JP2016121983A - Radio clock, date and time information acquisition method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio clock, a date and time information acquisition method and a program capable of precisely and efficiently acquiring date and time information.SOLUTION: The radio clock includes: radio wave reception means that receives a radio wave from a satellite and identifies a received code string from the received satellite radio wave conforming to a predetermined format; expected code string generation means that generates an expected code string which is expected in advance as at least a part of the identified received code string; matching means that sequentially matches expected code strings against received code strings in order to detect an expected code string from a received code string; and date and time acquisition means that, when an expected code string is detected, acquires the present date and time based on a timing at which the expected code string was detected. The expected code string includes a code in which time-corresponding information containing information relevant to the present time transmitted according a predetermined format can change according to transmission period.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a radio clock, a date / time information acquisition method, and a program for acquiring date / time information by receiving radio waves from a positioning satellite.

  2. Description of the Related Art Conventionally, there is an electronic timepiece (radio timepiece) having a function of accurately keeping a date and time by receiving radio waves from a navigation satellite (positioning satellite) according to GNSS (Global Navigation Satellite System) and acquiring date and time information. . This radio timepiece does not require manual operation by the user, and can accurately keep the date and time counted and displayed in various parts of the world.

  However, the load related to the reception of satellite radio waves is very large compared to the load related to the counting and display of the date and time in the electronic timepiece. There is a problem that this leads to an increase in size and weight. Therefore, conventionally, various techniques for reducing power consumption have been developed.

  One technique for reducing such power consumption is to shorten the radio wave reception time. Patent Document 1 discloses a technique for receiving a predetermined portion including date and time information according to a format (navigation message) of a signal transmitted from a GPS satellite and temporarily stopping reception while unnecessary information is being transmitted. Yes. At this time, in order to avoid misidentification of the date and time, parity data corresponding to the block including the predetermined portion is acquired, and the consistency of the received data is confirmed.

JP 2009-36748 A

  However, data portions that are not related to date / time information do not necessarily need to be acquired accurately, and the receiving method that requires the consistency of these unnecessary data portions by parity data reduces the acquisition efficiency of date / time information. There are challenges.

  An object of the present invention is to provide a radio timepiece, a date information acquisition method, and a program that can acquire accurate date information more efficiently.

In order to achieve the above object, the present invention provides:
A radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave;
An assumed code string generating means for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
With
The assumed code string includes a code that can change according to a transmission cycle in which time correspondence information including information related to the current time is transmitted according to the predetermined format.

  According to the present invention, there is an effect that accurate date and time information can be acquired more efficiently.

It is a block diagram which shows the electronic timepiece of embodiment of this invention. It is a figure explaining the format of the navigation message which a GPS satellite transmits. It is a flowchart which shows the control procedure of a date acquisition process. It is a flowchart which shows the control procedure of a date information reception process. It is a figure which shows the comparison result of the data reception time required with the electronic timepiece of 1st Embodiment, and the data reception time by the conventional 3 word reception. It is a figure explaining the setting of a reception start timing. It is a flowchart which shows the control procedure of the date information reception process performed with the electronic timepiece of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a functional configuration of an electronic timepiece 1 as a first embodiment of a positioning device and a radio timepiece of the present invention.

The electronic timepiece 1 is a radio timepiece capable of receiving date and time information by receiving radio waves from a positioning satellite (hereinafter referred to as GPS satellite) related to at least GPS (Global Positioning System) in the United States.
The electronic timepiece 1 includes a host CPU 41 (Central Processing Unit), a ROM 42 (Read Only Memory), a RAM 43 (Random Access Memory), an oscillation circuit 44, a frequency dividing circuit 45, a time measuring circuit 46 as a time measuring means, A display unit 47, a display driver 48, an operation unit 49 as an operation means, a power supply unit 50, a satellite radio wave reception processing unit 60, and an antenna AN are provided.

  The host CPU 41 performs various arithmetic processes and controls the overall operation of the electronic timepiece 1. The host CPU 41 reads out a control program from the ROM 42, loads it into the RAM 43, and performs various operation processes such as date and time display, arithmetic control and display related to various functions. In addition, the host CPU 41 operates the satellite radio wave reception processing unit 60 to receive radio waves from the positioning satellite, and acquires date information and position information obtained based on the received contents.

  The ROM 42 is a mask ROM, a rewritable nonvolatile memory, or the like, and stores a control program and initial setting data. The control program includes a program 421 relating to control of various processes for acquiring various information from the positioning satellite.

  The RAM 43 is a volatile memory such as SRAM or DRAM, and provides a working memory space to the host CPU 41 to store temporary data and various setting data. The various setting data includes a home city setting of the electronic timepiece 1, a date / time counting, and a setting relating to whether or not daylight saving time is applicable for display. Some or all of the various setting data stored in the RAM 43 may be stored in a nonvolatile memory.

  The oscillation circuit 44 generates and outputs a predetermined frequency signal determined in advance. For example, a crystal oscillator is used for the oscillation circuit 44.

  The frequency dividing circuit 45 divides the frequency signal input from the oscillation circuit 44 into a frequency signal used by the time measuring circuit 46 or the host CPU 41 and outputs the frequency signal. The frequency of the output signal may be changeable based on the setting by the host CPU 41.

  The timer circuit 46 counts the current date and time by counting the number of times the predetermined frequency signal (clock signal) input from the frequency divider 45 is input and adding it to the initial value. As the timing circuit 46, a value stored in the RAM may be changed by software, or a dedicated counter circuit may be provided. The date and time counted by the timing circuit 46 is not particularly limited, but is any of accumulated time from a predetermined timing, UTC date and time (Coordinated Universal Time), or preset date and time of the home city (local time). It is. Further, the date and time itself counted by the timer circuit 46 does not necessarily have to be held in the format of year / month / day, hour / minute / second. The clock signal input from the frequency dividing circuit 45 to the time counting circuit 46 has a slight deviation from the accurate time passage, and the magnitude of the deviation per day (the rate) varies depending on the operating environment, for example, the temperature, Usually, it is within ± 0.5 seconds.

The display unit 47 includes, for example, a display screen such as a liquid crystal display (LCD) or an organic EL (Electro-Luminescent) display, and digital display related to date and time and various functions by using either a dot matrix method or a segment method or a combination thereof. Perform the action.
The display driver 48 outputs a drive signal corresponding to the type of the display screen to the display unit 47 based on a control signal from the host CPU 41 to cause display on the display screen.

The operation unit 49 receives an input operation from the user and outputs an electrical signal corresponding to the input operation to the host CPU 41 as an input signal. The operation unit 49 includes, for example, a push button switch crown switch.
Alternatively, a touch sensor is provided so as to overlap the display screen of the display unit 47, and the display screen functions as a touch panel that outputs an operation signal according to detection of a contact position and a contact mode related to a user's contact operation by the touch sensor. Thus, the display unit 47 and the operation unit 49 may be provided integrally.

  The power supply unit 50 includes a battery and supplies power related to the operation of the electronic timepiece 1 to each unit with a predetermined voltage. Here, a solar panel and a secondary battery are used as the battery of the power supply unit 50. The solar panel generates electromotive force by the incident light and supplies power to each part such as the host CPU 41. When surplus power is generated, the solar panel stores the power in the secondary battery. On the other hand, when the power that can be generated by the amount of incident light from the outside to the solar panel is insufficient with respect to the power consumption, power is supplied from the secondary battery. Alternatively, a button type primary battery may be used as the battery.

  The satellite radio wave reception processing unit 60 receives the radio waves by identifying and capturing C / A codes (pseudorandom noise) specific to each positioning satellite in synchronization with the radio waves from the positioning satellites via the antenna AN, Necessary information is acquired by demodulating and decoding the navigation message transmitted by the positioning satellite. The satellite radio wave reception processing unit 60 includes a module CPU 61 (assumed code string generation unit, verification unit, date and time acquisition unit, error determination unit, control unit, error range calculation unit), a memory 62, and a storage unit 63 (history storage unit, An array storage unit), an RF unit 64, a baseband conversion unit 65, a capture tracking unit 66, and the like.

