JP4555360B2 - Receiver that receives emergency breaking news in digital terrestrial television broadcasting - Google Patents

Description

  The present invention relates to a technology for transmitting and receiving emergency information in digital terrestrial television broadcasting, and in particular, a receiver for receiving promptly and surely when an emergency warning broadcast or an earthquake early warning is issued, and the receiver The present invention relates to a transmission device for reliably transmitting to a user.

  In television broadcasting and radio broadcasting, there is a broadcasting system called emergency warning broadcasting so that when a disaster such as an earthquake or tsunami occurs, it can be quickly transmitted to viewers. This system is provided with a mechanism that allows a terminal that has not been activated to be activated before the broadcast that conveys emergency information is started.

  In the ISDB-T (Integrated Services Digital Broadcasting-Terrestrial, ARIB standard STD-B31) system, which is a Japanese terrestrial digital television broadcast, TMCC (Transmission and Multiplexing Configuration Carrier Control: Emergency Control Carrier Transmission Control: Flag for Emergency Control Transmission Control) Have.

  The ISDB-T digital terrestrial television receiver includes a transmission control signal receiving circuit that detects an emergency warning broadcast activation flag stored in the TMCC carrier when the receiver is not powered. When the emergency alert broadcast activation flag is 1 (corresponding to “with activation control (with emergency alert broadcast)”), the receiver can be turned on to prompt the user of the receiver to view the emergency alert broadcast. .

  In order to realize this, the transmission control signal receiving circuit in the receiver must always monitor the emergency warning broadcast activation flag. That is, the standby power consumption of the receiver is often a problem because the emergency warning broadcast activation flag is constantly monitored even though the receiver is in a standby mode for saving power consumption. is there.

  Several technologies have been disclosed that operate with this standby power consumption suppressed, start a receiver that has not been supplied with power, and inform the receiver of the presence or absence of an emergency warning broadcast (for example, Patent Document 1, Patent Document 1). Patent Document 2).

  For example, in the receiver disclosed in Patent Document 1, the transmission control signal receiving circuit includes a synchronization holding circuit based on the frame synchronization signal of the TMCC signal, and the frame and frame units (at the timing indicated by the count value by the synchronization holding circuit) By performing the intermittent operation outside the frame, power consumption can be saved. The power-on timing in the frame is, for example, about 30 msec from the synchronization signal to the emergency warning broadcast activation flag.

  Further, the receiver disclosed in Patent Document 2 achieves lower power consumption by simplifying the circuit configuration of the transmission control signal receiving circuit. Furthermore, in order to obtain diversity combining, all four TMCC signals in the partial reception segment are used to improve the reception accuracy of the emergency warning broadcast activation flag.

  On the other hand, the Japan Meteorological Agency started providing earthquake early warnings (see Non-Patent Document 1, for example) to the general public from October 1, 2007. Along with this, television and radio broadcasting stations have started broadcasting such as displaying or sounding the television screen with a chime sound when an emergency earthquake warning is announced. In addition, a part of the earthquake early warning radio broadcast started on April 1, 2008.

  In the case of digital terrestrial television broadcasting, especially in the case of partial reception one-segment services, the delay required for signal processing such as radio frequency (RF) signal demodulation, error correction, and codec processing for video, etc. There will be a delay of several seconds.

  Similarly to the case of emergency alert broadcasting, the reception is not possible without a mechanism for supplying power to the receiver.

  Therefore, a technique using an AC carrier is disclosed in addition to receiving a start flag by a TMCC signal for transmission in terrestrial digital television broadcasting such as disaster and disaster prevention information including earthquake early warning (for example, Patent Document 3). reference). According to this technology, the type of emergency early warning and the start or end are presented by a combination of an emergency warning broadcast start flag of a TMCC carrier and a signal type bit placed on a specific AC carrier in a partial reception segment, for example. . In addition, the emergency information descriptor of the ARIB standard STD-B10 and the video / audio of the emergency breaking news are transmitted using the AC carrier. The emergency information descriptor includes a signal type bit and is transmitted as an AC signal of a partially received segment, and video / audio is stored as an AC signal of another segment.

  In this technology, when the receiver is not turned on, or when another channel is received, control is performed to prompt power-on or channel switching, and the TMCC in the partial reception segment is used for this control. After receiving the signal and the AC signal, after the power is turned on or after the channel is switched, other disaster / disaster prevention information and video / audio are reproduced.

JP 2006-319771 A JP 2007-104221 A JP 2007-243936 A “Technical reference materials on overview and processing methods of earthquake early warnings,” Japan Meteorological Agency Earthquake Volcano, [Search on January 31, 2008], Internet <URL: http://www.seisvol.kishou.go.jp/ eq / EEW / kaisetsu / Whats_EEW / reference.pdf>

  The techniques disclosed in Patent Documents 1 to 3 are all the same techniques in that they aim to quickly start up a digital terrestrial television broadcast receiver. In addition, all the techniques disclosed in Patent Documents 1 to 3 are based on the premise that frame synchronization is established in the reception signal of the TMCC signal or the AC signal.

  In particular, Patent Document 3 receives both a TMCC signal and an AC signal. This complicates the circuit configuration and has room for improvement in terms of power consumption.

  Furthermore, even when the terrestrial digital television broadcast is not received at the receiver, in order to quickly respond to the emergency warning broadcast or the earthquake early warning, even in a situation where the antenna is housed or folded, the reception sensitivity is poor. It is required to be able to receive.

  In other words, even when the quality of the received signal is insufficient and timing synchronization in units of frames is insufficient, the emergency warning broadcast or the earthquake early warning activation flag is detected, and the emergency early warning is given to the receiver (receiver user) having the receiver. It is necessary to be able to receive information of (emergency warning broadcast or earthquake early warning). Needless to say, if the receiver can recognize the reception of the emergency bulletin, the user of the receiver can extend the antenna to obtain a better reception state.

  The present invention relates to a receiver for receiving an emergency early warning in digital terrestrial television broadcasting, which enables quick and reliable transmission of an emergency early warning to a receiver of the digital terrestrial television broadcast, and a transmission for transmitting the emergency early warning. To provide an apparatus.

  In a system that transmits emergency early warning information using eight AC (Auxiliary Channel) carriers in a partial reception segment of digital terrestrial television broadcasting, on the transmission side, N bits ( N is an integer) and is transmitted by assigning at least a combination of the states of “emergency warning broadcast activation flag” and “emergency earthquake early warning activation / identification flag”. At this time, in order to distinguish between normal times or when an emergency warning broadcast or an earthquake early warning is issued, a part or all of the N-bit code string is not inverted (or inverted) according to a predetermined rule. Can be identified on the receiving side in the state (ie, in-phase (or reverse-phase) value) that corresponds to either “emergency warning broadcast activation flag” or “emergency earthquake early warning activation / identification flag” And send. On the other hand, the reception side receives 8 AC signals in the partial reception segment, performs a correlation operation corresponding to the state of the N-bit code string stored in the AC signal, and obtains a correlation coefficient as a result of the correlation operation. The frame synchronization timing is detected from the presence or absence of the peak value of N and corresponds to either the state of the N-bit code string (that is, the “emergency warning broadcast activation flag” or “emergency earthquake early warning activation / identification flag”). Based on the calculation value of the correlation calculation by the code sequence for each state combination), at least the state of the “emergency warning broadcast activation flag” or “emergency earthquake early warning activation / identification flag” is determined, and the emergency alarm broadcasting or emergency earthquake When recognizing that a breaking news has been issued, the emergency breaking news transmitted together with the N-bit code string is read into eight AC signals, and the emergency terminal is read on the display of the receiving terminal. Display the broadcast with a letter, or the sound from the speaker of the terminal, or in vibration by a vibrator of the terminal, to inform the occurrence and content of the emergency bulletin to the user's terminal.

That is, a receiver according to the present invention is a receiver that receives an AC signal from a terrestrial digital television broadcast wave,
Telegram information for storing a flag that also serves as a synchronization signal and emergency warning information including emergency warning broadcast or emergency earthquake warning information is transmitted as an AC signal having the same frame length as the TMCC signal from the transmission device by an AC carrier. Pre-defined so that
In order to identify the presence or absence of emergency alert broadcasting and the presence or absence of earthquake early warning, the flag has N bits (N is a symbol string pattern of a plurality of flags including an emergency alert broadcasting flag and an emergency earthquake early warning flag. A positive integer)
Storage means for storing in advance a pattern sequence corresponding to the plurality of code sequence patterns;
AC extraction means for receiving a terrestrial digital television broadcast wave and extracting an AC signal;
Correlation calculation means for executing a sliding correlation calculation on the extracted AC signal based on the pattern string read from the storage means, and generating a correlation coefficient as a result of the correlation calculation corresponding to the code string pattern of each system When,
Flag detection means for separating the peak value of the correlation coefficient corresponding to the code string pattern of each system into a signal indicating the state of each flag and a signal for frame synchronization;
Flag monitoring means for identifying the presence / absence of an emergency warning broadcast and the presence / absence of an emergency earthquake warning from the state of each of the separated flags,
Frame synchronization detection means for detecting frame synchronization timing from the separated frame synchronization signal;
When it is identified by the flag monitoring means that there is an emergency warning broadcast, or there is an emergency earthquake warning, the contents of the emergency warning broadcast or the contents in synchronization with the frame synchronization timing detected by the frame synchronization detection means AC information analysis means for analyzing the contents of the earthquake early warning ,
The correlation calculation means is characterized in that the odd-numbered frame and the even-numbered frame in the received AC signal are individually identified to detect the peak value of the correlation coefficient and determine the state of the flag .

  Further, in the receiver according to the present invention, the correlation calculating means separately identifies odd frames and even frames in the received AC signal, detects a peak value of the correlation coefficient, and determines the state of the flag. It is characterized by.

  Further, in the receiver according to the present invention, in the synchronous modulation mode of mode 3 in the partial reception segment of the ISDB-T digital terrestrial television broadcast wave, the emergency bulletin having the same content is transmitted as eight AC signals. The correlation calculation means performs a correlation calculation on the eight AC signals to obtain a diversity gain, and determines the state of the flag.

  Further, in the receiver according to the present invention, only when the state of the flag determined by the correlation calculating means indicates that there is an emergency earthquake warning or emergency warning broadcast, decoding corresponding to the emergency warning broadcast or emergency earthquake warning is decoded. The apparatus further comprises means.

  The receiver according to the present invention further comprises prediction information calculation means for calculating prediction information of seismic intensity and arrival prediction time of the area where the receiver is located from information decoded by the decoding means.

  In the receiver according to the present invention, the corresponding emergency alert broadcast or emergency earthquake bulletin is decoded only when the state of the flag determined by the correlation calculating means indicates that there is an emergency earthquake bulletin or emergency alert broadcast. It is further characterized by further comprising control means for switching the power supply of the receiver so that the power is supplied in a sufficient period.

  Further, in the receiver according to the present invention, when the flag does not acquire a flag value indicating that there is an emergency earthquake warning or an emergency warning broadcast, in the intra-frame intermittent reception operation or the inter-frame intermittent reception operation, Power is supplied to the decoding means.

  In the receiver according to the present invention, the decoding means decodes the emergency earthquake bulletin by making a majority decision between a plurality of frames.

  In the receiver according to the present invention, the telegram information is in the synchronous modulation mode of mode 3 in the partial reception segment of the ISDB-T terrestrial digital television broadcast wave, and the emergency information of the same content is converted into eight AC signals. The decoding means decodes the earthquake early warning information from the eight AC signals in order to obtain diversity gain.

  In the receiver according to the present invention, the message information includes a parity bit of a predetermined difference set cyclic code system, and the decoding means performs error correction based on the difference set cyclic code system, and It is characterized by decoding.

  In the receiver according to the present invention, the warning generating means may display characters on a display provided in the receiver, generate a sound from a speaker provided in the receiver, or vibrate by a vibrator provided in the receiver. It is characterized in that a warning is issued or a warning is generated perceptually in an operation different from that in a normal operation.

  Further, in the receiver according to the present invention, the prediction information calculation means is information on occurrence of an earthquake in the telegram information, instead of calculating the prediction information of the seismic intensity and the predicted arrival time of the area where the receiver is located. Alternatively, the information and the occurrence time or the maximum predicted seismic intensity, or the information of the area where there is a risk of strong shaking due to the earthquake, is configured as a prediction information extraction unit configured to send to the warning generation unit .

