JP5012947B2 - Time information acquisition device and radio clock - Google Patents

Description

  The present invention relates to a time information acquisition device that receives a standard time radio wave and acquires the time information, and a radio clock equipped with the time information acquisition device.

  Currently, in Japan, Germany, the United Kingdom, Switzerland, etc., long standard time radio waves are transmitted from transmitting stations. For example, in Japan, standard time radio waves with amplitude modulation of 40 kHz and 60 kHz are transmitted from transmitting stations in Fukushima Prefecture and Saga Prefecture, respectively. The standard time radio wave includes a sequence of codes constituting a time code indicating the year, month, day, hour and minute, and is transmitted in one cycle of 60 seconds. That is, the period of the time code is 60 seconds.

  A timepiece (radio timepiece) capable of receiving a standard time radio wave including such a time code, taking out the time code from the received standard time radio wave, and correcting the time has been put into practical use. The reception circuit of the radio clock accepts the standard time radio wave received by the antenna and demodulates the standard time radio signal amplitude-modulated by a band pass filter (BPF) for extracting only the standard time radio signal, envelope detection, etc. A demodulation circuit and a processing circuit that reads a time code included in the signal demodulated by the demodulation circuit are provided.

  The conventional processing circuit synchronizes at the rising edge of the demodulated signal, and then binarizes at a predetermined sampling period to obtain TCO data of a unit time length (1 second) which is a binary bit string. Further, the processing circuit measures the pulse width of the TCO data (that is, the time of bit “1” or the time of bit “0”), and codes “P”, “0” corresponding to the width. "Or" 1 "is determined, and time information is acquired based on the determined code sequence.

  In a conventional processing circuit, a process of second synchronization processing, minute synchronization processing, code acquisition, and matching determination is performed from the start of reception of standard time radio waves to acquisition of time information. When processing cannot be completed properly in each process, the processing circuit needs to start processing from the beginning. For this reason, processing may have to be performed again and again due to the influence of noise included in the signal, and the time until the time information can be acquired may be significantly increased.

  Second synchronization is to detect the rise of a code that arrives every second among the codes indicated by the TCO data. The minute synchronization is to specify the start position of the minute. Data according to the JJY standard can be realized by detecting a portion where the position marker “P0” arranged at the end of the frame and the marker “M” arranged at the beginning of the frame are continuous. Since the beginning of the frame is recognized by the above-mentioned minute synchronization, code acquisition is started thereafter, and after acquiring the data for one frame, the parity bit is checked, and an impossible value (year, month, day, and time cannot actually occur) Value) is determined (consistency determination). For example, minute synchronization finds the beginning of a frame and may take 60 seconds. Of course, it takes several times as long to detect the beginning of a frame over several frames.

  In Patent Document 1, TCO data obtained by binarizing a demodulated signal at a predetermined sampling interval (50 ms) is acquired, and a data group consisting of binary bit strings every second (20 samples) is listed. It becomes. The apparatus disclosed in Patent Document 1 includes this bit string, a binary bit string template representing the code “P: position marker”, a binary bit string template representing the code “1”, and a binary bit string representing the code “0”. Each of the templates is compared with each other to obtain the correlation, and it is determined by the correlation whether the bit string corresponds to the code “P”, “1”, or “0”.

JP 2005-249632 A JP 2009-216544 A

  In the technique disclosed in Patent Document 1, TCO data, which is a binary bit string, is acquired and matched with a template. In a state where the electric field strength is weak or a state where a lot of noise is mixed in the demodulated signal, many errors are included in the acquired TCO data. Therefore, it is necessary to finely adjust the filter for removing noise from the demodulated signal and the threshold of the AD converter to improve the quality of TCO data.

  Further, Patent Document 2 generates input waveform data for one frame (60 seconds), has a similar data length, and predicts corresponding to the current time according to the time based on the internal clock (base time). There is disclosed a technique for generating waveform data, comparing sample values of input waveform data with corresponding sample values of predicted waveform data, and detecting the number of errors. In the technique of Patent Document 2, the predicted waveform data is shifted by 1 bit (the sample value at the end of the data becomes the first sample value), and the sample value of the input waveform data and the shifted predicted waveform data newly correspond to each other. Repeat the comparison with the sample value. Repeat the process only 60 times, find the predicted waveform data with the smallest number of errors from the number of errors for each of the predicted waveform data, and obtain the base time error based on the number of shifts of the found predicted waveform data To do.

  In the technique of Patent Document 2, input waveform data for 60 seconds is required. Further, it is necessary to generate 60 types of predicted waveform data by shifting and to compare the sample values of the input waveform data and the sample values of the predicted waveform data. Therefore, there is a problem that it takes a processing time to acquire input waveform data and compare sample values. In addition, since the reception status of radio waves is not always constant, it is desirable to shorten the reception time of standard time radio waves in order to acquire input waveform data.

  An object of this invention is to provide the time information acquisition apparatus and radio timepiece which can acquire the present time based on a standard time radio wave reliably and in a shorter time.

The object of the present invention is to sample the signal of the standard radio wave at a predetermined sampling period from the second start position detected in the standard time radio wave including a time code representing the received time information, and sample each sample point. An input waveform data pattern generation means for generating an input waveform data pattern having a value of one or more unit time lengths, the value of which is either a first value indicating a low level or a second value indicating a high level; ,
The sample value of each sample point takes either the first value or the second value, has the same time length as the input waveform data pattern, and each is a base timed by an internal time measuring means A predicted waveform data pattern that represents a sequence of codes based on time, and that generates a plurality of predicted waveform data patterns whose start position is the base time and a time shifted by a predetermined number of seconds before and after the base time Generating means;
It is determined whether or not the sample value of the input waveform data pattern matches the sample value of the predicted waveform data pattern, counts the number of errors indicating a mismatch, and calculates the number of errors for each of the plurality of predicted waveform data patterns. Error detection means to obtain;
Current time correcting means for correcting the base time based on the head position of the predicted waveform data pattern indicating the minimum number of errors;
A predicted waveform data pattern to be generated by determining the predetermined number of seconds based on a time difference between the time when the base time is corrected by the current time correction means and the base time, and a predetermined timing accuracy. And a control means for determining the number of times.

  In a preferred embodiment, the input waveform data pattern generated by the input waveform data pattern generation means has one sample value for each code, and the input waveform data pattern generation means For each code, a plurality of data values at different positions are acquired, and a sample value for the code is determined based on the plurality of data values.

  In another preferred embodiment, the current time correction means indicates the number of errors of the minimum value when the minimum value of the number of errors is smaller than a maximum allowable number of errors predetermined corresponding to the number of samples. The base time is corrected based on the head position of the predicted waveform data pattern.

