JP2018010004A - Satellite radio wave receiving device, radio controlled clock, information acquisition method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satellite radio wave receiving device, a radio controlled clock, an information acquisition method, and a program with which it is possible to accurately acquire a time-of-day information while suppressing an unnecessary load and power consumption.SOLUTION: A satellite radio wave receiving device of the present invention comprises satellite radio wave reception means, and acquisition means for identifying the array of codes included in a received radio wave and the reception timing of the array, with the code value of each of a plurality of codes being inverted under a prescribed condition for each code block, the acquisition means deciding a supposed code for which the inversion corresponding to radio wave reception timing is not taken into account, identifying a plurality of received codes from the received radio wave, collating the supposed code within a preset deviation width from the reception timing of the received codes against each of the received codes, holding information pertaining to the collation result for each deviation amount with regard to the plurality of received codes, determining for each code block that the one having larger number of matches and mismatches is conformant, and identifying a deviation amount in which the integrated number of conformants corresponding to the integrated value per deviation amount of the number of conforming codes in a plurality of code blocks satisfies a prescribed conformance condition.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a satellite radio wave receiver, a radio timepiece, an information acquisition method, and a program that receive radio waves from positioning satellites.

  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 date and time in the electronic timepiece, and the response to the reception of satellite radio waves is due to the increase in the size of the battery and the accompanying electronic timepiece. There is a problem that this leads to an increase in size and weight. Therefore, various techniques have been developed in the past to reduce power consumption related to reception of satellite radio waves.

  One technique for reducing such power consumption is to shorten the radio wave reception time. According to Patent Document 1, reception is performed in accordance with a transmission timing of a predetermined part including date and time information according to a format (navigation message) of a signal transmitted from a GPS satellite, and reception is temporarily stopped while unnecessary information is transmitted. The technology is disclosed. 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, if the received time information is decoded after identifying each received code and further collation operations such as parity check are performed, the processing load during radio wave reception eventually increases, and the memory capacity and power There is a problem that it easily leads to an increase in consumption.

  An object of the present invention is to provide a satellite radio wave receiver, a radio timepiece, an information acquisition method, and a program that can accurately acquire time-related information while suppressing unnecessary processing load and power consumption.

In order to achieve the above object, the present invention provides:
Receiving means for receiving radio waves including a code signal transmitted from a satellite;
An acquisition means for identifying an arrangement of a plurality of codes constituting a code signal included in the radio wave received by the receiving means and a reception timing of the arrangement;
With
The plurality of codes are respectively inverted when a value of each code determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
The acquisition means includes
A verification code string including an assumed code determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the satellite related to the radio wave received by the receiving means is generated. ,
Identify each code as a received code from the received radio wave,
The received code and the received code are collated with each other within the preset deviation width with respect to the reception timing of the identified received code, and the matched received code and the assumed code are matched. Holding information related to the matching result shown for a plurality of the received codes for each deviation amount within the deviation width,
The number of matches or mismatches for each code block is determined as the match, and the number of matches corresponding to the value obtained by adding the number of matches in the plurality of code blocks for each deviation amount is calculated. ,
A satellite radio wave receiver characterized in that a deviation amount satisfying a predetermined coincidence number corresponding to the number of accumulated matches is identified as a coincidence deviation amount.

  According to the present invention, there is an effect that information relating to time can be accurately acquired while suppressing unnecessary processing load and power consumption.

It is a block diagram which shows the function structure of the electronic timepiece of embodiment of this invention. It is a figure explaining the format of the navigation message currently transmitted from the GPS satellite. It is a figure explaining collation of a code. It is a figure explaining collation of a code. It is a flowchart of a date acquisition process. It is a flowchart of a date information reception process. It is a flowchart of the pattern collation process called by the date information reception process. It is a flowchart of the reliability determination process called by the date information reception process. It is a flowchart of the reliability determination process called in the modification 1 of a date information reception process. It is a flowchart which shows the modification 2 of date information reception processing. It is a flowchart of the pattern matching process called in the modification 2 of the date information reception process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a functional configuration of an electronic timepiece 1 which is an embodiment of a radio timepiece of the present invention.

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

  The host CPU 41 is a processor (control means) that 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 date / time counting, home city settings related to time zone selection in display, and settings related to availability of daylight saving time. 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 may be 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). Further, the date and time counted by the clock circuit 46 does not necessarily have to be held in the format of year / month / day and hour / minute / second. The magnitude of the deviation (day rate) per day between the clock signal input from the frequency dividing circuit 45 to the time measuring circuit 46 and the accurate time passage varies depending on the operating environment, for example, temperature, and is usually ± 0. Within 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 as the operation unit 49 so as to overlap the display screen of the display unit 47, and the display screen is a touch panel that outputs an operation signal according to detection of a contact position or a contact mode related to a user's contact operation by the touch sensor. May function.

  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. As the battery of the power supply unit 50, here, a solar panel and a secondary battery are used. 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 navigation messages transmitted by positioning satellites. The satellite radio wave reception processing unit 60 includes a module CPU 61 as an acquisition unit (processor), a memory 62, a storage unit 63, an RF unit 64 as a reception unit, a baseband conversion unit 65, a capture tracking unit 66, and the like. Prepare.

  The module CPU 61 is a processor that controls the operation of the satellite radio wave reception processing unit 60 in response to input of control signals and setting data 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 date and time information by decoding the received radio wave, and in addition to the code string for comparison and verification (verification code string) generated in advance by predicting the demodulated reception code without decoding. Collation code string generation means, code identification means, collation means, result holding means, coincidence determination means, and deviation amount identification means for performing coincidence detection by comparison and collation and identifying deviation from the expected reception date and time (reception timing) Can function as.

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 memory | storage part 63 memorize | stores the history of various setting data regarding GPS positioning, positioning, and date information acquisition. 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 precise orbit information (ephemeris), predicted orbit information (almanac), the 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 for performing positioning and specifying the local time information, and a program 631 for receiving and acquiring date and time information, and is read out and executed by the module CPU 61. Is done.

  The RF unit 64 receives a satellite radio wave in the L1 band (1.57542 GHz for GPS satellites), selectively passes and amplifies a signal (code signal) transmitted from the positioning satellite, and converts it to an intermediate frequency signal. 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). A received code string and an array of a plurality of codes).
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. The type of the C / A code included in the received radio wave and the phase of the C / A code are identified. Further, the acquisition and tracking unit 66 uses the identified C / A code and its phase to continuously acquire a code string of a navigation message transmitted from a positioning satellite corresponding to the C / A code. Phase information is fed back to the converter 65, and the received radio wave is demodulated to identify each code (received code).
In addition to the module CPU 61, a memory 62, a storage unit 63, a baseband conversion unit 65, and a capture tracking unit 66 can be included in the acquisition means.

  The satellite radio wave reception processing unit 60 is directly supplied with electric power from the electric power supply unit 50, and is turned on / off by a control signal of 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.

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 an observation point, so that the positioning signals transmitted from the receivable positioning satellites can be received. Information on the current position of the satellite and date and time information are acquired from four or more positioning satellites (three on the assumption that it is the ground surface), and the difference between these acquisition data and acquisition timing, Based on the difference in propagation time (distance) from the positioning satellite, the position coordinates and date / time of the observation point in the three-dimensional space can be determined. Further, by acquiring date / time information from one positioning satellite, it is possible to acquire the current date / time within an error range of propagation time from the positioning satellite (less than about 100 msec).

  From the positioning satellite, a code string (navigation message) indicating information related to the date and time, information related to the position of the satellite, status information such as the health status of the satellite, etc. is phase-modulated by a C / A code (pseudorandom noise). Thus, the spectrum is spread and transmitted. These signal 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 this C / A code is repeated at a cycle of 1 msec. 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) is detected.

Each frame data is composed of 5 subframes (6 seconds each). Further, each subframe is composed of 10 words (each 0.6 seconds, in order WORD1 to WORD10). Each word is 30 bits long. That is, a 50-bit code per second is transmitted from the GPS satellite.
The data formats of WORD1 and WORD2 are the same in all subframes. WORD 1 includes a 14-bit telemetry message (TLM Message) following a preamble that 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, a subframe ID (Subframe-ID) indicating a subframe number (period number) is indicated by 3 bits, and 6 bits of parity data are 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).

  Here, the date and time (GPS date and time) counted by the GPS satellite does not include a deviation due to the implementation of leap seconds. Accordingly, since there is a difference between the GPS date and time and the UTC date and time, the date and time acquired by receiving the radio wave from the GPS satellite needs to be converted into the UTC date and output. In addition, when controlling the reception timing of a radio wave from a GPS satellite based on the date and time counted by the timing circuit 46 or estimating the date and time of reception, the date and time of the timing circuit 46 is converted into a GPS date and time. It is necessary to use it.

Next, the acquisition operation of date information in the electronic timepiece 1 of the present embodiment will be described.
The TOW-Count transmitted from the positioning satellite, the subframe ID, and the WN in subframe 1 are assumed to have a code arrangement and reception timing based on the navigation message format (signal transmission format, satellite type) and the current date and time. obtain. In the electronic timepiece 1 of the present embodiment, a collation code string including such an imaginable code (assumed code) is generated in advance, and the reception timing (assumed based on the date and time counted by the time counting circuit 46 of the received code) The position of the verification code string is shifted within a shift width corresponding to the error of the time counting circuit 46 with respect to the reception timing), and sequentially compared with the assumed code in the verification code string. And the information (date information) concerning the exact date according to the amount of deviation in which a plurality of received codes and an assumed code match, and the contents of the collation code string (assumed code) is acquired.

