 operates unnecessarily long and consumes a large amount of current when the radio wave of the satellite signal does not reach.

  Next, timing control for executing the above reception operation will be described.

  FIG. 2 shows a timing chart for explaining an example of the satellite signal reception operation. FIG. 4A shows the operating state of the RF receiving unit 12, and FIG. 4B shows the operating state of the baseband unit (memory unit 13, signal processing circuit 15, and decoder 18).

  In FIG. 2, M1 to M3 indicate the entire operation period from the time when the satellite signal is received until the time information is acquired from the preliminary acquisition process, and F1 to F4 indicate that the satellite signal cannot be confirmed by performing the preliminary acquisition process. Each operation period is shown when it ends.

  In the electronic timepiece 1 of this embodiment, as shown in the operation periods M1 to M3 in FIG. 2, the satellite signal is received once a day to acquire time information.

  On the other hand, if the satellite signal is not confirmed in the preliminary acquisition process performed at the time of the reception process, the reception process is performed again after a short time such as one hour as shown in the operation periods F1 to F4. It has become. In the example of FIG. 2, the satellite signal is not captured in the third reception operation (operation period F1 to F3) on the first day, and the satellite signal is successfully received in the fourth reception operation (operation period M1). Yes. The satellite signal has been successfully received on the second day by the second reception operation (operation period M2) and on the third day by the first reception operation (operation period M3).

  FIG. 3 shows a timing chart for explaining an example of a detailed reception operation at the time of reception. FIGS. 7A to 7C show on / off operations of the RF receiver 12, the capture circuit 16, and the tracking circuit 17, respectively. In this figure, F1 to F3, m1 are periods related to the preliminary capturing process.

  Specifically, as shown in the periods F1 to F3 and m1 in FIG. 3, the RF receiving unit 12 operates for a very short time (for example, 10 msec) before the pre-acquisition processing, and the received signal during this period is stored in the memory unit. 13 is accumulated. Subsequently, the power of the RF receiver 12 is turned off, and an operation clock is supplied to the capture circuit 16 so that the capture circuit 16 operates. Then, the reception signal stored in the memory unit 13 is supplied to the acquisition circuit 16 and an acquisition process is executed for a short time (for example, several seconds) to determine whether or not the satellite signal is included in the reception signal.

  If the satellite signal is not confirmed, as shown in the periods F1 to F3 in FIG. 3, the supply of the operation clock to the capturing circuit 16 is subsequently interrupted, and the configuration related to the reception of the satellite signal is not so long. It will be in a waiting state only for time (for example, 1 hour).

  In the preliminary acquisition process, as shown in FIG. 3, the RF receiver 12 operates only for a very short time immediately before that, so the electronic timepiece 1 is placed in a place where the radio wave of the satellite signal does not reach for a long period. Even if a large number of preliminary acquisition processes are executed, the power consumption does not increase so much.

  On the other hand, if the satellite signal is confirmed, as shown in the period M1 in FIG. 3, after the preliminary acquisition process in the period m1, the power of the RF receiver 12 is turned on, and the received signal is transmitted via the selector 14 to the signal. It is supplied to the processing circuit 15. When the reception signal is supplied, the signal processing circuit 15 first supplies an operation clock to the acquisition circuit 16 and completes acquisition of the satellite signal in a short time (period H1 in FIG. 3).

  In this acquisition process, since the satellite signal has just been acquired in the immediately preceding preliminary acquisition process, in a short time based on the spread code (satellite number), the frequency and the shift amount of the synchronization point of the acquired satellite signal. Satellite signal acquisition can be completed.

  When the satellite signal is acquired, the operation clock of the acquisition circuit 16 is stopped, the operation clock is supplied to the tracking circuit 17, and the received signal is demodulated (period H2 in FIG. 3). The demodulated signal is decoded by the decoder 18 and necessary information such as time information is sent to the CPU 20.

  Next, the reception control & time adjustment process for realizing the satellite signal reception operation and the reception process schedule control as described above will be described in detail with reference to a flowchart.

  FIG. 4 shows a flowchart of the reception control & time adjustment process executed by the CPU 20.

  This reception control & time adjustment process is started when the electronic timepiece 1 is reset, and thereafter continuously executed. When the reception control & time correction process is started, first, as preparation for the preliminary acquisition process, the CPU 20 causes the RF reception unit 12 to perform a reception operation, and receives the waveform data of the reception signal in the RAM 13a of the memory unit 13 in time series. It accumulates in order (step S1). Specifically, the power of the RF receiving unit 12 is turned on by the power control signal, the operation clock is supplied to the memory unit 13 by the clock supply circuit 19, the data storage command is issued to the memory controller 13b, and the received signal is Accumulate in chronological order. At this time, since the operation of the signal processing circuit 15 is unnecessary, the operation clock to the capturing circuit 16 and the tracking circuit 17 is stopped.

