JP6699697B2 - Radio wave receiver, electronic clock, satellite radio wave reception method, and program - Google Patents

Description

The present invention relates to a radio wave receiving device that receives a radio wave transmitted from a positioning satellite , an electronic clock , a satellite radio wave receiving method, and a program .

  BACKGROUND ART Conventionally, there is an electronic timepiece that receives a radio wave transmitted from a positioning satellite related to the Global Positioning System (GNSS) and acquires the date and time and the position. In this electronic timepiece, the received transmission radio wave is amplified, frequency-converted and filtered by an RF (Radio Frequency) circuit, and demodulated and decoded by demodulation signal processing to obtain necessary information.

  When receiving the transmitted radio waves from the positioning satellites, the satellite signals related to the receivable transmitted radio waves are promptly searched and captured from the transmitted radio waves from the plurality of positioning satellites, and the captured multiple satellite signals are parallelized. There is an inherent circumstance that it is necessary to acquire the data by a receiver, and a receiver capable of obtaining sufficient sensitivity is required to perform such an operation. Therefore, the RF circuit mounted on the electronic timepiece is required to have high gain and low noise figure (NF), and as a result, the power consumed by the RF circuit greatly affects the power consumption of the entire electronic timepiece. .. Therefore, the power consumption of the RF circuit has been reduced as part of the suppression of the power consumption of the electronic timepiece.

  For example, Patent Document 1 discloses a receiving apparatus that suppresses power consumption by stopping power supply to an RF circuit after capturing a satellite signal and supplying power to the RF circuit only at a timing when necessary information can be acquired. There is.

JP, 2009-300274, A

  However, the reception state of the radio waves from the positioning satellite changes greatly depending on the environment of the receiving side. Therefore, if the reception operation is performed uniformly without considering the reception state, there is a problem that excessive power consumption may occur.

An object of the present invention is to provide a radio wave receiving device , an electronic timepiece , a satellite radio wave receiving method, and a program capable of optimizing power consumption according to the reception state of radio waves transmitted from positioning satellites.

The present invention, in order to achieve the above object,
Signal amplifying means for receiving the transmission radio wave from the positioning satellite and amplifying the signal of the received transmission radio wave,
A signal amplified by the signal amplifying unit is input, a satellite signal is captured from the signal, demodulation processing is performed on the captured satellite signal, and a demodulating unit that sets the gain of the signal amplifying unit,
Information acquisition means for acquiring at least one of position information and date and time information from the satellite signal,
Equipped with
The demodulation means , based on the number of the predetermined portion for identifying the position of the satellite signal in the transmission format of the captured satellite signal identified by the information acquisition means within the position identification time, the signal amplification means. The radio wave receiving device is characterized in that the gain of is set .

  According to the present invention, there is an effect that the power consumption can be optimized according to the reception state of the radio wave transmitted from the positioning satellite.

It is a block diagram which shows the functional structure of the electronic timepiece which concerns on 1st Embodiment of the receiver and electronic timepiece of this invention. It is a block diagram which shows the function structure of a GPS reception process part. It is a block diagram which shows the function structure of an RF amplification part. It is a figure explaining the operation mode of an RF amplification part. It is a figure explaining the transmission format of a satellite signal. It is a flow chart which shows the control procedure of local time acquisition processing. It is a flow chart which shows the control procedure of the date acquisition processing concerning a 2nd embodiment. It is the 1st part of the flow chart which shows the control procedure of local time acquisition processing concerning a 3rd embodiment. It is the 2nd part of the flowchart which shows the control procedure of the local time acquisition process which concerns on 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a functional configuration of an electronic timepiece 1 according to a first embodiment of a radio wave receiving device and an electronic timepiece of the invention.

  The electronic timepiece 1 is, but not limited to, an analog electronic timepiece that displays the date and time using hands. The electronic timepiece 1 includes a CPU 20 (Central Processing Unit) (date and time correction means), a ROM 21 (Read Only Memory), a RAM 22 (Random Access Memory), an oscillation circuit 23, a frequency dividing circuit 24, and a clock circuit 25 (clocking time). Means), the GPS reception processing unit 10 and its antenna 10a, the standard radio wave reception unit 26 and its antenna 26a, the drive circuit 27, the operation unit 28, the power supply unit 29, the light amount sensor 30, the second hand 41 and the same. A wheel train mechanism 51 for rotation, a minute hand 42 and a wheel train mechanism 52 for its rotation, an hour hand 43 and a wheel train mechanism 53 for its rotation, a date wheel 44 and a wheel train mechanism 54 for its rotation, The stepping motors 61, 62, 64 for operating the row mechanisms 51 to 54 are provided. Of these, the portion including the GPS reception processing unit 10 and the antenna 10a corresponds to a radio wave reception device.

  The CPU 20 performs various kinds of arithmetic processing, and also controls the overall operation of the electronic timepiece 1. The CPU 20 controls the operation of the pointer and causes the pointer to perform various displays including the date and time. Further, the CPU 20 operates the standard radio wave reception unit 26 to acquire the reception data and calculate the date and time. Further, the CPU 20 operates the GPS reception processing unit 10 to acquire date and time information, and corrects the date and time counted by the clock circuit 25 based on the obtained date and time information.

  The ROM 21 stores programs 221 for various controls executed by the CPU 20. The program 221 includes, for example, a date and time correction program that corrects the date and time counted by the clock circuit 25.

  The RAM 22 provides the CPU 20 with a working memory space and stores temporary data. The RAM 22 also stores date and time correction, positioning results, data indicating the set time zone and pointer position, and the like.

The oscillator circuit 23 generates and outputs a predetermined frequency signal. The oscillator circuit 23 includes, for example, a crystal oscillator.
The frequency dividing circuit 24 divides the frequency signal output from the oscillation circuit 23 into a signal of a frequency used by the CPU 20 and the time counting circuit 25, and outputs the signal. The output frequency may be configured to be changeable by a control signal from the CPU 20.

  The clock circuit 25 counts the current date and time by counting the frequency-divided signal input from the frequency divider circuit 24 and adding it to an initial value indicating a predetermined date and time. The date and time counted by the clock circuit 25 can be corrected by a control signal from the CPU 20.

  The operation unit 28 receives an input operation from the user. The operation unit 28 includes, for example, a push-button switch and a crown, detects a motion such as a push-button switch being pressed, a crown being pulled out, and a rotating operation being performed, and the operation type 28 is determined according to the motion type. The electric signal is output to the CPU 20.

  The standard radio wave reception unit 26 receives radio waves in the long wavelength band using the antenna 26a, demodulates the time signal output (TCO) of the amplitude-modulated standard radio wave, and outputs the time signal output to the CPU 20. The tuning frequency for the radio wave in the long wavelength band by the standard radio wave reception unit 26 is adjusted by the control of the CPU 20 according to the transmission frequency from the standard radio wave transmission station to be received. Further, the standard radio wave reception unit 26 performs various processes for improving the reception sensitivity, digitizes the analog signal at a predetermined sampling frequency, and outputs the digitized signal to the CPU 20.

  The GPS reception processing unit 10 receives a radio wave in the L1 band (1.57542 GHz) using the antenna 10a, demodulates and decodes a spread spectrum transmission radio wave from a positioning satellite, here, a GPS satellite, and decodes the satellite signal ( Decipher the navigation message). Further, the GPS reception processing unit 10 calculates the current date and time and the current position based on the decoding result. The content of the decrypted satellite signal is output to the CPU 20 in a predetermined format. Operation control relating to reception, decoding and output of these is performed by the CPU 123 (FIG. 2) provided in the GPS reception processing unit 10. The configurations for performing the operations related to demodulation, decoding, decoding and control in the GPS reception processing unit 10 are collectively formed as a module on a single chip and connected to the CPU 20. The operation of the GPS reception processing unit 10 is controlled by the CPU 20 to be turned on/off independently of the operations of the other units of the electronic timepiece 1. When the operation of the GPS reception processing unit 10 is off, the power supply to the GPS reception processing unit 10 is also interrupted to save power. The detailed configuration of the GPS reception processing unit 10 will be described later.

  The power supply unit 29 supplies power related to the operation of each unit with a predetermined voltage. The power supply unit 29 has a battery, and as the battery, for example, a solar panel and a secondary battery are provided. Alternatively, a replaceable button-type battery may be used as the battery.