  In the receiver according to the present invention, the decoded earthquake early warning includes a region code for identifying a plurality of regions, predicted seismic intensity information in each region, and predicted arrival time information in each region, and the predicted information calculation means includes A position detection means for detecting position information representing the regional position of the receiver; and a current time detection means for detecting current time information representing the current time of the receiver, the area code, the predicted seismic intensity From the information, the predicted arrival time information, and the position information and the current time information, the seismic intensity of the area where the receiver is located and the predicted information of the predicted arrival time are calculated.

  In the receiver according to the present invention, the decoded emergency earthquake bulletin includes information on the occurrence time of the earthquake, the latitude and longitude of the epicenter, the depth of the epicenter, and the magnitude, and the prediction information calculation means includes the receiver. Position detecting means for detecting position information representing the regional position of the receiver, and current time detecting means for detecting current time information representing the current time of the receiver, the occurrence time of the earthquake, the latitude of the epicenter and From the information on the longitude, the depth of the epicenter, and the magnitude, and the position information and the current time information, the seismic intensity and the predicted arrival time of the area where the receiver is located are calculated. .

  In the receiver according to the present invention, the decoded earthquake early warning includes information on the current time, the elapsed time from the occurrence of the earthquake to the current time, the latitude and longitude of the epicenter, the depth of the epicenter, and the magnitude information. The prediction information calculation means includes position detection means for detecting position information indicating a local position of the receiver, the current time, the elapsed time, the latitude and longitude of the epicenter, the depth of the epicenter, And, based on the magnitude information and the position information, prediction information of the seismic intensity and the predicted arrival time of the area where the receiver is located is calculated.

  According to the present invention, it is possible to quickly and surely transmit an emergency warning broadcast or an earthquake early warning to a terrestrial digital television broadcast receiver.

  First, a transmission apparatus and a receiver according to an embodiment of the present invention will be described.

Example 1
The transmission apparatus according to the first embodiment of the present invention is an emergency bulletin based on the format of the telegram information according to the first embodiment described later (hereinafter, the information including the emergency warning broadcast and the earthquake early warning is collectively referred to as emergency bulletin). Transmission is performed using an AC carrier among subcarriers multiplexed in the OFDM (Orthogonal Frequency Division Multiplexing) scheme of terrestrial digital television broadcasting of the ISDB-T scheme. The hardware configuration of the transmission apparatus related to ISDB-T digital terrestrial television broadcasting is known and not shown.

That is, the flag has the same frame length as that of the TMCC signal (preferably, the same phase reference as that of the TMCC signal), the flag including the bit for identifying the presence / absence of the earthquake early warning that also serves as the synchronization signal, The telegram information (the format of telegram information to be described later) for storing the emergency bulletin including the information is defined in advance so as to be transmitted from the transmission device on the AC carrier. In order to facilitate understanding of the present invention, the case where all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting will be described, but the present invention can also be applied to other modes. Note that

  For example, when a broadcaster receives, for example, an earthquake early warning from the Japan Meteorological Agency, at least the same earthquake early warning information based on the format example of the telegram information of the first embodiment, that is, information on seismic intensity and arrival prediction time is transmitted by the transmitting device. Along with the N-bit (N is an integer) code string assigned to the combination of the status of the “emergency warning broadcast activation flag” and “emergency earthquake early warning activation / identification flag”, all the AC information carried by the eight AC carriers Store and transmit to the receiver 1. In normal times, or when an emergency warning broadcast or an earthquake early warning is issued, a part or all of the N-bit code string is in a non-inverted (or inverted) state (that is, in-phase (or in-phase)) according to a predetermined rule. Or the opposite phase) value), and the statuses corresponding to the “emergency warning broadcast activation flag” and “emergency earthquake early warning activation / identification flag” are distinguished and transmitted.

  On the other hand, the receiver 1 (described in detail later) receives eight AC signals in the partial reception segment, performs a correlation operation corresponding to the state of the N-bit code string stored in the AC signal, and performs a correlation operation. The frame synchronization timing is detected from the presence / absence of the peak value of the correlation coefficient, which is the result of the Based on the calculation value of the correlation calculation by the code string for each combination of the corresponding states), at least the state of the “emergency warning broadcast activation flag” or “emergency earthquake early warning activation / identification flag” is determined, When recognizing that the earthquake early warning has been issued, the emergency early warning transmitted along with the N-bit code string to the eight AC signals is read and a warning is generated. As a method for generating a warning, the emergency warning is displayed in characters on the display of the terminal equipped with the receiver 1, or a sound is generated on the speaker of the terminal, or the terminal is vibrated by vibration of the vibrator of the terminal. Inform users of the occurrence of emergency warnings and their contents.

  In the ISDB-T digital terrestrial television broadcasting, it is possible to know the presence or absence of emergency warning broadcasting by detecting the emergency warning broadcasting activation flag of the TMCC signal. On the other hand, in the case of earthquake early warnings and other emergency early warnings, there is no mechanism currently in operation along with the transmission of that information, so any terminal (including any electronic device such as a mobile phone, PC, table clock) Needs to be equipped with a receiver 1 according to the present invention. Therefore, the receiver 1 according to the present invention can be provided in any device such as a mobile phone, a personal digital assistant (PDA), a wristwatch, a table clock, a personal computer, or a home appliance.

  Here, in order for the receiver 1 to receive an emergency warning such as an emergency warning broadcast or an emergency earthquake warning, the receiver 1 needs to know that the emergency warning is started immediately before or when the emergency warning is received. Therefore, the correlation calculation described later is performed.

  Furthermore, in the case of a receiving terminal of the one-segment service, it can be easily predicted that the receiving terminal is turned off and an antenna for receiving the one-seg signal may be housed. When the antenna is housed, the antenna gain may not be sufficiently obtained, and the frame timing may not be sufficiently synchronized. Even in such a case, it is necessary for the receiver 1 to detect an activation flag such as an emergency warning broadcast. Even in this case, the emergency warning broadcast can be performed regardless of the presence or absence of frame synchronization by the correlation calculation described later according to the present invention. Alternatively, the status of the activation flag such as the earthquake early warning can be confirmed, and at the same time, the frame synchronization is detected so that the emergency warning broadcast or the earthquake early warning can be received.

  As described above, the terminal equipped with the receiver 1 according to the present invention also supports emergency bulletins other than emergency warning broadcasts such as emergency earthquake bulletins, the receiver 1 is turned off, and the antenna is sufficiently accommodated. A receiver 1 that can quickly and reliably transmit and receive a start flag such as an emergency warning broadcast or an earthquake early warning even when a broadcast wave cannot be received with a high reception quality and frame timing synchronization is not established. provide.

  First, in order to improve the understanding of the transmission apparatus and the receiver 1 according to an embodiment of the present invention, a description will be given with reference to FIG. FIG. 1 shows the principle of the transmission / reception method of the activation flag for receiving the emergency early warning disclosed in the present invention in the case of transmitting / receiving only the emergency warning broadcast activation flag.

  On the transmission side, instead of setting the emergency warning broadcast activation flag to “1” (with emergency warning broadcast), an 8-bit code is assigned. In this case, “111101001” is transmitted instead of “1”. In normal times, that is, when there is no emergency warning broadcast, the emergency warning broadcast activation flag is “0” (no emergency warning broadcast). In this case, the sign bit of the previous 8 bits is inverted, “01100001” that is 4-bit rotationally shifted is transmitted.

  The receiving side waits for a signal transmitted with “11101001” which sets the emergency alert broadcast activation flag to “1”. When the signal is received, 8 symbols of the received signal are accumulated, and a correlation coefficient is calculated with the code “11110001”. As shown in FIG. 1, the correlation calculation is performed for each modulation signal value of the BPSK wave, that is, “1,1,1, −1,1, −1, −1,1” and “1,1,1, − 1,1, -1, -1, -1, "or" 1,1,1, -1,1, -1, -1, -1, "and" -1,1,1, -1, -1, -1, " 1, -1,1, "(or" -1, -1, -1, -1, -1, -1,1,1, -1 "and" -1, -1, -1, -1, -1, -1,1, "). 1, -1 "or" -1, -1, -1, 1, -1, 1, 1, -1 "and" 1, -1, -1, 1, 1, 1, 1, -1 " ).

  As a result, during normal times when the code “00010110” is transmitted, the correlation coefficient at the receiver 1 is uncorrelated, and thus a noise-like value near 0 continues.

  On the other hand, when an emergency warning broadcast is transmitted from a broadcasting station transmitting apparatus in which a code “111101001” is transmitted, the receiver 1 detects a high numerical value equivalent to the autocorrelation coefficient, and thereby the emergency warning broadcast Can be recognized.

  Although the BPSK wave is shown in FIG. 1, the DBPSK wave is used when the modulation format is the same as that of the TMCC signal. Even when DBPSK waves are used, that is, "1, 1, 1, -1, 1, -1, -1, 1" or "-1, -1, -1, 1, -1, 1, 1". , -1 "instead of" -1, 1, -1, -1, 1, 1, 1, -1 "(when the start phase is" 1 "), or" 1, -1, 1, 1 , −1, −1, −1, 1 ”(when the start phase is“ 1 ”), the result is obtained in the same manner.

  In the first embodiment, particularly in the case of transmitting and receiving an emergency bulletin regarding “how much earthquake / seismic intensity occurs in which region”, which is desired in the distribution of the emergency earthquake bulletin, first, an emergency transmitted by the transmission side is first transmitted. A message information format including information will be described.

  The current public emergency earthquake bulletin provides information on areas where seismic intensity of 4 or higher is estimated when strong shaking (seismic intensity of 5 or lower) is estimated anywhere in Japan.

  In other words, the subject is an emergency bulletin regarding the region name, the maximum predicted seismic intensity in the region, and the predicted arrival time of the main motion of the earthquake in the region. The message information format of the first embodiment shown in FIG. 2 includes message information for storing these emergency bulletins.

  For example, when a broadcaster receives an emergency earthquake bulletin from the Japan Meteorological Agency, the information on the same earthquake early warning based on the format example of the telegram information of the first embodiment, that is, the area name, the maximum predicted seismic intensity in the area, The information of the emergency earthquake bulletin such as the predicted arrival time of the main motion of the earthquake is stored in all the AC information carried by the eight AC carriers and transmitted to the receiver 1.

  “Various flags (synchronization signal)” represents the main part of the transmission / reception method of the activation flag for receiving the emergency early warning of this embodiment. Information such as “emergency warning broadcast activation flag”, “emergency earthquake early warning activation / identification flag”, “other flags”, “normal” / “training” identification, emergency early warning “cancel”, and the like are presented.

  Of these, the emergency warning broadcast activation flag, emergency earthquake warning activation / identification flag, and other flags for emergency early warning are synchronized with each other by performing correlation calculation on the receiving side. ) Is assigned a code string of N bits (N bit represents the total length of the code string indicating the flag, and N is an integer) so that the flag value can be determined regardless of whether or not it is established.

  This is based on the fact that if the value of N is set to a value in the vicinity of 16, the sensitivity is equivalent to the detection of the synchronization signal of the TMCC signal, and the frame synchronization using the synchronization signal of the TMCC signal is performed on the receiving side. By detecting the peak value based on the result of the correlation calculation (correlation coefficient) with the N-bit code string even in the reception signal that is in the vicinity of the threshold value and in an unestablished frame synchronization state, the flag value Can be detected. Therefore, the detection of the activation flag in the receiver 1 of the present embodiment does not depend on the establishment of frame synchronization.

  FIG. 3 shows a format example of “various flags (synchronization signal)”. Here, 26 bits (21 bits only for the portion corresponding to N) are allocated. “Emergency earthquake warning start / identification flag”, “emergency warning broadcast start flag”, and “other flags” are each assigned 7 bits, corresponding to flag values “1” and “0”, respectively. “1110100” and “0001011” are input as the bits to be performed (in the case of the first frame). In the second frame, “0100111” and “1011000” are input. One bit is assigned to each of “normal” / “training” identification and “cancellation” of the emergency bulletin, and when “1” is transmitted, it is “training” and “cancel” is notified. It is done. As the “reserved bit (flag)”, 3 bits are prepared, and the last bit among them is used as a buffer bit, and a part of the circuit in the receiver 1 for reducing the power consumption when the start flag is monitored is used. In the case of intermittent operation of power supply, it is possible to secure a buffering time between detection of a start flag and supply of power to a necessary circuit so that data can be detected. Become. In the remaining 2 bits, “tsunami warning” or “volcanic eruption warning” can be put in combination with “other flags”.