  In addition to the code that changes according to the date and time as described above, the assumed code may include a constant code regardless of the transmission period, such as a preamble or a spare bit. 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”, are not predictable, but are “0”. It may be assumed and added to the assumed code.

Furthermore, the code arrangement received at the time of the reception of the latest one or more satellite radio waves and the date and time of reception thereof are stored in the storage unit 63, and the code position in the navigation message is stored in the stored code arrangement. Accordingly, the change from the previous reception cannot be completely predicted, but when the elapsed time from the previous reception is short, it can be usually determined that there is no change within the elapsed time, for example, a telemetry message of WORD1 May be used as an assumed code, or an assumed code is a combination of a part or all of a telemetry message and a code string that changes according to the above-described fixed code string or transmission cycle. May be. Judgment as to whether or not it can be included in the assumption code is not limited to the case where it is simply performed based on the elapsed time from the previous reception, and a condition such as whether or not it has changed even after multiple receptions is 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.

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

  The assumed codes do not have to be all continuous in the collation code string, and may be divided into a plurality of different code string portions. For example, the assumed code may be determined by the reserved bits that are the 23rd and 24th bits of WORD1 and the TOW-Count that is the 1st to 17th bits of WORD2 across the parity bits of the 25th to 30th bits of WORD1. . Here, the assumed code and the code that cannot be assumed in the verification code string can be identified by setting an assumed availability flag (identification information) corresponding to each code. The arrangement of the possibility flag may be generated together with the generation of the verification code string.

  Here, when collating each assumed code of the collation code string with the received code, the code string corresponding to the information actually transmitted from the GPS satellite is the end of the previous word (word block) for each word (code block). The sign of the 1st to 24th bits can be inverted (under a predetermined condition) according to the parity data which is the code (inverted code) of the 30th bit). 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 in the non-inverted state according to the transmission information, whereas this inverted code is “1” If there is, the codes of the 1st to 24th bits of the next word are all the code strings corresponding to the transmission information inverted. Therefore, when all of the assumed code that does not consider inversion and each non-inverted received code are compared and collated correctly, the matching result is a perfect match, and the assumed code that does not consider inversion and each inverted received code If all are compared and collated correctly, the collation results are completely inconsistent.

  In the reception timing of the received code, there is a phase (code number) shift corresponding to the difference between the timing assumed based on the date and time counted by the timer circuit 46 and the date and time counted by the timer circuit 46. As described above, since the rate of the time counting circuit 46 is 0.5 seconds / day (1/48 [sec / h]), the time counting circuit 46 is set according to the elapsed time tp [h] from the most recent date and time correction. The maximum deviation width dt (half of the maximum deviation width) from the exact date and time of counting is estimated as dt = tp / 48. That is, the accurate date and time tc is estimated to be in the range of t−dt ≦ tc ≦ t + dt with respect to the date and time t counted by the time counting circuit 46.

  In the electronic timepiece 1 of the present embodiment, it is assumed that the received code r (t) acquired at the date and time t (assumed reception timing) counted by the timing circuit 46 is in the range of t−dt ≦ tc ≦ t + dt. Each assumed code is collated without considering the inversion described above, and the collation results obtained for a plurality of dates and times t are each element of the array according to the relative position within the assumed range of this exact date and time tc. Is added to each to identify the best match (match / mismatch) timing.

FIG. 3 and FIG. 4 are diagrams for explaining code collation in the electronic timepiece 1 of the present embodiment.
As shown in FIG. 3 (a), after 6 days (144 hours) have elapsed since the previous correction of the date and time of the timing circuit 46, the date and time counted by the timing circuit 46 is received at 03 seconds of a certain hour at the UTC time. Is started, the accurate second value of the date and time tc is estimated to be between 00 seconds and 06 seconds (maximum deviation width dt = 3.0 sec). When the difference between the UTC date and time and the GPS date and time is 17 seconds, the second value of this date and time is between 17 seconds and 23 seconds in the GPS date and time. Furthermore, when it takes 2 seconds from the start of reception until the radio wave from the GPS satellite is captured and the acquisition of the code is started, the acquisition start of the code is between 19 seconds and 25 seconds as the second value of the GPS date and time. Become. In this case, the generated collation code string includes 19 to 25 seconds as the second value of the GPS date and time, and further includes from the latest 25 seconds to 31 seconds after 6 seconds (transmission period) corresponding to one subframe. I can do it. In addition, since the code before 19 seconds is unnecessary after the generation of the verification code string, only the verification code string starting with the 19-second code can be stored and held. At this time, since the word including the leading code starting from 19.00 seconds starts from 18.60 seconds, the leading code is the 21st bit of the word. The position in the word of the first code is stored as an offset value q.

  As shown in FIG. 3B, when the reception code r (t0) at the date and time t0 (here, the second value is 22 seconds) counted by the timing circuit 46 is first acquired, the date and time t0− 301 assumption possibility flags p (i) from an assumption possibility flag p (0) corresponding to dt (here 19 seconds) to an assumption possibility flag p (100 dt) corresponding to the date and time t0 + dt (here 25 seconds). The code c (i) indicating that the assumption of the code c (i) is “possible” in the collation code string c, that is, the assumption code (for example, p (i) = 1) The received code r (t0) is compared with each other. This array number i represents a relative position (a value corresponding to the amount of deviation) within an accurate expected date and time range (that is, within a deviation width).

  When the possibility flag p (i) indicates that the code c (i) can be assumed and collation is performed, 1 is added to the collation number N (i). Here, as described above, p (i) = 1 is set when the assumption is possible, and p (i) = 0 is set when the assumption is impossible. good. In addition, as a result of the collation, those that have been matched are added with 1 and retained as the number of matches E (i) as information relating to the collation result indicating match or mismatch.

  The above processing operation is repeated each time one newly received code is identified. As described above, since the GPS satellite transmits a code of 50 bits per second, this processing operation is repeated at an interval ε = 20 [msec]. Or it is not restricted to the case where one received code is identified every 20 msec, for example, by identifying the code type every 1 msec, the code type rs (t0-0) to 20 times in the reception period of one code. rs (t0-19) may be acquired. Even in this case, the code c (i) of the collation code string c to be compared with the 20 code types may be one. For example, when the reception strength decreases, the identification result may vary among these 20 code types. In this case, the probability that the 20 code types are the same is greater than ½, and depends on, for example, the code error rate (BER).

  As described above, since the signal from the positioning satellite is transmitted with the inversion or non-inversion of the code determined in units of words (every 30 bits), the demodulated code sequence is the verification code sequence in units of the word. The coincidence or disagreement with each assumed code of c changes. That is, when the number of coincidences E (i) between the assumed code and the received code is simply accumulated across a plurality of words, the number of coincident parts and the number of inconsistent parts of the code are mixed every time the code is inverted. The matching phase cannot be obtained properly.

Therefore, the electronic timepiece 1 counts the number of matches and the number of matches between the assumed code and the received code in units of words in the matching code string c (for each code block), and matches the larger of the number of matches and the number of mismatches. It is determined as a number (match determination) and converted to a match frequency F (i) (integrated match number) that is a value corresponding to the larger value. Then, by accumulating this match frequency F (i) for a plurality of words, a match degree for each shift amount (phase) is obtained, and a match that is likely as a match shift amount (a predetermined match condition is satisfied). A deviation amount (matching deviation amount) of the code string c is determined. Here, the coincidence frequency F (i) is obtained by the following mathematical formula (1).
F (i) = | N (i) −2 × E (i) | (1)

  That is, the matching frequency F (i) is equal to the number N of collations when the codes of the number N (i) of collation are completely coincident (E (i) = N (i)) or completely disagree (E (i) = 0). It becomes equal to (i) and takes the maximum value. When the number of matches and the number of mismatches are half each (E (i) = N (i) / 2), the minimum value is “0”. The coincidence frequency F (i) is not limited to that according to Equation (1) as long as it is a value that equally handles matching and mismatching.

  The coincidence number E (i) of each code in word units is converted into the coincidence frequency F (i) and added, and the collation number N (i) is added to the cumulative collation number T (i) (integrated collation number). Is done. The coincidence number E (i) and the collation number N (i) are initialized to “0” and used for the next collation in units of words.

  That is, in the memory 62 of the electronic timepiece 1, an array of the number of matches E (i), the number of matches N (i), the number of matches F (i), and the cumulative number of matches T (i) is assumed for the electronic watch 1 respectively. A number corresponding to the maximum deviation width is assigned. For example, as described above, the maximum deviation width can be ± 3 seconds. In this case, the number of arrangements is 301 pieces.

  As shown in FIG. 4 (a), the received code r (t0 + εk) after the elapsed time εk from the first identified received code r (t0) is the (k + 1) th received code, and an accurate expected date and time range Is (t0 + εk−dt) ≦ tc ≦ (t0 + εk + dt). Then, the assumed code in the codes c (k) to c (100dt + k) of the matching code string corresponding to this range is compared and matched with the received code r (t0 + εk) based on the possibility flag p (k) to p (100dt + k). The The presence / absence of matching between these codes c (k) to c (100dt + k) and the received code r (t0 + εk) and the matching result are the number of matching N (0) to N (100dt) and the number of matching E (0) to E (100dt). ). In addition, the collation number N and the coincidence number E corresponding to the end of the word among the codes c (k) to c (100dt + k) are initialized by being accumulated and converted into the cumulative collation number T and the coincidence frequency F, respectively. .