  The module CPU 61 controls the operation of the satellite radio wave reception processing unit 60 in accordance with a control signal and setting data input from the host CPU 41. The module CPU 61 reads out necessary programs and setting data from the storage unit 63, operates the RF unit 64, the baseband conversion unit 65, and the acquisition tracking unit 66 to receive and demodulate the received radio waves from each positioning satellite. To get date and time information. The module CPU 61 obtains the date and time information by decoding the received radio wave, and compares and collates the demodulated received code string with a preset code string for comparison and collation (collation code string) without decoding. Can be detected.

The memory 62 is a RAM that provides a working memory space to the module CPU 61 in the satellite radio wave reception processing unit 60. In addition, the memory 62 temporarily stores code string data generated for comparison with the received code string.
The storage unit 63 stores various setting data related to GPS positioning and positioning history. As the storage unit 63, various nonvolatile memories such as a flash memory and an EEPROM (Electrically Erasable and Programmable Read Only Memory) are used. The data stored in the storage unit 63 includes orbit information (ephemeris), predicted orbit information (almanac), previous positioning date and time, and position of each positioning satellite. Further, the storage unit 63 stores data relating to time zones around the world and implementation information of daylight saving time as a time difference table. When positioning is performed, the time difference table is referred to, and local time information such as a time difference from Coordinated Universal Time (UTC) in standard time at the current position and daylight saving time implementation information is specified.
The storage unit 63 stores a program 631 for performing positioning and specifying the local time information. The program 631 is read out and executed by the module CPU 61.

  The RF unit 64 receives satellite radio waves in the L1 band (1.57542 GHz for GPS satellites), selectively passes and amplifies signals from the positioning satellites, and converts them to intermediate frequency signals. The RF unit 64 includes an LNA (low noise amplifier), a BPF (band pass filter), a local oscillator, a mixer, and the like.

The baseband conversion unit 65 applies the C / A code of each positioning satellite to the intermediate frequency signal obtained by the RF unit 64 to generate a baseband signal, that is, a code string (a predetermined format) related to a navigation message (predetermined format). Received code string) is acquired.
The acquisition and tracking unit 66 calculates a correlation value between the intermediate frequency signal obtained by the RF unit 64 and the C / A code at each phase of each positioning satellite, and identifies the peak thereof. Identify the signal from the positioning satellite being received and its phase. In addition, the acquisition and tracking unit 66 uses the C / A code of the identified positioning satellite and the phase thereof to continuously acquire a code string related to the navigation message from the positioning satellite, with respect to the baseband conversion unit 65. Provides feedback of phase information.
The RF unit 64, the baseband conversion unit 65, and the acquisition tracking unit 66 constitute a radio wave receiving unit.

  The satellite radio wave reception processing unit 60 is directly supplied with power from the power supply unit 50, and is turned on / off by a control signal from the host CPU 41. That is, the satellite radio wave reception processing unit 60 is powered off separately from the host CPU 41 and the like that are always operating during periods other than the period during which radio wave reception from the positioning satellite, date and time acquisition, and calculation operations related to positioning are performed. Is done. Further, in the satellite radio wave reception processing unit 60 of the present embodiment, it is possible to switch to an in-flight mode for limiting radio wave use during the flight period of the aircraft based on an input operation to the operation unit 49. During the in-flight mode, the host CPU 41 prohibits the satellite radio wave reception processing unit 60 from being turned on. Alternatively, only the radio wave reception operation in the satellite radio wave reception processing unit 60 may be prohibited during the in-flight mode.

Next, the format of the navigation message transmitted from the GPS satellite will be described.
In GNSS, a plurality of positioning satellites are distributed on a plurality of orbits, and transmission waves of a plurality of different positioning satellites can be received simultaneously from each point on the ground, thereby transmitting from the receivable positioning satellites. By acquiring information related to the current position of the positioning satellite and date and time information from four or more positioning satellites (three on the assumption that it is the ground surface), these acquisition data, That is, the position coordinates and date / time in the three-dimensional space can be determined based on the difference in propagation time (distance) from each positioning satellite.

  From the positioning satellite, information related to date and time, information related to the position of the satellite, status information such as the health status of the satellite, and the like are spectrum-spread by a C / A code (pseudo-random noise) and transmitted. These transmission formats (navigation message formats) are determined for each positioning system.

FIG. 2 is a diagram for explaining the format of a navigation message transmitted from a GPS satellite.
In GPS, a total of 25 pages of 30-second frame data are transmitted from each GPS satellite, so that all data is output in a 12.5 minute cycle. In the GPS, a unique C / A code is used for each GPS satellite, and 1023 codes (chips) are arranged at 1.023 MHz and transmitted at a cycle of 1 ms. Since the top of this chip is synchronized with the internal clock of the GPS satellite, by detecting this phase shift for each GPS satellite, the phase shift according to the propagation time, that is, the distance from the GPS satellite to the current position. (Pseudo distance, distance index value) is detected.

  Each frame data is composed of five subframes (6 seconds). Further, each subframe is composed of 10 words (each 0.6 seconds, in order WORD1 to WORD10). The data formats of WORD1 and WORD2 are the same in all subframes. WORD1 includes a 14-bit telemetry message (TLM Message) following a preamble which is an 8-bit fixed code string, followed by a 1-bit Integrity status flag and a 1-bit spare bit, 6-bit parity data is arranged. In WORD2, 17-bit TOW-Count (also referred to as Z count) indicating the elapsed time within the week is indicated, and an Alert flag and an Anti-spoof flag are each indicated by 1 bit. Then, subframe-ID indicating a subframe number (period number) is indicated by 3 bits, and 6-bit parity data is arranged with 2 bits for parity data matching interposed therebetween.

  Data after WORD3 varies depending on the subframe. WORD3 of subframe 1 includes a 10-bit WN (week number) at the beginning. Subframes 2 and 3 mainly include ephemeris (precision orbit information), and a part of subframe 4 and subframe 5 transmit almanac (predicted orbit information).

Next, the acquisition operation of date information in the electronic timepiece 1 of the present embodiment will be described.
Usually, in order to obtain date and time information, it is necessary to receive the WN of subframe 1 and the TOW-Count of each subframe, decode them according to the format of the navigation message, and obtain the date and time. However, if the date is known and it is not necessary to obtain which week the current date is, only the TOW-Count value and the synchronization timing can be obtained, and this is combined with the known information. The complete date and time can be acquired. As described above, when the time lag (rate) counted by the time counting circuit 46 is sufficiently small, it is very rare that a lag of one day or more occurs, and in many cases, reception of WN can be omitted. . In the electronic timepiece 1 of the present embodiment, when the received code string is decoded to acquire date / time information, the elapsed time since the previous date / time information was acquired has not elapsed for a predetermined period, for example, one month or more. Is set so that reception of WN can be omitted.

  However, in order to acquire the value of TOW-Count, it is necessary to identify which part of the code sequence of the navigation message is received. In addition, when the received signal is demodulated, if the TOW-Count code sequence is not correctly identified, an incorrect date and time will be obtained, so information that ensures accuracy is usually obtained together. The

  In the electronic timepiece 1 of the present embodiment, the module CPU 61 of the satellite radio wave reception processing unit 60 generates an assumed code string assumed to be received in advance with a predetermined bit length. Then, the module CPU 61 collates this assumed code string with the actually received code string to determine whether or not the correct date and time has been received, and the assumed code string and the received code string In accordance with the timing (detection timing) at which the coincidence is detected, synchronization with the correct current date and time is achieved. That is, accurate date and time information is acquired from the detection timing of the assumed code string and the date and time indicated by the assumed code string.

  The assumed code string includes, for example, a constant code regardless of the transmission cycle, such as a preamble or a spare bit, or a change in date and time such as TOW-Count, subframe ID, WN, that is, a transmission cycle of a subframe. A part or all of the code string that changes in accordance with can be included. In addition, codes such as Alert flag and Anti-spoof flag, which are normally “0” and are not preferably used in the case of “1” (predetermined flags related to transmission status) are not necessarily predictable. However, it may be added to the assumed code string assuming “0”.