  The light amount sensor 30 is provided, for example, in the vicinity of the dial provided on the display side of the electronic timepiece 1 and at a position capable of receiving light incident from the outside on the display side. , Measure the amount of light emitted. As the light quantity sensor 30, for example, a photodiode is used. The light amount sensor 30 outputs an electric signal (voltage signal or current signal) according to the amount of incident light, is digitally sampled by an ADC (analog/digital converter) (not shown), and is input to the CPU 20. Alternatively, when a solar panel is used as the power supply unit 29, the incident light amount may be measured based on the electromotive force generated by the solar panel.

  The second hand 41, the minute hand 42, the hour hand 43, and the date indicator 44 (some or all of them are collectively referred to as a pointer) are pointers indicating the second, minute, hour, and date when displaying the date and time, respectively. is there. Here, the second hand 41, the minute hand 42, and the hour hand 43 are needle-like hands whose rotation axis is substantially the center of the dial provided on the surface (display surface) of the electronic timepiece 1, and the scales provided on the dial. The time, various function types, and states are indicated by pointing to or signs. The date dial 44 is a rotary disc or an annular member provided on the back side of the dial (opposite to the display surface) in parallel with the dial, and is on one circumference of the surface facing the dial. Signs indicating the date are provided at equal intervals, and the date is indicated by exposing any one of the signs from the opening provided in the dial.

  The train wheel mechanism 51 is a gear train that transmits the rotation of a predetermined angle (here, 6 degrees) to the second hand 41 every time the stepping motor 61 is rotationally driven. The train wheel mechanism 52 transmits the rotation of a predetermined angle (here, 1 degree) to the minute hand 42 every time the stepping motor 62 is rotationally driven. The train wheel mechanism 53 rotates in association with the rotation of the train wheel mechanism 52 and transmits 1/12 of the rotation of the minute hand 42 to the hour hand 43. That is, the hour hand 43 rotates 30 degrees each time the minute hand 42 rotates 360 degrees, and the minute hand 42 makes 12 rotations on the dial while the hour hand 43 rotates 360 degrees. The train wheel mechanism 54 transmits rotation of a predetermined angle to the date dial 44 every time the stepping motor 64 is rotationally driven. The date indicator 44, for example, is rotated and moved 360/31 degrees by the rotation operation of 1440 steps, and the sign exposed from the opening changes by one day.

  In each of the stepping motors 61, 62, 64, the rotor rotates a predetermined angle with respect to the stator in accordance with the drive pulse input from the drive circuit 27. The rotation of the rotor is transmitted to the train wheel mechanisms 51 to 54 as described above.

  The drive circuit 27 outputs a drive pulse of a predetermined voltage to the stepping motors 61, 62, 64 according to the control signal from the CPU 20. The drive circuit 27 can change the length (pulse width) of the drive pulse according to the state of the electronic timepiece 1 and the like. Further, when a control signal for driving a plurality of hands at the same time is input, the drive circuit 27 shifts the output timings of the drive pulses from each other and outputs them, thereby reducing the peak of the load.

FIG. 2 is a block diagram showing a functional configuration of the GPS reception processing unit 10.
The GPS reception processing unit 10 includes a BPF (Band Pass Filter) 13, an RF signal processing unit 11 connected to the BPF 13, a local oscillator 14 and a baseband signal processing unit 12 connected to the RF signal processing unit 11, and the like. .

  The BPF 13 selectively passes only the radio wave signal of the component of a predetermined frequency band including the L1 band among the transmission radio waves from the GPS satellite received by the antenna 10a, and outputs it to the RF amplification unit 111 of the RF signal processing unit 11. It is a filter to do. For the BPF 13, for example, a SAW (Surface Acoustic Wave) filter is used.

  The RF signal processing unit 11 includes an RF amplification unit 111 (signal amplification means), a frequency conversion unit 112, an analog filter 113, an IF (Intermediate Frequency) amplification unit 114, and an ADC (Analog-Digital Converter: analog). -Digital converter) 115.

  The RF amplification unit 111 amplifies the radio signal input from the BPF 13 and outputs it to the frequency conversion unit 112. The RF amplification unit 111 is a variable gain amplifier (VGA) capable of controlling gain.

FIG. 3 is a block diagram showing a functional configuration of the RF amplification unit 111.
The RF amplification unit 111 includes two LNAs 116a and 116b (Low Noise Amplifier) (amplification unit) connected in series in this order between the BPF 13 and the frequency conversion unit 112, and an input and an output of the LNA 116a. A switch 117a (switching unit) that short-circuits and bypasses the LNA 116a to pass a signal (pass-through), and a switch 117b (switching unit) that short-circuits the input and the output of the LNA 116b and bypasses the LNA 116b to allow a signal to pass. A logic circuit 118 or the like that outputs a signal for turning on (conducting) or turning off (non-conducting) the switches 117a and 117b based on a control signal input from the CPU 123 to the switches 117a and 117b is provided. The power supply voltage is independently supplied to the LNAs 116a and 116b. When the switch 117a is on, the supply of the power supply voltage to the LNA 116a is stopped, and when the switch 117b is on, the supply of the power supply voltage to the LNA 116b is stopped.
The RF amplification unit 111 performs signal amplification only by the LNA 116a when the switch 117a is turned off and the switch 117b is turned on, and also performs signal amplification by only the LNA 116b when the switch 117a is turned on and the switch 117b is turned off. I do. Further, when both the switches 117a and 117b are turned on, signal amplification is not performed.

The gain and noise figure (NF) of the LNAs 116a and 116b are preset to predetermined values, and the gain, NF, and power consumption of the RF amplification unit 111 are determined depending on which of the LNAs 116a and 116b performs signal amplification. Here, NF is the ratio of the SNR (Signal-Noise Ratio) of the input signal to the SNR of the output signal. As the NF of the RF amplification unit 111 is smaller, the GPS reception processing unit 10 can receive a signal with higher sensitivity.
In this embodiment, the gains of the LNAs 116a and 116b are set so that the NF of the LNA 116a is 3 dB and the NF of the LNA 116b is 8 dB. In this way, the LNA 116a is set to have a higher gain and a lower noise figure than the LNA 116b, and the power consumption of the LNA 116a is larger than that of the LNA 116b. With such a configuration, by selecting which of the LNAs 116a and 116b is used for signal amplification in the RF amplification section 111 or whether neither of them is used, the RF amplification section 111 is controlled to have gain, NF, and power consumption. Can be operated in a plurality of different operation modes.

FIG. 4 is a diagram illustrating an operation mode of the RF amplification unit 111.
The operation mode of the RF amplification unit 111 is selected from a high power mode, a medium power mode, and a low power mode in order from the highest power consumption.
In the high power mode, the switch 117a is turned off and the switch 117b is turned on, the RF amplification unit 111 performs signal amplification only by the LNA 116a, and the NF of the RF amplification unit 111 becomes 3 dB.
In the medium power mode, the switch 117a is turned on and the switch 117b is turned off, and the RF amplification unit 111 performs signal amplification only by the LNA 116b, and the NF of the RF amplification unit 111 becomes 8 dB.
In the low power mode, the switches 117a and 117b are both turned on, and the RF amplification unit 111 does not perform signal amplification by any of the LNAs 116a and 116b. In this case, the NF of the entire RF signal processing unit 11 is determined by the NF of the circuit element (mixer circuit or the like) of the frequency conversion unit 112 located after the RF amplification unit 111. The NF of the circuit element of the frequency conversion unit 112 is, for example, 15 dB, and this value is described in the low power mode column of FIG.
In the electronic timepiece 1, the CPU 123 makes settings (operation settings) for operating the RF amplifier 111 in any of these operation modes. A specific control method for setting this operation will be described later.

  The local oscillator 14 is a reference frequency source composed of TCXO (Temperature Compensated Crystal Oscillator) or the like, and outputs a signal of the reference frequency (local frequency) to the frequency conversion unit 112.

  The frequency conversion unit 112 includes a mixer circuit such as an analog multiplier and a PLL circuit that outputs a signal of a local frequency generated using the signal from the local oscillator 14 to the mixer circuit, and is amplified by the RF amplification unit 111. The mixed signal is mixed with the signal of the local frequency and down-converted to the IF band.

  The analog filter 113 includes, for example, a low-pass filter (LPF), and attenuates unnecessary frequency band components of the IF band signal input from the frequency conversion unit 112.

  The IF amplification unit 114 is, for example, an amplifier composed of VGA similar to the RF amplification unit 111, and amplifies the signal filtered by the analog filter 113 in the IF band output to the baseband signal processing unit 12.

  The ADC 115 converts the IF band analog signal amplified by the IF amplifier 114 into a digital signal and outputs the digital signal to the baseband signal processor 12.