The end of the word can be determined based on the offset value q described above. That is, the position of the array number i satisfying the relationship of the following formula (2) is the end of each word when the sum of the array number i, the count number k related to the number of code identifications, and the offset value q is an integer value j.
i + q + k = 30 × j (2)
Thus, the collation number N (i) and the coincidence number E (i) are calculated every 30 times each time the received code is identified and collation is performed, and the cumulative collation number T (i) and the coincidence frequency F (i). The position where the integration is performed is shifted one by one.

  As shown in FIG. 4B, for example, when one received code is identified every 20 msec in synchronization with each code, 22 assumed codes for the first word with respect to the array number i = 10. If 10 of them match, N (10) = 22 and E (10) = 10 are counted. When collation with all assumed codes for the word is completed, these are converted, integrated, and transferred to F (10) = 2, T (10) = 22, and E (10), N (10) Is initialized.

  Then, for the next word, for example, when E (10) = 9 and N (10) = 16 are counted for 16 assumed codes, the value of N (10) is added to T (10). Thus, T (10) = 38, and 2 that is the coincidence frequency obtained by converting E (10) is added to F (10), and F (10) = 4. Thus, when the number of matches E (10) is about half of the number of matches N (10), the match frequency F (10) is smaller than the cumulative number of matches T (10).

  On the other hand, regarding the array element number i = 200, there are 22 assumed codes for the first word, and when all of them match, N (200) = 22 and E (200) = 22 are counted. Then, after conversion and addition to obtain F (200) = 22 and T (200) = 22, E (200) and N (200) are initialized.

  If there are 22 assumed codes for the next word and only one of them is matched, N (200) = 22 and E (200) = 1 are counted. In this case, since the coincidence frequency converted from E (200) is 20, this value is added to the coincidence frequency F (200), and F (200) = 42. N (200) = 44. Thus, when the number of matches E (200) is equal to the number of matches (200) or close to “0”, the match frequency F (200) is a value close to the cumulative number of matches T (200). Become.

  Similarly, as shown in FIG. 4C, when the code type for each code is determined 20 times every 1 msec, the number of verifications N (10), N (200) and the cumulative verification number T are counted. (10), T (200) is 20 times. The coincidence numbers E (10) and E (200) are counted in the same manner, and the coincidence frequencies F (10) and F (200) are similarly calculated. At the end, F (10) = 46 for T (10) = 760, while F (200) = 876 for T (200) = 880.

Of the cumulative collation number T (i) obtained in this way, for a certain cumulative collation number T (i1), the corresponding matching frequency F (i1) is equal to or sufficiently equal to the cumulative collation number T (i1). Probability (matching probability) that the probability that the collation code sequence c and the received code that are phase-shifted corresponding to the sequence number i1 coincide with the received code by chance due to misidentification of codes of other code sequences, The timing at which the verification code string c matches the received code is identified by sufficiently increasing the probability that the verification code string c shifted in phase corresponding to the array element number i2 matches the received code. The Considering the lifetime of the electronic timepiece 1, for example, 10 to 20 years, and the frequency of execution of this collation operation, for example, once a day, the occurrence probability of “0” and “1” in each binary code ( If all of them are halved, the probability of occurrence of erroneous identification is made sufficiently low. For example, the match probability is set to a predetermined reference value, here 10 ⁻ The number of assumed codes (cumulative collation number, reference collation number) required to make it less than ⁸ is 27. This probability is set directly or indirectly by a setting operation by the user (for example, different reference values may be set in association with expressions such as “strict”, “normal”, “loose”). It may be possible to move up and down.

FIG. 5 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). This date / time information includes information on the maximum value of the deviation based on the elapsed time since the date / time of the previous time counting circuit 46 was corrected. 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. 6 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 settings such as securing and allocation of a memory area and an operation check (step S201). The module CPU 61 acquires the date / time information output from the host CPU 41 in step S102, converts the acquired UTC date / time into GPS date / time, and estimates an accurate date / time range based on the error information ( Step S202).

  The module CPU 61 generates an array of the possibility flag p (i) and the collation code string c in a range including all codes that are assumed to be received in the estimated accurate date and time range, and the offset of the collation code string c. A value q is determined (step S203; collation code string generation step). At this time, the module CPU 61 performs memory allocation and initialization operations for the collation number N (i), the cumulative collation number T (i), the coincidence number E (i), and the coincidence frequency F (i). The module CPU 61 starts receiving radio waves from GPS satellites (step S204) and captures radio waves from receivable GPS satellites (step S205). The module CPU 61 applies to the C / A code of each GPS satellite while shifting the phase of the signal obtained from the received radio wave and attempts to perform reverse spectrum spreading, so that any one or a predetermined number or less of GPS satellites can be obtained. Detect and capture the signal.

  When the signal from the GPS satellite is captured, the module CPU 61 starts identifying each code of the received data while tracking the GPS satellite with the captured phase (step S206). Further, the module CPU 61 sets an initial value “0” for the count number k. Based on the difference between the timing at which the verification code string c and the possibility flag p (i) are generated in the process of step S203 and the timing at which the identification of the code is actually started, the module CPU 61 The arrangement of the possibility flag p (i) and the offset value q are corrected (step S207).

  The module CPU 61 obtains the code every time one code is identified, and adds 1 to the count number k (step S208; code identification step). The module CPU 61 calls and executes a pattern matching process (step S209), and then calls and executes a reliability determination process as a deviation amount identifying step (step S210). The module CPU 61 determines whether or not the reliability is OK based on the determination result obtained in the process of step S210 (step S211). If it is determined that it is not OK (“NO” in step S211), the module CPU 61 determines whether or not a timeout period has elapsed since the start of radio wave reception from a GPS satellite (step S212). If it is determined that the time has elapsed (“YES” in step S212), the processing of the module CPU 61 proceeds to step S216. If it is determined that the time has not elapsed (“NO” in step S212), the module CPU 61 additionally generates a code c (i) of the verification code string c and an assumption possibility flag p (i) as necessary. (Step S213). As used herein, the case where it is expected that the reliability OK judgment cannot be obtained with the data of 12 seconds from the first generated code string length, for example, the second value from 19 seconds to 31 seconds. Or the case where the reliability OK determination is not obtained with the data.

  At this time, the code data portion of the collation code string c that has become unnecessary and the corresponding possibility flag p (i) can be deleted. Further, in order not to increase the array number more than necessary, the array number i of the remaining and added codes c (i) and the corresponding possibility flag p (i) corresponding to the number of erased codes is added. May be prepended. In this case, the offset value q and the count number k are corrected together. Then, the process of the module CPU 61 returns to step S208.

  If it is determined that the reliability is OK in the determination processing in step S211 (“YES” in step S211), the module CPU 61 indicates the timing of the code array determined to be reliability OK and the date and time indicated by the verification code string. Based on the above, the accurate GPS date / time is acquired, and the acquired GPS date / time is converted into UTC date / time, and the timing is set (step S214). The module CPU 61 outputs date and time information to the host CPU 41 in accordance with the set timing (step S215). Then, the process of the module CPU 61 proceeds to step S216.

  When the process proceeds to step S216, the module CPU 61 ends the reception of radio waves from the GPS satellite (step S216). Then, the module CPU 61 ends the date / time information reception process.

  FIG. 7 is a flowchart showing the control procedure of the pattern matching process called in step S209 of the date / time information reception process.

  When the pattern matching process is called, the module CPU 61 sets the array element number i to “0”, which is an initial value (step S801).

  The module CPU 61 refers to the assumption availability flag p (i + k) and determines whether or not the symbol c (i + k) is a symbol that can be assumed (step S802). If it is determined that it cannot be assumed (“NO” in step S802), the process of the module CPU 61 proceeds to step S806.

  When it is determined that the code c (i) is an assumed code (“YES” in step S802), the module CPU 61 adds an assumption availability flag p (i + k), that is, “1” to the verification number N (i). In step S803, it is determined whether or not the acquired received code r and code c (i + k) are equal (step S804; collation step). If it is determined that they are not equal (“NO” in step S804), the processing of the module CPU 61 proceeds to step S806.

If it is determined that the received code r and the code c (i + k) are equal (“YES” in step S804), the module CPU 61 adds “1” to the coincidence number E (i) (step S805). Then, the process of the module CPU 61 proceeds to step S806.
The processing of steps S802 and S805 constitutes a result holding step.

  In step S806, the module CPU 61 determines whether or not the remainder (mod) obtained by dividing the total value of the array element number i, the count number k, and the offset value q by “0”, that is, i + k + q. It is determined whether or not the value is a multiple of 30 (step S806). This determination process is performed, for example, based on whether or not the remainder when i + k + q is divided by 30 is “0”. If it is determined that it is a multiple of 30 (“YES” in step S806), the module CPU 61 converts the coincidence number E (i) into the coincidence degree F (performs coincidence determination), and the match degree F is converted into the coincidence degree F. Add to the currently set match frequency F (i). Further, the module CPU 61 adds the collation number N (i) to the cumulative collation number T (i) (step S807; match determination step). Then, the process of the module CPU 61 proceeds to step S808. If it is determined that it is not a multiple of 30 (“NO” in step S806), the processing of the module CPU 61 proceeds to step S808.