  However, between the first frame and the second frame (assuming repeated transmission, a number is assigned to each frame and the same is applied to an odd frame and an even frame from that number). It is used differently. This corresponds to the transmission using two frames to transmit the result of calculating the maximum predicted seismic intensity in a maximum of eight areas in the example of the message information format described in FIG. Which is the first frame and which is the second frame is recognized by recognizing the difference between these codes.

  If the “Emergency Earthquake Warning Start / Identification Flag” and the “Emergency Warning Broadcast Start Flag” are “1” and the Earthquake Early Warning and Emergency Warning Broadcast are performed (“Other Flag” is “0”) In order to know on the receiving side, the receiver 1 to be described later performs a correlation operation with the received signal using “111010011101000001011” having a code length of 21 bits in the first frame, for example. On the other hand, in the second frame, correlation calculation is performed using “010011101001111011000” having a code length of 21 bits. Although there are two time differences for one frame, the correlation calculation is performed on the received AC signal using both the code of the first frame and the code of the second frame, and the code length contributing to the correlation calculation is increased. Thus, the sensitivity of the change in the correlation calculation result can be doubled.

  When the receiver 1 detects the peak value of the correlation coefficient as a result of the correlation calculation, the “emergency earthquake warning start / identification flag” and the “emergency warning broadcast start flag” are “1” and “ Since “other flag” is detected as “0” every 1 frame or every 2 frames, frame synchronization is performed when frame synchronization is not established, and other “various flags (synchronization signals)” Is determined. For example, it is determined whether this broadcast is “training” or “normal” (actual emergency bulletin). Further, it is determined whether it is “normal” (actual emergency bulletin) or “cancel” (cancellation of the bulletin).

  The receiver 1 can also determine the presence or absence of a flag such as “tsunami warning” in the “reserved bit (flag)” when the “other flag” corresponds to “1”.

  The receiver 1 activates the terrestrial digital television broadcast receiver or the AC information analysis unit described later when it is not activated, and stores the emergency message stored following the message information format of the first embodiment. The information of earthquake early warning can be read.

  In the description of FIG. 3, codes assigned to each of the three flags of “emergency earthquake warning start / identification flag”, “emergency warning broadcast start flag” and “other flags” in “various flags (synchronization signal)”. All the columns are the same 7 bits, and each combination of the same “1110100” and “0001011” (the second frame is “0100111” and “1011000”) (a total of 21 bits). It is good.

Further, for example, 21 bits are extracted from a bit string having a 31-bit period generated by a generator polynomial (x ⁵ + x ² +1), for example, “0011101001000010101110”, which is divided into 7 consecutive bits, and 3 bits of the first frame. Each of the two flags may be assigned to “Emergency Earthquake Warning Activation / Identification Flag”, “Emergency Warning Broadcast Activation Flag”, and “Other Flags”. The flag value “0” is the phase inversion. Similarly, in the second frame, a 7-bit code string is created from the continuation and repetition 21 bits of this bit string, “110001111100110100100”.

  Hereinafter, the information of the emergency earthquake bulletin in the message information format of the first embodiment will be described.

  FIG. 2 conveys the area by the area code, and stores a plurality of information about the maximum predicted seismic intensity in the area and the predicted arrival time of the main motion of the earthquake in the area (the message information format in FIG. 2 can store a maximum of 8 information). .) Is a format example for storing and transmitting information for the region. It is assumed that the frame is transmitted by two consecutive frames composed of 204 consecutive bits, and is transmitted repeatedly for a necessary period.

  “Number of districts (total)” describes the total number of districts corresponding to the earthquake early warning. For example, if Hokuriku, Koshin, and Tohoku are the targets, 3 corresponds. Since the regional classification is 14 at the maximum, 4 bits are allocated. On the other hand, “the number of regions (remaining number)” is a value counted down every time one region is displayed, and indicates that there is no data after “0000”.

  “Region ○” (where ○ is a positive integer of 1, 2,..., 8) is a “regional unit” region, and the region codes such as Hokkaido, Tohoku, Kanto, Hokuriku, etc. are set. This is the unit area as described with the example (see Figure 4). In the region code example of FIG. 4, the reason why the region code is not a simple serial number is that it has extensibility. Here, 6 bits are assigned to the area code.

  The “maximum predicted seismic intensity” corresponds to seismic intensity 4 or higher of 4, 5 weak, 5 strong, 6 weak, 6 strong, or 7. “Strong” and “Weak” are distinguished by numerical values 1 and 0, respectively, and each is distinguished by 4-bit “0100”, “0101”, “1101”, “0110”, “1110”, “0111”. To do.

  “Predicted arrival time” is the estimated time at which the main motion of the earthquake will reach the area in units of hours, minutes, and seconds, and “arrival predicted difference time” (simply expressed as “difference time”) is The difference time with the predicted arrival time in the first region. The first region is assumed to be the point where the main motion of the earthquake reaches the earliest, and after the second region, the main motion of the earthquake arrives with a positive delay time.

  On the receiver 1 side, when using the time in seconds obtained by subtracting the current time from the “estimated arrival time” (excluding the first region, the arrival time of the first region is added to the difference time of each region), It can be displayed as the remaining time until the earthquake.

  The “estimated arrival time” is expressed in 12 hours, the hour display is 4 bits, the minutes and seconds are 6 bits, for example, 10:25:37 is “1010 | 011001 | 100101” (total 16 Bit), and binary numbers in units of hours, minutes, and seconds. Note that “|” is inserted only as a notation here to make it easy to see the distinction between hour, minute, and second, and is not inserted in actual transmission.

  The “phase reference” and the “parity bit” are the same as those of the TMCC signal, and in the case of ISDB-T terrestrial digital television broadcasting, based on one symbol of the OFDM method, the DBPSK signal has the same 204 symbols as the TMCC signal. 204 bits are allocated to form one frame. Therefore, the signal of the message information format shown in FIG. 2 is transmitted in two frames of the OFDM signal. The “parity bit” stores, for example, a parity bit for error correction based on a predetermined difference set cyclic code system.

As with the TMCC signal, the “phase reference” is SP (Scattered) of carrier number i.
A value based on the same generator polynomial (x ¹¹ + x ⁹ +1) as the value Wi of the BPSK signal assigned to the (Pilot) signal is applicable. An AC carrier is used for transmission of telegram information in the first embodiment. For example, the AC carrier in the partial reception segment (segment number # 0) of the ISDB-T terrestrial digital television broadcast wave is carrier number # 7, # 89, # 206, # 209 in the case of the mode 3 synchronous modulation unit. , # 226, # 244, # 377 and # 407. Wis stored as the “phase reference” described in the AC information carried by the eight AC carriers are 0, 0, 0, 1, 1, 1, 1 and 1, respectively. Note that a modulation method other than BPSK can be used, and a method to be used in advance on the transmission side and the reception side is determined together with the above-described difference set cyclic code method.

  Therefore, the transmitting apparatus according to the first embodiment of the present invention uses such telegram information (the telegram information format shown in FIG. 2), so that an emergency alert that can be detected regardless of the establishment of frame synchronization on the receiving side. Information on the presence or absence of broadcast or earthquake early warning (information related to activation / identification) can be transmitted to the receiver 1, and “how much earthquake of magnitude / seismic intensity will occur when the receiver 1 described below is required. "Can be promptly and reliably performed.

  Next, the receiver of Example 1 by this invention is demonstrated.

  As described above, on the transmission side, as telegram information including the earthquake early warning (format of telegram information shown in FIG. 2), for example, synchronization signals are sent to eight AC carriers in a partial reception segment of digital terrestrial television broadcasting. Also, “Earthquake Early Warning Start / Identification Flag” that identifies the presence or absence of an Earthquake Early Warning, “Emergency Warning Broadcast Start Flag” that identifies the presence or absence of an emergency warning broadcast, a region code that identifies multiple regions, Emergency early warning including maximum predicted seismic intensity and predicted arrival time in each region is transmitted with parity code for error correction.

  The receiver 1 of Example 1 by this invention receives the format of the message | telegram information shown in FIG. Here, the receiver 1 can be included in any device such as a mobile phone, a personal digital assistant (PDA), a wristwatch, a table clock, a personal computer, or a home appliance.

  FIG. 5 is a block diagram of the receiver 1 according to the first embodiment. The receiver 1 according to the first embodiment includes an antenna 5, an AC receiver 2, an AC information analyzer 3, a synchronization holding / power controller 4, a warning generator 22, a power circuit 21, and an AC receiver 2. A first power switch 19 for switching the power supply to the AC information analysis unit 3, and a second power switch 20 for switching the power supply to the AC information analysis unit 3.

  The AC reception unit 2 includes a frequency conversion circuit 6, an AD conversion circuit 7, an FFT 8, an AC extraction circuit 9, a correlation calculation circuit 10, a start flag detection circuit 11, and a frame synchronization detection circuit 12. .

  Further, the AC information analysis unit 3 includes an error correction circuit 16, an AC decoding circuit 17, and an information processing circuit 18.

  The information processing circuit 18 may further include a position detection unit and a current time detection unit.

  The synchronization holding / power control unit 4 includes a frame synchronization holding circuit 13, a timing control circuit 14, and an activation flag monitoring circuit 15.

  Hereinafter, the function of each component of the receiver 1 shown in FIG. 5 will be described.

  The frequency conversion circuit 6 removes unnecessary frequency components from the digital terrestrial television broadcast wave input from the antenna 5 using a predetermined filter, selects a designated channel, converts the frequency into an intermediate frequency signal, and appropriately converts the frequency. This circuit amplifies and outputs. This channel selection can also be predetermined by the receiver.

  The AD conversion circuit 7 converts the intermediate frequency signal output from the frequency conversion circuit 6 into digital, and sends out a digital baseband signal.

  The FFT 8 performs an FFT (Fast Fourier Transform) operation on the effective symbol period of the OFDM symbol, and demodulates it into an OFDM format stream. The effective symbol period can be defined by performing symbol synchronization by guard interval correlation or the like, and performs an FFT operation at an FFT sample frequency according to a predetermined transmission mode.

  The AC extraction circuit 9 extracts an AC carrier from the OFDM format stream, performs delay detection from the DBPSK wave, performs 0 or 1 level determination, and obtains a bit stream of the AC signal. The correlation calculation circuit 10 is supplied with an AC signal immediately after delay detection from an AC carrier or DBPSK wave extracted from an intermediate OFDM format stream. The bit stream of the AC signal whose level is determined is supplied to the AC information analysis unit 3.

  Also, when diversity transmission is performed using eight AC carriers, each corresponding signal is received and extracted, and then added before level determination in the AC extraction circuit 9 or before input to the correlation calculation circuit 10. As a result, signal reception performance can be improved and reliable transmission can be realized.

  Correlation calculation circuit 10 receives an AC signal after delay detection from an AC carrier or DBPSK wave extracted from an OFDM stream (or an AC signal after addition synthesis in the case of diversity reception), and is necessary for flag determination Correlation calculation is performed using N-bit correlation code strings for various systems.

  Here, there are several patterns in the N-bit correlation code string for the system necessary for flag determination, depending on the setting conditions. In terms of the main conditions, there are three flags, “Earthquake Early Warning This corresponds to a code string for each combination of “start / identification flag”, “emergency warning broadcast start flag”, and “other flags”. FIG. 6 shows a combination example of each flag and a correlation code string for the first frame (the second frame is in parentheses). In the figure, all combinations for the three flags are presented, but combinations that are not used for actual transmission are included.

  FIG. 7 shows an embodiment of the correlation calculation circuit 10.

  In this case, among the combinations of the three flags in FIG. 6, the range of the combination in which the emergency warning is implemented is (1) emergency warning broadcast only (code string pattern 1), (2) emergency warning broadcast and other (code It is assumed that there are four patterns of column pattern 2), (3) only the earthquake early warning (code string pattern 3), and (4) none (code string pattern 4).