  In another preferred embodiment, the current time correction means takes into consideration the minimum value of the number of errors and the second smallest value, and the minimum value is smaller than the second smallest value. When the distance is more than the above, the base time is corrected based on the head position of the predicted waveform data pattern indicating the minimum number of errors.

In yet another preferred embodiment, the control means determines that the number of sample values increases as the received strength of the received standard time radio wave decreases.
The input waveform data pattern generation means generates an input waveform data pattern according to the determined number of sample values.

In a preferred embodiment, the control means calculates an assumed maximum error based on the time difference and the timing accuracy,
The predicted waveform data pattern generation means generates a plurality of predicted waveform data patterns such that the head position is within the range of the maximum error.

Another object of the present invention is to provide the time information acquisition device,
The internal time measuring means for measuring the current time by an internal clock;
This is achieved by a radio timepiece comprising time display means for displaying the current time measured by the internal time measuring means or corrected by the current time adjusting means.

  According to the present invention, it is possible to provide a time information acquisition device and a radio timepiece that can acquire the current time based on the standard time radio wave reliably and in a shorter time.

FIG. 1 is a block diagram showing the configuration of the radio-controlled timepiece according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration example of the receiving circuit 16 according to the present embodiment. FIG. 3 is a block diagram showing the configuration of the signal comparison circuit 18 according to the present embodiment. FIG. 4 is a flowchart showing an outline of processing executed in the radio timepiece 10 according to the present embodiment. FIG. 5 is a flowchart showing in more detail step 405 according to the present embodiment. FIG. 6 is a diagram for explaining input waveform data, an input waveform data pattern, and a plurality of predicted waveform data patterns according to the present embodiment. FIG. 7 is a diagram illustrating an example of a standard time radio signal according to the JJY standard. FIG. 8 is a diagram showing in more detail each of the codes constituting the standard time radio signal according to the JJY standard. FIG. 9 is a diagram illustrating an example of an allowable maximum BER table according to the present embodiment. FIG. 10 is a block diagram showing the configuration of the signal comparison circuit 18 according to the second embodiment. FIG. 11 is a diagram illustrating a data configuration example of JJY code and input waveform data for one second in the present embodiment. FIG. 12 is a flowchart showing in more detail step 405 according to the second embodiment. FIG. 13 is a diagram for explaining input waveform data, an input waveform data pattern, and a plurality of predicted waveform data patterns according to the second embodiment. FIG. 14 is a diagram for explaining an effective value of the number of errors according to the second embodiment. FIG. 15 is an example of a graph of the number of errors for each predicted waveform data pattern. FIGS. 16A and 16B are other graphs showing the correspondence between the predicted waveform data pattern and the number of errors, respectively. FIG. 17 is a diagram showing an example of a reliability determination table according to another embodiment of the present invention. FIG. 18 is a flowchart illustrating an example of coincidence determination according to another embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the embodiment of the present invention, a standard time radio wave in a long wave band is received, the signal is detected, a sequence of codes indicating a time code included in the signal is extracted, and based on the sequence of the codes The radio timepiece for correcting the time is provided with the time information acquisition device according to the present invention.

  Currently, standard time radio waves are transmitted from a predetermined transmitting station in Japan, Germany, the United Kingdom, Switzerland, and the like. For example, in Japan, standard time radio waves with amplitude modulation of 40 kHz and 60 kHz are transmitted from transmitting stations in Fukushima Prefecture and Saga Prefecture, respectively. The standard time radio wave includes a string of codes constituting a time code indicating the year, month, day, hour and minute, and is transmitted in one cycle of 60 seconds. Since one code has a unit time length (1 second), one cycle can include 60 codes.

  FIG. 1 is a block diagram showing the configuration of the radio-controlled timepiece according to the first embodiment of the present invention. As shown in FIG. 1, the radio timepiece 10 includes a CPU 11, an input unit 12, a display unit 13, a ROM 14, a RAM 15, a receiving circuit 16, an internal clock circuit 17, and a signal comparison circuit 18.

  The CPU 11 reads out a program stored in the ROM 14 at a predetermined timing or in response to an operation signal input from the input unit 12, expands the program in the RAM 15, and configures the radio clock 10 based on the program. Execute instructions and data transfer. Specifically, for example, by receiving the standard time radio wave by controlling the receiving circuit 16 every predetermined time, a sequence of codes included in the standard time radio signal is obtained from digital data based on the signal obtained from the receiving circuit 16. Specific processing is performed to correct the base time BT, which is the time obtained by the internal clock circuit 17 based on this code sequence, and to transfer the base time obtained by the internal clock circuit 17 to the display unit 13. To do.

  In the present embodiment, as will be described later, the processing start time Now is specified using the base time BT, which is the time obtained by the internal clock circuit 17, and a predetermined time before and after the processing start time Now is set as the start time. A plurality of predicted waveform data patterns having one or more unit time lengths are generated, and the plurality of predicted waveform data patterns are compared with the input waveform data pattern generated from the received waveform.

  As a result of the comparison, the code included in the received signal is specified, the error between the base time BT and the time based on the received signal is calculated, and the base time BT in the internal time measuring circuit 17 can be corrected.

  The input unit 12 includes a switch for instructing execution of various functions of the radio timepiece 10, and outputs a corresponding operation signal to the CPU 11 when the switch is operated. The display unit 13 includes a dial, an analog pointer mechanism controlled by the CPU 11, and a liquid crystal panel, and displays a time based on the base time measured by the internal clock circuit 17. The ROM 14 stores a system program, an application program, and the like for operating the radio timepiece 10 and realizing a predetermined function. The program for realizing the predetermined function includes a second pulse position detection process, a comparison process between the predicted waveform data pattern and the input waveform data pattern in this embodiment, a minute leading position detection process, and a code decoding A program for controlling the signal comparison circuit 18 for processing and the like is also included. The RAM 15 is used as a work area for the CPU 11 and temporarily stores programs and data read from the ROM 14, data processed by the CPU 11, and the like.

  The reception circuit 16 includes an antenna circuit, a detection circuit, and the like, obtains a signal demodulated from the standard time radio wave received by the antenna circuit, and outputs the signal to the signal comparison circuit 18. The internal clock circuit 17 includes an oscillation circuit, counts clock signals output from the oscillation circuit, counts time based on the base time, and outputs time data to the CPU 11.