  The baseband signal processing unit 12 includes a frequency conversion unit 121, a capture tracking unit 122 (capturing unit), a CPU 123 (information acquisition unit, setting changing unit), a RAM 124, a storage unit 125, and the like.

  The frequency conversion unit 121 includes a signal integration/integration circuit that converts the IF band digital signal output from the ADC 115 into a baseband frequency.

  The acquisition and tracking unit 122 is a C/A code generator for generating a C/A code for capturing a satellite signal, and is for synchronizing the generated C/A code with the C/A code of the satellite signal. A matched filter, a carrier phase comparator, a frequency comparator, etc. are provided to perform signal processing related to satellite signal acquisition and tracking (tracking).

  The CPU 123 performs various kinds of arithmetic processing and integrally controls the overall operation of the GPS reception processing unit 10. The CPU 123 causes the acquisition and tracking unit 122 to perform signal processing related to acquisition and tracking of satellite signals. Further, the CPU 123 outputs a control signal to the logic circuit 118 of the RF amplification unit 111 to set the operation of the RF amplification unit 111. Further, the CPU 123 determines the time zone based on the acquired position information and date/time information of the satellite signal, and acquires the local time.

  The RAM 124 provides the CPU 123 with a working memory space and stores temporary data. The RAM 124 also functions as a history storage unit, and stores the date and time information, position information, and predicted trajectory data that have been received and acquired so far for a predetermined period or amount.

  The storage unit 125 is a non-volatile memory such as a flash memory or an EEPROM (Electrically Erasable and Programmable Read Only Memory), and stores the stored contents regardless of the power supply state to the GPS reception processing unit 10. The storage unit 125 stores various operation control programs and setting data. The operation control program includes a local time setting program that acquires position information and date/time information from a satellite signal, and sets local time based on current position information, etc., and a date/time acquisition program that acquires date/time information from a satellite signal. Is included. The setting data includes data related to the operation setting of the RF amplification unit 111, set values for obtaining predicted orbit information and date and time data of each GPS satellite, and map information for calculating local time according to the current position. Be done. The operation control program may be stored in a dedicated ROM, read at startup, and loaded into the RAM of the control unit.

  Next, a transmission format of satellite signals from GPS satellites received by the GPS reception processing unit 10 will be described.

FIG. 5 is a diagram illustrating a transmission format of a satellite signal. FIG. 5A shows the content of a frame composed of five subframes, and FIG. 5B shows the content of words included in the subframe.
The satellite signal (navigation message) transmitted from the GPS satellite is composed of 25 frames in 30-second units as shown in FIG. Each frame includes 5 subframes of 6 second unit, and each subframe includes 10 words (WORD) of 0.6 second unit.

  As shown in FIG. 5B, each word is composed of 30 bits. Of these, the formats of WORD1 and WORD2, which are the two words from the beginning of each subframe, are common to all subframes. WORD1 represents a telemetry word (TLM), of which the first 8 bits are a preamble of a fixed pattern used for synchronization. Therefore, the position in the subframe (transmission format) of the satellite signal is specified by the preamble. WORD2 represents a handover word (HOW), of which the first 17 bits are TOW (Time of Week) indicating the date and time (elapsed time within the week) on and after the day of the week.

  On the other hand, each word after WORD3, which is the third word from the beginning of each subframe, shows different contents for each subframe. In WORD3 of the first subframe (subframe 1), the first 10 bits indicate the week number WN. The week number WN represented by 10 bits represents a week number with a cycle of 1024 weeks, and the first cycle starts on January 6, 1980 and the second cycle starts on August 22, 1999. ..

  WORDs 3 to 10 of the second and third subframes (subframes 2 and 3) include precise orbit information (ephemeris) of the GPS satellite itself which is transmitting the satellite signal. In addition, WORDs 3 to 10 of the fourth and fifth subframes (subframes 4 and 5) include rough orbit information (almanac) of all satellites.

  The last 6 bits of each word of each subframe are a parity bit used to determine the matching of the acquired data.

The GPS reception processing unit 10 acquires precision orbit information of the subframes 2 and 3 from satellite signals of at least three GPS satellites, calculates the current position of the electronic timepiece 1 on the ground based on the precision orbit information, and The precise orbit information of the subframes 2 and 3 is acquired from the satellite signals of at least four GPS satellites, and the three-dimensional current position of the electronic timepiece 1 is calculated based on the precise orbit information. Here, the time information necessary for position calculation is obtained by acquisition of subframe 1, external input (or a combination of external input and the acquired handover word), and the like.
Further, the GPS reception processing unit 10 uses the calculated current position and the map information stored in the storage unit 125 to specify the time zone and calculates the local time.
Further, the GPS reception processing unit 10 acquires the date and time by the combination of the week number WN and the intra-week elapsed time TOW acquired from the reception data of the subframe 1.

Next, the local time acquisition process executed by the GPS reception processing unit 10 of the electronic timepiece 1 will be described.
FIG. 6 is a flowchart showing the control procedure by the CPU 123 of the local time acquisition processing executed by the GPS reception processing unit 10.

  The local time setting process is executed, for example, by transmitting a control signal from the CPU 20 to the GPS reception processing unit 10 in response to an input operation of a positioning operation command to the operation unit 28 by the user. Alternatively, when the electronic timepiece 1 satisfies a predetermined condition for starting the local time setting process, for example, once a day at a predetermined time or the light amount measured by the light amount sensor 30 is first determined by a predetermined reference in a day. It may be automatically started when the level is reached or higher.

  When the local time acquisition process is started, the CPU 123 of the GPS reception processing unit 10 sets the operation setting of the RF amplification unit 111 and sets the operation mode of the RF amplification unit 111 to the high power mode (step S101). Specifically, the CPU 123 transmits a control signal to the logic circuit 118 of the RF amplification unit 111 to turn off the switch 117a and turn on the switch 117b, thereby bypassing the LNA 116b and transmitting the signal, and the RF amplification unit 111 transmits the LNA 116a. Amplify the signal only by itself.

The CPU 123 operates the acquisition and tracking unit 122 to search for a satellite signal, and acquires the number of satellite signals acquired in a predetermined acquisition period (here, 1 second) from the start of the search (step S102).
A satellite signal transmitted from a GPS satellite is phase-modulated (spread spectrum) by a C/A code unique to each GPS satellite, and demodulated by using the same C/A code as that C/A code. A demodulated signal can be acquired. In step S102, the acquisition tracking unit 122 acquires the data related to the C/A code of each GPS satellite from the storage unit 125, causes the matched filter to generate the C/A code, and determines the phase and the C/A code of the satellite signal. By synchronizing, the C/A code that can demodulate the satellite signal included in the received transmission radio wave is identified. In the present specification, this C/A code identification operation is also referred to as satellite signal search or satellite signal acquisition.

The CPU 123 determines whether 6 or more satellite signals have been captured within 1 second from the start of satellite signal search in step S102 (step S103).
Here, the GPS reception processing unit 10 can calculate the current position if the position information can be acquired from at least three satellite signals as described above. However, if noise is mixed in the demodulated signal including the captured satellite signal or if the satellite constellation is not good, the necessary information may not be acquired, so some of the captured satellite signals cannot be used. In order to complete the positioning even in case, the satellite signals of 6 or more are captured with a margin.
When it is determined that 6 or more satellite signals have been captured within 1 second from the start of satellite signal search (“Y” in step S103), the CPU 123 ends the satellite signal search by the acquisition tracking unit 122, While the acquisition tracking unit 122 tracks the satellite signal, the satellite signal is decoded to identify the preamble included in WORD1 of any subframe (step S104). Since the preamble is included in the head word of each subframe, the time (6 seconds) corresponding to the transmission time for one subframe is the position identification time for identifying the preamble.
Here, the tracking of the satellite signal (tracking) is an operation of controlling the phase of the C/A code in order to keep the C/A code generated by the acquisition tracking unit 122 synchronized with the C/A code of the satellite signal. ..
In addition, frequency conversion is performed on the received signal from the positioning satellite, and the signal (demodulated signal) including the navigation message is extracted from the received signal by spectrum despreading using the C/A code while tracking the satellite signal. Described as demodulation.