Further, the code sequence received at the time of the most recent reception of one or more satellite radio waves and the reception date and time (reception history) are stored in the storage unit 63, and the navigation message is stored in the stored code sequence. The change from the previous reception cannot be completely predicted depending on the code position (that is, the type of information), but if the elapsed time from the previous reception is short, it usually has to be changed within the elapsed time What can be determined, for example, a WORD1 telemetry message may be used as an assumed code string, or a part or all of a telemetry message may be combined with a fixed code string or a code string that changes according to the transmission cycle. An assumed code string may be used. Judgment as to whether or not it can be used for the assumed code string is not limited to the case where it is simply performed based on the elapsed time since the previous reception, and additional conditions such as using a code that has never changed in multiple receptions are added. May be.
Similarly, when data related to the positioning satellite orbit such as almanac data is acquired and the time until the next update has not elapsed, the data related to the orbit can also be included in the assumed code string.

  In particular, the assumed code string includes at least a part on the least significant bit (LSB) side of the TOW-Count and subframe ID (time correspondence information) that change reflecting the time of transmission in each transmission cycle. It is preferable to generate the assumed code string by using the date and time counted by the time counting circuit 46, and this can further reduce the possibility of erroneous identification due to a difference in one transmission cycle (one subframe). . In addition, when it is estimated that the error is so small that reception of different subframes is not expected in this way, it is possible to adjust the timing deviation of the date and time data of the time measuring circuit 46 only by the detection timing. The estimation of the error is obtained based on, for example, the ratio (rate) of the date / time error counted by the timing circuit 46 and the elapsed time since the previous date / time correction was performed. As described above, when the rate of the timing circuit 46 is 0.5 seconds / day, the estimated value of the error 30 days after the previous (most recent) date correction is 15 seconds.

  The parity data arranged in the 25th to 30th bits of each word is the required bit data among the 29th or 30th parity code in the previous word and the 1st to 24th bits in the same word. Is calculated based on Therefore, it is difficult to assume the parity codes of the 29th and 30th bits in the previous word, and in the electronic timepiece 1 of this embodiment, these parity data are not included in the assumed code string.

  The code sequences to be collated and identified need not all be continuous and may be divided into a plurality of different code string portions, but the overall reception length is a normal short-time reception, for example, three-word reception ( 90 bits), and a total of two words of WORD1 and WORD2 including a preamble, a TOW-Count including current time information, and parity data (error correction code) for the TOW-Count. More preferably, it is in a range shorter than 60 bits which is the length (data block length).

  Here, when collating the assumed code string with the received code string, the code string corresponding to the information actually transmitted from the GPS satellite is the parity data of the last bit (30th bit) of the previous word for each word. The 1st to 24th bit codes (codes other than parity data) are inverted in accordance with the (inverted code) code. That is, when the inverted code is “0”, the code of the 1st to 24th bits of the next word is transmitted as it is according to the transmission information, whereas the inverted code is “1”. The codes of the 1st to 24th bits of the next word are all the code strings corresponding to the transmission information inverted. Therefore, at the time of collation, one of the following processes is performed. (1) Generate a plurality of code sequences based on transmission information assumed according to the inverted code and perform collation, respectively. (2) Whether the assumed code sequence and the received code sequence completely match in word units, Or if it is completely mismatched, if it is completely mismatched, further identify the inverted code in the word before the word and check whether the inverted code is “1”, (3) When the assumed code string and the received code string completely match or do not completely match in word units, it is assumed that the assumed code string is detected from the received code string.

  In the case of (1), the processing load related to collation increases, in the case of (2), the processing after detection of the assumed code string increases, and in the case of (3), the possibility of misidentification Therefore, any one may be appropriately determined according to the user's preference and the performance of the electronic timepiece 1.

  When the detection (reception) of these assumed code strings is determined, if the same code string as the assumed code string appears in a position other than the originally assumed position (unexpected position), an incorrect date and time is acquired. Cases arise. The probability that the same code string as the assumed code string appears in the unexpected position increases as the assumed code string becomes shorter, while the reception time becomes longer as the assumed code string becomes longer. Therefore, in the electronic timepiece 1 of the present embodiment, the appearance probability of “0” and “1” in each binary code is simplified to be equally ½, and date / time data within the product life of the electronic timepiece 1 is simplified. The length of the assumed code string is set by setting the reference value of the number of appearances and the appearance rate so that the number of appearances and the appearance rate of the assumed code string are sufficiently smaller than the assumed number of receptions and the frequency. .

That is, since the appearance probability of a certain N-bit code string is (1/2) ^N , it is sufficient if the appearance probability is sufficiently small. For example, in order to make the appearance probability less than 10 ⁻⁸ , N ≧ 27, and in order to make the appearance probability less than 10 ⁻⁶ , N ≧ 20. Assuming that the product life of the electronic timepiece 1 is 20 years and the reception operation is performed 6 times a day, the expected number of receptions is 43830 times. Therefore, when N = 20, there is an error even once during the product life. The probability of occurrence of identification is about 4.2%. When N = 27, the probability of occurrence of erroneous identification is about 0.033%.
The reference value of the appearance probability may be set in advance, or directly or indirectly (for example, “strict”, “normal”, “loose”, etc.) based on a user setting input operation to the operation unit 49. Different reference values may be set in association with the expression).

FIG. 3 is a flowchart showing a control procedure by the host CPU 41 of date and time acquisition processing in the electronic timepiece 1 of this embodiment.
This date and time acquisition process is started when an input operation of an execution command to the operation unit 49 by the user is detected or when conditions such as a predetermined reception time and reception timing are satisfied.

  When the date and time acquisition process is started, the host CPU 41 activates the satellite radio wave reception processing unit 60 (step S101). In addition, the host CPU 41 transmits, to the satellite radio wave reception processing unit 60, initial setting data indicating that the acquisition target is date / time information and date / time information counted by the timing circuit 46 (step S102). Then, it waits for data output from the satellite radio wave reception processing unit 60. During this standby, the host CPU 41 may cause the display unit 47 to display that it is receiving.

  The host CPU 41 waits for a signal from the satellite radio wave reception processing unit 60 and acquires date / time data (step S103). Then, the host CPU 41 stops the satellite radio wave reception processing unit 60 (step S104) and corrects the date and time counted by the timer circuit 46 (step S105). Further, the host CPU 41 updates the reception history stored in the RAM 43 (Step S106). Then, the host CPU 41 ends the date acquisition process.

FIG. 4 is a flowchart showing a control procedure by the module CPU 61 of date / time information reception processing in the electronic timepiece 1 of the present embodiment.
This date and time information reception process is started when the satellite radio wave reception processing unit 60 is activated by the host CPU 41 and the acquisition target information output from the host CPU 41 in the process of step S102 is date and time information.

  When the date / time information reception process is activated, the module CPU 61 performs initial setting and operation check. The module CPU 61 acquires the date and time information output from the host CPU 41 in the process of step S102, determines the content of the navigation message to be received, and determines the reception start timing and reception period according to the content (step S201).

  The module CPU 61 generates an assumed code string of a code string portion to be identified during a predetermined reception period (step S202). When the length and position of the assumed code string can be changed, the module CPU 61 acquires the setting related to the change from the storage unit 63 and generates an appropriate assumed code string. The module CPU 61 starts receiving radio waves from GPS satellites at an appropriate timing (step S203), and captures radio waves from receivable GPS satellites (step S204). The module CPU 61 detects and captures a signal from the GPS satellite by applying inverse spectrum spread by applying the C / A code of each GPS satellite while shifting the phase with respect to the signal obtained from the received radio wave.

  When the signal from the GPS satellite is captured, the module CPU 61 acquires a code string (received code string) of the received data while tracking the GPS satellite (step S205). The module CPU 61 collates a predetermined bit length corresponding to the arrangement width of the assumed code string in the acquired reception data with the generated assumed code string (step S206). The module CPU 61 determines whether or not a portion where the received data and the assumed code string completely match is detected (step S207). If it is determined that a completely matching portion has not been detected (“NO” in step S207), the module CPU 61 is at least 6 seconds (transmission cycle for one subframe) from the start of collation with the assumed code string. Is determined, that is, whether or not the head position of the code string having a predetermined bit length to be verified among the received code strings has been shifted by 6 seconds or more (step S208). If it is determined that 6 seconds have not elapsed ("NO" in step S208), the processing of the module CPU 61 proceeds to step S210.