  When the process proceeds to step S808, the module CPU 61 determines whether or not the array element number i is 100 dt or more (step S808). That is, the module CPU 61 determines whether or not all the assumed codes within the assumed range from the code c (k) to the code c (100 dt + k) are compared with the received code r. When it is determined that the array number i is not 100 dt or more, that is, there is an assumed code that is not compared and collated within the assumed range (“NO” in step S808), the module CPU 61 sets the array number i to “1” is added (step S809). Then, the module CPU 61 returns the process to step S802. When it is determined that the array element number i is 100 dt or more, that is, it is determined that all the assumed codes within the assumed range have been compared with the received code r (“YES” in step S808), the module CPU 61 The pattern matching process ends and the process returns to the date / time information reception process.

  FIG. 8 is a flowchart showing the control procedure of the reliability determination process called in step S210 of the date / time information reception process.

  When the reliability determination process is called, the module CPU 61 extracts the largest match frequency F (i) as the maximum match frequency Fmax (step S901). The module CPU 61 determines whether or not the maximum matching frequency Fmax is larger than the reference matching frequency Fth (step S902). If it is determined that it is not greater than the reference matching frequency Fth (“NO” in step S902), the processing of the module CPU 61 proceeds to step S906.

  When it is determined that the maximum match frequency Fmax is greater than the reference match frequency Fth (“YES” in step S902), the module CPU 61 corresponds to the array element number i of the match frequency F (i) from which the maximum match frequency Fmax was obtained. The cumulative collation number T (i) to be acquired is acquired (step S903). The module CPU 61 determines whether or not the maximum matching frequency Fmax is equal to the acquired cumulative collation number T (i) (step S904). If it is determined that they are equal (“YES” in step S904), the module CPU 61 determines that the reliability is OK (step S908), ends the reliability determination process, and returns the process to the date / time information reception process.

  When it is determined that the maximum matching frequency Fmax and the cumulative matching number T (i) are not equal (“NO” in step S904), the module CPU 61 determines the matching frequency F (i) for which the maximum matching frequency Fmax is obtained. ) And the corresponding accumulated collation number T (i) are reset to “0”, and then the process proceeds to step S906.

  When the process proceeds from step S902 or step S905 to step S906, the module CPU 61 determines whether or not the remainder obtained by dividing the count number k by 300 (that is, the number of codes for one subframe) is “0”. A determination is made (step S906). If it is determined that it is “0” (“YES” in step S906), the module CPU 61 initializes the cumulative collation number T (i) and the matching frequency F (i) for all the array element numbers i, It returns to “0” (step S907). Then, it is assumed that the module CPU 61 is reliable NG (step S909). Then, the module CPU 61 ends the reliability determination process and returns the process to the date / time information reception process. If it is determined that it is not “0” (“NO” in step S906), the processing of the module CPU 61 proceeds to step S909.

  As described above, the matching frequency F (i) is identified only in units of words, so that the provisional matching frequency Ft (i) = F (i) + | N (i) is used in order to make a determination in real time. −2 × E (i) | is calculated by overwrite update every time, and the largest of the temporary matching frequencies Ft (i) is equal to or greater than the reference matching frequency Fth and equal to T (i) + N (i) It may be determined whether or not. In this case, however, it is desirable not to calculate the added value | N (i) −2 × E (i) | when N (i) = 1.

[Modification 1]
Next, Modification 1 of the date / time information reception process executed by the electronic timepiece 1 will be described.
In the date and time information reception process of this modification, the probability of misidentification is not only when the matching code string and the received code r are matched, but also when there is an imperfect match including a small number of errors. By setting the reliability OK within a range where the signal is sufficiently suppressed, the date and time information can be acquired even when the reception intensity of the radio wave from the positioning satellite is low and the S / N ratio (SNR) is low.

In this electronic timepiece 1, the condition for determining that the probability of misidentification can be kept low in the case of an imperfect match is that the assumed code in the collation code string with each shift amount (phase shift) with respect to the arrangement of the received code r And the appearance probability (first appearance probability) related to the minimum value of the number of non-matches (ie, the maximum value of the total number of matches compared to the cumulative number of matches) and the second smallest non-match number (ie, the second largest) It is determined based on the appearance probability (second appearance probability) related to the total number of matches). Assuming that the appearance probabilities of “0” and “1” in each code are ½, the appearance probability P is a value obtained by returning the cumulative collation number T and the coincidence frequency F to the coincidence number E, that is, the probability mismatch number. the nonmatching number Eb = (T-F) / 2 which is an equivalent value _can be expressed by ^{_{P = T C Eb / 2 T}} . For example, the occurrence probability of the received code sequence including a non-match of the 3 bits in the received code is checked against the 44 bits of the assumed sign (41-bit match of) _is a ^{_{44 C 3/2 44 = 7.53}} × 10 -10 is there. Moreover, the occurrence probability of the received code sequence including one bit of disagreement (27 bits match) of the collated received code and 28 bits of the assumed _code, at ^{_{28 C 1/2 28 = 1.04}} × 10 -7 is there.

  Here, as described above, the possibility of misidentification may be excluded based only on the appearance probability related to the minimum non-matching number. However, in the case of an incomplete match, the possibility that a code string similar to the collation code string c appears in the actual received code string by chance increases, so the appearance of such a similar code string can be eliminated. More preferably, additional conditions are set. For example, when almost all codes of TOW-Count are “0” or “1”, when these code strings are used as assumed codes, the verification code string c and the received code string have a slight phase shift. In many cases, these codes “0” and “1” coincide with each other in many portions. Further, when TOW-Count or the like is a periodic code string (for example, when “0” and “1” are alternately arranged), the phase shift of the cycle or the phase shift of the half cycle is Again many codes match. Therefore, in this case, the number of non-matches is smaller than in a normal phase shift state, and the probability of erroneous identification increases due to noise (radio wave reception intensity) or the like. Therefore, in such a case, the start of radio wave reception is put on hold until a timing at which a more preferable assumed code is arranged, or such an undesirable possible code is not included in the assumed code. I can do it.

  First, the length (300 bits) corresponding to one period of each subframe within the assumed range of the phase shift of the verification code string c set in accordance with the maximum amount of date / time shift estimated based on the rate of the clock circuit 46. The verification code and the reception code are collated over each other. Then, the maximum match frequency Fmax which is the maximum match frequency within the phase shift setting range and the second match frequency Fmax2 which is the second highest match frequency are extracted, and these and the maximum match cumulative verification number corresponding to them. The minimum non-match number Ebmin = (Tmax−Fmax) / 2 and the next-point non-match number Ebmin2 = (Tmax2−Fmax2) / 2 are calculated using Tmax and the next point match cumulative check number Tmax2.

Next, the ratio (probability ratio) of the appearance probability P1 related to the minimum non-match number Ebmin to the appearance probability P2 related to the next-point non-match number Ebmin2 is calculated as the risk Pd. When the risk Pd = P1 / P2 is equal to or less than a predetermined reference value (reference ratio), it is determined that the probability of erroneous identification is sufficiently small.
The reference value Pm (reference ratio) to be compared with the risk degree Pd depends on the product life and radio wave reception frequency, that is, the estimated number of receptions within the product life and the accuracy required for the product, as in the above embodiment. In this case, for example, Pm = 10 ⁻⁸ .
It is not necessary to calculate the appearance probabilities P1 and P2 when calculating the risk Pd. Further, when the cumulative collation number T (i) becomes large and the calculation formula of the risk Pd becomes complicated, and the load increases or the calculation time becomes long, the risk Pd is appropriately set using an approximate expression. You may calculate by an approximate value. As the approximate expression, for example, linear approximation or Stirling formula is preferably used.

  In the electronic timepiece 1 of the present embodiment, when the reception state is good according to the SNR (signal index value related to reception intensity) at the start of code identification (predetermined timing), the reliability determination based on the above-described perfect match is performed. If the reception state is not good, the reliability for avoiding misidentification is considered in consideration of this incomplete match. In addition, if reliability is not determined even after a predetermined time (upper verification time), for example, 6 seconds for one subframe, has passed in the reliability determination based on perfect match, an error that considers imperfect match is considered. The process proceeds to the determination of reliability related to avoidance of identification, every time data (10 words, 300 bits (number of unit codes)) of data for one subframe (a predetermined period of the navigation message) is acquired. Judgment is made.

  In the date / time information reception process of the first modification, only the content of the reliability determination process called in the date / time information reception process shown in FIG. 6 is different from the date / time information reception process in the above embodiment. Only the contents of will be described.

FIG. 9 is a flowchart showing a control procedure by the module CPU 61 of the reliability determination process called in the date / time information reception process of the present modification.
Compared with the reliability determination process of FIG. 8 called in the date / time information reception process of the above-described embodiment, the reliability determination process deletes the processes of steps S905 to S907, and steps S911, S912, and S921 to S926. The process is the same except that the process is added. The same processing contents are denoted by the same reference numerals, and detailed description thereof is omitted.

  When this reliability determination process is called, the module CPU 61 determines whether or not the SNR of the received radio wave in the vicinity of the first code identification time is less than a predetermined intensity reference value Sth (step S911). If it is determined that the SNR is less than the intensity reference value (“YES” in step S911), the processing of the module CPU 61 proceeds to step S921.