  The correlation calculation circuit 10 illustrated in FIG. 7 includes four systems of sliding correlation calculation units 101, 102, 103, and 104, and four systems of memories 101a, 102a, and 104 that store pattern sequences corresponding to four types of code sequence patterns, respectively. 103a and 104a, and after the input AC signal is distributed to four systems, each of the sliding correlation calculation means 101, 102, 103, and 104 and the corresponding four systems of memories 101a, 102a, 103a, and 104a, respectively. "Flag 1", "flag 2", "flag 3" and "flag 4" which are four types of correlation coefficients are calculated and output based on the information of the code string patterns 1 to 4 read out from.

  Each of the sliding correlation calculation means 101, 102, 103, and 104 performs a correlation calculation every time one symbol is advanced, and outputs a correlation coefficient calculation result (see FIG. 8A).

  Here, for example, the waveform data of an AC signal of one sample transmitted by one symbol is expressed by an 8-bit numerical value, and the amplitude phase characteristic of the AC carrier received by the influence of propagation on the receiving side is reflected. Consider performing a correlation operation on bit sample values.

  In addition, there is a time difference of one symbol at the input / output per stage (data that is held one symbol at a time triggered by a symbol clock that is phase-synchronized with a frame synchronization holding circuit described later is shifted between registers). Consider a case where a shift register (not shown) is used. Therefore, in the case of 8 bits, 8 multistage shift registers having the number of stages corresponding to the length of the symbol string for which the correlation operation is performed are used. The shift timing for each symbol of the 8-system multistage shift register is controlled in synchronization with the symbol period, and the input / output of each system is always in the order from a predetermined most significant bit to the least significant bit. Is maintained.

  Here, the length of the symbol string for which correlation calculation is performed is the length of the code string given to the flag shown above, and in the case of only the first or second frame (the code shown in FIG. 8A). It is 21 in the columns 200, 200 ′). At this time, there are 20 shift registers. Similarly, when the correlation calculation is performed across the first frame and the second frame (code strings 201 and 202 illustrated in FIG. 8B), the length of the symbol string of the correlation calculation is 21 + 204 = 225, The number of stages of the shift register is 224. However, the first 21 stages and the last 21 stages contribute to the correlation calculation (see FIG. 8B).

  For this reason, each of the sliding correlation calculation means 101, 102, 103, and 104 incorporates eight systems of 20-stage (or 224-stage) multistage shift registers, and each input of each shift register and each output of each stage. Represents an 8-bit numerical value for each of the 8 systems. The 8-bit numerical value output from each stage of the shift register corresponds to the symbol delay of the output of each stage of the multistage shift register, and the value of each bit of the code string stored in the code string pattern memory Based on the above, the sign of each 8-bit value is inverted (or non-inverted), and then the total number of stages is added. The inversion of positive and negative is based on 2's complement, and a margin of plus 4 to 8 bits is allowed in the process of operation.

  Therefore, each of the sliding correlation calculation means 101, 102, 103, 104 is used when the input code string pattern matches the code string pattern in the memory and the phase (time) at the time of calculation matches (autocorrelation). A peak value is output, and if the code string pattern does not match or there is a shift in the phase (time) of the code string pattern, a value near 0 is output.

  Each of the four systems of sliding correlation calculation means 101, 102, 103, 104 performs a correlation calculation for each symbol in accordance with code string patterns 1 to 4 output from different code string pattern memories, and outputs a result.

  The sliding correlation calculation means 101 connected to the code string pattern 1 outputs a peak value to the calculation result of the correlation coefficient when only the flag value of the “emergency warning broadcast activation flag” is “1”. The correlation coefficient calculation result is input to the next-stage activation flag detection circuit 11 as a “flag 1” signal. Similarly, the sliding correlation calculation means 102 connected to the code string pattern 2 calculates the correlation coefficient when the flag values of “emergency warning broadcast activation flag” and “other flags” are all “1”. The peak value is output to the result.

  The correlation coefficient calculation result is input to the next-stage activation flag detection circuit 11 as a “flag 2” signal. The sliding correlation calculation means 103 connected to the code string pattern 3 generates a peak value in the calculation result of the correlation coefficient when only the flag value of the “emergency earthquake warning start / identification flag” is “1”. The correlation coefficient calculation result is input to the next-stage activation flag detection circuit 11 as a “flag 3” signal. Then, the sliding correlation calculation means 104 connected to the code string pattern 4 has a flag value “0” for any of the “emergency earthquake warning start / identification flag”, “emergency alarm broadcast start flag”, and “other flags”. In the normal state, the peak value is generated in the correlation coefficient calculation result. The correlation coefficient calculation result is input to the next-stage activation flag detection circuit 11 as a “flag 4” signal.

  FIG. 9 shows a calculation example of the “flag 1” signal in one embodiment of the correlation calculation circuit 10.

  As shown in FIG. 9 (a), the output signal of the “flag 1” signal subjected to the sliding correlation calculation based on the code string pattern 1 (21 bits in total) for detecting the “emergency warning broadcast activation flag” A 21-bit code string indicating that the “emergency warning broadcast activation flag” is “1” and that the “emergency earthquake early warning activation / identification flag” and the “other flags” are “0” is transmitted. In this case, peak values are observed at the 21st sample (= 21st symbol) and the 429th sample when the “phase reference” sample of the first frame is the 0th sample (= 0th symbol). The interval at which is observed is 2 frames (= 408 symbols). On the other hand, as shown in FIG. 9B, when any of the flags in normal times is “0”, no particularly prominent peak value is observed in the output signal of the “flag 1” signal.

  As shown in the correlation coefficient calculation result of FIG. 9, when the technique disclosed in the present invention is used, the detection of frame timing and the detection of various flags can be performed simultaneously.

  As shown in FIG. 9C, when the length of the code string pattern is long, the correlation coefficient when the code strings do not match can be suppressed smaller than when the code string pattern is short, and Since it can be increased when they match, it is effective to use a 224-stage sliding correlation calculation means that uses the calculation of correlation coefficients over two frames.

  FIG. 10 shows an embodiment of the activation flag detection circuit 15.

  The activation flag detection circuit 15 shown in FIG. 10 includes four systems of level determination units 151, 152, 153, and 154 and three types of OR adders 155, 156, and 157. Each of the level determiners 151, 152, 153, and 154 has a threshold value that determines the amplitude value of the input signal in advance for each symbol (determines that the peak value of the calculation result of the correlation coefficient is “1”). By comparing, “1” and “0” are determined, and the symbol period for detecting the peak value is output. The OR adders 155, 156, and 157 perform an OR operation and output the operation result. Note that the OR operation referred to here is the following operation.

  0 + 0 = 0, 0 + 1 = 1, 1 + 0 = 1, 1 + 1 = 1

  Therefore, the activation flag detection circuit 15 inputs the four flag detection signals “Flag 1” to “Flag 4” output from the correlation calculation circuit 10, and outputs the four system level determination units 151, 152, 153, 154. Each determines whether the flag value of each signal is “1” or “0”, and each of the following three OR adders 155, 156, and 157 “emergency warning broadcast activation flag”, The signals corresponding to the functions of the “emergency earthquake warning start / identification flag” and “other flags” are separated into signals for (emergency warning broadcast) of the activation flag monitoring circuit 15 and the activation flag monitoring circuit 15 Signals for (Earthquake Early Warning, etc.) and signals for synchronization detection of the frame synchronization detection circuit 12 are converted, and each signal is output to the corresponding circuit.

  Here, the signal for the (emergency warning broadcast) of the activation flag monitoring circuit 15 receives the output of the level determination unit 151 of the “flag 1” signal and the output of the level determination unit 152 of the “flag 2” signal, and When the flag value of the “emergency warning broadcast activation flag” is “1”, which is an output of the OR adder 155 that performs a logical sum operation, “1” is output for a predetermined symbol period. A terrestrial digital television broadcast receiver provided separately in the terminal of the receiver 1 through the activation flag monitoring circuit 15 (refers to a receiver for viewing a program (not shown). In the case of incorporating the receiver 1 of the present invention, A power switch (not shown) that switches the power supply that activates the terrestrial digital television broadcast receiver when the terrestrial digital television broadcast receiver is not activated. Control signal.

  As for the signal for the emergency flag (Earthquake Early Warning, etc.) of the activation flag monitoring circuit 15, the output of the level determination unit 152 of the “flag 2” signal and the output of the level determination unit 153 of the “flag 3” signal are input, and the logical sum When the flag value indicated by the “emergency earthquake warning start / identification flag” or “other flag” is “1”, which is an output of the OR adder 156 that performs an operation, “1” is output for a predetermined symbol period. . This is input to the activation flag monitoring circuit 15 and contributes to the control of the first power switch 19 and the second power switch 20.

  As the signal for synchronization detection of the start flag monitoring circuit 15, the outputs of the level determiners 151, 152, 153, and 154 with respect to all the inputs of the “flag 1” signal to the “flag 4” signal are input, respectively, and an OR operation is performed. The output of the OR adder 157 and input to the frame synchronization detection circuit 12. In every combination of flags, every two frames or one frame (however, this depends on the N-bit code string and the configuration of the correlation calculation circuit 10. For example, the code string in FIG. When the code string pattern is used, the flag value is “1” at the last symbol of “various flags (synchronization signal)”.

  The frame synchronization detection circuit 12 receives the output of the synchronization detection signal from the activation flag detection circuit 11 and generates the generation period of the flag value “1” detected every two frames or every frame in the output of the activation flag detection circuit 11. For example, a frame synchronization signal (reset pulse) is generated at the start timing of the frame of the AC signal. Further, emergency breaking synchronization establishment information indicating whether or not emergency breaking frame synchronization is established is generated based on the frame synchronization signal.

  The timing control circuit 14 and the frame synchronization holding circuit 13 in the synchronization holding / power control unit 4 are always supplied with power from the power supply circuit 21.

  The frame synchronization holding circuit 13 is composed of, for example, a clock generator and a counter. The clock generated by the clock generator is counted by the counter, and a frame pulse is generated every time the count value reaches a predetermined value and the count value is frame-synchronized. Reset is performed according to the signal (reset pulse), and the frame pulse is supplied to the timing control circuit 14. Thereby, the frame synchronization holding circuit 13 can generate a self-held frame pulse.

  Based on the frame pulse from the frame synchronization holding circuit 13 and the emergency early warning synchronization establishment information from the frame synchronization detection circuit 12, the timing control circuit 14 is either an inter-frame intermittent reception mode described later or an intra-frame intermittent reception mode, Alternatively, the intermittent reception mode of these combinations is arbitrarily determined, and an on / off (0 or 1 value) control signal is transmitted at the timing of each intermittent reception mode.

  The start flag monitoring circuit 15 is provided with two types of flag signals from the start flag detection circuit 11 (in this embodiment, mainly “emergency alarm broadcast start flag” and “emergency earthquake warning start / identification flag” or “other flags”. )) And the timing of the control signal from the timing control circuit 14 (the leading symbol of the N-bit code string of “various flags (synchronization signal)” following “phase reference”), the values of the various flags ( Monitor the result of the correlation operation.

  The start flag monitoring circuit 15 starts the emergency alert broadcast from the state where the signal value related to the “emergency alert broadcast start flag” among the various flag signals of the two systems input from the start flag detection circuit 11 is “0” in normal times. Whether or not the flag value is changed to “1” indicating that there is, and if the flag value of “1” is determined, the receiver of the digital terrestrial television broadcasting separately provided in the terminal of the receiver 1 A control signal based on the flag value is transmitted to the above-mentioned receiver for viewing a program (not shown). That is, when the terrestrial digital television broadcast receiver is not activated, the power switch for switching the power supply to activate the terrestrial digital television broadcast receiver is turned on, and the terrestrial digital television broadcast Enables the receiver to receive emergency alert broadcasts. In addition, when the receiver of the terrestrial digital television broadcast is watching another broadcast that does not receive the emergency alert broadcast, the emergency alert broadcast can be received according to the conditions set based on the selection by the user of the receiver in advance. Controls the channel switch for switching to the channel.