  If it is determined that 6 seconds have elapsed ("YES" in step S208), the module CPU 61 generates an assumed code string corresponding to the next subframe (that is, based on the time after the transmission period of the subframe). Generate and update (step S209). Then, the process of the module CPU 61 proceeds to step S210.

  When the process proceeds to step S210, the module CPU 61 determines whether or not a timeout time has elapsed from the start of reception (step S210). The timeout time is set to a predetermined number of subframes or the like, and may be appropriately changed according to the battery capacity at the start of reception, the elapsed time since the previous reception, or the like. If it is determined that the timeout time has not elapsed (“NO” in step S210), the process of the module CPU 61 returns to step S205, and the module CPU 61 continues to acquire the received data and is newly acquired. Depending on the received data, the range of the code string having a predetermined bit length to be compared with the assumed code string is shifted in the process of step S206. If it is determined that the timeout time has elapsed (“YES” in step S210), the processing of the module CPU 61 proceeds to step S212.

  When it is determined in the determination process in step S207 that a completely matched portion is detected between the received data and the assumed code string (“YES” in step S207), the module CPU 61 responds to the matched assumed code string. The date and time is acquired, and data of this date and time is output to the host CPU 41 in synchronization with the start timing of the date and time (that is, the start timing of the next subframe) (step S211).

  When the process proceeds to step S212, the module CPU 61 stops the satellite radio wave reception processing unit 60 (step S212). Then, the module CPU 61 ends the date / time information reception process.

  FIG. 5 shows a comparison between the data reception (tracking) time required for detecting the complete match of the 28-bit code in the electronic timepiece 1 of the present embodiment and the data reception time by the conventional three-word reception (with parity check). It is a figure which shows a result. The horizontal axis indicates the radio wave intensity (power value [dBm]) of the input signal from the GPS satellite, and the vertical axis indicates the time (sec) required to obtain necessary data. Here, the data reception time related to the conventional 3-word reception is 6 seconds until WORD1-WORD3 in the next subframe is received when an error is detected in the parity check for 3 words of WORD1-WORD3. When the reception is continued, an actual measurement value of the time from when the radio wave from the GPS satellite is captured until the tracking of the radio wave from the captured GPS satellite is completed is shown. Further, the data reception time according to the reception method of the present embodiment is such that, when it is assumed that an error occurs at a random code position at the same error rate as the code identification according to the actual measurement, there is an error in code identification in the assumed code string. This is an estimate of the data reception time when data reception is continued for 6 seconds until a code string at the same position in the next subframe is transmitted when a complete match is not detected.

  As indicated by the broken line (b), in the conventional receiving method, when the radio wave intensity of the input signal is less than −140 dBm, the time required for receiving data is several times as long as the radio wave intensity is further reduced to −144 dBm. It will be significantly longer until. On the other hand, the data reception time of the electronic timepiece 1 of the present embodiment indicated by the solid line (a) does not increase greatly even if the radio wave intensity is reduced to about −144 dBm (about several tens of percent or less). ), Prompt and accurate date and time information is acquired.

As described above, the electronic timepiece 1 of the first embodiment receives a satellite radio wave from a positioning satellite and identifies a satellite radio wave reception processing unit that identifies a received code string in a predetermined format according to the received satellite radio wave. The module CPU 61 as an assumed code string generation unit is assumed in advance as at least a part of the identified received code string. The RF CPU 64 includes the RF unit 64, the baseband converter 65, the acquisition tracking unit 66, and the module CPU 61. The module CPU 61 as a collating means detects the assumed code string from the received code string by sequentially collating the generated expected code string and the received code string, and serves as a date and time obtaining means. The module CPU 61 obtains the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string. . At this time, in the assumed code string, subframe periods in which time correspondence information such as TOW-Count and subframe ID including information related to the current time is transmitted according to the format of the navigation message transmitted from the positioning satellite to be received, respectively. Is included that can change depending on
Compared to the case of using parity bits, unnecessary bit data alignment is not required, and accurate date and time information can be acquired as long as the bit data to be compared can be aligned. Date and time information can be acquired.

  In addition, it is not necessary to decode the received code string by generating an assumed code string and collating it with the received code string before or during the reception of satellite radio waves, so the assumed code string is detected in the received code string The date and time can be acquired immediately after being done.

  In particular, the possibility of re-reception may be reduced when the reception condition is bad, so the rate of increase in reception time in a bad reception environment is reduced, and further, the power consumption required for reception is increased. Can be suppressed.

  In addition, the clock circuit 46 that counts the date and time is provided, and the module CPU 61 as the date and time acquisition means only acquires the timing deviation of the date and time counted by the timing circuit 46 according to the detection timing of the assumed code string in the received code string. Since the date and time can be adjusted, the processing in the case where a shift in subframe units is not assumed is simplified, and the date and time can be acquired more easily and efficiently.

  Further, the module CPU 61 includes a time counting circuit 46 that counts the date and time, and the module CPU 61 as the assumed code string generation unit includes at least a TOW-Count that represents time correspondence information based on the date and time counted by the timing circuit 46, a subframe ID, and the like. An assumed code string including a predetermined number of lower-order bit codes is generated, and the module CPU 61 as the date and time acquisition unit combines the current date and time by combining the date and time counted by the timer circuit 46 with the detection timing of the assumed code string in the received code string. Therefore, it is possible to reduce the possibility of erroneous identification due to a subframe unit shift or the like. Also, since the number of bits is larger than the number of bits of the fixed code string, the use of these can reduce the possibility of erroneous identification and improve accuracy.

  Further, the module CPU 61 as the assumed code string generation means responds to the time after one subframe when the time (6 seconds) for one subframe has elapsed from the received code string without detecting the assumed code string. Since the assumed code string is updated based on the information, it is possible to easily attempt to detect the assumed code string again in the next subframe even if the detection fails due to low reception intensity or a lot of noise.

  The time correspondence information included in the assumed code string includes a value corresponding to a subframe ID that is a cycle number indicating the number of the transmission cycle. That is, not only the TOW-Count but also a value that changes with the passage of time can be assumed in the subframe ID as well, so that it has the same effect as the TOW-Count depending on the number of bits used in the assumed code string. It can be used. Further, by using the assumed code string at the same time as TOW-Count, the occurrence of erroneous identification can be more effectively suppressed. In addition, since it is arranged in the WORD 2 in the vicinity of the TOW-Count, it is possible to generate a long assumed code string more efficiently than the increase in the number of received bits.

  In addition, the length of the assumed code string is determined so that the probability that the assumed code string appears in a position other than the originally assumed position in the received code string is less than a predetermined reference value. It is possible to reduce the possibility that the code string appears in a place other than the originally assumed position in the received code string and erroneous identification occurs at a necessary level.

  In particular, the probability of appearance of an assumed code string at an unexpected position is obtained as a binary having a probability of ½ in each binary code forming the received code string. Therefore, the length of the assumed code string can be determined by a calculation standard that is not easily deviated from the above.

  In addition, since the reference value is determined based on the estimated number of satellite radio waves received by the radio wave receiving means, a strict standard is set for a radio clock that is frequently used for a long period of time, and is used less frequently and / or for a short period of time. In the radio timepiece, a loose reference can be set, and in any case, the date and time can be acquired with optimum efficiency while keeping the number of erroneous identifications within a range that does not cause a major problem.

  In addition, an operation unit 49 that accepts a user operation is provided, and the reference value is determined according to a setting input to the operation unit. It is possible to determine a proper balance between the reception time of satellite radio waves.

  Also, the length of the received code string is determined to be less than the data block length including the preamble, the TOW-Count, and the parity data for the TOW-Count, so there is no problem in the radio wave reception state and re-reception does not occur. The shortest reception time can be made shorter than normal two-word reception.

  Further, the module CPU 61 as the assumed code string generating means generates an assumed code string corresponding to a plurality of different code string parts in the received code string, so even if a difficult code is inserted in the middle of the received code string. It is possible to generate an assumed code string having an appropriate bit length as a whole while skipping the interval.