If it is determined that the SNR is not less than the intensity reference value Sth (“NO” in step S911), it is determined whether or not the count number k is less than 300 (step S912). If it is determined that it is not less than 300 (“NO” in step S912), the processing of the module CPU 61 proceeds to step S921.
If it is determined that the count number k is less than 300, the process of the module CPU 61 proceeds to step S901. Thereafter, if it is determined in step S904 that the maximum matching frequency Fmax is not equal to the corresponding accumulated collation number T (i) (“NO” in step S904), the processing of the module CPU 61 is performed in step S909. Migrate to

  When branching from the determination processing of steps S911 and S912 to the processing of step S921, the module CPU 61 determines whether or not the remainder obtained by dividing the count number k by 300 is 0 (step S921). If it is determined that it is not 0 (“NO” in step S921), the processing of the module CPU 61 proceeds to step S909.

  If it is determined that the remainder is 0 (“YES” in step S921), the module CPU 61 uses the remaining matching number E (i) and matching number N (i) for each array number i. Each is included in the matching frequency F (i) and the cumulative matching number T (i) (step S922). The module CPU 61 extracts the maximum coincidence frequency Fmax and the maximum coincidence cumulative collation number Tmax that maximize F (i) / T (i), and the second largest coincidence degree Fmax2 and the next point coincidence cumulative collation. The number Tmax2 is extracted (step S923). When the cumulative matching number T (i) is the same for the array element number i, the maximum matching frequency Fmax and the next matching frequency Fmax2 may be simply extracted according to the magnitude of the matching frequency F (i). . The module CPU 61 calculates the minimum non-match number Ebmin and the next-point non-match number Ebmin2 using these extracted values (step S924). The module CPU 61 calculates the ratio of the appearance probability P1 of the minimum non-match number Ebmin to the appearance probability P2 of the next point non-match number Ebmin2 as the risk Pd (step S925).

The module CPU 61 determines whether or not the common logarithm log (Pd) of the risk Pd is ⁻⁸ or less, that is, whether or not the risk Pd is 10 ⁻⁸ or less (step S926). If it is determined that the value is equal to or lower than −8 (“YES” in step S926), the processing of the module CPU 61 proceeds to step S908. If it is determined that it is not −8 or less (“NO” in step S926), the processing of the module CPU 61 proceeds to step S909.

[Modification 2]
Next, a second modification of the date / time information reception process executed by the electronic timepiece 1 will be described.
In the date and time information reception processing of this modification, phase shifts (shift amounts) including a large number of non-matches are excluded from the phase shift candidates with matching timings during the process, and the process is omitted.

  In the electronic timepiece 1 of the second modified example, the candidate flag X is added to the memory 62 as parameters in addition to the number of matches E (i), the number of matches N (i), the number of matches F (i), and the cumulative number of matches T (i). (I) is stored. Here, the candidate flag X (i) is included in the candidates in which the sequence of the received code r and the collation code string c having the phase shift (timing shift) corresponding to the array number i match in phase (code). This is a binary flag that is set to “0” in the case and “1” if it is not included. The initial values of the candidate flags X (i) are all “0” and are changed to “1” when they are removed from the candidates.

As described above, the timing corresponding to the one with the largest match frequency F (i) becomes a match candidate with the arrangement of the received code r, and therefore the match frequency F (i) is equal to the cumulative verification number T (i). With respect to the number of codes that becomes sufficiently small and can be identified within the timeout period, the matching frequency F (i that cannot be the maximum matching frequency Fmax or the next matching frequency Fmax2 or cannot be OK in the reliability determination. ) Can be excluded from the candidates. As such a condition (a lower limit standard related to the relationship between the cumulative matching number T (i) and the matching frequency F (i)), for example, the lower limit of the ratio of the matching frequency F (i) to the cumulative matching number T (i) For example, it is less than the reference value, or more than the upper limit value of the difference value between the cumulative collation number T (i) and the matching frequency F (i). For example, in the case where F (i) / T (i) <0.2 or the case where T (i) −F (i) ≧ 20 in the cumulative collation number T (i) equal to or greater than the predetermined reference number Tth, The candidate flag X (i) is changed to “1”, and the subsequent verification and parameter update are stopped.
Note that if the conditions for removal from candidates are relaxed (the conditions for leaving candidates are severe), the processing load is reduced, but the second-point match frequency Fmax2 tends to be inaccurate often, so the calculation accuracy of the risk level Pd decreases. . However, if all parameters other than the parameter related to one sequence number i are excluded from the candidates, the reliability determination based on the risk Pd is not performed, and the phase shift timing related to the one sequence number i is determined by the erasing method. May be identified as the coincidence timing.

FIG. 10 is a flowchart showing a second modification of the date / time information receiving process executed by the electronic timepiece 1. FIG. 11 is a flowchart of the pattern matching process called in the second modification of the date / time information receiving process.
In this date / time information reception process, the processes of steps S221 and S222 are added to the date / time information reception process of the above-described embodiment, and the processes of steps S821 to S823 are added to the contents of the pattern matching process in step S209. The same processing contents are denoted by the same reference numerals and description thereof is omitted.

  When the pattern matching process in step S209 is called and the value of the array element number i is initialized in the process in step S801 as shown in FIG. 11, the module CPU 61 determines whether the candidate flag X (i) is 0 or not. Is determined (step S821). If it is determined that the value is 0 (“YES” in step S821), the processing of the module CPU 61 proceeds to step S802. If it is determined that the value is not 0, that is, 1, the process of the module CPU 61 proceeds to step S808.

  When the matching frequency F (i) and the cumulative collation number T (i) are calculated in the process of step S807 and the coincidence number E (i) and the collation number N (i) are initialized, the module CPU 61 executes the cumulative collation. It is determined whether or not the ratio of the coincidence frequency F (i) to the number T (i) is less than the lower limit reference value Rth (step S822). This determination process may be executed only when the cumulative collation number T (i) is equal to or greater than the predetermined reference number Tth.

  When it is determined that the value is less than the lower limit reference value Rth (“YES” in step S822), the module CPU 61 sets the candidate flag X (i) to 1 (step S823). Then, the process of the module CPU 61 proceeds to step S808. If it is determined that the value is not less than the lower limit reference value Rth (“NO” in step S822), the process of the module CPU 61 proceeds to step S808.

  When the pattern matching process is completed and the process returns to the date and time information reception process, as shown in FIG. 10, the module CPU 61 determines whether or not the candidate flag X (i) is “0”. Is determined (step S221). If it is determined that there is not one remaining (“NO” in step S221), the processing of the module CPU 61 proceeds to step S210. If it is determined that there is only one remaining (“YES” in step S221), the module CPU 61 performs the processing in step S214, assuming that the phase difference corresponding to the remaining one candidate flag X (i) matches. Move on to processing.

  If it is determined in the determination process in step S211 that the reliability is not OK ("NO" in step S211), the module CPU 61 determines whether all candidate flags X (i) are 1 or not. A determination is made (step S222). If it is determined that all candidate flags X (i) are 1 (“YES” in step S222), the processing of the module CPU 61 proceeds to step S216. When it is determined that any candidate flag X (i) is not 1 (“NO” in step S222), the processing of the module CPU 61 proceeds to step S212.

  When extracting the maximum match frequency Fmax and the next match frequency Fmax2 in the reliability determination process, the candidate flag X (i) may or may not include the match frequency F (i) related to the array element number i of 1. good. Since the matching frequency F (i) does not increase after the candidate flag X (i) becomes 1, the matching frequency F (i) is newly selected as the maximum matching frequency Fmax and the next matching frequency Fmax2. Absent. Therefore, it is possible to reduce the processing load because it is determined whether or not to include in the extraction target with reference to the candidate flag X (i) and to include in the extraction target without referring to the candidate flag X (i). It will suffice if it is selected.

As described above, the satellite radio wave reception processing unit 60 included in the electronic timepiece 1 of the present embodiment is included in the radio wave received by the RF unit 64 and the RF unit 64 that receives the radio wave including the code signal transmitted from the satellite. A module CPU 61, a memory 62, a storage unit 63, a baseband conversion unit 65, a capture tracking unit 66, and the like as an acquisition means for identifying a plurality of code sequences forming a code signal and reception timing of the sequences. Each code value determined according to the content indicated by the code signal is inverted for each word consisting of 30 codes according to the parity data in the word preceding the word, and the acquisition means is a verification code string generation means As shown by the code signal according to the type of positioning satellite and the reception timing related to the radio wave received by the RF unit 64 Generates a collation code string including an assumed code determined without considering inversion according to the assumed contents, identifies a plurality of codes as received codes from the received radio wave as a code identification means, and identifies as a collation means The received code and the received code are collated with each other within the preset deviation width with respect to the received timing of the received code, and as a result holding unit, the matched received code matches the assumed code or The information related to the result of matching related to the mismatch is held for a plurality of received codes for each shift amount within the shift width, and as a match determination unit, the greater of the number of matches or mismatches is determined as a match for each code block. Then, a match frequency F (i) corresponding to a value obtained by integrating the number of matches in a plurality of words for each shift amount is calculated, and the match frequency F (i) is set to a predetermined match as a shift amount identifying unit. Identifying satisfies deviation amount as a matching shift amount.
In this way, each assumed code of the collation code string does not consider the inversion of the code, and it is determined that the larger of the number of matches and the number of mismatches between the assumed code and the received code for each word matches. The number of matches can be appropriately counted for the portion, and the number of matches and the number of mismatches are generally the same in the portion that does not match. Therefore, it is not necessary to store and collate a large number of collation code strings generated over a plurality of words according to the combination of inversion patterns, and to efficiently and appropriately receive and process while reducing memory capacity and processing amount. It is possible to identify an amount of deviation between an accurate date and time assumed for load and power consumption.