  On the other hand, when the activation flag monitoring circuit 15 determines that the flag value “1” indicating that there is an emergency warning broadcast is changed to the normal “0” state, the timing control circuit 15 When the receiver of the terrestrial digital television broadcast is activated so that only the flag values of various flags are constantly monitored at the timing of the control signal from 14, based on the selection by the user of the receiver reserved in advance. The power supply to the terrestrial digital television broadcast receiver is cut off. In addition, when the channel of the terrestrial digital television broadcast receiver is switched to a channel capable of receiving the emergency alert broadcast, the channel is received before receiving the emergency alert broadcast based on the selection by the user of the receiver. Switch the channel to the selected channel.

  On the other hand, the activation flag monitoring circuit 15 indicates that the value of the signal relating to the “emergency earthquake early warning activation / identification flag” or “other flag” among the two types of flag signals input from the activation flag detection circuit 11 is normal. When the flag value of “1” is determined by monitoring whether the flag value is changed from “0” to “1” indicating that there is an earthquake early warning or other emergency early warning In this case, the intermittent reception mode is canceled, the first power switch 19 is switched so that the power supply to the AC reception unit 2 is continuously performed, and the power supply to the AC information analysis unit 3 is performed. The second power switch 20 is switched to decode information of various other flags included in the AC signal and telegram information such as an emergency earthquake warning.

  At this time, the normal startup flag monitoring circuit 15 switches on / off of the first power switch 19 based on the control signal from the timing control circuit 14 to control the power supply of the AC receiver 2. In addition, the activation flag monitoring circuit 15 turns off the second power switch 20 in a normal state to cut off the power supply to the AC information analysis unit 3.

  On the contrary, the activation flag monitoring circuit 15 determines that the flag value “1” indicating that there is an emergency earthquake warning or other emergency warning is changed to the normal “0” state. Controls the power supply to the AC receiver 2 by the first power switch 19 so that only the flag values of the various flags are constantly monitored at the timing of the control signal from the timing control circuit 14, and the AC information analysis The second power switch 20 is switched so as to cut off the power supply to the unit 3.

  In this way, the activation flag monitoring circuit 15 operates so as to constantly monitor only the flag values of various flags in normal times.

  As a result, it is possible to reliably and immediately obtain emergency bulletin information while significantly saving power consumption.

  The activation flag monitoring circuit 15 may be controlled to supply power to the AC information analysis unit 3 in the intra-frame intermittent reception operation or the inter-frame intermittent reception operation so as to acquire only all the information of the emergency early warning. it can. In particular, when operating in the inter-frame intermittent reception operation, the error correction circuit 16 can be operated so as to send the result of majority decision between a plurality of frames.

  The AC information analysis unit 3 uses the frame synchronization signal generated by the frame synchronization detection circuit 12 (that is, the output of the frame synchronization holding circuit 13 in FIG. 5) when power is supplied to the AC information analysis unit 3. Synchronously, the error correction circuit 16 corrects the error of the AC signal, and the AC decoding circuit 17 decodes the contents after the various flags (telegram information of the AC signal) in a decoding format corresponding to the encoding method on the transmission side, The information of the emergency earthquake bulletin stored in the other information of the flag and the message information of the AC signal, that is, the contents of the “emergency earthquake bulletin” is output.

  When the “other flag” is a code string indicating “1”, for example, when a “tsunami” warning is issued, the information processing circuit 18 creates a message such as “emergency warning broadcast (tsunami warning)”, for example. Then, viewing of the emergency warning broadcast based on the tsunami warning is displayed on the warning generation means 22 to notify the user of the receiver 1.

  When the “emergency earthquake early warning start / identification flag” is a code string indicating “1”, the information processing circuit 18 is based on the “emergency earthquake early warning” output from the AC decoding circuit 17, for example, “emergency earthquake early warning”. Create a message such as “Earthquake Early Warning: Beware of Strong Shakes in XX Areas” or “Emergency Earthquake Early Warning: Magnitude △△ Strong Earthquake in XX Prefecture. Beware of Strong Shakes”.

  In the case where the telegram information is set so as to be received in the synchronous modulation mode of mode 3 in the partial reception segment of the ISDB-T terrestrial digital television broadcast wave, the eight emergency bulletins with the same contents are provided. In the case where it is preliminarily specified to be transmitted by an AC carrier, the AC decoding circuit 17 obtains diversity gain in the AC extraction circuit 9 or the error correction circuit 16 in the same manner as the correlation calculation circuit 10 performs. Therefore, the emergency bulletin can be decoded from the eight AC carriers.

  Alternatively, when the telegram information includes a parity bit of a predetermined difference set cyclic code system, the error correction circuit 16 performs error correction based on the difference set cyclic code system, and the AC decoding circuit Then, the emergency bulletin is decoded.

  As described above, in the receiver 1 according to the present invention, various modes of detecting or correcting AC information errors and decoding can be considered, and will be collectively described as “decoding means”.

  In the case of “Emergency Earthquake Early Warning” from the decoded emergency early warning, the information processing circuit 18 may calculate prediction information of seismic intensity and arrival prediction time in each region. For example, based on the area code, predicted seismic intensity information and predicted arrival time information, and current position and current time information in emergency bulletin, calculate the seismic intensity and predicted arrival time prediction information for the area where the receiver is located. Create a bulletin of emergency bulletin specialized for the machine 1.

  In this case, the information processing circuit 18 can also be configured to include position detection means as means for obtaining the current position and current time detection means as means for obtaining the current time (not shown).

  The position detection means detects position information representing the regional position of the receiver. Preferably, in the fixed reception, the position detection means is input by the user of the receiver at the time of installation, position detection by GPS (Global Positioning System), or NIT included in the received signal of the terrestrial digital television broadcast wave being received. For mobile or mobile reception, such as identification of a broadcast station based on (Network Information Table) (network identification), or the like, or identification of a broadcast station based on NIT included in a received signal of terrestrial digital television broadcast, In the case of a mobile phone, its own position can be detected from base station information, in the case of a wireless LAN, hot spot information (including a manual location input if the location can be recognized), and the like.

  The current time detection means detects current time information indicating the current time of the receiver. Preferably, the current time detection means includes a time setting by a user input of the receiver, a standard radio wave (radio clock, JJY), GPS, or a TDT (Time signal included in a received signal of a terrestrial digital television broadcast wave received. Current time information can be detected from (Date Table) or the like. Alternatively, the current time detection means can detect the current time based on a signal from the base station when the receiver is provided in a mobile phone.

  The warning generation means 22 presents a quick report sentence extracted and created by the information processing circuit 18. For example, when the receiver has a text display, the warning generation means 22 presents “Emergency Earthquake Early Warning (Japan Meteorological Agency): Beware of strong shaking. When the receiver has a speaker, it outputs a sound that reads out a similar quick report along with an alarm sound. Further, when the receiver 1 has a vibrator, a vibration warning is issued so that a warning is perceptually generated in an operation different from that in the normal operation, or attention is given to a display or a speaker (not shown) by the vibration warning. . Alternatively, when the receiver 1 is provided in any device such as a mobile phone, a personal digital assistant (PDA), a wristwatch, a table clock, a personal computer, etc., it generates sound from a speaker using the functions of these devices. It is also possible to generate a vibration warning by a vibrator, or to generate a warning perceptually by an operation different from that during normal operation.

  Here, the interframe intermittent reception mode and the intraframe intermittent reception mode will be described.

  If the intermittent reception mode is used, the power consumption of the receiver can be significantly reduced.

  Further, in order to improve the reliability of AC signal synchronization establishment, the inter-frame intermittent reception mode can be preferably used. Alternatively, the intra-frame intermittent reception mode can also be used to detect an error and make a majority decision even when the AC signal synchronization is reliable.

  The inter-frame intermittent reception mode is determined, for example, when emergency early warning synchronization establishment information indicating that AC signal synchronization is not established is supplied. In this case, the ON duration of the first power switch is at least one frame. For example, when only one frame is used, the power consumption of the receiver 1 can be greatly reduced. Furthermore, for example, when two frames are used, the reliability of the received signal can be improved by using even parity. Alternatively, for example, when 3 frames are used, it is possible to improve the reliability of the received signal by making a majority decision.

  It should be noted that since odd frames (the above-mentioned first frame) and even frames (the second frame) can be received separately, it is preferable that the corresponding correlation code strings are different. Further, the determination based on the even parity or the majority determination can be performed based on whether or not a peak value appearing as a result of the correlation coefficient by each code string is detected.

  If the transmission mode of terrestrial digital television broadcasting is mode 3 and the guard interval ratio (GI ratio) is 1/8, one frame is 231.336 msec. In the inter-frame intermittent reception mode, there is no restriction on the power-on timing of the AC receiver 2, and for example, the on / off interval is set to a predetermined value (for example, every 10 seconds).

  Thus, by setting the power supply time to the AC receiver 2 when the AC signal synchronization is not established to be one frame or longer, it is possible to prevent the AC signal from being missed and to improve the reliability of the received signal. it can. In addition, standby power consumption can be reduced by increasing the on / off interval.

  The intra-frame intermittent reception mode is determined, for example, when emergency early warning synchronization establishment information indicating that AC signal synchronization is established is supplied. In this case, the ON duration of the first power switch is, for example, 30.618 msec = (27/204) frame, the power is turned on from the last symbol of the frame before the AC signal, and the required bits, for example, “various” When the last symbol of the “flag (synchronization signal)” is received, the power is shut off.

  Thus, the standby power consumption can be reduced by setting the power supply time to the AC receiver 2 at the time of establishment of synchronization of the AC signal to 27 symbols.

  Hereinafter, the receiving operation of the receiver according to the first embodiment of the present invention will be described in more detail.

  First, the receiver 1 according to the first embodiment performs symbol synchronization by the guard interval correlation or the like from the OFDM signal received in the selected channel by the AC receiver 2, and extracts the AC signal through the FFT operation.

  Furthermore, the receiver 1 according to the first embodiment uses the AC receiver 2 based on “various flags (synchronization signal)” multiplexed in the AC signal included in the message information (format of the message information shown in FIG. 2). AC signal frame synchronization is performed.

  Then, according to the timing obtained based on the frame synchronization, the receiver 1 of the first embodiment includes an AC signal from an AC carrier to be DBPSK demodulated, included in the telegram information (the format of the telegram information illustrated in FIG. 2), By correlation calculation with the correlation code string based on the combination of each flag of “Emergency Warning Broadcast Start Flag”, “Emergency Early Warning Start / Identification Flag” and “Other Flags” in “Various Flags (Synchronization Signals)” The activation flag monitoring circuit 15 monitors the peak value of the detected correlation coefficient.

  When the “emergency warning broadcast activation flag” is “1”, the receiver 1 performs the terrestrial digital television broadcast when the receiver for the terrestrial digital television broadcast (not shown) provided in the receiver 1 is not activated. The power switch for switching the power supply for starting the broadcast receiver is turned on, and the emergency digital terrestrial broadcast receiver can receive the emergency warning broadcast.

  In addition, when the receiver of the terrestrial digital television broadcast is watching another broadcast that does not receive the emergency warning broadcast, the receiver 1 is urgent according to the conditions set in advance based on the selection by the user of the receiver. Controls the channel switch for switching to a channel that can receive alarm broadcasts.

  On the other hand, when the “emergency earthquake early warning start / identification flag” or “other flags” is “1”, the receiver 1 receives the subsequent telegram information by the AC information analysis unit 3 and the remaining “various flags ( "Synchronization signal)" flag is checked, and when "Other flag" is "1", it is set in the "Tsunami" flag ("Reserved bit (flag)" in "Various flags (synchronization signal)" in Fig. 3) ) Is “1”, the AC information analysis unit 3 creates a quick report to alert the “tsunami warning” and the warning generation means 22 causes the receiver 1 (or the reception) Display on the display device of the device equipped with the machine 1). Alternatively, at the same time, a warning sound and / or sound is emitted from a speaker included in the receiver (or a device including the receiver).

  The receiver 1 first recognizes the area code when the “emergency earthquake warning start / identification flag” is “1”.

  On the other hand, the receiver 1 can have position detecting means for detecting position information indicating the regional position of the receiver 1, and can recognize its own position.