  FIG. 2 is a block diagram showing a configuration example of the receiving circuit 16 according to the present embodiment. As shown in FIG. 2, the receiving circuit 16 includes an antenna circuit 50 that receives a standard time radio wave, a filter circuit 51 that removes noise from the standard time radio signal received by the antenna circuit 50, and a high frequency that is an output of the filter circuit 51. An RF amplification circuit 52 that amplifies the signal, and a detection circuit 53 that detects the signal output from the RF amplification circuit 52 and demodulates the standard time radio signal, and the signal demodulated by the detection circuit 53 is the signal comparison circuit 18. Is output.

  FIG. 3 is a block diagram showing the configuration of the signal comparison circuit 18 according to the present embodiment. As shown in FIG. 3, the signal comparison circuit 18 according to this exemplary embodiment includes an input waveform data generation unit 21, a received waveform data buffer 22, a predicted waveform data pattern generation unit 23, a waveform cutout unit 24, an error detection unit 25, It has a coincidence determination unit 26 and a second synchronization execution unit 27.

  The input waveform data generation unit 21 converts the signal output from the receiving circuit 16 into digital data whose value takes one of a plurality of values (“1” or “0”) at a predetermined sampling interval. Convert to In the first embodiment, for example, the sampling interval is 50 ms, and data of 20 samples per second can be acquired. The reception waveform data buffer 22 sequentially stores the data generated in the input waveform data generation unit 21. The reception waveform data buffer 22 can store a plurality of unit time lengths (1 unit time: 1 second) of data (for example, 20 seconds of data). Will be erased.

  Further, the input waveform data generation unit 21 determines the sample position D (n) of the input waveform data every second, that is, every code from the second start position after the second position is determined by the second synchronization by the second synchronization execution unit 27. Is generated. In this case, for example, data corresponding to a predetermined time zone (500 ms to 800 ms) is obtained from the values acquired at the predetermined sampling interval, and there are many data values “1” and “0”. By determining whether or not, the sample value D (n) of the input waveform data per second can be obtained.

  In the first embodiment, data corresponding to one code generated by the input waveform data generation unit 21 is referred to as input waveform data, and the value thereof is referred to as a sample value. A plurality of code data acquired over a plurality of seconds is referred to as an input waveform data pattern. Also in the predicted waveform data pattern generation unit 23 described below, data corresponding to one code is referred to as predicted waveform data, and data of a plurality of codes is referred to as a predicted waveform data pattern.

  The predicted waveform data pattern generation unit 23 generates a plurality of predicted waveform data patterns to be compared with the input waveform data pattern. The plurality of predicted waveform data patterns will be described in detail later. The waveform cutout unit 24 extracts an input waveform data pattern having the same time length as the predicted waveform data pattern from the received waveform data buffer 22.

  The second synchronization execution unit 27 detects the second start position in the input waveform data generated by the input waveform data generation unit 21 by, for example, a known conventional method. For example, in a standard time radio wave according to JJY, as shown in FIG. Therefore, it is possible to detect the leading position of the second by detecting the rising edge of this signal.

  The error detection unit 25 calculates the number of errors indicating a mismatch between each of the plurality of predicted waveform data patterns and the input waveform data pattern. As described above, the input waveform data pattern has the sample value D (n) of the input waveform data per second. Similarly, the predicted waveform data pattern has a sample value P (n) of predicted waveform data per second. Therefore, if the sample value of the input waveform data is compared with the sample value of the corresponding predicted waveform data and the number of errors is counted up by “1” in the case of a mismatch, the number of errors can be calculated. It becomes possible.

  Further, the coincidence determination unit 26 calculates a bit error rate (BER) based on the number of errors for each of the plurality of predicted waveform data patterns, and calculates a predicted waveform data pattern that matches the input waveform data pattern based on the calculated BER. Identify.

  FIG. 4 is a flowchart showing an outline of processing executed in the radio timepiece 10 according to the present embodiment. The process shown in FIG. 4 is mainly executed by the CPU 11 and the signal comparison circuit 18 based on instructions from the CPU 11. As shown in FIG. 4, the CPU 11 and the signal comparison circuit 18 (hereinafter also referred to as “CPU 11 or the like” for convenience of description) detect the second pulse position (step 401). The process of detecting the second pulse position is also referred to as second synchronization.

  Second synchronization is realized by the second synchronization execution unit 27 of the signal comparison circuit 18 by, for example, a known conventional method. By the second synchronization, the second start position in the input waveform data is specified, and a time difference Δt between the start of the input waveform data and the specified second start position is obtained.

  FIG. 7 is a diagram illustrating an example of a standard time radio signal according to the JJY standard. As shown in FIG. 7, the standard time radio signal according to the JJY standard is transmitted in a predetermined order with the JJY code. In the standard time radio signal of JJY, symbols indicating “P”, “1” and “0” having a unit time length of 1 second are connected. The standard time radio wave has 60 seconds as one frame, and one frame includes 60 codes. Further, in the standard time radio wave, the position marker “P1”, “P2”,... Or the marker “M” arrives every 10 seconds, and the position marker “P0” and the frame arranged at the end of the frame. By detecting the portion where the marker “M” arranged at the head of the frame continues, the head of the frame that arrives every 60 seconds, that is, the head position of the minute can be found. Second synchronization is to find the head position of any one of the 60 codes.

  FIG. 8 is a diagram showing in more detail each of the codes constituting the standard time radio signal according to JJY. As shown in FIG. 8, JJY includes codes indicating “P”, “1”, and “0” having a unit time length of 1 second. In the code “0”, the high level (value “1”) is set in the first 800 ms section, and the low level (value “0”) is set in the remaining 200 ms section. In the code “1”, the high level (value “1”) is set in the first 500 ms section, and the low level (value “0”) is set in the remaining 500 ms section. In addition, in the code “P”, the high level (value “1”) is set in the first 200 ms section, and the low level (value “0”) is set in the remaining 800 ms section.

  FIG. 6 is a diagram for explaining input waveform data, an input waveform data pattern, and a plurality of predicted waveform data patterns according to the present embodiment. In FIG. 6, consider input waveform data 600 in which the processing start time Now based on the base time BT, which is the time measured by the internal clock circuit 17, becomes the data head. The second synchronization execution unit 27 performs second synchronization, which indicates that the second head position is behind the processing start time Now based on the base time BT by Δt on the time axis. Hereinafter, in the input waveform data, data is cut out based on Now + Δt and a position separated from Now + Δt in seconds. Hereinafter, the time Now + Δt is referred to as a code head time. The base time BT refers to the time measured by the internal clock circuit 17 of the electronic timepiece 10 according to the present embodiment. The processing start time Now is the time when reception of the standard time radio wave according to the base time BT is started.