  Subsequently, the CPU 20 determines whether or not the received signal data for a predetermined time (for example, 10 milliseconds) has been accumulated in the RAM 13a of the memory unit 13 (step S2), and the signal reception and data accumulation in step S1 are performed until the data is accumulated. Continue processing.

  Then, when the data accumulation is completed, the CPU 20 executes a preliminary acquisition process for causing the acquisition circuit 16 to acquire the satellite signal using the accumulated received signal data (step S3). Specifically, first, the power of the RF receiving unit 12 is turned off by the power control signal, the operation clock is supplied to the memory unit 13 and the capturing circuit 16 by the clock supply circuit 19, and a command is issued to the memory controller 13b to generate data. Are repeatedly read in chronological order. In addition, a selection control signal is output to the selector 14 and the output on the memory unit 13 side is sent to the capturing circuit 16. At this time, since the operation of the tracking circuit 17 is unnecessary, the operation clock to the tracking circuit 17 is stopped. A detailed description of this preliminary capturing process will be described later.

  When the preliminary acquisition process is completed, the CPU 20 confirms the state of the acquisition circuit 16 and determines whether or not a satellite signal has been acquired by the preliminary acquisition process, that is, whether or not a GPS satellite has been found from the received signal (step S4). ). As a result, if the satellite signal is not captured, it can be assumed that the radio wave of the satellite signal has not arrived. Therefore, first, the operation of the circuit that receives the GPS satellite signal is stopped (step S11). That is, the RF receiving unit 12 is kept powered off, and the operation clock to the memory unit 13 and the signal processing circuit 15 is stopped.

  Further, the next reception processing timing is set to a short time such as one hour later so that the satellite signal can be received when the electronic timepiece 1 moves to the place where the radio wave of the satellite signal reaches next time. Then, this reception control & time adjustment process by the CPU 20 is set in a standby state (step S12). Then, when the next reception processing timing comes, the processing from step S1 is executed again.

  On the other hand, if it is determined in step S4 that the satellite signal has been captured, the CPU 20 first causes the RF receiver 12 to perform a reception operation and causes the capture circuit 16 to receive the satellite signal. The satellite signal is captured and synchronized with the GPS satellite side (step S5). Specifically, the power of the RF receiver 12 is turned on by the power control signal, the input of the selector 14 is switched to the RF receiver 12 side, and the clock supply circuit 19 supplies the operation clock to the capture circuit 16. The operation clock to the tracking circuit 17 is stopped.

  In the acquisition process of step S5, since the acquisition process for the satellite signal a little earlier is completed by the preliminary acquisition process of step S3, the spreading code (satellite number) and the signal frequency of the satellite signal are determined by the preliminary acquisition process. By using the captured settings as they are and calculating the cross-correlation value of the signal while adjusting only the shift amount of the synchronization point of the satellite signal, the satellite signal is captured in a short time and synchronized with the GPS satellite. be able to.

  When synchronization with the GPS satellite is established, the CPU 20 operates the tracking circuit 17 and the decoder 18 to cause the tracking circuit 17 to track and demodulate the satellite signal, and further to decode the signal demodulated by the decoder 18. The decrypted received data is input (step S6). Specifically, the supply of the operation clock to the capture circuit 16 is stopped and the supply of the operation clock to the tracking circuit 17 is started while the RF receiver 12 is turned on and the selector 14 is switched to the RF receiver 12 side. . Then, the output data of the decoder 18 is taken in. The operation clock to the memory unit 13 remains stopped.

  Subsequently, the CPU 20 determines whether or not necessary data has been acquired from the transmission data from the GPS satellite (step S7), and continues to capture the output data of the decoder 18 until necessary data is acquired.

  As a result, when necessary data is acquired, the process proceeds to the next step, where the current time is obtained based on the received data from the GPS satellite, and the time measured by the time measuring unit 24 is corrected (step S8: time correcting means). Then, the power of the RF receiving unit 12 is turned off by the power control signal, the operation clock to the signal processing circuit 15 and the memory unit 13 is stopped, and the operation of the entire circuit for receiving the satellite signal is stopped (step S9).

  Subsequently, since the timing time of the timing unit 24 can be corrected, the timing of the next reception process is set to, for example, 24 hours later (or the predetermined time on the next day), and this reception control of the CPU 20 until the set time is reached. & The time correction process is set to a standby state (step S10). Then, when the next reception processing timing comes, the processing from step S1 is resumed.

  Of the above steps, the first control means is performed by the processes of steps S1 to S3, the second control means is performed by the processes of steps S3 to S4, the third control means is performed by the processes of steps S4 to S7, and steps S9 to S12 are performed. The intermittent reception control means is configured by the above processing.

  FIG. 5 shows a detailed flowchart of the preliminary capture process executed in step S3 of FIG.