The CPU 123 determines whether or not 6 or more satellite signal preambles have been identified in 6 seconds, which is the position identification time defined for identifying the preamble (step S105). When it is determined that 6 or more satellite signal preambles have been identified within 6 seconds from the start of the preamble identification operation (“Y” in step S105), the CPU 123 sets the operation of the RF amplification unit 111 to perform RF amplification. The operation mode of the unit 111 is set to the low power mode (step S106). Specifically, the CPU 123 transmits a control signal to the logic circuit 118 of the RF amplification unit 111 and turns on both the switches 117a and 117b to bypass the LNAs 116a and 116b to allow the signal to pass therethrough, and the RF amplification unit 111 transmits the LNA 116a. , 116b, so that the signal is not amplified.
After the RF amplification unit 111 shifts to the low power mode, the CPU 123 receives (downloads) the satellite signal and decodes it to acquire various navigation messages while causing the acquisition and tracking unit 122 to track the satellite signal (step S114).

When it is determined that 6 or more satellite signal preambles have not been identified within 6 seconds from the start of the preamble identification operation (“N” in step S105), the CPU 123 determines the 3 to 5 satellite signal preambles within 6 seconds. Is identified (step S107). When it is determined that the preambles of the satellite signals of 3 to 5 have been identified within 6 seconds from the start of the preamble identification operation (“Y” in step S107), the CPU 123 sets the operation of the RF amplification unit 111 to perform RF operation. The operation mode of the amplification unit 111 is set to the medium power mode (step S108). Specifically, the CPU 123 transmits a control signal to the logic circuit 118 of the RF amplification unit 111 to turn on the switch 117a and turn off the switch 117b, thereby bypassing the LNA 116a and allowing the signal to pass therethrough, and the RF amplification unit 111 transmits the LNA 116b. Amplify the signal only by itself. After the RF amplification unit 111 shifts to the medium power mode, the CPU 123 shifts the processing to step S114.
Further, when it is determined that the preambles of the satellite signals of 3 to 5 are not identified within 6 seconds from the start of the preamble identification operation (“N” in step S107), the CPU 123 sets the RF amplification unit 111 to the high power mode. The process proceeds to step S114 while maintaining the above.

  On the other hand, when it is determined in step S102 that 6 or more satellite signals have not been captured within 1 second from the start of satellite signal search ("N" in step S103), the CPU 123 sets the RF amplifier 111 to the high power mode. The satellite signal search is continued while maintaining the above. The CPU 123 determines whether 6 or more satellite signals have been captured within the capture period set longer than the capture period (1 second) in step S102 (step S109), and 6 or more satellite signals have been captured. If determined (“Y” in step S109), the CPU 123 ends the satellite signal search by the acquisition tracking unit 122, decodes the satellite signal while causing the acquisition tracking unit 122 to track the satellite signal. A preamble included in WORD1 of any subframe is identified (step S112).

The CPU 123 determines whether 6 or more satellite signal preambles have been identified within 6 seconds from the start of the preamble identification operation (step S113). If it is determined that 6 or more satellite signal preambles have been identified in 6 seconds ("Y" in step S113), the CPU 123 shifts the processing to step S108 and sets the operation of the RF amplification unit 111. The operation mode of the RF amplification unit 111 is set to the medium power mode.
When it is determined that 6 or more satellite signal preambles have not been identified within 6 seconds from the start of the preamble identification operation (“N” in step S113), the CPU 123 maintains the RF amplification unit 111 in the high power mode. The process proceeds to step S114 as it is.

  On the other hand, when it is determined in step S109 that 6 or more satellite signals have not been captured ("N" in step S109), the CPU 123 has passed the specified time (here, 30 seconds) from the start of satellite signal search. It is determined whether or not (step S110), if the specified time has not elapsed (“N” in step S110), the process returns to step S109, and if the specified time has elapsed ( In step S110, "Y"), it is determined whether three or more satellite signals have been captured (step S111). When it is determined that three or more satellite signals have been captured (“Y” in step S111), the CPU 123 shifts the processing to step S112 and determines that three or more satellite signals have not been captured. If so (“N” in step S111), the local time acquisition process is terminated.

  The CPU 123 determines in step S114 whether or not the satellite signal reception is completed (step S115). Specifically, it is determined whether or not predetermined information in the navigation message, that is, the ephemeris, the week number WN, and the weekly elapsed time TOW are acquired (step S115). When it is determined that these pieces of predetermined information have not been acquired (“N” in step S115), the CPU 123 determines whether or not the specified time has elapsed from the start of receiving satellite signals (step S117). ), if the specified time has not elapsed (“N” in step S117), the process returns to step S115, and if the specified time has elapsed (“Y” in step S117) local time acquisition process To end.

When it is determined that the predetermined information in the navigation message of the satellite signal has been acquired (“Y” in step S115), the CPU 123 calculates the local time (LT) using the acquired information and It is output to the CPU 20 of the main body of the timepiece 1 (step S116). Specifically, since ephemeris of at least three satellite signals have been acquired by step S115, the current position is calculated using these ephemeris, and the ephemeris is stored in the storage unit 125 based on the calculated current position. The time zone (TZ) (time difference from Coordinated Universal Time (UTC)) is determined and acquired by referring to the map information. Further, the UTC is acquired from the week number WN and the weekly elapsed time TOW, and the local time is calculated by LT=UTC+TZ. If the map information stored in the storage unit 125 includes information related to daylight saving time (DST), the daylight saving time corresponding to the current position is acquired from the map information and the calculated current position, and LT= Local time is calculated by UTC+TZ+DST.
The CPU 123 ends the local time acquisition process when the calculation and output in local time are completed.

  As described above, in the local time acquisition process of the present embodiment, whether or not six or more satellite signals are captured in one second in the satellite signal search operation (steps S103 and S109) and the preamble identification operation is performed in six seconds. Depending on whether or not a predetermined number or more of preambles of satellite signals have been identified (steps S105, S107, S113), the reception state of the transmitted radio wave is a good state, an intermediate state inferior to the good state, or a defective state inferior to the intermediate state. Is determined, and the operation setting of the RF amplification unit 111 is performed so that the operation mode of the RF amplification unit 111 is the low power mode, the medium power mode, or the high power mode, respectively, according to the determination result. Specifically, the gain of the RF amplification unit 111 in the operation setting that is set when it is determined that the reception state is the good state (first reception state) is such that the reception state is the intermediate state or the poor state (the second reception state). ), the operation setting is performed so as to be smaller than the gain of the RF amplification unit 111 in the operation setting set when it is determined that In addition, the gain of the RF amplification unit 111 in the operation setting set when the reception state is determined to be the intermediate state (first reception state) is that the reception state is the poor state (second reception state). The operation setting is performed so as to be smaller than the gain of the RF amplification unit 111 in the operation setting set when the determination is made.

  The operation setting of the RF amplification unit 111 in the local time acquisition processing is performed during a period in which a subframe of the satellite signal which does not include the ephemeris, the week number WN, and the weekly elapsed time TOW is transmitted, that is, the subframe 4 or In the period in which frame 5 is transmitted, the preamble of WORD1, TOW of WORD2, and the period in which the parity bit of each word is not transmitted (that is, the period shaded in FIG. 5B) Be seen.

As described above, the electronic timepiece 1 of the present embodiment receives the transmission radio wave from the GPS satellite, and the RF amplification unit 111 that amplifies the signal of the received transmission radio wave, and the signal amplified by the RF amplification unit 111. Is input to capture a satellite signal including position information and date/time information from the signal, and a CPU 123 that acquires at least one of position information and date/time information from the satellite signal captured by the capture/tracking unit 122. The CPU 123 determines the reception state of the transmission radio wave based on the processing status of at least one of the acquisition tracking unit 122 and the CPU 123, and sets the operation of the RF amplification unit 111 according to the determined reception state. The CPU 123 determines that the gain in the operation setting set when the reception state is determined to be the first reception state is the second reception state in which the reception state is inferior to the first reception state. The operation setting is performed so that it is smaller than the gain in the operation setting that is set.
As a result, the power consumption can be optimized according to the reception state of the radio waves transmitted from the GPS satellites. That is, when the reception state is good, the operation setting is performed so that the RF amplification unit 111 operates in the operation mode in which the gain is low (that is, the power consumption is low and the NF is high) in the range where the satellite signal can be appropriately acquired. Be seen. For this reason, it is possible to eliminate the waste of signal amplification with high gain (low NF) despite the good reception state, and appropriately increase the gain when the reception state is bad, so that the gain in the RF amplification unit 111 is increased. (Or NF) and power consumption can be balanced.