  When the second synchronization (step 401) ends, the CPU 11 or the like determines whether there is a final correction time Tlast acquired in the previous process and stored in a predetermined area of the RAM 15 (step 402). Note that Tlast is reset when the entire electronic timepiece 10 is reset or when the user operates the input unit 12 to change the time of the internal clock circuit 17. Therefore, in such a case, it is determined No in step 402.

  When it is determined Yes in step 402, the CPU 11 and the like calculate an assumed maximum error ΔS, which is an assumed error, from the internal clock accuracy Pr in the electronic timepiece 10 (step 403). ΔS is calculated based on the following equation.

ΔS = Pr × (BT-Tlast)
(BT-Tlast) indicates a period from the time when the time was corrected in the previous process to the time BT timed by the internal clock circuit 17, that is, a period when the time is not corrected. When Pr is a value corresponding to a monthly difference of ± 15 seconds (for example, 15 seconds), if (BT-Tlast) is 30 days, ΔS is 15 seconds.

  Next, it is determined whether the assumed maximum error ΔS is larger than the threshold value Sth (step 404). In the present embodiment, when the electronic timepiece 10 has a monthly difference of ± 15 seconds and the time is not adjusted within 30 days (that is, Sth corresponds to 30 days), the present embodiment is applied. Time acquisition processing using a plurality of predicted waveform data patterns is executed (step 405). When ΔS is the number of seconds, 2ΔS + 1 multiple predicted waveform data patterns are generated.

  FIG. 5 is a flowchart showing in more detail step 405 according to the present embodiment. As shown in FIG. 5, the waveform cutout unit 24 of the signal comparison circuit 18 reads input waveform data from the received waveform data buffer 22, and has an input having a time length of a predetermined number of seconds from the second head position Now + Δt based on the second synchronization. A waveform data pattern DP is generated. In the example shown in FIG. 6, the input waveform data pattern DP for 5 seconds of the sample values D (0) to D (4) of the input waveform data is shown (see reference numeral 602). Actually, the number of sample values D (n) (n = 0 to N−1) is determined by the reception strength of the standard time radio wave received by the receiving circuit 16. For example, the CPU 11 may determine the number of sample values so that the number of sample values increases as the reception intensity of the standard time radio wave decreases, with N-1 = 20 being the minimum value.

  In FIG. 6, sample values D (0) to D (4) are started from times Now + Δt, Now + Δt + 1, Now + Δt + 2, Now + Δt + 3, Now + Δt + 4, and values (“0” or “1” each indicating one sign). ")including.

  Next, the predicted waveform data pattern generation unit 23 generates a plurality of predicted waveform data patterns whose start times are shifted in the range of ΔS before and after the process start time Now based on the base time (step 502). That is, the predicted waveform data pattern generation unit 23 generates a plurality of predicted waveform data patterns having the same time length as the input waveform data pattern, each having Now ± ΔS as the head of the pattern. In the example illustrated in FIG. 6, ΔS = 2 (seconds), and five predicted waveform data patterns of ΔS = −2 to 2 are generated.

  The first predicted waveform data pattern PP (0) to the fifth predicted waveform data pattern PP (4) (see reference numerals 610 to 614) have patterns of Now-2, Now-1, Now, Now + 1, Now + 2, respectively. It is the start time. For example, the first predicted waveform data pattern PP (0) includes a sample value P (-2) corresponding to a code at time Now-2, a sample value P (-1) corresponding to a code at time Now-1, and a time. The sample value P (0) corresponding to the code at Now, the sample value P (1) corresponding to the code at time Now + 1, and the sample value P (2) corresponding to the code at time Now + 2.

  Next, the error detection unit 25 compares the input waveform data pattern DP and each of the plurality of predicted waveform data patterns with the sample values of the corresponding codes, and calculates the number of errors corresponding to the mismatch of the sample values (Step) 503). In the example of FIG. 6, the input waveform data pattern DP is compared with each of the predicted waveform data patterns PP (0) to PP (4).

  For example, consider a comparison between the input waveform data pattern DP and the first predicted waveform data pattern PP (0). In this case, the corresponding sample values, ie D (0) and P (-2), D (1) and P (-1), D (2) and P (0), D (3) and P (1), D (4) and P (2) are respectively compared. Further, considering the comparison between the input waveform data pattern DP and the second predicted waveform data pattern PP (1), D (0) and P (-1), D (1) and P (0), D ( 2) and P (1), D (3) and P (2), D (4) and P (3) are compared, respectively.

  As a result of the comparison of the corresponding code data, the number of errors becomes “0” if the two match. If the two do not match, the number of errors is “1”. The error detection unit 25 calculates the total number of errors in all corresponding code data.

Next, the coincidence determination unit 26 calculates a bit error rate (BER) corresponding to each of the plurality of predicted waveform data patterns based on the number of errors (total number of errors) calculated for each of the plurality of predicted waveform data patterns. Calculate (step 504). For example, the bit error rate (BER) can be obtained by calculating (total number of errors) / (number of samples I of input waveform data pattern). The coincidence determination unit 26 finds the minimum bit error rate (minimum BER) among the bit error rates BER (step 505). Thereafter, the coincidence determination unit 26 obtains an allowable maximum bit error rate BER _max (I) determined by the number of samples I of the input waveform data pattern (step 506), and the minimum BER is the allowable maximum bit error rate BER _max ( I) It is judged whether it is smaller (step 507).

Hereinafter, the bit error rate will be described. The allowable maximum bit error rate BER _max (I) increases as the number of received data (the number of samples of the input waveform data pattern) increases (that is, the data length increases). That is, as the data length increases, the reliability of data matching increases even if the error rate increases.

  In order to prevent erroneous match determination in the match determination between the input waveform data pattern and the predicted waveform data pattern, it is necessary to make the probability (error rate) of coincidence of data close to “0” as much as possible. .

  If the radio timepiece 10 receives the standard time radio wave 24 times a day and repeats it for 100 years and makes a mistake only once, the probability of mismatch is about 1/10 ^ 6 = 1 / (24 × 365 × 100). Hereinafter, regarding the probability of mismatch, 1/10 ^ 8 is considered as the target value with a margin.

The probability that the input waveform data pattern (sample value: “0” or “1”) of N bits (N samples) coincides with the predicted waveform data pattern by chance is the appearance probability of “0” and “1” are equal. In this case:
P0 = P1 = 0.5 (P0: probability that “0” appears, P1: probability that “1” appears)
If the probability of mismatch is P0 ^ N <1/10 ^ 8, then N ≧ 27. This means that reliability is obtained when 27 bits of data are received and all of the N bits match the predicted waveform data pattern. If the number of bits N is smaller than this, it means that reliability cannot be obtained.