  In addition, the receiver 1 can have a current time detecting unit that detects current time information indicating the current time of the receiver 1, and can recognize the current time.

  The receiver 1 acquires seismic intensity information and predicted arrival time that are subsequently read out when the position of the receiver itself matches or is included in the area described in the area code.

  Subsequently, the receiver 1 uses the information processing circuit 18 to calculate the difference between the acquired predicted arrival time and the current time.

  Then, the receiver 1 converts the calculated seismic intensity information and the time difference from the current time of the predicted arrival time into text characters by the warning generation means 22, and receives the receiver 1 (or a device including the receiver 1). Is displayed on the display. Alternatively, at the same time, a warning sound and / or a sound is emitted from a speaker included in the receiver 1 (or a device including the receiver 1). From these displays or sounds, the user of the receiver 1 can know the occurrence of the earthquake and the predicted time. Note that the method of generating a warning is not limited to these, and there is a method of mimicking a second hand of an analog clock.

  The telegram information format of FIG. 2 transmits information of up to eight regions by two frames with 204 symbols as one frame. In the case of ISDB-T terrestrial digital television broadcasting mode 3 and a guard interval ratio of 1/8, since the length of one frame is 0.231 seconds, it takes at least 0.5 seconds to receive these two frames. Some degree of time is required.

  Even if the earthquake early warning is issued and the broadcast station puts it on the radio wave and the timing of transmission and reception is taken into account, transmission from the broadcast station, detection of various flags (synchronization signals) at the receiver, emergency early warning Can be read out in about 2 to 3 seconds, and prompt earthquake early warning transmission is possible.

  Furthermore, if the two-frame telegram information format is divided into two sets of AC carriers and each of them is transmitted in the same frame, 0.2-0. The time of about 5 seconds can be shortened.

  On the other hand, it is possible to transmit the information related to the same earthquake early warning on each of the 8 or 4 AC signal lines on the transmitting side, and perform DBPSK demodulation on all carriers on the receiving side and perform majority determination after level judgment or analog By combining the amplitude levels and determining the level, diversity gain is obtained, reception with lower received power is possible, and reliable transmission is possible.

  Furthermore, correlation coefficients are calculated using correlation code sequences corresponding to odd frames and even frames, and the correlation peak values of “various flags (synchronization signals)” are monitored over two frames. By doing so, the reliability of the received various flags can be increased. Alternatively, the correlation peak value of “various flags (synchronization signal)” is monitored over three frames, and the reliability of the received various flags can be increased by determining the majority of the results.

  In the 204-bit transmission, 82 bits are parity bits. For example, as with the TMCC signal of the ISDB-T system, the number of target bits is different, but by performing error correction encoding using a shortened code of the difference set cyclic code (273, 191) and the like, Since at least 8-bit error correction is possible, the reliability can be further increased.

  As described above, when the receiver 1 is applied to a mobile phone that receives, for example, an ISDB-T terrestrial digital television broadcast wave, the mobile phone is in standby mode in order to save power. It is necessary to start up the receiver 1 promptly at the timing when the emergency warning broadcast or the earthquake early warning is issued with less power.

  In the receiver 1 according to the present embodiment, in the case of the message information format of FIG. 2, the power is supplied to the AC receiver 2 of the receiver 1 that functions as an emergency early warning detection at the last bit of one frame after frame synchronization is established. Since the power is turned off at the last bit (26th bit) of the “various flags (synchronization signal)”, even lower power consumption can be realized.

  Therefore, with the configuration of the receiver 1 according to the first embodiment, when an emergency warning, particularly an earthquake early warning is issued, the AC receiver 2 is continuously turned on, and the AC information analyzer 3 is immediately turned on. By doing so, the information based on the earthquake early warning can be promptly transmitted to the user of the receiver 1.

  Next, a transmitter and a receiver according to a second embodiment of the present invention will be described.

(Example 2)
The components of the hardware of the transmission apparatus and receiver according to the second embodiment of the present invention are the same as those of the first embodiment, but the aspect of the message information format is different. The operation is different. Therefore, a more detailed description of the same components as those in the first embodiment is omitted. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  The message information format of the first embodiment presents a case in which the corresponding area, seismic intensity, and predicted arrival time are directly communicated in the message information transmitted by the transmitting device, particularly the message information at the time of the earthquake early warning. In this case, the earthquake early warning can be transmitted promptly while suppressing the load on the receiver, but the regional framework cannot be communicated more precisely than a certain level. Further, since transmission by two frames is required, the delay is increased or reception power necessary for transmission is increased as compared with the case of transmitting by only one frame.

  Therefore, it is desirable that the receiver 1 has a message information format that assumes that arithmetic processing for predicting seismic intensity and arrival time shown in Non-Patent Document 1, for example, can be executed without a large load. In other words, it is desirable to reduce the message information of the emergency bulletin to be transmitted, and to set the message information format that allows transmission of message information limited to one frame.

  Therefore, in Example 2, another message information format is presented. FIG. 11 shows a format example of the telegram information in the second embodiment when the receiver calculates the maximum predicted seismic intensity and the predicted arrival time. Note that the receiver of the second embodiment can be installed in any device such as a mobile phone, a personal digital assistant (PDA), a wristwatch, a table clock, a personal computer, or a home appliance as in the first embodiment.

  FIG. 11 shows a format for storing and transmitting information on the occurrence time of an earthquake, the position of the epicenter (latitude, longitude, depth) and magnitude information.

  Here, the “phase reference” is the same as that used in the message information format of FIG. Here, since the contents including the operation are the same, detailed description is omitted.

  “Various flags (synchronization signals)” represent the main part of the transmission / reception method of the activation flag for receiving the emergency bulletin disclosed in the present invention, “emergency warning broadcast activation flag”, “emergency earthquake bulletin activation / identification This is an N-bit code string that presents information such as “flag”, “other flags”, “normal” / “training” identification, and “cancel” for emergency bulletin. Also in the second embodiment, the same “various flags (synchronization signals)” (FIG. 3) used in the message information format of FIG. 2 of the first embodiment can be used.

However, another format example is shown here. Of the 26-bit “various flags (synchronization signal)” code string, 21 bits corresponding to an N-bit code string are obtained from, for example, a 31-bit bit string generated by a generator polynomial (x ⁵ + x ² +1). In this example, only 21 bits are extracted. This case is shown in FIG. The bit string “001101001000010101110” is divided into 7 consecutive bits, and each of three flags, ie, “emergency earthquake warning start / identification flag”, “emergency warning broadcast start flag”, and “other flags” The value is “1”. The flag value “0” is obtained by inverting each phase.

  The remaining flags of “various flags (synchronization signals)” are the same as those in the message information format of FIG. That is, there are 1 bit each for “normal” / “training” identification, “cancel” for emergency bulletin, and 3 bits for “reserve bit (flag)”. Since this is the same as in the first embodiment, detailed description thereof is omitted.

  In the second embodiment using the message information format of FIG. 11, only the message information format for one frame is shown because the required emergency bulletin can be transmitted in one frame. However, the “various flags (synchronization signal)” may be transmitted separately as the first frame and the second frame, or the odd frame and the even frame. Further, for example, a 21-bit code string or a 26-bit code string may be collectively inverted in phase.

  Further, unless the contents of the “various flags (synchronization signal)” are changed, that is, unless an emergency bulletin is announced, the same information is repeatedly transmitted in the message information format of FIG.

  Hereinafter, items characteristic of the second embodiment will be described.

  “Earthquake occurrence time” is the time when the earthquake occurred, estimated after the P-wave observation, and transmitted to the broadcasting station by the general earthquake early warning, in units of month, day, hour, minute, second Communicate the displayed value.

  The time of “Earthquake occurrence time” is displayed as 24 hours, the month is displayed as 4 bits, the day is displayed as 5 bits, the hour is displayed as 5 bits, and the minutes and seconds are displayed as 6 bits. On the third day, 13:25:37, “0001 | 00101 | 01101 | 011001 | 100101” (26 bits in total) is displayed as a binary number in units of month, day, hour, minute, and second. Note that “|” is inserted only as a notation here in order to make it easy to see the distinction between month, day, hour, minute, and second, and is not inserted in actual transmission.

  “Latitude of the epicenter” and “longitude of the epicenter” represent the position of the epicenter on the ground surface. For example, latitude and longitude expressed with 1/10 degree accuracy such as 36.3 degrees north latitude and 136.5 degrees east longitude. Longitude. These are expressed as a numerical value of 10 times excluding the decimal point, with north latitude and east longitude being positive values, south latitude and west longitude being negative values.

  Therefore, in the case of the message information format of the second embodiment, the “seismic latitude” and “seismic longitude” are 363 and 1365, respectively, and 12 bits are assigned to each in binary numbers such as “000101101011” and “010101010101”. To express. Note that the negative value of south latitude or west longitude is a one's complement. For example, 36.3 degrees south latitude is expressed as “111010010100”.

  The “depth of the epicenter” is the depth of the epicenter from the ground surface, and is expressed as a numerical value with the unit [km]. For example, in the case of 30 km, it is 30, and is represented by a 10-bit binary number “0000011110”.

  “Magnitude” is a magnitude value indicating the magnitude of the earthquake, and is a numerical value with one decimal place, for example, 3.5. This is expressed as a 10-fold numerical value. In the format of the message information in the second embodiment, it is 35, and it is assumed to be an 8-bit binary number “00010011”.

  The message information format of the second embodiment using the message information format of FIG. 11 is an AC carrier in a partial reception segment (segment number # 0) of an ISDB-T terrestrial digital television broadcast wave, for example, synchronous modulation in mode 3 In the case of a copy, the same information is copied to each of eight 204 symbols and one frame of carrier numbers # 7, # 89, # 206, # 209, # 226, # 244, # 377 and # 407, respectively. And transmit.

  In the message information format of the first embodiment, information is stored and transmitted in a form of 408 symbols, that is, divided into two frames, so that the mode 3 of the ISDB-T terrestrial digital television broadcasting and the guard interval ratio of 1/8 are set. In some cases, a time of at least about 0.5 seconds was necessary.

  In the case of the message information format of the second embodiment, since it can be transmitted in 204 frames, that is, in one frame, the time required for calculating the seismic intensity of Equation (1) described later and the arrival prediction from the travel time table such as JMA2001 When the time required to calculate the time is negligible compared to 1 frame, the information is transmitted by 2 frames while maintaining diversity by 8 AC carriers, compared to the case of the telegram information format of the first embodiment. It is possible to transmit emergency bulletin information in a time shortened by about a second.

  In this embodiment, for example, when a broadcaster receives an emergency earthquake bulletin from the Japan Meteorological Agency, the same emergency bulletin based on the format example of the telegram information of the second embodiment, that is, the occurrence time of the earthquake, the latitude of the epicenter is transmitted by the transmitting device. The longitude, depth, and magnitude information are stored in all the AC information carried by the eight AC carriers together with the “various flags (synchronization signals)” and transmitted to the receiver.

  The “phase reference”, “various flags (synchronization signal)”, and “parity bit” corresponding to the data state are always transmitted regardless of the presence or absence of emergency bulletin.

  In the receiver according to the second embodiment, the information processing circuit 18 includes the information on the occurrence time of the earthquake, the latitude and longitude of the epicenter, the depth of the epicenter, and the magnitude decoded by the AC decoding circuit 17; The seismic intensity and arrival time prediction information for the area where the receiver is located are calculated from the position information detected by the current time detection means (not shown) and the current time information detected by the current time detection means (not shown).

  Specifically, according to Non-Patent Document 1, the receiver of the second embodiment uses the information processing circuit 18 to acquire the position information (latitude, longitude, depth) of the acquired earthquake source and the magnitude of the earthquake for the seismic intensity prediction. From the (magnitude) and ground reinforcement, the seismic intensity and the predicted arrival time of strong ground motion (main motion) are calculated. Furthermore, the absolute time of the predicted arrival time can also be calculated by adding the time of occurrence of the earthquake.

  The information processing circuit 18 calculates the seismic intensity and the predicted arrival time of strong ground motion (main motion) as follows.

The seismic intensity is _calculated as a measured seismic intensity I _INSTR by the calculation formula described in Non-Patent Document 1 below.