Further, the acquisition means (deviation amount identification means) calculates the cumulative collation number T (i) obtained by counting the deviation amount, that is, the number of times of collation for each array number i, and the cumulative collation equal to or greater than the reference coincidence frequency Fth. The matching condition includes that the matching frequency F (i) equal to the number T (i) is obtained, and the shift amount (array number i) from which the matching frequency F (i) satisfying the matching condition is obtained is used as the matching shift amount. Identify.
In this way, by specifying the array element number i relating to the amount of deviation in which the received code r having the reference matching frequency Fth or more completely matches the assumed code, the matching result with the assumed code existing over a plurality of words can be easily and appropriately determined. This makes it possible to identify the correct deviation amount while reducing the possibility of misidentification of the deviation amount.

Further, the reference matching frequency Fth is such that the matching probability that the assumed code and the received code r are continuously matched with the number of matching equal to the reference matching frequency Fth is less than a predetermined reference value (for example, 10 ⁻⁸ ). Determined. In this way, by determining the reference matching frequency Fth stochastically, a deviation amount in which the received code r and the assumed code completely match with an appropriate accuracy according to the desired accuracy required for the electronic timepiece 1 is identified. I can do it.

  In addition, the match probability is obtained by halving all the probabilities that the assumed code and the received code r match, so that the match deviation amount is identified with appropriate accuracy based on an average probability based on easy calculation. I can do it.

In addition, the acquisition unit calculates the cumulative collation number T (i) obtained by counting the number of collations performed for each deviation amount as the collation unit, and as the deviation amount identification unit, compared with the cumulative collation number T (i). The maximum match frequency Fmax (that is, the minimum match value) with respect to the cumulative match number T (i) (maximum match cumulative match number Tmax) in the deviation amount (sequence number i) where the maximum match frequency F (i) (maximum match frequency Fmax) is obtained. The appearance probability P1 of the non-match number Ebmin) is the second highest match frequency F (i), that is, the cumulative check number T (i) in the deviation amount (array number i) from which the next-point match frequency Fmax2 is obtained. The match condition includes that the match probability includes a value equal to or less than a predetermined reference value Pm as compared to the appearance probability P2 of the next-point match frequency Fmax2 (that is, the next-point non-match number Ebmin2) with respect to the next-point match cumulative check number Tmax2. Meet Maximum matching degree Fmax is obtained displacement amount (SEQ ID NO: i) identifying as a match shift amount.
As described above, even if the received code r and the assumed code do not completely match due to a lack of radio wave reception intensity, etc., it is erroneously recognized as a match with the assumed code of the collation code string c with another amount of deviation. When the possibility of being reduced is sufficiently reduced, it is possible to identify the amount of misalignment that is determined to be properly correct. Therefore, the reception time is not prolonged more than necessary. Even when the radio wave reception intensity is low and the reception time is extended to increase the number of words, the pattern of the verification code string c does not increase. Therefore, a large storage capacity is required, and unnecessary patterns are arranged in the middle. No processing is required.

  Further, since the appearance probability P1 and the appearance probability P2 are obtained as the values “0” and “1” of the received code r appear with a probability of ½, they are appropriately averaged by simple calculation. Based on the probability, the possibility of misidentification can be eliminated with the required accuracy.

  Also, the amount of coincidence deviation is identified every time a received code r is identified and collated with an assumed code, with 1 subframe, that is, 300 words of 10 words as the number of unit codes. As a result, for each shift amount, matching is appropriately determined for each word.

  In addition, the unit code number is 300 bits for one subframe in the GPS satellite navigation message format, so that the number of unit codes is a uniform cumulative check number T (i) without being affected by the number of assumed codes different for each word. The amount of deviation can be identified.

In addition, the acquisition means obtains a relationship between the cumulative collation number T (i) and the coincidence frequency F (i), for example, F (i) / T (i) is a predetermined lower limit reference, here 0.2 or more. The unsatisfactory deviation amount is excluded from the match deviation amount candidates, and at least one of the calculation of the cumulative collation number T (i) and the calculation of the coincidence frequency F (i) in the deviation amount is stopped.
As a result, the load can be reduced by the amount of processing related to the array element number i that does not clearly correspond to the matching deviation amount, so that power consumption can be reduced and the processing speed can be increased.

  In addition, the acquisition unit excludes a deviation amount in which the relationship between the cumulative collation number T (i) and the coincidence frequency F (i) does not satisfy the predetermined lower limit criterion from the matching deviation amount candidates, and the matching deviation amount candidates When there is only one amount that is not excluded, the one deviation amount is identified as the coincidence deviation amount. In this way, when there is only one matching deviation amount by the erasing method, the matching deviation amount is quickly identified even before sufficient data is acquired with the above method. It is possible to reduce the processing and increase the speed. When the received radio wave intensity is low and it is difficult to identify the matching deviation amount, a reference value may be set based on the received radio wave intensity so that this method is not used.

  In addition, the obtaining unit obtains the SNR related to the reception intensity of the radio wave from the positioning satellite in the vicinity of the identification timing of the first received code, and changes the matching condition according to the SNR. In other words, when it is difficult to identify the amount of mismatch due to complete matching from the beginning, it is possible to reduce the processing by omitting the processing related to complete matching from the beginning. In addition, the reference matching frequency Fth and the reference value Pm may be changed.

  In addition, the acquisition unit changes the matching condition when the matching frequency F (i) satisfying the matching condition is not obtained within a predetermined time, that is, six seconds of one subframe. As described above, when the identification of the matching deviation amount due to complete matching fails, the matching deviation amount is promptly determined by the reliability determination regarding incomplete matching based on the data acquired so far without repeating the same process. By switching to identification, it is possible to avoid unnecessary extension of radio wave reception time and processing time and increase in power consumption. Also in this case, the reference coincidence frequency Fth and the reference value Pm may be changed.

The acquisition unit generates an assumption availability flag p (i) for identifying whether each code c (i) of the verification code string c is an assumed code, and the assumption availability flag p (i) is used as a verification unit. ), The received code r and the assumed code are collated.
In this way, by providing each assumption possibility flag p (i), it is possible to easily identify the assumed code in the collation code string c and perform collation, thereby facilitating the processing.

  In addition, each time the received code r is identified, the acquisition unit compares the received code with an assumed code within a deviation width, and for each deviation amount, all of the assumed codes in the word are received codes. Every time it is matched with r, the match is determined and the match frequency F (i) is calculated, so that processing is performed in real time and distributed as much as possible without concentrating or delaying the processing more than necessary. Thus, the amount of coincidence deviation can be identified efficiently and promptly.

In addition, the electronic timepiece 1 of the present embodiment includes the satellite radio wave reception processing unit 60 described above, a clock circuit 46 that counts the date and time, a display unit 47 that performs display based on the date and time counted by the clock circuit 46, and a host CPU 41. And the acquisition means acquires the current date and time based on the reception timing assumed based on the date and time counted by the timing circuit 46 and the amount of coincidence deviation, and the host CPU 41 acquires the current date and time acquired by the acquisition means. Thus, the date and time counted by the time counting circuit 46 is corrected.
In this way, the date and time counted by the timer circuit 46 can be easily and appropriately kept accurate according to the date and time information acquired efficiently.

  Further, the acquisition unit sets the deviation width based on the date and time counted by the time measuring circuit 46 and the elapsed time from the timing when the date and time is corrected by the host CPU 41. Therefore, the electronic timepiece 1 can acquire date and time information without applying an unnecessary load by performing an amount of processing corresponding to an appropriate deviation width with easy deviation width setting.

  In addition, by using the information acquisition method related to the time as described above, it is possible to efficiently identify the amount of deviation between the correct date and time and the expected date and time with appropriate reception time, processing load, and power consumption.

  In addition, the satellite radio wave reception processing unit 60 can easily manage processing contents related to radio wave reception and time information acquisition by performing a control operation related to time information acquisition using a program 631 including date and time information reception processing, and a memory The amount of deviation between the correct date and time and the expected date and time can be identified efficiently and appropriately with reduced capacity and processing amount.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the above embodiment, each time a received code r is identified, it is collated with an assumed code within a deviation width, but a plurality of received codes corresponding to an assumed code for one word are collectively collected. Collation and match determination may be made.

  In the above-described embodiment, the shift width is set according to the elapsed time since the previous date / time correction. However, other parameters that may affect the date / time error such as temperature conditions may be included in the consideration.

  Further, in the above embodiment, the matching deviation amount is identified by a combination of these, taking the perfect match, the probabilistic misidentification elimination at the time of the incomplete match, and the erasing method as an example, but other factors are considered. You may do it. For example, according to the content indicated by the code that is regarded as non-match at the time of incomplete match, for example, a flag for anomaly notification, the identification process of the match deviation amount is terminated even if there is no problem in terms of probability. You can keep it running or start over. In addition, the present invention is applied even when the number of codes corresponding to the probabilistic condition is not identified and the amount of mismatch is identified when the assumed code for one subframe and the received code are completely matched. I can do it.