Actually, the appearance probabilities of “0” and “1” may not be equal. That is, the appearance probabilities are biased such that P0> P1. In such a case, P0> P1 when the same calculation as described above is performed. Commonly, the numerical value with the highest appearance probability is all N bits “0”, which is the maximum probability of mismatch. The appearance probability is P0 ^ N.

  Considering the bias of the code appearance probability as P0 = 0.55 and P1 = 0.45, if P0 ^ N <1/10 ^ 8 is solved, N ≧ 31. That is, as compared with the example of P0 = P1 (N = 27), it means that reliability cannot be obtained unless an extra 4 bits are received.

  The case where all of the N bits match has been described. However, in a weak electric field, it is rare that all bits match due to the influence of noise. Even if there is such an incomplete match with some unmatched bits, if there is one solution whose appearance frequency is 1/10 to 8 or less, it can be determined as a match.

  If the input waveform data pattern is N bits (N samples) and e is the number of samples that do not match the predicted waveform data pattern (number of error bits), the input waveform data pattern is predicted in the 0/1 code string of the data. There are one pattern that completely matches the waveform data pattern, and there are COMMIN (N, e) cases where there are e mismatches. COMBIN (N, e) is the number of combinations selected from N to e.

If N is sufficiently larger than e (that is, e << N), the individual appearance probability of the incomplete match can be regarded as being almost equal to the appearance probability of the complete match. Under P0> P1, the highest appearance probability among all incomplete matches is P0 ^ N · COMBIN (N, e). If this value is 1/10 ^ 8 or less, even an incomplete match can be regarded as a match. This can be expressed as:
P0 ^ N · COMBIN (N, e) <1/10 ^ 8
When this equation is solved for N when e = 1, N ≧ 40.

Similarly, the following results are obtained by calculating for e = 10, 21, 31, 42.
e = 10 N ≧ 80 BER = 0.125
e = 21 N ≧ 120 BER = 0.175
e = 31 N ≧ 160 BER = 0.194
e = 42 N ≧ 200 BER = 0.21
Thus, it can be seen that the allowable error bit number e required for ensuring reliability changes according to the reception bit number N.

  In general, as N increases, e increases, so if this characteristic is used, the reception time is lengthened and the number of bits (number of sample values) N is increased even when the time cannot be adjusted due to poor BER. If so, there is a high possibility that the time can be corrected.

In the present embodiment, for each range of the number of samples of input waveform data, for example, an allowable maximum BER table as shown in FIG. 9 is provided. The coincidence determination unit 26 can acquire the corresponding BER _max (I) according to the number of samples I of the input waveform data pattern (step 506).

The coincidence determination unit 26 compares the minimum BER acquired in step 505 with the BER _max (I) acquired in step 506, and determines whether or not the minimum BER <BER _max (I) is satisfied (step 507). If it is determined Yes in step 507, the coincidence determination unit 26 uses correction information as information indicating successful correction and information on the predicted waveform data pattern indicating the minimum BER (information indicating a deviation from BT). The data is output to the CPU 11 (step 508).

  The deviation time ΔT from the base time BT is expressed as follows.

ΔT = BT + s− (BT + Δt) = s−Δt
Here, s is the time of deviation from the base time BT in the first code data of the predicted waveform data pattern.

  When it is determined No in step 507, the coincidence determination unit 26 outputs information indicating a correction failure to the CPU 11 as correction information (step 509). When the CPU 11 receives the correction success as the correction information (Yes in Step 406), the CPU 11 stores the base time BT in the RAM 15 as the final correction time Tlast (Step 407). Further, the base time BT is corrected based on the deviation time ΔT from the base time BT (step 408). In step 408, the CPU 11 displays the corrected current time on the display unit 13 in addition to correcting the time of the internal clock circuit 17.

  If it is determined NO in step 402 or NO in step 404, the CPU 11 detects the minute start position by a conventional well-known method (step 409), and codes every second from the minute start position. The current time is obtained by decoding minutes, hours, days of the week, etc. (step 410).

  According to the present embodiment, the waveform cutout unit 24 samples the signal of the standard radio wave at a predetermined sampling period from the second leading position, and the sample value at each sample point indicates a low level. An input waveform data pattern that takes one of the value and the second value indicating the high level and has one or more unit time lengths is generated. In addition, the predicted waveform data pattern generation unit 23 takes either the first value or the second value as the sample value of each sample point, and has the same time length as the input waveform data pattern. It represents a sequence of codes based on the base time BT timed by the internal time measuring circuit 17, and the start position thereof is a time shifted by the base time BT and a predetermined number of seconds (± ΔS) before and after the base time. A plurality of predicted waveform data patterns are generated. The error detection unit 25 determines whether the sample value of the input waveform data pattern matches the sample value of the predicted waveform data pattern, counts the number of errors indicating the mismatch, and determines each of the plurality of predicted waveform data patterns. The number of errors is acquired, and the coincidence determination unit 26 calculates an error in the base time BT based on the head position of the predicted waveform data pattern indicating the minimum number of errors. The CPU 11 determines a predetermined number of seconds based on the time difference between the time when the base time is corrected by the current time correction means and the current base time, and a predetermined timing accuracy, and a predicted waveform to be generated. Determine the number of data patterns. Therefore, according to the present embodiment, the number of predicted waveform data patterns is determined based on the time interval from the previous correction, and an increase in processing time due to the generation of a large number of predicted waveform data patterns can be avoided.

  In the present embodiment, the generated input waveform data pattern has one sample value for each code. In the acquisition of the sample value, the input waveform data generation unit 21 and the waveform cutout unit 24 acquire data values at a plurality of temporally different positions for each code, and about the code based on the plurality of data values Determine the sample value of. Thereby, the data length of the input waveform data pattern can be shortened, and the processing time can be further shortened.

  In the present embodiment, the coincidence detection unit 26, when the minimum value of the number of errors is smaller than an allowable maximum number of errors determined in advance corresponding to the number of samples, predictive waveform data pattern indicating the number of errors of the minimum value The base time error is acquired based on the head position of the. Thereby, the possibility of erroneous detection can be significantly reduced.

  Further, in the present embodiment, the CPU 11 determines that the number of sample values increases as the received intensity of the received standard time radio wave decreases, and inputs according to the determined number of sample values. A waveform data pattern is generated. Therefore, it is possible to generate an input waveform data pattern and a predicted waveform data pattern having an optimal data length according to the reception intensity.