  When the process proceeds to the preliminary acquisition process, first, the acquisition circuit 16 initializes a variable in which the value of the carrier frequency of the satellite signal assumed to be acquired is stored (step S21), and sets the above variable as the set value of the carrier frequency. The value is applied (step S22).

  Subsequently, in order to capture any of the satellite signals transmitted from a plurality of GPS satellites, the acquisition circuit 16 determines the satellite number (spreading code: for example, C / A code) of the satellite signal assumed as the acquisition target. The stored variable is initialized (step S23), and the satellite number to be captured is set with the value of this variable (step S24).

  The processing in steps S21 to S24 may be performed by the CPU 20 sequentially issuing commands to the capture circuit 16 and executed, or the capture circuit 16 automatically executes such processing at the start of operation. It can also be configured as follows.

  Next, the CPU 20 resets the read address in order to read the data of the received signal from the memory unit 13 in chronological order (step S25), and outputs the read address and the read command to the memory controller 13b. The received signal data is sequentially read out from 13 and supplied to the capture circuit 16. At the same time, the capture circuit 16 shifts the phase point (synchronization point) of the signal waveform to obtain a correlation value of a certain level or more between the signal waveform generated based on the settings of steps S22 and S24 and the received signal. (Step S26).

  Then, it is determined whether or not the reading of the received signal data from the RAM 13a is completed (step S27), and the data reading and the correlation value calculation in step S26 are continued until the reading is completed.

  By the loop processing of steps S26 and S27 described above, for example, 10 msec of received signal data accumulated in the RAM 13a is sent to the acquisition circuit 16, and a signal generated with one carrier frequency setting and one satellite number setting. An operation is performed to determine whether a certain level of correlation is obtained between the waveform and the received signal.

  When the data reading of one reception signal from the RAM 13a is completed, the correlation value calculated in step S26 is stored (step S28). For example, it is stored in a register of the signal processing circuit 15, or is read out by the CPU 20 and stored in the RAM 21.

  Subsequently, the acquisition circuit 16 sequentially changes the variable value of the acquisition target satellite number (step S29), and determines whether the calculation of the correlation value has been completed with the setting of all the satellite numbers corresponding to all the GPS satellites ( Step S30). If not, the process returns to step S24 to repeat the process of setting the satellite number to be captured.

  That is, by repeating the processing of steps S24 to S30, it is confirmed for all satellite numbers whether or not the satellite signal is included in the received signal stored in the RAM 13a, and the correlation value corresponding to each satellite number is obtained. It is supposed to be saved.

  If it is determined in the determination process in step S30 that the calculation of correlation values has been completed for all the satellite numbers, the process proceeds to the next step and the variable value of the carrier frequency of the acquisition target satellite signal is shifted by a predetermined amount. Change is made (step S31). Subsequently, it is determined whether or not the carrier frequency setting has been changed over the entire predetermined setting range (step S32). As a result, if not yet, the process returns to step S22 to repeat the process of setting the carrier frequency of the satellite signal to be captured.

  That is, by repeating the processes of steps S22 to S32, it is confirmed whether or not the satellite signal is included in the received signal stored in the RAM 13a for all carrier frequencies shifted by a predetermined amount within a predetermined setting range. Thus, a correlation value corresponding to each carrier frequency is stored.

  If it is determined in the determination process in step S32 that all carrier frequency settings have been changed, the preliminary acquisition process ends.

  Therefore, after completion of the preliminary acquisition process, the CPU 20 checks the correlation value stored in the register or RAM 21 to determine whether or not the satellite signal has been acquired from the received signal stored in the RAM 13a. It becomes possible. In addition, it is possible to identify which carrier frequency and which satellite number are used to acquire the satellite signal.

  As described above, according to the electronic timepiece 1 of this embodiment, the reception signal accumulated in the memory unit 13 is repeatedly sent to the acquisition circuit 16 to perform preliminary acquisition processing, and satellite signals are included by this preliminary acquisition processing. If it is determined that the satellite signal is not included, the reception process is executed. If it is determined that the satellite signal is not included, the reception process is not executed. It is only necessary to operate the RF receiving unit 12 for a very short time to be stored in the memory unit 13. Therefore, useless operation of the RF receiver 12 can be omitted and power consumption can be reduced.

  In addition, since the memory unit 13 stores the waveform data of the received signal for 10 milliseconds and is used for the preliminary acquisition process, it is possible to stably determine whether the received signal includes a satellite signal, The power consumption can be sufficiently reduced by shortening the operation time of the RF receiver 12.

  The RF receiver 12 outputs a signal obtained by frequency-converting and analog-digital conversion of the received signal, and the capturing circuit 16 and the tracking circuit 17 perform capturing processing and tracking processing on the analog-digital converted signal. Because of the configuration, the memory unit 13 can store the output of the RF receiving unit 12 in time series, read the stored data in time series, and send the data to the acquisition circuit 16 to execute the preliminary acquisition process.