  Further, the module CPU 61 as the assumed code string generating means generates the assumed code string including the preamble included in each subframe in the transmission cycle corresponding to the received satellite radio wave, that is, the GPS satellite. Highly accurate timing detection can be performed more reliably and efficiently with a combination of a preamble that is a sequence and a code sequence that changes every transmission period.

In addition, the transmission code string by the navigation message corresponding to the content of the transmission information from the GPS satellite that transmits the received satellite radio wave, each code in the unit block having 1 to 24 bits of each word as the unit The module CPU 61 as an assumed code string generation means includes an assumption that each code block is inverted for each unit block in the assumed code string. Each of the code string and an assumed code string including a code string that does not invert each code is generated, and the module CPU 61 as a collating unit collates the generated assumed code string and the received code string.
Therefore, it is possible to easily detect the assumed code string from the received code string regardless of the actual code inversion of each unit block.

  Further, the module CPU 61 as an assumed code string generation unit generates an assumed code string including at least one predetermined flag related to the transmission state such as an Alert flag, an Anti-spoof flag, and an Integrity status flag. These codes are not necessarily predictable, but by generating an assumed code string on the assumption that there is no problem, the date and time are acquired based on unintentionally defective received data. In general, the accuracy can be improved by increasing the number of bits of the assumed code string. Particularly, since the Alert flag and the Anti-spoof flag are between the TOW-Count and the subframe ID, the number of comparison bits can be increased without increasing the reception time. Thereby, date information can be acquired while improving the receiving accuracy more efficiently.

  In addition, a storage unit 63 is provided, and the storage unit 63 is used as a history storage unit that stores the reception history of the latest satellite radio wave, and as an array storage unit that stores a code arrangement acquired by reception of the latest satellite radio wave. The module CPU 61 as the assumed code string generation means, in accordance with the type of information relating to the code arrangement stored in the storage unit 63 as the arrangement storage means, of this code arrangement since the reception of the latest satellite radio wave. At least a part of the part determined not to change in time is included in the assumed code string. That is, although it is not always predictable, usually a telemetry message, which is a code sequence that does not change so much, is stored and used for an assumed code sequence when the elapsed time from the previous time is short, etc. The detection accuracy can be increased without increasing the possibility of causing a problem in the detection of the assumed code string.

  In addition, by using the date and time information acquisition method described above, date and time information can be efficiently acquired even when date and time information is acquired using a plurality of CPUs or radio wave receivers. Therefore, the reception time can be shortened or the acquisition accuracy can be improved in a balance according to the performance of the CPU and the radio wave receiving apparatus, the user's preference, and the like.

  The module CPU 61 of the computer (satellite radio wave reception processing unit 60) having radio wave receiving means for receiving the satellite radio wave and identifying a received code string in a predetermined format corresponding to the received satellite radio wave is connected to the module CPU 61 described above. Date and time information can be efficiently acquired by various computer terminals capable of receiving radio waves from positioning satellites according to the application and performance of the computer terminal, using a program for controlling the date and time information reception processing related to date and time acquisition. I can do it.

[Second Embodiment]
Next, an electronic timepiece according to a second embodiment of the present invention will be described.
The configuration of the electronic timepiece 1 according to the second embodiment is the same as that of the electronic timepiece 1 according to the first embodiment, and the description thereof is omitted by using the same reference numerals.

Next, the acquisition operation of date information in the electronic timepiece 1 of the second embodiment will be described.
In the electronic timepiece 1 of this embodiment, when the received code string and the assumed code string are collated, the condition determination and the collation timing adjustment are performed so that those having different transmission periods (subframes) are not collated. Other operations are the same as those of the electronic timepiece 1 of the first embodiment, and detailed description of the same operation contents is omitted.

  As described above, the timing circuit 46 generates a timing error within ± 0.5 seconds per day depending on operating conditions such as temperature. Therefore, as the time elapses from the most recent timing when the date and time counted by the timing circuit 46 is corrected, the maximum value of the date and time error of the timing circuit 46 increases, and the assumed code string and the received code string are different. The possibility of becoming a transmission cycle (subframe) increases. In the electronic timepiece 1 of the present embodiment, the reception start timing is set so that the transmission period of the code string that matches the assumed code string is always included in 6 seconds after the collation of the received code string and the assumed code string is started. To do. In addition, the timing of the previous date / time correction is stored in the storage unit 63 in advance, and at the start of the date / time operation, the module CPU 61 determines whether the elapsed time since the previous date / time correction is 6 days or more (that is, estimated). The maximum value of the error is ± 3 seconds or more, for a total of 6 seconds or more, and is more than half of the subframe length (transmission cycle) (reference time determined according to the transmission cycle) (total length of subframe If it is equal to or longer than the reference time, another date / time acquisition method, for example, the conventional three-word reception is performed to decode the code string related to the navigation message and the date / time. Switch to get.

FIG. 6 is a diagram illustrating the setting of the reception start timing.
Here, a case where the error of the date and time counted by the time counting circuit 46 is estimated to be ± 2 seconds or less will be described as an example.

  When reception is started at 00 seconds of a predetermined time by the date and time (UTC) of the clock circuit 46, as shown in FIG. 6A, this reception start timing is the time one minute before that at the correct time. This is any timing in 58 minutes in the minute and before 2 seconds in the same hour and minute as the time measuring circuit 46 (upper horizontal thick line). Since the date and time (GPS date and time) transmitted from the GPS satellite is deviated from the UTC date and time due to the implementation of leap seconds (described here as +17 seconds), the reception start timing is the GPS date and time. From 15 seconds to 19 seconds before the same hour and minute of the clock circuit 46. When it takes 2 seconds to capture a radio wave from a GPS satellite, the capture operation ends and the code string can be identified and acquired. That is, the earliest received code string that can be collated with the assumed code string The start timing (referred to as the collation start timing) is from 17 seconds to 21 seconds before (the middle horizontal thick line).

  The transmission of the data of each subframe transmitted from the GPS satellite is started every 6 seconds from 0 seconds per minute on the GPS date and time. Therefore, when the assumed code string is a predetermined bit (for example, a total of 28 bits including a preamble, TOW-Count, and a subframe ID) from the head (preamble) of each subframe, an accurate reception start time (UTC) is 58. If it is between 59 seconds and 59 seconds, the received code string of the subframe including the preamble starting at 18 seconds with GPS date and time (lower left horizontal thick line) is compared with the assumed code string. On the other hand, when the accurate reception start time (UTC) is between 59 seconds and 2 seconds, the received code string of the subframe including the preamble that starts at 24 seconds with GPS date and time (the lower right horizontal thick line) ) Is compared with the assumed code string. As a result, in any case, the TOW-Count and the subframe ID become different values between the assumed code string and the received code string, and the assumed code string and the received code string do not completely match.

  In the electronic timepiece 1 of this embodiment, the reception start timing and the collation start timing are set so that the code sequence in the same subframe as the assumed code sequence is always identified, acquired, and collated regardless of the error of the timing circuit 46. . For example, as shown in FIG. 6B, the reception start timing is set to 2 seconds (upward down arrow) at the UTC date and time in the clock circuit 46, so that the collation start timing is 19 seconds to 23 seconds before the GPS date ( Middle horizontal horizontal line). As a result, the corresponding portion to be compared with the assumed code sequence in the received code sequence is always that of the subframe including the preamble starting at 24 seconds (lower right thick horizontal line). Therefore, by generating what is assumed to be transmitted in a subframe from 24 seconds as an assumed code string, comparison and collation between the assumed code string and the received code string can be performed without depending on the error of the timing circuit 46. It becomes possible to carry out appropriately.