I _INSTR = 2.68 + 1.72 log (PGV) ± 0.21 (1)

Here, PGV is the maximum velocity [cm / s] at each point on the ground surface, and is calculated by the maximum velocity attenuation formula described in Non-Patent Document 1 (hard substrate, S wave velocity 600 m / s). It is a value obtained by multiplying the maximum speed PGV ₆₀₀ in the country by the ground amplification degree ARV _i at each target point in the national land numerical information.

PGV = 1.31 PGV ₆₀₀ × ARV _i (2)

The maximum velocity decay equation described in Non-Patent Document 1 is expressed by equation (3). Information required for calculating PGV ₆₀₀ [cm / s] is magnitude M, depth D [km] of the epicenter, and fault Only the shortest distance x [km].

log (PGV ₆₀₀ ) = 0.58 (M−0.171) +0.0038 D−1.29
−log (x + 0.028 × 10 ^{0.50 (M−0.171)} ) −0.002x (3)

  The receiver 1 has means for acquiring the position information, and since the point where the receiver is present is known, x can be easily calculated from the position information of the epicenter and the position information of the receiver.

Moreover, since ARV _i is a value depending on the location, it can be selectively used based on the position information by being stored in advance in the receiver.

Therefore, the measured seismic intensity I _INSTR can be easily calculated in the receiver 1 by acquiring the location information and magnitude of the epicenter which is unknown in the receiver 1 from the transmission side.

Since the measured seismic intensity I _INSTR is calculated as a numerical value including a decimal point, the maximum predicted seismic intensity in the seismic intensity class is determined based on the relationship between the two shown in FIG.

  On the other hand, the predicted arrival time (required arrival time) at the point where the receiver of the main motion is located is a travel time table (for example, JMA2001) indicated by the Japan Meteorological Agency based on the epicenter distance Δ [km] and the depth D [km] of the epicenter. ) Is used to add the earthquake occurrence time to the time calculated using The epicenter distance Δ is a value that can be calculated from the location information (latitude, longitude) of the epicenter and the location information of the receiver.

  Therefore, the predicted arrival time of the main motion can be easily calculated at the receiver by transmitting the location information of the epicenter and the occurrence time of the earthquake which are unknown in the receiver.

  The details of the receiving operation in the receiver of this embodiment are specifically performed as follows.

  First, in the receiver of the second embodiment, as in the first embodiment, the AC receiver 2 performs symbol synchronization from the OFDM signal received in the selected channel by guard interval correlation or the like, and performs an FFT operation to obtain an AC signal. To extract.

  Further, the receiver 1 according to the second embodiment uses the same technique as that of the first embodiment to generate “various types” of “various signals” multiplexed on the AC signal included in the telegram information (the format of the telegram information illustrated in FIG. 11) by the AC receiver 2. Frame synchronization of the AC signal is performed based on the “flag (synchronization signal)”.

  Then, the receiver 1 according to the second embodiment performs the DBPSK demodulation included in the telegram information (the format of the telegram information illustrated in FIG. 11) according to the timing obtained based on the frame synchronization by the same method as the first embodiment. Based on the combination of the AC carrier or AC signal and the “emergency warning broadcast activation flag”, “emergency earthquake early warning activation / identification flag” and “other flags” in the “various flags (synchronization signal)” The activation flag monitoring circuit 15 monitors the peak value of the correlation coefficient detected by the correlation calculation with the correlation code string.

  Since the operation related to the receiver of the digital terrestrial television broadcasting separately provided in the terminal of the receiver 1 when the “emergency warning broadcast activation flag” is “1” is the same as that of the first embodiment, the description here is as follows. Omitted.

  On the other hand, when the “emergency earthquake early warning activation / identification flag” or “other flags” is “1”, the receiver 1 receives the subsequent telegram information by the AC information analysis unit, and the remaining “various flags (synchronization) Signal ") flag, and when the" other flag "is" 1 ", the" tsunami "flag (assumed to be set in the" reserved bit (flag) "in FIG. 12) is" 1 ". When it is, the AC information analysis unit 3 creates a quick report that calls attention to the “tsunami warning”, and the warning generator 22 uses the warning generation means 22 to display the display device of the receiver 1 (or the device equipped with the receiver). Display above. Alternatively, at the same time, a warning sound and / or a sound is emitted from a speaker included in the receiver 1 (or a device including the receiver 1).

  Further, when the “emergency earthquake early warning activation / identification flag” is “1”, the receiver 1 receives the following telegram information by the AC information analysis unit 3 and analyzes it as follows.

  Here, as in the first embodiment, the receiver recognizes the position of its own receiver. Further, it is assumed that the receiver recognizes the current time.

  The receiver 1 uses the information processing circuit 18 to detect the position of the receiver 1 and the ground amplification degree based on the position of the receiver 1, the latitude, longitude, and depth of the epicenter that has been notified of the occurrence, and the magnitude. Is used to calculate the epicenter distance x and the calculations of equations (1) to (3) to calculate the predicted seismic intensity at the point where the receiver 1 is located.

  Then, the receiver 1 calculates the epicenter distance Δ by the information processing circuit 18 and calculates the predicted arrival time from the travel time table such as JMA2001.

  When the calculated predicted seismic intensity is equal to or greater than a reference value (for example, when the seismic intensity is 4 or greater), the receiver 1 calculates the difference between the calculated predicted arrival time and the detected current time. Then, the difference between the calculated predicted seismic intensity and the time is converted into text characters and displayed by the warning generation means 22 on the display device of the receiver 1 (or the device equipped with the receiver). Alternatively, at the same time, a warning sound and / or sound is emitted from a speaker included in the receiver 1 (or a device including the receiver). From these indications or sounds, the receiver 1 can know the occurrence of the earthquake and the predicted time. Note that the method of generating a warning is not limited to these, and there is a method of mimicking a second hand of an analog clock.

  As described above, when the predicted seismic intensity and the predicted arrival time can be calculated in the receiver 1, the broadcasting station, when the earthquake early warning is issued, the earthquake occurrence time, the location of the epicenter (latitude, longitude, depth) and It can be seen that the magnitude information may be transmitted to the receiver.

  The receiver 1 uses the information about the earthquake occurrence time, the epicenter latitude, longitude and depth, and the magnitude obtained from the transmission side, the position information of the receiver itself, the ground amplification degree, and the current time. The calculation of the seismic intensity of equation (1) and the predicted arrival time from the travel time table such as JMA2001 are performed.

  As a result, the receiver 1 promptly informs the user of the receiver 1 of the emergency breaking news including the information “how much earthquake of magnitude / seismic intensity will occur after what time”, and You can definitely get it.

  In addition, since the predicted arrival time is calculated for each position of the receiver 1, the receiver 1 can know a more accurate time.

  Further, according to the second embodiment, the same calculation is performed for other regions other than the region where the receiver 1 is located by selecting and setting another region selected by the user of the receiver 1 as desired. For example, when there is a possibility of strong shaking with a seismic intensity of 4 or more in the area where the selection setting is made, information such as necessary “maximum predicted seismic intensity” can be presented to the warning generation means 22.

  In the second embodiment, compared with the first embodiment, not only can transmission be performed in one frame, but the number of reserved bits is 28 bits. The “month” and “day” of the “earthquake occurrence time” can be omitted. For this reason, there is flexibility for additional usage such as extending various flags (synchronization signals) to transmit another control signal, and changing the error correction code to enhance transmission performance.

  Next, a transmission device and a receiver according to Embodiment 3 of the present invention will be described.

(Example 3)
The components of the hardware of the transmission device and the receiver according to the third embodiment of the present invention are the same as those of the first embodiment, but the aspect of the message information format is different. The operation is different. Therefore, a more detailed description of the same components as those in the first or second embodiment is omitted. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  The case where the receiver 1 of the first and second embodiments always detects the current time in its own receiver 1 when using the message information format of the first and second embodiments has been described. The receiver 1 according to the third embodiment corresponds to a case where the receiver 1 does not have a method for correcting or correcting the current time. In the third embodiment, the current time detecting unit can be omitted. That is, the transmission apparatus according to the third embodiment transmits the current time in addition to the earthquake early warning according to the message information format according to the third embodiment. Note that the receiver of the third embodiment can be installed in any device such as a mobile phone, a personal digital assistant (PDA), a wristwatch, a table clock, a personal computer, or a home appliance as in the first or second embodiment. is there.

  FIG. 14 shows a message information format according to the third embodiment when the current time is transmitted.

  The first “phase reference”, “various flags (synchronization signal)”, and “parity bit” are the same as the message information format in the first and second embodiments. The “seismic latitude”, “seismic longitude”, “seismic depth”, and “magnitude” are exactly the same as those in the message information format of the second embodiment.

  The portion of the message information format of the third embodiment that is different from the message information format of the second embodiment is “current time” assigned instead of “earthquake occurrence time” and “current time” from the occurrence of the earthquake to the current time. Elapsed time ".

  “Current time” is the Japan standard time at the time of output from the transmission device of the broadcasting station that changes from moment to moment. Stores a value that is advanced in advance with respect to the processing delay time in the transmission apparatus. That is, a numerical value displayed in units of month, day, hour, minute, and second is transmitted.

  The "current time" time is displayed in 24-hour format, and as with the "earthquake occurrence time" in Fig. 11, the month display is 4 bits, the day display is 5 bits, the hour display is 5 bits, and the minutes and seconds are displayed. A binary value is transmitted as a 6-bit numerical value.

  The change of “current time” is based on the second unit. In the case of ISDB-T terrestrial digital television broadcast mode 3 and a guard interval ratio of 1/8, the length of one frame is 0.231 seconds, so it is updated every 4 or 5 frames.

  “Elapsed time” is the value of the difference between the occurrence time of the earthquake and the “current time” when the earthquake occurs. Considering transmission with an elapsed time of a maximum of 100 seconds with 1/10 second accuracy, a 10-fold value is stored and transmitted in a 10-bit binary number.

  In the case of the message information format of the third embodiment, since it can be transmitted in 204 frames, that is, in one frame, the time required for calculating the seismic intensity of Equation (1) and the predicted arrival time from the travel time table such as JMA2001 When the time required for calculation is negligible compared to 1 frame, 0.2 seconds as compared with the case of the message information format of the first embodiment in which information is transmitted in 2 frames while maintaining diversity by 8 AC carriers. Information can be transmitted in a short time.

  In this embodiment, for example, when a broadcaster receives an earthquake early warning from the Japan Meteorological Agency, the same emergency earthquake early warning information based on the format example of the telegram information of the third embodiment, that is, the current time and an earthquake is generated by the transmitting device. Then, the elapsed time, the latitude and longitude of the epicenter, the depth of the epicenter, and the magnitude information are stored in all the AC information carried by the eight AC carriers and transmitted to the receiver. .

  However, “phase reference”, “various flags (synchronization signal)”, “current time”, “elapsed time” (= “1111111111” (when there is no emergency earthquake warning)), and “parity bit” corresponding to the data state Is always transmitted regardless of the presence of emergency bulletin.

  In the receiver 1 of the third embodiment, the information processing circuit 18 includes the current time acquired from the telegram information, the elapsed time from the occurrence of the earthquake to the current time, the epicenter latitude and longitude, the epicenter depth, and Using the magnitude-related information, the position information of its own receiver detected by the position detection means (not shown), and the ground amplification based on the position information, the calculation of seismic intensity of Equation (1) and JMA2001, etc. Calculate the estimated arrival time from the travel time table.

  Therefore, in the receiver 1 according to the third embodiment, the information processing circuit 18 includes the current time decoded by the AC decoding circuit 17, the elapsed time from the occurrence of the earthquake to the current time, the epicenter latitude and longitude, and the epicenter depth. And the magnitude information and the position information and the ground amplification level determined by the position information, the prediction information of the seismic intensity and the predicted arrival time of the area where the receiver is located is calculated.

  As a result, the receiver 1 promptly notifies the user of the receiver 1 of the emergency bulletin including the information “how much earthquake of magnitude / seismic intensity will occur after what time”, and You can definitely get it.