  Further, in the present embodiment, the CPU 11 calculates the assumed maximum error ΔS based on the time difference and the timing accuracy, and the predicted waveform data pattern generation unit 23 has a head position within the range of the maximum error (± ΔS). A plurality of predicted waveform data patterns are generated as follows. As a result, it is possible to minimize the number of predicted waveform data patterns while maintaining good accuracy.

  Next, a second embodiment of the present invention will be described. In the first embodiment, a sample value D (n) of input waveform data indicating one value is obtained for each code (every 1 second), and an input waveform data pattern for N seconds is generated (FIG. 6). Similarly to the input waveform data pattern, the predicted waveform data pattern also has sample values P (n) per second for N seconds. In the second embodiment, one code is divided into a plurality of sections (four sections), the value of each section is acquired, and input waveform data for one second is acquired. That is, the input waveform data for one second is composed of four sample values. Further, in comparison between input waveform data in the input waveform data pattern and predicted waveform data in the predicted waveform data pattern and detection of the number of errors, only a comparison result of sample values in a specific section is used as an effective value. .

  FIG. 10 is a block diagram showing the configuration of the signal comparison circuit 18 according to the second embodiment. As shown in FIG. 10, the signal comparison circuit 18 according to the second embodiment includes an input waveform data generation unit 21, a received waveform data buffer 22, a predicted waveform data pattern generation unit 23, a waveform cutout unit 24, and an error detection unit. 25, a coincidence determination unit 26, a second synchronization execution unit 27, and an effective value acquisition unit 28.

  The valid value acquisition unit 28 acquires only valid ones of comparison results (error detection) between an input waveform data pattern and a predicted waveform data pattern, which will be described later, and accumulates the number of errors. The operation of the valid value acquisition unit 28 will be described in detail later.

  FIG. 11 is a diagram illustrating a data configuration example of JJY code and input waveform data for one second in the present embodiment. As described above, JJY includes codes indicating “P”, “1”, and “0” having a unit time length of 1 second. Here, in the first 200 ms section (first section) of the code, all the codes indicate a high level (value “1”). In the subsequent 300 ms section (second section: 200 ms to 500 ms), only the symbol “P” indicates a low level (value “0”). Further, in the next 300 ms section (third section: 500 ms to 800 ms), only the code “0” is high level (value “1”) and the other codes “1” and “P” are low level (value “1”). 0 "). In the last 200 ms section (fourth section: 800 ms to 1000 ms), all codes indicate a low level (value “0”). Therefore, in this embodiment, the input waveform data (1100) corresponding to one code (for 1 second) is the sample value D (0, n) in each of the first to fourth intervals. , D (1, n), D (2, n) and D (3, n) (see reference numerals 1101 to 1104).

  Similarly, the predicted waveform data corresponding to one code is composed of sample values P (0, p), P (1, p), P (2, p) and P (3, p). Is done.

  The input waveform data generation unit 21 according to the second embodiment receives a signal output from the receiving circuit 16 at a predetermined sampling interval (for example, 64 samples per second), and the value is set at a predetermined sampling interval. It is converted into digital data that takes one of a plurality of values (“1” or “0”). Further, after the second synchronization is completed, the input waveform data generation unit 21 acquires the values of the second sample to the twelfth sample as the first interval from the input waveform data having 64 samples per second, and the value “ The sample value D (0, n) of the first section is determined depending on whether there is a larger value of “1” or “0”. Similarly, the input waveform data generation unit 21 sets the values of the 14th sample to the 30th sample, the 33rd sample to the 51st sample, and the 53rd sample to the 63rd sample as the second interval to the fourth interval, respectively. Based on this, sample values D (1, n), D (2, n), and D (3, n) for the second to fourth intervals are determined.

  Also in the second embodiment, the same processing as in FIG. 4 is executed. When it is determined Yes in step 404, the CPU 11 or the like executes time acquisition processing using a plurality of predicted waveform data patterns according to the present embodiment (step 405). FIG. 12 is a flowchart showing in more detail step 405 according to the second embodiment.

  The waveform cutout unit 24 of the signal comparison circuit 18 reads the input waveform data from the received waveform data buffer 22 and generates an input waveform data pattern DP having a time length of a predetermined number of seconds from the second head position Now + Δt based on the second synchronization. . In the example shown in FIG. 13, an input waveform data pattern for 4 seconds is shown. This input waveform data pattern includes sample values D (0, 0) to D (3, 0) constituting the first code data, and sample values D (0, 1) to D (3) constituting the second code data. , 1) Sample values D (0, 2) to D (3, 2) constituting the third code data and sample values D (0, 3) to D (3, 3 constituting the fourth code data )including.

  The predicted waveform data pattern generation unit 23 also generates a plurality of predicted waveform data patterns whose start times are shifted in the range of ΔS before and after the process start time Now based on the base time BT (step 1202). In the example illustrated in FIG. 13, five predicted waveform data patterns PP (0) to PP (4) are generated with ΔS = −2 to 2 as in the first embodiment.

  In the first predicted waveform data pattern PP (0), ΔS = −2, that is, the pattern start time is Now−2, and the first code data constituting the first code data of the first predicted waveform data pattern PP (0) is formed. 1st to 4th sample values P (0, -2), P (1, -2), P (2, -2), P (3, -2), 1st to 1st constituting the second code data 4th sample value P (0, -1), P (1, -1), P (2, -1), P (3, -1), 1st-4th which comprises the 3rd code data. Sample values P (0,0), P (1,0), P (2,0), P (3,0), and first to fourth sample values P constituting the fourth code data (0,1), P (1,1), P (2,1), P (3,1).

  Similarly, in the second predicted waveform data pattern PP (1), ΔS = −1 and the pattern start time is Now−1. In the third predicted waveform data pattern PP (2), ΔS = 0, the start time of the pattern is Now, and in the fourth predicted waveform data pattern data PP (3), ΔS = 1, The start time is Now + 1, and in the fifth predicted waveform data pattern data PP (4), the pattern start time is Now + 2.

  Next, the error detection unit 25 compares the input waveform data pattern DP and each of the plurality of predicted waveform data patterns with the corresponding codes, and calculates the number of errors corresponding to the code mismatch (step 1203). In the example of FIG. 13, the input waveform data pattern DP is compared with each of the predicted waveform data patterns PP (0) to PP (4).

  In the present embodiment, the input waveform data for one second of the input waveform data pattern has four sample values. Similarly, the predicted waveform data for one second of the predicted waveform data pattern has four sample values. Have Accordingly, a value match / mismatch is detected for the corresponding four sets of sample values per second.