  Here, the central time (central date and time) of the collation start timing that satisfies such conditions can be set in 2 seconds from 20 seconds to 22 seconds (the middle horizontal arrow in FIG. 6B). That is, in the electronic timepiece 1, when the estimated error time is within ± 3 seconds (the overall width is 6 seconds), 3 ± (3-error estimated time) seconds with respect to the start timing of a predetermined subframe. By comparing at any timing within this period (verification startable period), the received code string and the assumed code string related to the same subframe are compared and verified regardless of the size of the error estimation time. I can do it. The timing of 3- (3-error estimation time) seconds with respect to the head timing of the subframe is compared with the assumed code string and the received code string associated with the latest subframe in accordance with the date and time error of the clock circuit 46. Immediately after the timing to be collated, the timing of 3+ (3-error estimation time) seconds with respect to the head timing of the subframe is the earliest received code related to the next subframe according to the date and time error of the clock circuit 46 This is the timing at which the sequence and the assumed code sequence are compared and collated. The collation start timing may be arbitrarily determined every time within the collation start possible period, or a predetermined position such as the beginning of the collation start possible period (here, 20 seconds) or the central time (21 seconds, It may be fixed to the middle stage downward arrow in FIG.

  The reception start date and time is determined by back-calculating the verification start timing in consideration of the capture time. Here, an arbitrary timing (reception start period) or a predetermined timing (for example, a reception start period) 2 seconds before the collation start timing, that is, 1 to 3 seconds before the UTC date and time in the timing circuit 46 Reception starts at 1 second which is the head of 2 seconds and 2 seconds which is the central time). When the acquisition of the radio wave from the GPS satellite is completed in a shorter time than the considered acquisition time, the standby time can be set from the start of tracking of the radio wave and the identification of the code string to the start of collation. Setting the reception start timing closer to the beginning of the reception start period increases the possibility of starting collation as originally planned even if the actual acquisition time is longer than the considered acquisition time, while the reception state is Even if it is good, the reception time becomes long and the power consumption increases. Therefore, for example, the initial setting of the reception start timing may be set as the center time of the reception start period, and may be changed to the front or the rear according to the reception history or the like. Also, by setting the reception start timing as the central time of the reception start period, even if the timing of completion of capture does not deviate from the period in which collation can be started, in this case, whether or not it is within the period in which collation can be started. Even if the collation is started as it is without discriminating again, there is usually no problem.

FIG. 7 is a flowchart showing a control procedure by the module CPU 61 of date / time information reception processing executed by the electronic timepiece 1 of the second embodiment.
In the electronic timepiece 1 of the present embodiment, the date / time information reception process is the first implementation except that the processes of steps S221 to S224 are added to the date / time information reception process executed by the electronic timepiece 1 of the first embodiment. This is the same as the date and time information reception process executed by the electronic timepiece 1 of the embodiment, and the same processing contents are denoted by the same reference numerals and description thereof is omitted.

  When the date / time information reception process is started, the module CPU 61 obtains the previous reception timing from the storage unit 63 together with the date / time counted by the timing circuit 46 in the process of step S201, and the date / time of the timing circuit 46 is corrected. The maximum error assumed in accordance with the elapsed time since being done is calculated (step S201).

  The module CPU 61 determines whether or not the maximum error is less than ± 3 seconds (step S221). If it is determined that it is not less than ± 3 seconds (“NO” in step S221), the process of the module CPU 61 proceeds to step S224 and decodes the code string by a conventional method such as reception of 3 words from a GPS satellite. The date / time information is acquired (step S224). Then, the process of the module CPU 61 proceeds to step S211.

  If it is determined that the maximum error is less than ± 3 seconds (“YES” in step S221), the module CPU 61 always checks first regardless of the error when starting reception after the current date and time. The subframes that can be defined in the subframe are specified, and an assumed code string in the subframe is generated (step S202).

  The module CPU 61 specifies a reception start period in which the code sequence of the specified subframe can be acquired from the top regardless of an error in consideration of a preset acquisition time, and the current date and time is the reception start period. It is determined whether it is within (step S222). If it is determined that it is not within the reception start period (“NO” in step S222), the module CPU 61 repeats the determination process in step S222.

  If it is determined that it is within the reception start period (“YES” in step S222), the processing of the module CPU 61 proceeds to step S203.

  After the process proceeds to step S205 and acquisition of reception data (reception code string) is started, the module CPU 61 determines whether or not it is within the collation start possible period (step S223). If it is determined that the period is not within the collation start possible period (“NO” in step S223), the module CPU 61 repeats the process of step S223. If it is determined that it is within the collation start possible period (“YES” in step S223), the processing of the module CPU 61 proceeds to step S206.

  In the process of step S208, the module CPU 61 determines whether or not 6 seconds (transmission cycle for one subframe) or more has elapsed from the start of collation with the assumed code string, that is, a predetermined collation among the received code strings. It is determined whether or not the head position of the bit-length code string has been shifted from the position of the collation start timing by 6 seconds or more.

As described above, in the electronic timepiece 1 of the second embodiment, the module CPU 61 as the collating means is before the detection timing of the assumed code string predicted based on the date and time counted by the timer circuit 46 and the detection timing. The comparison and collation of the received code string and the assumed code string is started within a period of less than one subframe period.
Accordingly, it is possible to suppress the occurrence of a situation in which a match with the code sequence corresponding to the assumed code sequence in a subframe different from the assumed code sequence is compared and matching with the assumed code sequence is not detected.

Further, the module CPU 61 as the error range calculation means estimates the error range of the time measuring circuit 46 based on the elapsed time from the latest timing when the date and time counted by the time measuring circuit 46 was corrected since the previous satellite radio wave was received. The module CPU 61 serving as the collating means can start the collation start possible period in which the comparison and collation between the received code string and the assumed code string can be started in accordance with the expected detection range of the assumed code string that is predicted in consideration of the error range. The comparison collation between the received code string and the assumed code string is started.
As a result, as long as the error range of the clock circuit 46 is within ± 3 seconds in the radio wave reception from the GPS satellite, the received code string portion corresponding to the assumed code string in the same subframe as the assumed code string is always this assumption. Since the comparison is made with the code string, the situation where the received code string of the different subframes and the assumed code string are compared and collated without detecting the exact match portion is surely avoided regardless of the magnitude of the error. I can do it.

  In addition, the RF unit 64, the baseband conversion unit 65, and the acquisition tracking unit 66 of the satellite radio wave reception processing unit 60 have a timing for starting the reception of the satellite radio wave based on the collation startable period. As described above, the radio wave reception is appropriately started based on the collation startable period, so that it is possible to prevent the radio wave reception time from being unnecessarily prolonged and appropriately control the power consumption.

  In addition, the RF unit 64, the baseband conversion unit 65, and the acquisition tracking unit 66 of the satellite radio wave reception processing unit 60 receive the satellite before a predetermined time from the timing of starting the comparison and collation between the received code sequence and the assumed code sequence. Start receiving radio waves. In other words, the power consumption can be reduced easily and appropriately by determining the collation start timing of the assumed code string and the received code string and the reception start timing of the satellite radio wave according to the expected detection timing of the assumed code string. Efficient date and time information can be acquired. In particular, when the time required for capturing satellite radio waves is assumed to be substantially constant because the satellite radio wave reception environment does not change significantly each time, date and time information can be acquired more significantly and efficiently.

Further, the module CPU 61 serving as an error discriminating means determines whether the error of the clock circuit 46 estimated according to the elapsed time from the timing when the satellite radio wave was previously received and the date and time of the clock circuit 46 was corrected depends on the length of the subframe. The module CPU 61 as a date and time acquisition unit determines whether or not the time is equal to or longer than a predetermined reference time, and when it is determined that the error is not equal to or longer than the reference time, the predetermined number in the time correspondence information such as TOW-Count and subframe ID The date and time is acquired based on the assumed code string including the code of the lower bits of.
That is, when the error of the timing circuit 46 is large and there is a possibility that a deviation in subframe units may occur, it may take time to detect the assumed code string from the received code string, or it may not be detected. Therefore, by confirming that this is not the case, and detecting the assumed code string from the received code string, it is possible to perform the date information acquisition operation more appropriately and efficiently.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the above embodiment, the module CPU 61 as the control means performs all processing operations, but part or all of the processing may be executed by the host CPU 41. Further, the module CPU 61 and the host CPU 41 may be used together by a single CPU, and the storage unit 63 and the RAM 43 may be used together for storing the previous (most recent) reception history.