  Further, in the above-described embodiment, the process is performed separately for the complete match and the incomplete match, but the determination of the complete match may be included in the determination of the incomplete match. In this case, even though there is a maximum matching frequency Fmax in which the matching frequency F (i) is equal to the cumulative verification number T (i) by collating the codes equal to or higher than the reference matching frequency Fth, the next-point matching frequency Fmax2 is also If the matching condition is not satisfied stochastically because it is large, the appearance probability P1 = 0 may be set, the matching deviation amount may be identified, and the process may be terminated halfway.

  In the above embodiment, the code appearance probability is simply halved, but the present invention is not limited to this. For example, the number of codes actually identified may be reflected, or the value may be determined to change according to the generation range of the verification code string.

  Further, in the above embodiment, in the identification of the mismatch deviation amount related to the incomplete match, processing is performed for each reception and code identification for one subframe, but each of the deviation amounts within the deviation width is necessary. As long as each code number is collated and a match determination is possible, the process may be advanced at that stage. In addition, for the part that became odd according to the amount of deviation and the reception time, that is, the part at the time of code identification start and end where the collation code string to be collated is in the middle or in the middle of the word, In each case, the match determination may not be performed, or the end portion may be collated until each deviation amount is collated to the end of the word.

  Further, in the above embodiment, the criteria and method of match determination are changed according to the SNR around the time of initial code identification. However, when the SNR is reduced even during code identification, these criteria and methods are appropriately selected. May be switched. Further, not the SNR but the reception intensity itself may be used as a reference. Indirectly, the reference and the method may be changed according to the degree of variation in the determination of the code type acquired every 1 msec for 20 msec.

In the above embodiment, the detection result of the coincidence deviation amount is used for correcting the date and time counted by the timer circuit 46. However, the present invention is not limited to this. In addition, the satellite radio wave reception processing unit 60 is not limited to the case where the radio wave clock mainly having a function as a clock is provided, and may be mounted on other electronic devices. Further, the unit constituting the satellite radio wave reception processing unit 60 may be traded alone.
Further, the present invention is not limited to the case where the satellite radio wave reception processing unit 60 outputs an accurate date and time to the host CPU 41, and only the deviation time information is outputted to the host CPU 41, and the host CPU 41 is caused to change the date and time of the timing circuit 46 by the deviation time. May be.
Moreover, it is not restricted to acquiring all date information, For example, only time information may be sufficient.

In addition, each operation executed and controlled by the module CPU 61 as the processor in the date and time information reception process is not limited to the software control operation based on the program 631, and a part or all of them are dedicated logic (digital) circuits or analog electronic circuits. It may be performed by the dedicated hardware used. For example, the code identification operation may be performed by the acquisition and tracking unit 66 without the control of the module CPU 61.
In the above-described embodiment, the functional operation of the module CPU 61 as the acquisition unit and the functional operation of the host CPU 41 as the control unit are described separately. However, the same CPU may perform overall control.

  In the above embodiment, the collation code string c is generated, collated, and matched according to the radio wave reception from the GPS satellite. However, the positioning satellite according to another positioning system, for example, GLONASS in Russia, Europe The present invention can also be applied to the case where the code signal is transmitted in a format in which the inversion of the code can occur for every predetermined number of bits for Galileo and Japanese obi.

In the above description, the storage unit 63 formed of a nonvolatile memory has been described as an example of a computer-readable medium for an operation processing program such as date / time information reception processing related to the processing operation of the module CPU 61 according to the present invention. However, the present invention is not limited to this. Other computer-readable media include HDD (Hard Disk Drive), CD-ROM, DV
It is possible to apply a portable recording medium such as a D disk. 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>
Receiving means for receiving radio waves including a code signal transmitted from a satellite;
An acquisition means for identifying an arrangement of a plurality of codes constituting a code signal included in the radio wave received by the receiving means and a reception timing of the arrangement;
With
The plurality of codes are respectively inverted when a value of each code determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
The acquisition means includes
A verification code string including an assumed code determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the satellite related to the radio wave received by the receiving means is generated. ,
Identify each code as a received code from the received radio wave,
Each of the received code and the assumed code within a preset deviation width with respect to the reception timing of the identified received code are collated,
Holding information related to a matching result indicating matching or mismatching between the received code and the assumed code that have been matched for a plurality of the received codes for each shift amount within the shift width,
The number of matches or mismatches for each code block is determined as the match, and the number of matches corresponding to the value obtained by adding the number of matches in the plurality of code blocks for each deviation amount is calculated. ,
A satellite radio wave receiver characterized in that a deviation amount satisfying a predetermined coincidence with the cumulative number of matches is identified as a coincidence deviation amount.
<Claim 2>
The acquisition means includes
Calculate the total number of collations by counting the number of collations performed for each deviation amount,
The match condition includes that the accumulated match number equal to the accumulated match number equal to or greater than a predetermined reference match number is obtained,
The satellite radio wave receiver according to claim 1, wherein the deviation amount from which the accumulated number of matches satisfying the coincidence condition is obtained is identified as the coincidence deviation amount.
<Claim 3>
3. The satellite according to claim 2, wherein the reference collation number is determined such that a match probability that the assumed code and the received code match the reference collation number continuously is less than a predetermined reference value. Radio wave receiver.
<Claim 4>
4. The satellite radio wave receiving apparatus according to claim 3, wherein the match probability is obtained by halving all the probabilities that the assumed code and the received code match.
<Claim 5>
The acquisition means includes
Calculate the total number of collations by counting the number of collations performed for each deviation amount,
When the maximum number of integrated matches is obtained, the first appearance probability of the maximum number of integrated matches with respect to the number of integrated matches in the amount of deviation in which the maximum number of integrated matches is obtained is obtained. The match condition includes that the second occurrence probability of the second largest cumulative match number with respect to the cumulative matching number in the deviation amount is less than a predetermined reference ratio,
The satellite radio wave receiving apparatus according to any one of claims 1 to 4, wherein the deviation amount from which the maximum accumulated number of matches satisfying the coincidence condition is obtained is identified as the coincidence deviation amount.
<Claim 6>
6. The satellite radio wave according to claim 5, wherein the first appearance probability and the second appearance probability are values obtained by assuming that each value of the received code appears with a probability of 1/2. Receiver device.
<Claim 7>
The identification of the amount of coincidence deviation is performed each time a received code having a unit code number corresponding to one or a plurality of the code blocks is identified and collated with the assumed code. The satellite radio wave receiver described.
<Claim 8>
8. The satellite radio wave receiver according to claim 7, wherein the number of unit codes is a number of codes corresponding to a predetermined period in a signal transmission format corresponding to the satellite.
<Claim 9>
The acquisition means excludes a deviation amount in which the relationship between the cumulative matching number and the cumulative matching number does not satisfy a predetermined lower limit criterion from the matching deviation amount candidates, and counts the cumulative matching number in the deviation amount and the The satellite radio wave receiving apparatus according to any one of claims 5 to 8, wherein at least one of the calculation of the total number of matches is stopped.
<Claim 10>
The acquisition unit excludes a deviation amount that does not satisfy a predetermined lower limit criterion from a relationship between the accumulated collation number and the accumulated match number from the match deviation amount candidates, and is not excluded from the match deviation amount candidates. The satellite radio wave receiving apparatus according to any one of claims 5 to 9, wherein when there is only one quantity, the one deviation amount is identified as the matching deviation amount.
<Claim 11>
The said acquisition means acquires the signal index value which concerns on the reception intensity | strength of the electromagnetic wave from the said satellite at predetermined | prescribed timing, and changes the said matching conditions according to the said signal index value. The satellite radio wave receiver according to any one of the above.
<Claim 12>
12. The acquisition unit according to claim 1, wherein the acquisition unit changes the match condition when the accumulated number of matches satisfying the match condition is not obtained within a predetermined upper limit collation time. The satellite radio wave receiving device according to the item.
<Claim 13>
The acquisition means includes
Generating identification information for identifying whether each code of the verification code string is the assumed code;
The satellite radio wave receiving apparatus according to any one of claims 1 to 12, wherein the received code and the assumed code are collated with reference to the identification information.
<Claim 14>
The acquisition means includes
Each time the received code is identified, the received code is checked against the assumed code within the deviation width,
The match determination and the calculation of the number of integrated matches are performed each time all the assumed codes in the code block are collated with the received code for each of the deviation amounts. 14. The satellite radio wave receiver according to any one of items 13.
<Claim 15>
The satellite radio wave receiver according to any one of claims 1 to 14,
A time counting means for counting the date and time;
Display means for performing display based on the date and time counted by the time measuring means, control means,
With
The acquisition means acquires the current date and time based on the reception timing assumed based on the date and time counted by the time measuring means and the amount of coincidence deviation,
The radio timepiece characterized in that the control means corrects the date and time counted by the time measuring means based on the current date and time acquired by the acquisition means.
<Claim 16>
16. The radio wave according to claim 15, wherein the acquisition unit sets the deviation width based on a date and time counted by the time measuring unit and an elapsed time from a timing when the date and time is corrected by the control unit. clock.
<Claim 17>
An information acquisition method for identifying an array of a plurality of codes constituting a code signal included in a radio wave received by a receiving means that receives a radio wave including a code signal transmitted from a satellite and a reception timing shift amount of the array. ,
The plurality of codes constituting the code signal are inverted when each code value determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
A collation code string that generates a collation code string that includes an assumed code that is determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the radio wave received by the receiving means Generation step,
A code identification step for identifying a plurality of codes as received codes from the received radio wave,
A collation step of collating each of the assumed code and the received code within a preset deviation width with respect to the assumed reception timing of the identified received code;
A result holding step for holding a collation result related to matching or mismatching between the received code matched and the assumed code for a plurality of the received codes for each deviation amount within the deviation width;
A match determination step of determining, as a match, a larger one of the number of matches and mismatches for each code block, and calculating an integrated match number obtained by integrating the number of matches in a plurality of code blocks for each deviation amount,
A deviation amount identifying step for identifying a deviation amount that satisfies the predetermined matching condition for the total number of matches as a matching deviation amount,
An information acquisition method comprising:
<Claim 18>
A computer comprising receiving means for receiving radio waves including a code signal transmitted from a satellite,
A program that functions as an acquisition unit that identifies an array of a plurality of codes constituting a code signal included in a radio wave received by the reception unit and a reception timing of the array,
The plurality of codes constituting the code signal are inverted when each code value determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
The acquisition means includes
Generating a collation code string including an assumed code determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the radio wave received by the receiving unit;
Identify each code as a received code from the received radio wave,
Each of the received code and the assumed code within a preset deviation width with respect to the assumed reception timing of the identified received code are collated,
A collation result related to matching or mismatching of the collated received code and the assumed code is held for a plurality of the received codes for each deviation amount within the deviation width,
The number of matches and the number of matches in each code block is determined as a match, and the number of matches in a plurality of code blocks is calculated for each shift amount to calculate the total number of matches.
A program characterized by identifying an amount of deviation satisfying a predetermined coincidence as the total number of matches as a coincidence deviation amount.