  Further, the CPU 123 determines the reception state based on the number of satellite signals captured by the capture tracking unit 122 within a predetermined capture period (1 second) from the start of the operation related to capture. Further, the CPU 123 determines the reception state based on the number of identified preambles of the satellite signals within the position identification time (6 seconds). That is, when the CPU 123 as the acquisition unit or the information acquisition unit fails in the predetermined processing related to the acquisition and reception of the satellite signal, the CPU 123 as the gain setting unit determines the reception state based on the failure condition. Further, when the predetermined process fails, the CPU 123 as the gain setting unit sets the operation of the RF amplification unit 111 so that the gain of the RF amplification unit 111 (signal amplification unit) becomes large. Here, in the predetermined process related to the satellite signal capture and reception, the capture tracking unit 122 (capture means) captures a predetermined number of satellite signals within a predetermined capture period from the start of the capture operation, or the CPU 123. Identification of preambles relating to a predetermined number of satellite signals within the position identification time by the (information acquisition means) is included. As a result, it is possible to determine the reception state of the transmission radio wave by a simple method using the parameter peculiar to the receiving device that receives the transmission radio wave from the positioning satellite.

  Further, the CPU 123 determines the reception state from a plurality of predetermined stages, and sets the operation related to the gain discretely determined for each of the plurality of stages. Specifically, the RF amplification unit 111 includes LNAs 116a and 116b for amplifying an input signal and switches 117a and 117b for switching the LNAs 116a and 116b on and off, respectively, and operates the CPU 123 and the switches 117a and 117b. , The operation setting is performed by selecting the LNA that amplifies the signal input to the RF amplification unit 111 from the LNAs 116a and 116b. This makes it possible to change the operation mode of the RF amplification unit 111 and optimize the gain, NF, and power consumption with a simple configuration. Further, since the NF of the RF amplification unit 111 has a value that reflects the NF of the selected LNA, the NF of the RF amplification unit 111 can be easily set.

  The CPU 123 also sets the operation of the RF amplification unit 111 within a period in which a portion of the satellite signal that does not include position information and date/time information is received. As a result, the operation mode of the RF amplification unit 111 is changed during the period in which the position information and the date/time information used for the local time acquisition process are acquired, so that tracking of the satellite signal is lost and the position information and the date/time information are acquired. It is possible to prevent problems that cannot be performed.

  Further, the electronic timepiece 1 includes a time counting circuit 25 that counts the date and time, and a CPU 20 that corrects the date and time of the time counting circuit 25 using the date and time information when the CPU 123 of the GPS reception processing unit 10 obtains the date and time information. Prepare As a result, the electronic timepiece 1 can display the accurate date and time acquired from the satellite signal transmitted from the GPS satellite.

(Second embodiment)
Next, a second embodiment of the present invention will be described. The configuration of the electronic timepiece 1 of the second embodiment is the same as that of the first embodiment. In the second embodiment, the electronic timepiece 1 acquires date and time information using a radio wave transmitted from a GPS satellite (date and time acquisition processing), and corrects the date and time counted by the clock circuit 25 based on the acquired date and time information (date and time correction). Processing is different from the first embodiment. Below, it demonstrates centering around difference with 1st Embodiment.

  In the date and time correction processing performed in the second embodiment, a predetermined frequency, for example, a predetermined time once a day or a light amount measured by the light amount sensor 30 first becomes equal to or higher than a predetermined reference level in one day. When it is started. As the predetermined time, for example, 0:00:10 am is the first date and time correction processing execution time of the day. If acquisition of the date and time information fails at the first time and date correction processing execution time, even if reception of the standard radio wave is repeated every hour thereafter until the time and date information is successfully acquired, up to 5:00: 10 am good. In addition, as the predetermined reference level relating to the detected light amount, for example, the light amount measured when the sunlight is applied outdoors during the day is set.

When only the date and time information is acquired from the GPS satellite, the reception time is shortened by receiving only the part including the date and time information of the radio wave from one satellite, that is, not receiving the orbit information necessary for positioning (for example, Power consumption can be reduced. In this case, since the distance from the current position to the one satellite is not determined, for example, by correcting the propagation delay time based on the average distance, it is possible to acquire the date and time with sufficient accuracy (about several msec). Can be done.
The following describes the date and time acquisition process executed by the GPS reception processing unit 10 when the date and time information is acquired from GPS satellites.

FIG. 7 is a flowchart showing a control procedure by the CPU 123 of the date and time acquisition processing executed by the GPS reception processing unit 10.
When the date/time acquisition process is started, the CPU 123 sets the operation of the RF amplification unit 111 and sets the operation mode of the RF amplification unit 111 to the low power mode (step S201).

  The CPU 123 refers to the operation history stored in the RAM 124 and determines whether or not the date/time information acquisition process has failed consecutively for the past two days or more (step S202). When it is determined that the date and time acquisition process has failed continuously for the past two days or more (“Y” in step S202), the CPU 123 determines whether or not the date and time acquisition process has continuously failed for the past four days or more. It is determined whether or not (step S203). When it is determined that the date and time acquisition process has succeeded on any one of the past four days (“N” in step S203), the CPU 123 sets the operation setting of the RF amplification unit 111 and the RF amplification unit. The operation mode of 111 is set to the medium power mode (step S204). When it is determined that the date and time acquisition process has failed in the past four consecutive days (“Y” in step S203), the CPU 123 sets the operation setting of the RF amplification unit 111 and the RF amplification unit 111. The operation mode is set to the high power mode (step S205).

  When it is determined in step S202 that the date/time acquisition process has succeeded on any one of the past two days (“N” in step S202), the CPU 123 operates the acquisition tracking unit 122 to operate the satellite signal. Is searched for and the number of satellite signals acquired during a predetermined acquisition period (here, 1 second) is acquired (step S206).

  The CPU 123 determines whether or not one or more satellite signals have been captured within one second from the start of satellite signal search in step S206 (step S207). When it is determined that no satellite signal has been captured in one second (“N” in step S207), the CPU 123 ends the date and time acquisition process. If it is determined that one or more satellite signals have been captured in one second (“Y” in step S207), the CPU 123 terminates the satellite signal search by the acquisition and tracking unit 122, and causes the acquisition and tracking unit 122 to perform satellite acquisition. While tracking the signal, the satellite signal is received and decoded, and the weekly elapsed time TOW included in each subframe is acquired (step S208).

  In step S208, the CPU 123 determines whether or not the reception is completed when 6 seconds, which is the transmission time for one subframe, has passed, that is, whether the weekly elapsed time TOW has been acquired (step S209). .. When it is determined that the weekly elapsed time TOW has not been acquired (“N” in step S209), the CPU 123 ends the local time acquisition process.

  When it is determined that the weekly elapsed time TOW has been acquired within 6 seconds from the start of reception of the satellite signal (“Y” in step S209), the CPU 123 determines the local time based on the acquired weekly elapsed time TOW ( LT) is calculated and output to the CPU 20 of the electronic timepiece 1 body (step S210).

  On the other hand, when the operation setting of the RF amplification unit 111 is performed so that the RF amplification unit 111 operates in the medium power mode in step S204, or the RF amplification unit 111 operates in the high power mode in step S205. When the operation setting of the unit 111 is performed, the CPU 123 operates the acquisition and tracking unit 122 to search for a satellite signal, and acquires the number of satellite signals acquired in a predetermined acquisition period (here, 1 second). Yes (step S211).

  The CPU 123 determines whether or not at least one satellite signal has been captured in the predetermined capture period (1 second) in step S211 (step S212). When it is determined that no satellite signal has been captured in one second (“N” in step S212), the CPU 123 determines whether the prescribed time (here, 10 seconds) has elapsed from the start of satellite signal search. Whether or not it is determined (step S213), if the specified time has not elapsed (“N” in step S213), the process returns to step S211, and if the specified time has elapsed (in step S213). "Y"), the date/time acquisition process is terminated.

  When it is determined in step S212 that one or more satellite signals have been captured ("Y" in step S212), the CPU 123 acquires the weekly elapsed time TOW from the satellite signals as in step S208 (step S214). ..

  The CPU 123 determines whether or not the reception is completed when a predetermined time (here, 6 seconds) has elapsed from the start of receiving the satellite signal in step S214, that is, whether or not the weekly elapsed time TOW has been acquired (step). S215). When it is determined that the weekly elapsed time TOW has not been acquired (“N” in step S215), the CPU 123 determines whether the specified time (here, 60 seconds) has elapsed from the start of satellite signal reception. (Step S216), if the specified time has not elapsed (“N” in step S216), the process returns to step S214, and if the specified time has elapsed (“Y” in step S216). ") End the date and time acquisition process.