  For example, in FIG. 13, the first code data D (0,0) to D (3,0) of the input waveform data pattern and the first code data P (0, -2) of the predicted waveform data pattern PP (0). ~ P (3, -2), D (0,0) and P (0, -2), D (1,0) and P (1, -2), D (2,0) and P (2, -2), D (3, 0) and P (3, -2) are respectively compared, and a match or mismatch is detected.

  The number of errors when there is a mismatch is “1”, and the error detection unit 25 accumulates the number of errors of each of the first sample value to the fourth sample value. In the example of FIG. 13, between the input waveform data pattern and the predicted waveform data pattern PP (0), the number of errors (D (0, s) (s = 0 to 3) and P (0 , T) (the total number of errors of t = −2 to 1), which is E (0, 0) (see reference numeral 1401 in FIG. 14), the number of errors in the second section (D (1, s)) E (0, 1) (see reference numeral 1402 in FIG. 14), which is (the total number of errors of s = 0 to 3) and P (1, t) (t = −2 to 1), E (0,2) which is the number of errors in the section (the sum of the number of errors in each of (D (2, s) (s = 0 to 3) and P (2, t) (t = -2 to 1)) (Refer to reference numeral 1403 in FIG. 14) and the number of errors in the fourth section (D (3, s) (s = 0 to 3) and P (3, t) (t = −2 to 1) Total number of errors E (0, 3) (see reference numeral 1404 in Fig. 14) is obtained, as shown in Fig. 14, the other predicted waveform data patterns PP (1) to PP (4) are also in the same manner. The number of errors for each of the section to the fourth section is acquired.

  As shown in FIG. 11, the first section takes the value “1” in any of the signs “0”, “1”, and “P”. Further, the fourth section takes the value “0” in any of the codes “0”, “1”, and “P”. On the other hand, in the second section, the code “P” takes a value different from the other codes, and in the third section, the code “0” takes a value different from the other codes. Therefore, the code can be specified by referring to the values of the second and third intervals.

  In the second embodiment, the valid value acquisition unit 28 uses the total number of errors in the second section and the third section as a valid value for each of the predicted waveform data patterns. The total number of errors in the interval is added, and this addition result is used as the final total number of errors (see step 1204, reference numeral 1410 in FIG. 14).

The coincidence determination unit 26, based on the number of errors calculated for each of the plurality of predicted waveform data patterns (final sum of the number of errors), a bit error rate (BER) corresponding to each of the plurality of predicted waveform data patterns. Is calculated (step 1205). The bit error rate (BER) can be obtained by calculating (final sum of the number of errors) / (number of sample values I) as in the first embodiment. The coincidence determination unit 26 finds the minimum bit error rate (minimum BER) among the bit error rates BER (step 1206). Thereafter, the coincidence determination unit 26 obtains the allowable maximum bit error rate BER _max (I) determined by the received code data number I (step 1207), and the minimum BER is the allowable maximum bit error rate BER _max (I). It is determined whether it is smaller (step 1208).

  When it is determined Yes in step 1208, the coincidence determination unit 26 uses correction information as information indicating successful correction and information on the predicted waveform data pattern indicating the minimum BER (information indicating a deviation from BT). It outputs to CPU11 (step 1209). When it is determined No in step 1208, the coincidence determination unit 26 outputs information indicating a correction failure to the CPU 11 as correction information (step 1210).

  According to the second embodiment, the number of sample value comparisons per second (one code) is increased (four times) as compared with the first embodiment. Therefore, considering the number of samples to be received, it is equivalent to receiving four times as much data as in the first embodiment. Therefore, the reception time can be further shortened (about 1/4) as compared with the first embodiment.

  The number of received bits (number of samples) is N, and the number of allowable error bits is e. Similarly to the first embodiment, the bias of the code appearance probability is considered as P0 = 0.55 and P1 = 0.45. The probability of mismatch is also 1/10 ^ 8, as in the first embodiment. Under this condition, P0 ^ N · COMBIN (N, e) <1/10 ^ 8 was solved for e, and the allowable number of error bits e and the BER at that time were calculated.

  Hereinafter, the number of received bits (number of samples) is represented as N, and the number of received seconds is represented as S.

S = 10 N = 40 e = 1 BER = 0.1
S = 20 N = 80 e = 10 BER = 0.125
S = 30 N = 120 e = 21 BER = 0.175
S = 40 N = 160 e = 31 BER = 0.194
S = 50 N = 200 e = 42 BER = 0.210
S = 60 N = 240 e = 53 BER = 0.221
S = 90 N = 360 e = 87 BER = 0.242
Compared to the first embodiment, it is understood that the same allowable BER can be obtained with the reception time of ¼ that of the first embodiment.

  The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

For example, in the first and second embodiments, if the obtained minimum BER is equal to or greater than the maximum allowable bit error BER _max (I), it is determined that the correction has failed (step 1208, 1210). In this case, step 405 may be executed again. In the execution of step 405 again, the number of seconds (that is, the number of codes) of the input waveform data pattern is made larger than the number of seconds of the input waveform data pattern generated in the previous step 405. Increasing the reception time and increasing the number of bits (number of sample values) N increases the possibility of time correction.

  In the first embodiment and the second embodiment, the minimum BER and the allowable maximum bit error BERmax (I) are compared. However, the present invention is not limited to this, and other methods are adopted. It is also possible.

  For example, if the received standard time signal does not contain noise, the number of errors between the input waveform data pattern and the predicted waveform data pattern corresponding to the time to be corrected is “0” (that is, the bit error rate). BER is also “0”). For example, in FIG. 15 exemplifying the number of errors for the predicted waveform data pattern, a solid line graph indicates the number of errors for each predicted waveform data pattern PP when the reception status of the standard time radio wave is good. Thus, if the reception condition is good and the noise is not included in the signal, the number of errors becomes “0” for the predicted waveform data pattern PP (3), and the predicted waveform data pattern PP (3) It can be determined that the pattern matches the input waveform data pattern.

  However, in practice, since the standard time radio signal includes noise, the number of errors (and the bit error rate BER) takes a value larger than “0”, and as the noise increases, the number of errors ( And the bit error rate BER) also increases (see the broken line in FIG. 15).

  FIGS. 16A and 16B are examples of other graphs showing the correspondence between the predicted waveform data pattern and the number of errors, respectively. In the example shown in FIGS. 16A and 16B, numbers E1, E2,... Are assigned in order from the smallest error number. As shown in FIG. 16A, when the minimum value E1 of the number of errors is relatively close to the second smallest value E2, E1 and E2 are significantly separated (FIG. 16 ( Compared with b), it may be undesirable to determine that the predicted waveform data pattern PP (j) indicating the minimum value E1 matches the input waveform data pattern.