  Further, the module CPU 61 may cause the assumed code string and the received code string to be collated while shifting the acquired code one by one every time one bit is acquired, or a predetermined bit longer than the assumed code string. After acquiring a large number of received data, collation with the assumed code string may be performed collectively while shifting the phase. In the former case, when collation is terminated when the assumed code string is identified from within the received code string, if there is a misidentification, it ends as it is, but the received position after the original assumed position Even if the same code string as the assumed code string appears, no problem occurs. In the latter case, if the same code string as the assumed code string appears in the unexpected position in the received data regardless of the original assumed position, a process for identifying the correct position is required. However, misidentification can be avoided more effectively.

  In the above-described embodiment, the date / time information acquisition operation according to the present invention is performed when correcting the date / time of the timing circuit 46. The user may perform an input operation or may be acquired from another external device when the date and time related to the assumed code string is necessary.

  Further, in the above embodiment, it is determined whether or not to acquire the date / time information according to the present invention according to the estimation error of the timing circuit 46. However, when the magnitude of the error itself can be accurately estimated, etc. Alternatively, date code information may be acquired by generating an assumed code string based on the date and time reflecting the magnitude of the error and collating it with the received code string.

  In the above-described embodiment, the case of collating with a received radio wave from a GPS satellite has been described. However, collation with a code array related to a radio wave received from another positioning satellite, for example, a GLONASS satellite may be performed. . In this case, the string transmission time (2 seconds) may be used as a transmission cycle, and the string number may be used as time correspondence information.

  In the above embodiment, the appearance probability of the assumed code string at the unexpected position is calculated assuming that the appearance probability of “0” and “1” at each code position is ½, but a fixed code string or TOW As for the most significant bit of, the portion having an apparent appearance probability different from 1/2 may be calculated by setting the appearance probability separately.

  Moreover, the setting of the product life of the electronic timepiece 1 shown in the above embodiment and the frequency of radio wave reception per day is arbitrary. It may be set in advance according to the product, or may be changed as appropriate based on a user operation. Accordingly, the number of verification bits for obtaining the required accuracy can be increased or decreased accordingly.

  In the above-described embodiment, the reception in the same subframe and the collation with the assumed code string have been described with the WORD1 and WORD2 positions as the center. However, the reception is limited to the reception of the subframe 1 and includes the WN of WORD3 and the like. In addition, the data is not limited to subframe 1 and may be data of other subframes. Furthermore, an assumed code string may be generated across data of adjacent subframes.

  In the above embodiment, it has been described that it is preferable that the assumed code string includes a code string that changes in accordance with the transmission cycle (subframe). However, it is assumed that only such a changing code string is used. A code string may be generated, or a combination with a fixed code string may be used.

In the above description, the storage unit 63 formed of a nonvolatile memory is taken as an example of a computer-readable medium for an operation processing program related to positioning such as time zone calculation processing related to the processing operation of the module CPU 61 according to the present invention. Although described, it is not limited to this. As other computer-readable media, a portable recording medium such as an HDD (Hard Disk Drive), a CD-ROM, or a DVD disk can be applied. A carrier wave is also applied to the present invention as a medium for providing program data according to the present invention via a communication line.
In addition, the specific configuration, operation content, procedure, and the like shown in the above embodiment can be changed as appropriate without departing from the spirit of the present invention.

Although several 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 equivalents thereof. .
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.

[Appendix]
<Claim 1>
A radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave;
An assumed code string generating means for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
With
The radio-controlled timepiece, wherein the assumed code string includes a code that can change according to a transmission cycle in which time-related information including information related to the current time is transmitted according to the predetermined format.
<Claim 2>
It has time measuring means to count the date and time,
The radio timepiece according to claim 1, wherein the date and time acquisition unit acquires a timing deviation of the date and time counted by the time measuring unit according to the detection timing.
<Claim 3>
It has time measuring means to count the date and time,
The assumed code string generation means generates the assumed code string including codes of at least a predetermined number of lower bits among the code strings representing the time correspondence information based on the date and time counted by the timing means,
The radio timepiece according to claim 1, wherein the date and time acquisition unit acquires the current date and time by combining the date and time counted by the timing unit and the detection timing.
<Claim 4>
The assumed code string generation means, when a time equal to or longer than the transmission period has elapsed without detecting the assumed code string from within the received code string, based on the time correspondence information after the transmission period. 4. The radio timepiece according to claim 3, wherein the column is updated.
<Claim 5>
Error discriminating means for discriminating whether or not the error of the clocking means estimated based on the elapsed time from the most recent timing when the date and time counted by the clocking means has been corrected is equal to or greater than a reference time determined according to the transmission cycle; Prepared,
The date and time acquisition unit, when it is determined that the error is not equal to or greater than the reference time, acquires date and time based on the assumed code string including the code of the predetermined number of lower bits. 3. The radio timepiece according to 3 or 4.
<Claim 6>
The radio timepiece according to any one of claims 3 to 5, wherein the time correspondence information included in the assumed code string includes a value corresponding to a cycle number indicating a number of the transmission cycle.
<Claim 7>
The collating means is prior to the detection timing of the assumed code string predicted based on the date and time counted by the time measuring means, and within the range less than one transmission period from the detection timing, and the received code string The radio timepiece according to any one of claims 3 to 6, wherein collation with the assumed code string is started.
<Claim 8>
An error range calculating means for estimating an error range of the time measuring means based on an elapsed time from the most recent timing when the date and time counted by the time measuring means is corrected,
The collation means includes the collation within a collation startable period in which collation between the received code string and the assumed code string can be started according to a prediction range of the detection timing predicted in consideration of the error range. 8. The radio timepiece according to claim 7, wherein the radio timepiece is started.
<Claim 9>
9. The radio timepiece according to claim 8, wherein the radio wave receiving means has a timing for starting reception of a satellite radio wave based on the collation startable period.
<Claim 10>
9. The radio timepiece according to claim 8, wherein the radio wave reception means starts receiving a satellite radio wave a predetermined time before the timing of starting the collation.
<Claim 11>
The length of the assumed code string is determined such that the probability that the assumed code string appears in a position other than the position assumed in the received code string is less than a predetermined reference value. The radio timepiece according to any one of claims 1 to 10.
<Claim 12>
12. The radio timepiece according to claim 11, wherein the probability is obtained by assuming that a binary appears with a probability of 1/2 in each binary code forming the received code string.
<Claim 13>
13. The radio timepiece according to claim 11, wherein the reference value is determined based on an estimated number of satellite radio waves received by the radio wave receiving means.
<Claim 14>
Comprising an operation means for accepting a user's operation;
The radio wave timepiece according to any one of claims 11 to 13, wherein the reference value is determined according to a setting input to the operation means.
<Claim 15>
The length of the received code string is less than a data block length including at least one fixed code string that does not change for each transmission period, at least current time information among date information, and an error correction code for the time information. The radio timepiece according to claim 1, wherein the radio timepiece is defined as follows.
<Claim 16>
16. The radio timepiece according to claim 15, wherein the satellite radio wave is transmitted from a GPS satellite, and the data block length is a length of 2 words.
<Claim 17>
17. The radio timepiece according to claim 1, wherein the assumed code string generation unit generates the assumed code string corresponding to a plurality of different code string portions in the received code string.
<Claim 18>
The assumption code string generation unit generates the assumption code string by including fixed code strings each included in the transmission period corresponding to the received satellite radio wave. Radio wave clock as described in one.
<Claim 19>
The transmission code string in the predetermined format corresponding to the content of the transmission information from the positioning satellite that transmits the received satellite radio wave is transmitted by inverting each code in a predetermined unit block for each unit block. Including an inversion code that determines whether or not to
The assumed code string generating means includes an assumed code string including a code string obtained by inverting each code for each unit block in the assumed code string, and an assumed code string including a code string not inverting each code. Generate each
The collation means collates each assumed code string generated with the received code string.
The radio timepiece according to claim 1, wherein
<Claim 20>
The radio timepiece according to claim 1, wherein the assumed code string generation unit generates the assumed code string including at least one predetermined flag related to a transmission state. <Claim 21>
A history storage means for storing a reception history of the latest satellite radio wave;
An array storage means for storing a code array acquired by receiving the latest satellite radio wave;
With
The assumed code string generation means determines that, in accordance with the type of information relating to the code arrangement stored in the arrangement storage means, the code arrangement does not change within the elapsed time since the reception of the latest satellite radio wave. The radio timepiece according to any one of claims 1 to 20, wherein at least a part of the determined portion is included in the assumed code string.
<Claim 22>
A radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave;
An assumed code string generating means for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
A history storage means for storing a reception history of the latest satellite radio wave;
An array storage means for storing a code array acquired by receiving the latest satellite radio wave;
With
The assumed code string generation means determines that, in accordance with the type of information relating to the code arrangement stored in the arrangement storage means, the code arrangement does not change within the elapsed time since the reception of the latest satellite radio wave. A radio-controlled timepiece including at least a part of the assumed portion in the assumed code string.
<Claim 23>
Date and time information acquisition method by a control means using a radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave,
An assumed code string generation step for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
A collation step of detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
A date acquisition step of acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
Including
The date information acquisition method according to claim 1, wherein the assumed code string includes a code that can change according to a transmission cycle in which time correspondence information including information related to a current time is transmitted according to the predetermined format.
<Claim 24>
A computer comprising radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave,
Assumed code string generating means for generating an assumed code string assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string,
Function as
The assumption code string includes a code that can change according to a transmission cycle in which time correspondence information including information corresponding to a current time is transmitted according to the predetermined format.