When it is determined in step S215 that the date and time information has been acquired (“Y” in step S215), the CPU 123 determines based on the acquired weekly elapsed time TOW and the week number WN stored in the RAM 124 or the like. The local time (LT) is calculated and output to the CPU 20 of the main body of the electronic timepiece 1 (step S210).
When the output of the date and time information is completed, the CPU 123 ends the local time acquisition process.

  When the local time acquisition process ends, the CPU 20 of the electronic timepiece 1 corrects the date and time counted by the clock circuit 25 based on the date and time information output from the CPU 123 of the GPS reception processing unit 10 (date and time adjustment process).

As described above, in the electronic timepiece 1 according to the present embodiment, the CPU 123 determines the reception state based on the elapsed time (days) from the latest timing when the date and time information included in the satellite signal is acquired. That is, depending on whether or not the date/time acquisition processing (predetermined processing related to satellite signal acquisition and reception) has failed for a predetermined number of days (steps S201, S202), the reception state of the transmitted radio wave is in a good state, an intermediate state, or a bad state. It is discriminated which of the above is the case, and the operation setting of the RF amplification section 111 is performed so that the RF amplification section 111 is operated in the low power mode, the medium power mode, or the high power mode in accordance with the discrimination result. As a result, the receiving state can be determined only by referring to the past operation history, so that the processing can be performed at high speed without determining the receiving state in the subsequent steps. Further, in this way, when the date and time acquisition process fails for a predetermined number of days and the accuracy state of the date and time counted by the timing circuit 25 is deteriorated, the operation setting for operating the RF amplifier 111 with a higher gain is performed, By making the date and time acquisition process successful, it is possible to recover the precision state of the date and time counted by the time counting circuit 25.
Further, the operation mode of the RF amplification unit 111 in the date/time acquisition processing is set to the low power mode as an initial state (step S201). As a result, it is possible to suppress the problem that the power consumption of the RF amplification unit 111 increases more than necessary.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. The configuration of the electronic timepiece 1 according to the third embodiment is the same as that of the first and second embodiments. In the third embodiment, in the local time acquisition operation of the first embodiment, the reception state is determined based on the SNR (signal noise ratio) of the demodulated signal including the captured satellite signal. In the present embodiment, the CPU 123 also functions as a signal noise ratio calculation means. Below, it demonstrates centering around difference with 1st Embodiment.

  8 and 9 are flowcharts showing the control procedure by the CPU 123 of the local time acquisition processing executed by the GPS reception processing unit 10. In the local time setting process according to this modification, the processes of steps S118 to S122 are added to the local time acquisition process of the first embodiment shown in FIG. 6, and the process of step S111 is the process of step S111a. Since the other processes are the same, the same reference numerals are used for the same processes, and detailed description thereof will be omitted.

When it is determined in step S103 that 6 or more satellite signals have been captured within 1 second from the start of the satellite signal search (“Y” in step S103), the CPU 123 determines that the SNR of the demodulated signal related to the satellite signals of 6 or more is It is determined whether it is 30 dB or more (step S118). Specifically, the CPU 123 acquires the ratio (SNR) between the signal strength of the signal section and the signal strength of the noise section for the demodulated signal including the satellite signal captured by the capture tracking section 122 in step S102, and the ratio is predetermined. It is determined whether the value is equal to or more than the reference value (demodulation reference value) of, for example, 30 dB or more here. Hereinafter, in order to avoid complexity, the SNR of the demodulated signal including the satellite signal is also referred to as “SNR of satellite signal”.
When it is determined that the SNR of 6 or more satellite signals is 30 dB or more (“Y” in step S118), the CPU 123 shifts the processing to step S104, and the SNR of 6 or more satellite signals is 30 dB or more. When it is determined that the condition that there is is not satisfied (“N” in step S118), the CPU 123 shifts the processing to step S109.

  Similarly, when it is determined in step S109 that 6 or more satellite signals have been captured (“Y” in step S109), the CPU 123 determines whether the SNR of 6 or more satellite signals is 30 dB or more. (Step S119), if it is determined that the SNR of 6 or more satellite signals is 30 dB or more (“Y” in step S119), the process proceeds to step S112, and the SNR of 6 or more satellite signals is If it is determined that the condition of being 30 dB or more is not satisfied (“N” in step S119), the process proceeds to step S110.

  If it is determined in step S110 that the specified time (30 seconds) has elapsed from the start of satellite signal search (“Y” in step S110), the CPU 123 acquires three or more satellite signals, And it is determined whether or not the SNR of at least three satellite signals is 30 dB or more (step S111a). If three or more satellite signals are captured and it is determined that the SNR of at least three satellite signals is 30 dB or more (“Y” in step S111a), the CPU 123 shifts the processing to step S112, and When it is determined that the above satellite signals have been captured and the SNR of at least three satellite signals is 30 dB or more (“N” in step S111a), the local time acquisition processing is performed. To finish.

  As described above, in the local time acquisition processing of the third embodiment, it is determined whether or not the SNR of a predetermined number of satellite signals among the satellite signals captured by the capture and tracking unit 122 is 30 dB or more, and the predetermined number of satellites. Only when it is determined that the SNR of the signal is 30 dB or more, the process proceeds to the step of identifying the preamble of the satellite signal (steps S104 and S112).

  If it is determined in step S105 that 6 or more satellite signal preambles have been identified within 6 seconds from the start of the preamble identification operation (“Y” in step S105), the CPU 123 determines the SNR of 3 or more satellite signals. Is greater than or equal to a predetermined reference value (demodulation reference value), here, for example, 40 dB or more (step S120). When it is determined that the SNR of the satellite signals of 3 or more is 40 dB or more (“Y” in step S120), the CPU 123 shifts the processing to step S106, and when the SNR of the satellite signals of 3 or more is 40 dB or more. If not determined (“N” in step S120), the process proceeds to step S107.

  When it is determined in step S107 that the preambles of the satellite signals of 3 to 5 have been identified in 6 seconds (“Y” in step S107), the CPU 123 has an SNR of 3 or more satellite signals of 40 dB or more. If it is determined that the SNR of the satellite signals of 3 or more is 40 dB or more (“Y” in step S121), the process proceeds to step S108 and 3 or more. If it is not determined that the SNR of the satellite signal is 40 dB or more (“N” in step S121), the process proceeds to step S114.

  If it is determined in step S113 that 6 or more satellite signal preambles have been identified within 6 seconds from the start of the preamble identification operation (“Y” in step S113), the CPU 123 determines the SNR of 3 or more satellite signals. Is determined to be 40 dB or more (step S122), and if the SNR of 3 or more satellite signals is determined to be 40 dB or more (“Y” in step S122), the process proceeds to step S108. If it is not determined that the SNR of 3 or more satellite signals is 40 dB or more (“N” in step S122), the process proceeds to step S114.

  As described above, in the local time acquisition process of the third embodiment, when 6 or more (or 3 to 5) preambles of satellite signals are identified in 6 seconds, the SNR of 3 or more satellite signals is 40 dB or more. If it is not determined that the SNR of 3 or more satellite signals is 40 dB or more, the operation mode of the RF amplification unit 111 is set to the operation mode on the higher power side (that is, the lower NF side). The operation setting is made to shift.

  As described above, in the electronic timepiece 1 according to the third embodiment, the CPU 123 calculates the SNR of the demodulated signal including each satellite signal captured by the capture tracking unit 122, and determines the reception state based on the calculation result. To do. As a result, even if the demodulated signal contains a large amount of noise or the transmitted radio wave is attenuated due to reflection (e.g., multipath) and reaches the electronic timepiece 1, the RF amplification is performed accordingly. Since the operation setting of the unit 111 is performed, the RF amplification unit 111 can be controlled according to the reception state considering noise and multipath.

  Further, the CPU 123 determines the reception state based on the number of satellite signals related to the demodulated signal whose calculated SNR is equal to or higher than the predetermined reference value. This makes it possible to determine the reception state of the transmission radio wave by a simple method using the parameters peculiar to the receiving device that receives the transmission radio wave from the positioning satellite.

  Further, when the CPU 123 identifies the preamble of the captured satellite signal by a predetermined number of 3 or more within the position identification time (6 seconds) set for identifying the preamble, the satellite signal with the identified preamble is identified. Among them, the reception state is determined based on the number of satellite signals related to the demodulated signals whose calculated SNR is equal to or higher than a predetermined reference value. This makes it possible to determine the reception state of the transmission radio wave by a simple method using the parameters peculiar to the receiving device that receives the transmission radio wave from the positioning satellite.