  Therefore, in this embodiment, when the minimum value E1 of the number of errors and the second smallest value E2 are separated from each other by a predetermined value, it is determined that the minimum value E1 is reliable. In order to determine whether the distance is greater than the predetermined value, the lower limit of the second smallest value E2 is determined based on the error rate Pd, the number of samples N, and the minimum value E1 of the number of errors.

  If the error rate indicating that the minimum value E1 of the number of errors is not a coincidence point (that is, a point that coincides with the input waveform data pattern) is P, P can be expressed as a function of N, E1, and E2. .

P = f (N, E1, E2)
More specifically, for example, it can be expressed by the following formula.

ただし、Ｎ＞０、Ｅ１＜Ｅ２
上記エラー率Ｐを用いて、当該エラー率Ｐ（＝ｆ（Ｎ，Ｅ１，Ｅ２））が、判定基準値Ｐｄ（たとえば、Ｐｄ＝１ｅ−８）より小さい場合、つまり、
ｆ（Ｎ，Ｅ１，Ｅ２）＜Ｐｄである場合には、エラー数Ｅ１を一致点とすることの信頼性が十分あると判断する。

However, N> 0, E1 <E2
When the error rate P (= f (N, E1, E2)) is smaller than the determination reference value Pd (for example, Pd = 1e-8) using the error rate P, that is,
If f (N, E1, E2) <Pd, it is determined that there is sufficient reliability that the error number E1 is the coincidence point.

  Actually, the error rate P may be obtained according to the equation shown in the above equation 1, and the error rate P may be compared with a predetermined criterion value Pd. However, it may take a calculation time. Therefore, a reliability determination table indicating the lower limit value of E2 satisfying f (N, E1, E2) <Pd is stored in the RAM 15 for each combination of the sample number N and the minimum value E1 of the error number. Alternatively, the values of the reliability determination table may be read out. For example, as shown in FIG. 17, the reliability determination table 1700 includes the number of samples N (N = 1, 2, 3, 4,... In the example of FIG. 17) and the minimum number of errors (E1 = 1). 2,...), The lower limit value Emin (N, E1) of E2 is stored for each of (N, E1).

  FIG. 18 is a flowchart illustrating an example of the reliability determination process according to this embodiment. The process shown in FIG. 18 is executed instead of step 504 to step 507 in FIG. 5 of the first embodiment. As shown in FIG. 18, the coincidence determination unit 26 specifies the minimum number E1 of errors and the second smallest value E2 based on the number of errors for each predicted waveform data pattern (step 1801). Next, the coincidence determination unit 26 refers to the reliability determination table in the RAM 15 based on the number of samples N and the minimum value E1, and acquires the corresponding lower limit value Emin (N, E1) (step 1802).

  The coincidence determination unit 26 determines whether the value E2 is greater than or equal to the lower limit value Emin (step 1803). If YES is determined in step 1803, the process proceeds to step 508 with reliability. On the other hand, if No is determined in step 1803, the process proceeds to step 509 with no reliability. The above method can be similarly applied to the second embodiment.

  According to the above embodiment, considering not only the minimum value E1 of the number of errors but also the second smallest value E2, if the minimum value E1 is more than a predetermined distance from the second smallest value E2, For the minimum value E1, it is determined that the predicted waveform data pattern matches the input waveform data pattern with reliability. Thereby, it is possible to realize a highly reliable determination of coincidence.

10 radio time clock 11 CPU
12 Input unit 13 Display unit 14 ROM
15 RAM
16 Receiving Circuit 17 Internal Clock Circuit 18 Signal Comparison Circuit

Claims (7)

The standard radio wave signal is sampled at a predetermined sampling period from the second position detected in the standard time radio wave including the time code representing the received time information, and the sample value of each sample point becomes a low level. An input waveform data pattern generation means for generating an input waveform data pattern that takes one of a first value and a second value indicating a high level and has one or more unit time lengths;
The sample value of each sample point takes either the first value or the second value, has the same time length as the input waveform data pattern, and each is a base timed by an internal time measuring means A predicted waveform data pattern that represents a sequence of codes based on time, and that generates a plurality of predicted waveform data patterns whose start position is the base time and a time shifted by a predetermined number of seconds before and after the base time Generating means;
It is determined whether or not the sample value of the input waveform data pattern matches the sample value of the predicted waveform data pattern, counts the number of errors indicating a mismatch, and calculates the number of errors for each of the plurality of predicted waveform data patterns. Error detection means to obtain;
Current time correcting means for correcting the base time based on the head position of the predicted waveform data pattern indicating the minimum number of errors;
A predicted waveform to be generated by determining the predetermined number of seconds based on a time difference between the time when the base time is corrected by the current time correcting means and the current base time, and a predetermined timing accuracy. A time information acquisition apparatus comprising: control means for determining the number of data patterns.   The input waveform data pattern generated by the input waveform data pattern generation means has one sample value for each code, and the input waveform data pattern generation means has a plurality of codes for each code in acquiring the sample values. The time information acquisition apparatus according to claim 1, wherein data values at different positions in time are acquired, and a sample value for the code is determined based on the plurality of data values.   When the minimum value of the number of errors is smaller than a predetermined maximum allowable number of errors corresponding to the number of samples, the current time correction means is positioned at the head position of the predicted waveform data pattern indicating the number of errors of the minimum value. 3. The time information acquisition apparatus according to claim 1, wherein the base time is corrected based on the time information.   When the current time correction means considers the minimum value of the number of errors and the second smallest value, the minimum value is more than a predetermined distance from the second smallest value. The time information acquisition apparatus according to claim 1, wherein the base time is corrected based on a head position of a predicted waveform data pattern indicating the number of value errors. The control means determines that the number of sample values increases as the received intensity of the received standard time radio wave decreases,
5. The time information acquisition apparatus according to claim 1, wherein the input waveform data pattern generation unit generates an input waveform data pattern according to the determined number of sample values. 6. The control means calculates an assumed maximum error based on the time difference and the timing accuracy,
6. The predicted waveform data pattern generation unit generates a plurality of predicted waveform data patterns such that the head position is within the range of the maximum error. Time information acquisition device. The time information acquisition device according to any one of claims 1 to 6,
The internal time measuring means for measuring the current time by an internal clock;
A radio-controlled timepiece comprising time display means for displaying the current time measured by the internal time measuring means or corrected by the current time adjusting means.

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