  In addition, since the selector 14 for switching the input of the capture circuit 16 between the RF receiver 12 side and the memory unit 13 side is provided, the normal reception process and the preliminary capture process can be easily performed by switching the selector 14. The signal path can be switched.

  In addition, if the satellite signal reception schedule can receive the satellite signal, the standby time until the next reception is set longer, and if the satellite signal cannot be captured by the preliminary acquisition process, the standby time until the next reception is set shorter. Even in situations where radio waves do not reach much, satellite signals can be received with high probability when moving to a location where radio waves reach. Further, even when the preliminary acquisition process is performed many times in a place where radio waves do not reach, the power consumption of one preliminary acquisition process is very small as described above, so that the total power consumption is not so much.

  In addition, the above-described schedule control of the reception process and the satellite signal reception process including the preliminary acquisition process are particularly effective in the electronic timepiece 1 that acquires time information from the satellite signal and corrects the time. It becomes. That is, in the electronic timepiece 1 driven by a battery, the electric power required for driving the RF receiving unit 12 for several seconds is also greatly consumed. Therefore, it is a remarkable effect that the power consumption can be reduced by the preliminary capturing process. In addition, the electronic watch 1 such as a wristwatch sometimes has a low frequency of being taken out to the place where the radio wave of the satellite signal reaches due to the life pattern. It is possible to avoid a situation in which reception and time adjustment are not performed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the method for capturing satellite signals is not limited to the one shown in the above embodiment, and various known methods can be applied.

  In the above embodiment, the configuration in which the satellite signal receiving device according to the present invention is mounted to acquire time information in the electronic timepiece is illustrated. However, when the positioning device receives a satellite signal for position measurement. The reception processing method including the preliminary acquisition processing according to the present invention may be applied.

  In addition, the detailed configuration and the detailed method shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Electronic timepiece 11 Antenna 12 RF receiving part 13 Memory part 13a RAM
13b Memory Controller 14 Selector 15 Signal Processing Circuit 16 Capture Circuit 17 Tracking Circuit 18 Decoder 19 Clock Supply Circuit 20 CPU
24 Timekeeping Department

Claims (6)

In the satellite signal receiving device that receives the satellite signal sent from the positioning satellite,
A receiver for receiving signals in the frequency band of the satellite signal;
A storage unit capable of partially storing the signal received by the receiving unit as time-series data;
A capturing unit that captures the satellite signal from signals received by the receiving unit;
A tracking unit that tracks and demodulates the satellite signal captured by the capturing unit;
The received signal is temporarily stored in the storage unit, and the received signal is stored in the storage unit.Then, the reception unit is set in a non-operating state, and the time-series data stored in the storage unit is read and the First control means for repeatedly outputting to the capturing unit;
Second control means for determining whether or not the satellite signal is captured by the capturing unit by executing a control operation by the first control means when receiving a satellite signal from the positioning satellite;
When it is determined that the satellite signal has been captured by the second control means, the reception unit is operated to track and demodulate the satellite signal, while the satellite signal is not captured by the second control means. A third control unit that does not execute reception of the satellite signal while the reception unit is in a non-operating state,
A satellite signal receiving apparatus comprising: The receiver is
It is a configuration that receives a signal in the frequency band of the satellite signal, performs frequency conversion and digital conversion, and outputs it,
The capturing unit and the tracking unit are
2. The satellite signal receiving apparatus according to claim 1, wherein each of the signals subjected to frequency conversion and digital conversion by the reception unit is configured to perform acquisition, tracking, and demodulation processing. During the control operation of the first control means, the storage unit stores the time series data corresponding to a signal of 3 to 50 milliseconds, and the time series data is repeatedly output to the capturing unit. The satellite signal receiving apparatus according to claim 1 or 2 . A switching unit capable of switching the input of the capturing unit to either the receiving unit side or the storage unit side;
The first control means includes
4. The satellite signal receiving apparatus according to claim 1, wherein the switching unit is switched to the storage unit side to read out the time series data stored in the storage unit. Comprising intermittent reception control means for intermittently receiving the satellite signal;
The intermittent reception control means includes
When the satellite signal is captured and reception of the satellite signal is performed in the intermittently executed reception process, the first reception period is set to open the first period,
If it is determined that the satellite signal is not captured by the second control means in the reception process that is executed intermittently, and the satellite signal is not received, a second period shorter than the first period is opened and the next The satellite signal receiving apparatus according to claim 1, wherein the satellite signal receiving apparatus is set to perform the following reception process. A time measuring means for measuring time;
Time correction means for taking out time information from the satellite signal demodulated by the tracking unit and correcting the time measured by the time measuring means;
The satellite signal receiver according to claim 1, comprising:

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