1 Electronic clock 41 Host CPU
42 ROM
421 program 43 RAM
44 Oscillator 45 Divider 46 Clock circuit 47 Display unit 48 Display driver 49 Operation unit 50 Power supply unit 60 Satellite radio wave reception processing unit 61 Module CPU
62 Memory 63 Storage unit 631 Program 64 RF unit 65 Baseband conversion unit 66 Acquisition tracking unit AN Antenna

Claims (24)

A radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave;
An assumed code string generating means for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
With
The radio-controlled timepiece, wherein the assumed code string includes a code that can change according to a transmission cycle in which time-related information including information related to the current time is transmitted according to the predetermined format. It has time measuring means to count the date and time,
The radio timepiece according to claim 1, wherein the date and time acquisition unit acquires a timing deviation of the date and time counted by the time measuring unit according to the detection timing. It has time measuring means to count the date and time,
The assumed code string generation means generates the assumed code string including codes of at least a predetermined number of lower bits among the code strings representing the time correspondence information based on the date and time counted by the timing means,
The radio timepiece according to claim 1, wherein the date and time acquisition unit acquires the current date and time by combining the date and time counted by the timing unit and the detection timing.   The assumed code string generation means, when a time equal to or longer than the transmission period has elapsed without detecting the assumed code string from within the received code string, based on the time correspondence information after the transmission period. 4. The radio timepiece according to claim 3, wherein the column is updated. Error discriminating means for discriminating whether or not the error of the clocking means estimated based on the elapsed time from the most recent timing when the date and time counted by the clocking means has been corrected is equal to or greater than a reference time determined according to the transmission cycle; Prepared,
The date and time acquisition unit, when it is determined that the error is not equal to or greater than the reference time, acquires date and time based on the assumed code string including the code of the predetermined number of lower bits. 3. The radio timepiece according to 3 or 4.   The radio timepiece according to any one of claims 3 to 5, wherein the time correspondence information included in the assumed code string includes a value corresponding to a cycle number indicating a number of the transmission cycle.   The collating means is prior to the detection timing of the assumed code string predicted based on the date and time counted by the time measuring means, and within the range less than one transmission period from the detection timing, and the received code string The radio timepiece according to any one of claims 3 to 6, wherein collation with the assumed code string is started. An error range calculating means for estimating an error range of the time measuring means based on an elapsed time from the most recent timing when the date and time counted by the time measuring means is corrected,
The collation means includes the collation within a collation startable period in which collation between the received code string and the assumed code string can be started according to a prediction range of the detection timing predicted in consideration of the error range. 8. The radio timepiece according to claim 7, wherein the radio timepiece is started.   9. The radio timepiece according to claim 8, wherein the radio wave receiving means has a timing for starting reception of a satellite radio wave based on the collation startable period.   9. The radio timepiece according to claim 8, wherein the radio wave reception means starts receiving a satellite radio wave a predetermined time before the timing of starting the collation.   The length of the assumed code string is determined such that the probability that the assumed code string appears in a position other than the position assumed in the received code string is less than a predetermined reference value. The radio timepiece according to any one of claims 1 to 10.   12. The radio timepiece according to claim 11, wherein the probability is obtained by assuming that a binary appears with a probability of 1/2 in each binary code forming the received code string.   13. The radio timepiece according to claim 11, wherein the reference value is determined based on an estimated number of satellite radio waves received by the radio wave receiving means. Comprising an operation means for accepting a user's operation;
The radio wave timepiece according to any one of claims 11 to 13, wherein the reference value is determined according to a setting input to the operation means.   The length of the received code string is less than a data block length including at least one fixed code string that does not change for each transmission period, at least current time information among date information, and an error correction code for the time information. The radio timepiece according to claim 1, wherein the radio timepiece is defined as follows.   16. The radio timepiece according to claim 15, wherein the satellite radio wave is transmitted from a GPS satellite, and the data block length is a length of 2 words.   17. The radio timepiece according to claim 1, wherein the assumed code string generation unit generates the assumed code string corresponding to a plurality of different code string portions in the received code string.   The assumption code string generation unit generates the assumption code string by including fixed code strings each included in the transmission period corresponding to the received satellite radio wave. Radio wave clock as described in one. The transmission code string in the predetermined format corresponding to the content of the transmission information from the positioning satellite that transmits the received satellite radio wave is transmitted by inverting each code in a predetermined unit block for each unit block. Including an inversion code that determines whether or not to
The assumed code string generating means includes an assumed code string including a code string obtained by inverting each code for each unit block in the assumed code string, and an assumed code string including a code string not inverting each code. Generate each
The collation means collates each assumed code string generated with the received code string.
The radio timepiece according to claim 1, wherein   The radio timepiece according to claim 1, wherein the assumed code string generation unit generates the assumed code string including at least one predetermined flag related to a transmission state. A history storage means for storing a reception history of the latest satellite radio wave;
An array storage means for storing a code array acquired by receiving the latest satellite radio wave;
With
The assumed code string generation means determines that, in accordance with the type of information relating to the code arrangement stored in the arrangement storage means, the code arrangement does not change within the elapsed time since the reception of the latest satellite radio wave. The radio timepiece according to any one of claims 1 to 20, wherein at least a part of the determined portion is included in the assumed code string. A radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave;
An assumed code string generating means for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
A history storage means for storing a reception history of the latest satellite radio wave;
An array storage means for storing a code array acquired by receiving the latest satellite radio wave;
With
The assumed code string generation means determines that, in accordance with the type of information relating to the code arrangement stored in the arrangement storage means, the code arrangement does not change within the elapsed time since the reception of the latest satellite radio wave. A radio-controlled timepiece including at least a part of the assumed portion in the assumed code string. Date and time information acquisition method by a control means using a radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave,
An assumed code string generation step for generating an assumed code string that is assumed in advance as at least a part of the identified received code string;
A collation step of detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
A date acquisition step of acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string;
Including
The date information acquisition method according to claim 1, wherein the assumed code string includes a code that can change according to a transmission cycle in which time correspondence information including information related to a current time is transmitted according to the predetermined format. A computer comprising radio wave receiving means for receiving a satellite radio wave and identifying a received code string in a predetermined format according to the received satellite radio wave,
Assumed code string generating means for generating an assumed code string assumed in advance as at least a part of the identified received code string;
Collating means for detecting the assumed code string from within the received code string by sequentially collating the generated assumed code string and the received code string;
Date and time acquisition means for acquiring the current date and time based on the detection timing of the assumed code string when the assumed code string is detected in the received code string,
Function as
The assumption code string includes a code that can change according to a transmission cycle in which time correspondence information including information corresponding to a current time is transmitted according to the predetermined format.

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