  Further, in the third embodiment, it is determined whether or not the SNR of the satellite signal captured by the capture and tracking unit 122 is 30 dB or more, and whether the SNR of the satellite signal in which the preamble is identified is 40 dB or more. Is determined. In this way, by making the reference value in the former determination smaller than the reference value in the latter determination, it is possible to shorten the time during which the search operation of the satellite that consumes a relatively large amount of power is performed, and the electronic timepiece 1 Power consumption can be kept low.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made.
For example, in each of the above-described embodiments, an example has been described in which only the operation mode of the RF amplification unit 111 as the signal amplification unit is changed according to the reception state, but the present invention is not limited to this. For example, the gain of at least one of the analog filter 113 and the IF amplification unit 114 as the signal amplification unit may be changed in accordance with the change of the operation mode of the RF amplification unit 111. In this case, in order for the dynamic range of the signal input to the ADC 115 to fall within a range in which the ADC 115 can perform appropriate conversion, the analog filter 113 or the IF amplifier 114 of the RF amplifier 111 is operated for each operation mode. At least one gain is changed to a predetermined value. Here, the gain of the analog filter 113 is adjusted by changing the pass frequency band. Like the RF amplification unit 111, the IF amplification unit 114 may adjust the gain by changing the number of LNAs to be used among the plurality of LNAs, or may adjust the gain by another method.

  Further, in each of the above-described embodiments, the NF values of the LNAs 116a and 116b of the RF amplification section 111 are set to 3 dB and 8 dB, respectively, but these values are appropriately changed according to the signal power of the satellite signal received, etc. Good. Also, the example in which the gain and NF of the RF amplification unit 111 are changed by bypassing one of the two LNAs 116a and 116b and transmitting the signal has been described, but the method of changing the gain and NF of the RF amplification unit 111 is the same. However, other methods may be used.

  Further, in each of the above embodiments, the operation mode of the RF amplification unit 111 is selected from three modes with different power consumption, but the present invention is not limited to this, and the number of operation modes is two, or four or more. May be.

  In each of the above embodiments, the operation setting is made so that the operation mode of the RF amplification unit 111 is selected from an operation mode using only one of the two LNAs 116a and 116b and an operation mode not using any of the LNAs 116a and 116b. However, the present invention is not limited to this. For example, both the switches 117a and 117b are turned off according to the reception state, and the RF amplification unit 111 is operated in an operation mode (hereinafter, referred to as sensitivity priority mode) in which amplification is performed using both the LNAs 116a and 116b. The operation setting of the RF amplification unit 111 may be performed. The sensitivity priority mode consumes more power than the high power mode, but the NF of the RF amplification unit 111 is lower than that in the high power mode. Therefore, the GPS reception processing unit 10 can receive the transmission radio wave from the GPS satellite with higher sensitivity. The operation mode of the RF amplification unit 111 may be selected from all of the sensitivity priority mode, the high power mode, the medium power mode, and the low power mode, or may be selected from the two or three operation modes. Good.

  Further, in each of the above-described embodiments, an example has been described in which the reception state is discriminated from among three predetermined stages and the operation setting relating to the gain discretely determined according to each of the three stages is performed. It is not limited to this. For example, the gain (and NF and power consumption) of the RF amplification unit 111 can be changed with a continuous value, and the CPU 123 sets the gain of the RF amplification unit 111 to one of continuous values according to the reception state. The operation setting may be performed by setting to.

Further, in each of the above-described embodiments, the example in which the intra-week elapsed time TOW is acquired as the date/time information in the local time calculation process or the date/time acquisition process has been described. When the week number WN is not acquired and is not stored in the RAM 124 or the like, the week elapsed time TOW and the week number WN may be acquired as the date and time information.
In addition, in the first and third embodiments, the example in which the position information and the date and time information are acquired in the local time calculation process has been described. However, for example, when only the time zone is determined based on the position information, only the position information is acquired. You may get it.

  In the second embodiment, the example in which the CPU 123 determines the reception state based on the elapsed time from the latest acquisition of the date/time information included in the satellite signal has been described, but the present invention is not limited to this, and for example, the date/time concerned. The reception status may be determined based on the number of times of failure in acquisition of date and time information after the latest timing when the information was acquired.

  In the first and third embodiments, the reception state is determined by whether or not 6 (3 in step S111) satellite signals are captured within a predetermined capture period from the start of satellite signal search (step S103). , S109, S111), the number of satellite signals serving as a criterion for determination is not limited to 6 (or 3), and if the current position on the ground is 3 or more, the number of satellite signals that can be captured is within the range. It can be any number. Further, the predetermined acquisition period for performing the above determination is one second from the start of the satellite signal search (steps S103 and S109), but it is not limited to this, and the reception state of the radio wave transmitted from the GPS satellite and the GPS reception processing unit 10 are not limited thereto. You may change according to the characteristic of.

  In the first and third embodiments, the reception state is determined depending on whether 6 or more or 3 or more satellite signal preambles have been identified within 6 seconds from the start of the preamble identification operation (steps S105, S113, S107), the number of satellite signals serving as a criterion for determination is not limited to 6 or 3, and if the number is 3 or more that can acquire the two-dimensional current position, it can be any number within the range of the number of satellite signals that can be captured. can do. Further, the period for making the above-mentioned determination is not limited to 6 seconds from the start of the satellite signal search, and may be changed according to the reception state of the radio waves transmitted from the GPS satellites and the characteristics of the GPS reception processing unit 10.

  In addition, in the third embodiment, it is determined whether or not the SNR of the captured satellite signal is 30 dB or more (steps S118, S111a, S119), and the SNR of the satellite signal with the preamble identified is 40 dB or more. Although it is determined whether or not there is any (step S120, S121, S122), the reference value serving as a reference for the determination is not limited to 30 dB or 40 dB, and for example, according to the gain and NF settings in each operation mode of the RF amplification unit 111. You may change it to a value.

  Further, in the third embodiment, the reception state of both the captured satellite signal and the satellite signal for which the preamble is identified is determined based on the number of satellite signals for which the SNR value of the demodulated signal is equal to or greater than a predetermined value. However, only one of them may be discriminated.

  Further, in the third embodiment, the reception state is determined based on the number of satellite signals whose SNR value of the demodulated signal is a predetermined value or more, but the present invention is not limited to this. As another example of the control using the SNR, the CPU 123 sets the range in which the number of satellite signals related to the demodulated signal whose calculated SNR is equal to or larger than a predetermined reference value is equal to or larger than the number necessary for the information acquisition by the CPU 123. The operation setting may be performed so that the gain of the RF amplification unit 111 is minimized. According to this, the power consumption of the RF amplification unit 111 can be reduced within a range where the information can be acquired by the CPU 123, so that the power consumption of the electronic timepiece 1 can be reduced according to the reception state of the radio wave transmitted from the positioning satellite. Can be optimized.

  Further, in the third embodiment, the navigation message is received for all the captured satellite signals after determining the reception state based on the number of satellite signals whose SNR of the demodulated signal is equal to or greater than the predetermined value. The mode of control based on the SNR of satellite signals is not limited to this. For example, among the captured satellite signals, the navigation message may be acquired only for those satellite signals whose SNR of the demodulated signal is greater than or equal to a predetermined value, or a predetermined number of satellite signals are selected in descending order of the SNR of the demodulated signal. However, the navigation message may be acquired only for the selected satellite signal.

  Further, in the third embodiment, when the SNR is acquired, the satellite signal and noise intensities are continuously acquired for a predetermined period (for example, several seconds), and the satellite signal and the noise related to the multipath signal are acquired from the stability of the signal. May be specified and the use of the satellite signal may be excluded.

  Further, in each of the above-described embodiments, various processes using satellite signals transmitted from GPS satellites as positioning satellites have been described, but the types of positioning satellites are not limited to GPS satellites, and GLONASS and Galileo are available. Other satellite signals transmitted from positioning satellites related to GNSS such as the above may be used.

  In each of the above embodiments, the GPS reception processing unit 10 calculates the local time from the position information and the date and time information acquired from the satellite signal, but the GPS reception processing unit 10 outputs the position information and the date and time information. The acquired CPU 20 may calculate the local time.

Further, in each of the above-described embodiments, an analog electronic timepiece using a pointer is described as an example, but the electronic timepiece to which the present invention is applicable is not limited to this, and an electronic timepiece that performs digital display and a digital display and an analog display. It may be an electronic timepiece that also uses a display.
In addition, the specific details such as the configuration, the control content, and the procedure thereof described in the above-described embodiment can be appropriately changed without departing from the spirit of the present invention.