1 Electronic clock 41 Host CPU
42 ROM
421 program 43 RAM
44 Oscillation circuit 45 Frequency division circuit 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 E Number of matches Ebmin Minimum number of non-matches Ebmin Secondary number of non-matches F Maximum number of matches Fmax Maximum number of matches Fmax Second-point match frequency k Count number N Number of collation p Possible flag P1 Appearance probability P2 Appearance probability Pd Danger level q Offset value r Received code T Cumulative collation number Tmax Maximum match cumulative collation number Tmax2 Secondary match accumulative collation number X Candidate flag

Claims (18)

Receiving means for receiving radio waves including a code signal transmitted from a satellite;
An acquisition means for identifying an arrangement of a plurality of codes constituting a code signal included in the radio wave received by the receiving means and a reception timing of the arrangement;
With
The plurality of codes are respectively inverted when a value of each code determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
The acquisition means includes
A verification code string including an assumed code determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the satellite related to the radio wave received by the receiving means is generated. ,
Identify each code as a received code from the received radio wave,
Each of the received code and the assumed code within a preset deviation width with respect to the reception timing of the identified received code are collated,
Holding information related to a matching result indicating matching or mismatching between the received code and the assumed code that have been matched for a plurality of the received codes for each shift amount within the shift width,
The number of matches or mismatches for each code block is determined as the match, and the number of matches corresponding to the value obtained by adding the number of matches in the plurality of code blocks for each deviation amount is calculated. ,
A satellite radio wave receiver characterized in that a deviation amount satisfying a predetermined coincidence with the cumulative number of matches is identified as a coincidence deviation amount. The acquisition means includes
Calculate the total number of collations by counting the number of collations performed for each deviation amount,
The match condition includes that the accumulated match number equal to the accumulated match number equal to or greater than a predetermined reference match number is obtained,
The satellite radio wave receiver according to claim 1, wherein the deviation amount from which the accumulated number of matches satisfying the coincidence condition is obtained is identified as the coincidence deviation amount.   3. The satellite according to claim 2, wherein the reference collation number is determined such that a match probability that the assumed code and the received code match the reference collation number continuously is less than a predetermined reference value. Radio wave receiver.   4. The satellite radio wave receiving apparatus according to claim 3, wherein the match probability is obtained by halving all the probabilities that the assumed code and the received code match. The acquisition means includes
Calculate the total number of collations by counting the number of collations performed for each deviation amount,
When the maximum number of integrated matches is obtained, the first appearance probability of the maximum number of integrated matches with respect to the number of integrated matches in the amount of deviation in which the maximum number of integrated matches is obtained is obtained. The match condition includes that the second occurrence probability of the second largest cumulative match number with respect to the cumulative matching number in the deviation amount is less than a predetermined reference ratio,
The satellite radio wave receiving apparatus according to any one of claims 1 to 4, wherein the deviation amount from which the maximum accumulated number of matches satisfying the coincidence condition is obtained is identified as the coincidence deviation amount.   6. The satellite radio wave according to claim 5, wherein the first appearance probability and the second appearance probability are values obtained by assuming that each value of the received code appears with a probability of 1/2. Receiver device.   The identification of the amount of coincidence deviation is performed each time a received code having a unit code number corresponding to one or a plurality of the code blocks is identified and collated with the assumed code. The satellite radio wave receiver described.   8. The satellite radio wave receiver according to claim 7, wherein the number of unit codes is a number of codes corresponding to a predetermined period in a signal transmission format corresponding to the satellite.   The acquisition means excludes a deviation amount in which the relationship between the cumulative matching number and the cumulative matching number does not satisfy a predetermined lower limit criterion from the matching deviation amount candidates, and counts the cumulative matching number in the deviation amount and the The satellite radio wave receiving apparatus according to any one of claims 5 to 8, wherein at least one of the calculation of the total number of matches is stopped.   The acquisition unit excludes a deviation amount that does not satisfy a predetermined lower limit criterion from a relationship between the accumulated collation number and the accumulated match number from the match deviation amount candidates, and is not excluded from the match deviation amount candidates. The satellite radio wave receiving apparatus according to any one of claims 5 to 9, wherein when there is only one quantity, the one deviation amount is identified as the matching deviation amount.   The said acquisition means acquires the signal index value which concerns on the reception intensity | strength of the electromagnetic wave from the said satellite at predetermined | prescribed timing, and changes the said matching conditions according to the said signal index value. The satellite radio wave receiver according to any one of the above.   12. The acquisition unit according to claim 1, wherein the acquisition unit changes the match condition when the accumulated number of matches satisfying the match condition is not obtained within a predetermined upper limit collation time. The satellite radio wave receiving device according to the item. The acquisition means includes
Generating identification information for identifying whether each code of the verification code string is the assumed code;
The satellite radio wave receiving apparatus according to any one of claims 1 to 12, wherein the received code and the assumed code are collated with reference to the identification information. The acquisition means includes
Each time the received code is identified, the received code is checked against the assumed code within the deviation width,
The match determination and the calculation of the number of integrated matches are performed each time all the assumed codes in the code block are collated with the received code for each of the deviation amounts. 14. The satellite radio wave receiver according to any one of items 13. The satellite radio wave receiver according to any one of claims 1 to 14,
A time counting means for counting the date and time;
Display means for performing display based on the date and time counted by the time measuring means;
Control means;
With
The acquisition means acquires the current date and time based on the reception timing assumed based on the date and time counted by the time measuring means and the amount of coincidence deviation,
The radio timepiece characterized in that the control means corrects the date and time counted by the time measuring means based on the current date and time acquired by the acquisition means.   16. The radio wave according to claim 15, wherein the acquisition unit sets the deviation width based on a date and time counted by the time measuring unit and an elapsed time from a timing when the date and time is corrected by the control unit. clock. An information acquisition method for identifying an array of a plurality of codes constituting a code signal included in a radio wave received by a receiving means that receives a radio wave including a code signal transmitted from a satellite and a reception timing shift amount of the array. ,
The plurality of codes constituting the code signal are inverted when each code value determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
A collation code string that generates a collation code string that includes an assumed code that is determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the radio wave received by the receiving means Generation step,
A code identification step for identifying a plurality of codes as received codes from the received radio wave,
A collation step of collating each of the assumed code and the received code within a preset deviation width with respect to the assumed reception timing of the identified received code;
A result holding step for holding a collation result related to matching or mismatching between the received code matched and the assumed code for a plurality of the received codes for each deviation amount within the deviation width;
A match determination step of determining, as a match, a larger one of the number of matches and mismatches for each code block, and calculating an integrated match number obtained by integrating the number of matches in a plurality of code blocks for each deviation amount,
A deviation amount identifying step for identifying a deviation amount that satisfies the predetermined matching condition for the total number of matches as a matching deviation amount,
An information acquisition method comprising: A computer comprising receiving means for receiving radio waves including a code signal transmitted from a satellite,
A program that functions as an acquisition unit that identifies an array of a plurality of codes constituting a code signal included in a radio wave received by the reception unit and a reception timing of the array,
The plurality of codes constituting the code signal are inverted when each code value determined according to the content indicated by the code signal satisfies a predetermined condition for each code block composed of a predetermined number of codes,
The acquisition means includes
Generating a collation code string including an assumed code determined without considering the inversion according to the content assumed to be indicated by the code signal according to the type and reception timing of the radio wave received by the receiving unit;
Identify each code as a received code from the received radio wave,
Each of the received code and the assumed code within a preset deviation width with respect to the assumed reception timing of the identified received code are collated,
A collation result related to matching or mismatching of the collated received code and the assumed code is held for a plurality of the received codes for each deviation amount within the deviation width,
The number of matches and the number of matches in each code block is determined as a match, and the number of matches in a plurality of code blocks is calculated for each shift amount to calculate the total number of matches.
A program characterized by identifying an amount of deviation satisfying a predetermined coincidence as the total number of matches as a coincidence deviation amount.

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