Although some embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and the equivalent scope thereof. ..
The inventions described in the scope of the claims attached first to the application for this application will be additionally described below. The claim numbers listed in the appendices are as defined in the claims initially attached to the application for this application.

[Appendix]
<Claim 1>
Signal amplifying means for receiving the transmission radio wave from the positioning satellite and amplifying the signal of the received transmission radio wave,
Capture means for inputting the signal amplified by the signal amplifying means, and capturing a satellite signal including position information and date/time information from the signal,
Information acquisition means for acquiring at least one of the position information and the date and time information from the satellite signal captured by the capturing means,
A gain that determines the reception state of the transmitted radio wave based on the processing status of at least one of the acquisition means and the information acquisition means, and performs an operation setting related to the gain of the signal amplification means according to the determined reception status. Setting means,
Equipped with
The gain setting means is in a second reception state in which the gain in the operation setting set when the reception state is determined to be the first reception state is inferior to the first reception state in the reception state. The radio wave receiving device, wherein the operation setting is performed so as to be smaller than the gain in the operation setting set when it is determined.
<Claim 2>
2. The gain setting means determines the reception state based on the number of the satellite signals captured by the capturing means within a predetermined capturing period from the start of the operation related to the capturing. Radio wave receiver.
<Claim 3>
The gain setting means acquires the information of a predetermined portion of the captured satellite signal for identifying a position in the transmission format of the satellite signal within a position identification time determined for identifying the predetermined portion. 3. The radio wave receiving apparatus according to claim 1, wherein the reception state is determined based on the number identified by the means.
<Claim 4>
A signal-noise ratio calculating means for calculating a signal-noise ratio of a demodulated signal demodulated including each of the satellite signals captured by the capturing means,
The radio wave receiving apparatus according to claim 1, wherein the gain setting unit determines the reception state based on a calculation result of the signal noise ratio by the signal noise ratio calculation unit.
<Claim 5>
The gain setting means determines the reception state based on the number of the satellite signals related to the demodulated signal whose signal-to-noise ratio calculated by the signal-to-noise ratio calculating means is equal to or more than a predetermined demodulation reference value. The radio wave receiving device according to claim 4.
<Claim 6>
The gain setting means acquires the information of a predetermined portion of the captured satellite signal for identifying a position in the transmission format of the satellite signal within a position identification time determined for identifying the predetermined portion. When the means identifies a predetermined number of 3 or more, the demodulation in which the signal-to-noise ratio calculated by the signal-noise ratio calculating means is equal to or greater than a predetermined demodulation reference value among the satellite signals in which the predetermined portion is identified The radio wave receiving apparatus according to claim 4, wherein the reception state is determined based on the number of the satellite signals related to the signal.
<Claim 7>
In the gain setting means, the number of satellite signals related to the demodulated signal whose signal noise ratio calculated by the signal noise ratio calculating means is equal to or more than a predetermined demodulation reference value is necessary for the information acquiring means to acquire information. The radio wave receiving apparatus according to claim 4, wherein the operation setting is performed so that the gain is minimized within a range of a number or more.
<Claim 8>
The gain setting unit determines the reception state based on the elapsed time from the latest timing when the information acquisition unit acquires the date and time information included in the satellite signal or the number of times the date and time information has failed to be acquired after the timing. The radio wave receiving device according to claim 1, wherein
<Claim 9>
The gain setting means determines the reception state from a plurality of predetermined stages, and performs the operation setting related to the gain discretely determined for each of the plurality of stages. The radio wave reception device according to claim 1.
<Claim 10>
The signal amplification means,
A plurality of amplification units for amplifying the input signal,
A switching unit that switches ON/OFF of each of the plurality of amplification units,
The gain setting unit performs the operation setting by operating the switching unit and selecting an amplification unit that amplifies the signal input to the signal amplification unit from the plurality of amplification units. The radio wave receiving device according to claim 9.
<Claim 11>
11. The gain setting means sets the operation within a period in which a portion of the satellite signal that does not include the position information and the date and time information is received. The radio wave receiver described.
<Claim 12>
A radio wave receiving device according to any one of claims 1 to 11,
A time counting means for counting the date and time, and a date and time correcting means for correcting the date and time of the time measuring means using the date and time information when the date and time information is acquired by the information acquiring means,
An electronic timepiece comprising:

1 Electronic Timepiece 10 GPS Reception Processing Section 11 RF Signal Processing Section 111 RF Amplification Section 116a, 116b LNA
117a, 117b Switch 118 Logic circuit 112 Frequency conversion part 113 Analog filter 114 IF amplification part 115 ADC
12 baseband signal processing unit 121 frequency conversion unit 122 acquisition and tracking unit 123 CPU
124 RAM
125 storage unit 13 BPF
14 Local oscillator 10a Antenna 20 CPU
21 ROM
22 RAM
23 oscillator circuit 24 frequency divider circuit 25 clock circuit 26 standard radio wave receiver 26a antenna 27 drive circuit 28 operation unit 29 power supply unit 30 light source sensor 41 second hand 42 minute hand 43 hour hand 44 date wheel 51, 52, 53, 54 wheel train mechanism 61, 62,64 stepping motor

Claims (7)

Signal amplifying means for receiving the transmission radio wave from the positioning satellite and amplifying the signal of the received transmission radio wave,
A signal amplified by the signal amplifying unit is input, a satellite signal is captured from the signal, demodulation processing is performed on the captured satellite signal, and a demodulating unit that sets the gain of the signal amplifying unit,
Information acquisition means for acquiring at least one of position information and date and time information from the satellite signal,
Equipped with
The demodulation means , based on the number of the predetermined portion for identifying the position of the satellite signal in the transmission format of the captured satellite signal identified by the information acquisition means within the position identification time, the signal amplification means. A radio wave receiving device, characterized in that the gain of the radio wave is set . When the demodulation means identifies a predetermined portion of the captured satellite signal for identifying the position in the transmission format of the satellite signal by a predetermined number of 3 or more, the satellite signal by which the predetermined portion is identified calculating a signal-to-noise ratio of, claim 1 in which the calculated signal noise ratio and sets the gain of the signal amplifying means on the basis of the number of the satellite signal is greater than or equal to a predetermined reference value Radio receiver. The demodulating means adjusts the gain of the signal amplifying means so that the gain is smallest in a range in which the number of the satellite signals whose calculated signal-to-noise ratio is a predetermined reference value or more becomes a predetermined number or more. The radio wave receiver according to claim 2 , wherein the radio wave receiver is set. The signal amplification means,
A plurality of amplification units for amplifying the input signal,
A switching unit that switches ON/OFF of each of the plurality of amplification units,
The demodulation unit sets the gain by operating the switching unit to select an amplification unit that amplifies the signal input to the signal amplification unit from the plurality of amplification units. The radio wave receiver according to any one of Items 1 to 3 . A radio wave receiving device according to claim 1 ;
A timekeeping means for counting the date and time,
Date and time correction means for correcting the date and time of the clock means using the date and time information when the date and time information is obtained by the information obtaining means,
An electronic timepiece comprising: A method of receiving satellite radio waves,
A signal amplification step of receiving a transmission radio wave from a positioning satellite and amplifying the signal of the received transmission radio wave,
A capturing step of receiving a signal amplified by the signal amplifying step and capturing a satellite signal from the signal;
A gain setting step of demodulating the satellite signal captured by the capturing step and setting a gain for amplifying the signal of the signal amplifying step,
An information acquisition step of acquiring at least one of position information and date/time information from the satellite signal,
Including,
In the gain setting step , the signal amplification is performed based on the number of the predetermined portion for identifying the position of the satellite signal in the transmission format of the captured satellite signal identified by the information acquisition step within the location identification time. A satellite radio wave receiving method characterized by setting a step gain . A processor of a satellite radio wave receiving device having a signal amplification means for receiving a transmission radio wave from a positioning satellite and amplifying a signal of the received transmission radio wave,
Capture means for receiving a signal amplified by the signal amplifying means and capturing a satellite signal from the signal,
Gain setting means for demodulating the satellite signal captured by the capturing means and setting a gain for amplifying the signal of the signal amplifying means,
Information acquisition means for acquiring at least one of position information and date/time information from the satellite signal,
Function as
The gain setting means amplifies the signal based on the number of the predetermined portion of the captured satellite signal for identifying the position in the transmission format of the satellite signal identified by the information acquisition means within the position identification time. Set the means gain
Program which is characterized a call.

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