  Other operations of the receiver 1 in the third embodiment are almost the same as those in the second embodiment described above. The receiver 1 in the third embodiment is located at the position of the receiver 1 and the position of the receiver 1 of the receiver. Calculate the epicenter distance x using the ground amplification degree, the latitude, longitude and depth of the epicenter that received the notification of the occurrence, and the magnitude, and perform the calculations of equations (1) to (3) The receiver 1 calculates a predicted seismic intensity at a point, calculates an epicenter distance Δ, and calculates a predicted arrival time as a required time from the epicenter from a travel time table such as JMA2001.

  When the calculated predicted seismic intensity is equal to or greater than a reference value (for example, when the seismic intensity is 4 or more) by the information processing circuit 18, the receiver 1 obtains the “elapsed time” acquired from the calculated required time and the message information. The difference between the calculated predicted seismic intensity and the time is converted into text characters and displayed on a display device of the receiver 1 by, for example, a warning generation means (or a device equipped with the receiver). . Alternatively, at the same time, a warning sound and / or sound is emitted from a speaker included in the receiver (or a device including the receiver). From these indications or sounds, the receiver 1 can know the occurrence of the earthquake and the predicted time. Note that the method of generating a warning is not limited to these, and there is a method of mimicking a second hand of an analog clock.

  In the receiver of the third embodiment, this corresponds to receiving the “current time”, so that the clock of the receiver 1 can be corrected.

  However, since this “current time” is transmitted in units of seconds, there is a difference in jitter from the frame length. In consideration of standby power, it is not desirable to always receive all AC signals. Therefore, for example, in the case of ISDB-T terrestrial digital television broadcasting mode 3 with a guard interval ratio of 1/8, the time is corrected once a day, for example, about 10 samples every 48 consecutive frames. It is preferable to do this based on the “current time”.

  Next, a transmission device and a receiver according to Embodiment 4 of the present invention will be described.

Example 4
The hardware components of the transmission apparatus and receiver according to the fourth embodiment of the present invention are the same as those according to the first to third embodiments. Compared with those of the first to third embodiments, the information processing circuit 18 of the receiver 1 is different in that it mainly operates as an information extraction circuit, but the other operations are the same. That is, the information processing circuit 18 according to the fourth embodiment uses the above-described message information instead of the information processing circuit 18 according to the first to third embodiments calculating the prediction information of the seismic intensity and the predicted arrival time of the area where the receiver 1 is located. Among them, the information on the occurrence of the earthquake, or the information and the information on the occurrence time or the maximum predicted seismic intensity are extracted and transmitted to the warning generating means 22. Therefore, a more detailed description of the same components as those in the first to third embodiments is omitted. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  In the fourth embodiment, the receiver 1 that has received the earthquake early warning reports, in the warning generation means 22, for example, “Earthquake early warning: Be wary of strong shaking in the XX region” or “Emergency earthquake early warning: An earthquake with a strong magnitude Δ △ has occurred. Please be wary of strong shaking. ”A warning is presented to the user of the receiver 1.

  The aspect of the fourth embodiment is suitable for application when it is important to promptly call attention and alert. In the above-described first to third embodiments, it is possible to promptly and reliably notify the information “how much magnitude / seismic intensity will occur after what time” required by the user of the receiver 1. To be obtained.

  In the above-described Examples 1 to 3, for example, when an area where a seismic intensity of 5 or lower is expected somewhere in Japan, an earthquake with a seismic intensity of 4 or higher occurs in the area where the receiver 1 exists. The information calculated by the information processing circuit 18 of the receiver 1, for example, the remaining time until the main motion of the earthquake arrives, is presented to the warning generation means. In other words, for example, the user of the receiver 1 notifies the receiver 1 (or the receiver) of an information such as “Earthquake Early Warning: An earthquake with a seismic intensity of 4 in Δ ○ area after △ Δ seconds. It is received by text on the display unit of the equipment) or by voice from the speaker.

  However, for example, at the initial stage of introduction of the transmitter and receiver according to the present invention, there is a case where the calculation load by the information processing circuit 18 is heavy and the calculation of the remaining time etc. is not in time within the required time. It may also happen that there are receiver users who are upset by presenting the time remaining until the arrival of the main motion and are unable to take the necessary warning measures against the earthquake. Furthermore, in the case of a dedicated broadcast receiver, it may be necessary to present the information transmitted by the broadcast station as it is for system and operational reasons. Example 4 is applied to such a case.

  The operation example of the receiver 1 which receives the message | telegram information format of FIG. 2 used by description of Example 1 is shown. Since the message information format is the same as that in the first embodiment, the description thereof is omitted.

  The operation of the receiver of the fourth embodiment will be described using FIG. 5 again. In the receiver according to the fourth embodiment, the information processing circuit 18 detects the “emergency earthquake” decoded by the AC decoding unit 3 when the activation flag monitoring circuit 15 determines a flag value indicating that there is “emergency earthquake early warning” information. Information necessary for creating a breaking news sentence is extracted from the contents of the breaking news and sent to the warning generating means 22.

  The warning generation means 22 presents a quick report sentence extracted and created by the information processing circuit 18. For example, when the receiver 1 (or the device equipped with the receiver) has a text display, the warning generation means 22 displays “Emergency Earthquake Early Warning (Japan Meteorological Agency): Strong shaking. △△ Region ”etc. When the receiver 1 (or a device including the receiver) has a speaker, a sound that reads out a similar quick report is output together with an alarm sound. In addition, when the receiver 1 (or a device including the receiver) has a vibrator, a vibration warning is issued so that a warning is perceptually generated by an operation different from the normal operation, or a vibration warning is issued. Call attention to display and speaker.

  In addition, even when the flag value indicating that there is “Emergency Earthquake Early Warning” information is transmitted without limiting the area, the warning generation means 22 does not require the emergency earthquake acquired by the user of the receiver 1. A bulletin may be presented.

  The information processing circuit 18 generates a warning message only when the position of the receiver can be detected by a position detection unit (not shown) and the receiver 1 is in the corresponding area indicated by “Emergency Earthquake Early Warning”. It is also possible to output to the means. For this reason, it is preferable that the setting of whether or not to use the function of the position detection means can be selected by the setting of the user of the receiver 1.

  Since other operations of the receiver 1 in the fourth embodiment are the same as those in the above-described embodiment, detailed description thereof will be omitted. For example, the operation of the fourth embodiment is performed even if the message information format of FIGS. 11 and 14 is used. Can be realized. For example, the bulletin sentence presented by the warning generation means 22 can be as follows.

  “Earthquake Early Warning (Japan Meteorological Agency): ● Hour ▲ Minutes x Seconds, magnitude △ earthquake occurred in XX prefecture. Be wary of strong shaking”.

  In addition, the information processing circuit 18 can calculate and present only the seismic intensity although the remaining time is not presented. At this time, as described above, when the position of the receiver 1 can be detected by the position detection unit, the receiver 1 calculates the corresponding area calculated from the “emergency earthquake warning” according to the setting of the user of the receiver 1. Only when the seismic intensity is, for example, 4 or more, a preliminary report can be output to the warning generating means 22.

  As described above, according to the fourth embodiment, the user of the receiver 1 can quickly and surely obtain the emergency bulletin.

Next, a transmission device and a receiver according to Embodiment 5 of the present invention will be described.
(Example 5)
The hardware components and operations of the transmission apparatus and the receiver according to the fifth embodiment of the present invention are the same as those of the fourth embodiment except for a part of the operation of the activation flag detection circuit 15, and detailed description thereof is omitted. . In the fifth embodiment, the message information format is different from the above-described embodiments. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  An example of the message information format in the fifth embodiment is shown in FIG. This is an example of the case where an emergency earthquake bulletin is transmitted, in particular, an emergency earthquake bulletin, and a message almost equivalent to the current emergency earthquake bulletin is presented at the receiver. In other words, “Earthquake occurrence time”, “Earthquake location code”, “Maximum predicted seismic intensity”, and “Strong earthquake area with seismic intensity of 4 or more (prefecture unit)” are transmitted from the transmitting side, and the receiver receives the information from these information “Earthquake early warning (Japan Meteorological Agency): ● Hour ▲ Minute × Second, earthquake occurred in XX prefecture. Predicted seismic intensity △. Be alert to strong shaking in the following areas: △△ prefecture, □□ prefecture, ・This is an example in the case of presenting the message “.

  Here, “Earthquake occurrence time” is the time when the earthquake occurred, estimated after observation of the P wave and transmitted to the broadcasting station by the general earthquake early warning, displayed in units of hours, minutes, and seconds Communicate the numerical value.

  The time of “earthquake occurrence time” is displayed in 24 hours, the hour display is 5 bits, the minutes and seconds are 6 bits, for example, 13:25:37 is “01101 | 011001 | 100101” (total 17 bits) and binary numbers in units of hours, minutes, and seconds. In order to make it easy to see the distinction between hour, minute, and second, “|” is inserted only as a notation here, and is not inserted in actual transmission.

  The “Earth Place Name Code” is obtained by binarizing the last 3 digits of the epicenter place code in the 4-digit emergency earthquake early warning for general use used when distributing the “Earthquake Early Warning”. Therefore, it becomes BCD code notation of 4 bits for each digit.

  FIG. 16 is an example (part) of a table showing the relationship between the “Earth Place Name Code”, the epicenter name, and its bit notation.

  The “maximum predicted seismic intensity” corresponds to seismic intensity 4 or higher of 4, 5 weak, 5 strong, 6 weak, 6 strong, or 7. “Strong” and “Weak” are distinguished by numerical values 1 and 0, respectively, and each is distinguished by 4-bit “0100”, “0101”, “1101”, “0110”, “1110”, “0111”. To do. However, this maximum predicted seismic intensity is the maximum predicted seismic intensity that is expected to be observed in any region of Japan due to the earthquake, not for each specific region. When this value is less than seismic intensity 5, emergency earthquake warning is issued.

  The “strong earthquake area with seismic intensity 4 or more (prefecture unit)” is a “region where strong shaking is estimated” for each prefecture used in the emergency earthquake warning for general public. This area is based on prefectures, but there are currently 56 locations nationwide (see FIG. 17), such as dividing Hokkaido into four, and 1 bit is assigned to each location, indicating 1 or 0 as the target. .

  For example, when Tokyo, Kanagawa, and Izu Islands are predicted to have a seismic intensity of 4 or more, the bits assigned to these three areas are set to 1, and the others are set to 0. Therefore, on the transmitting side, data based on this value is transmitted, and on the receiving side, based on this value, “Earthquake Early Warning (Japan Meteorological Agency): ● Hour ▲ Minute × Second, earthquake occurred in XX prefecture. Be wary of strong shaking in the following areas: Tokyo, Kanagawa, Izu Islands.

  The message information format of the fifth embodiment using the message information format of FIG. 15 is also the AC carrier in the partial reception segment (segment number # 0) of the ISDB-T terrestrial digital television broadcast wave, for example, synchronous modulation in mode 3 In the case of a copy, the same information is copied to each of eight 204 symbols and one frame of carrier numbers # 7, # 89, # 206, # 209, # 226, # 244, # 377 and # 407, respectively. And transmit.

  In the case of the message information format of the fifth embodiment, since it can be transmitted in 204 symbols, that is, in one frame, the message of the first embodiment in which information is transmitted in two frames while maintaining diversity by eight AC carriers. Compared to the information format, information can be transmitted in a time shortened by about 0.2 seconds.

  It should be noted that the “phase reference”, “various flags (synchronization signal)”, and “parity bit” corresponding to the data state are always set regardless of whether or not there is an emergency bulletin, as in the first to fourth embodiments. To transmit.

  However, since “phase reference” and “parity bit” are the same as the telegram information format in the first to fourth embodiments, description thereof is omitted, but “various flags (synchronization signals)” have a point to be careful.

  Specifically, the bit length of the “strong earthquake region (unit of prefecture) with seismic intensity of 4 or more” is 56 bits, which is related to the large amount of information compared to “various flags (synchronization signal)”. If an arbitrary value is entered in these 56 bits (actually, variation in each bit is assumed in the bit arrangement depending on the region, and it is possible to deal with it by setting the bit arrangement based on it, but here There is a case where the information stored in the “strong earthquake area with seismic intensity of 4 or more (prefectural unit)” is stored as the same information as “various flags (synchronization signal)”. Therefore, in order to achieve the object “even when frame synchronization is not established” which is the object of the present invention, “various flags (synchronization signals)” are set between the odd frame and the even frame, or the first frame and the second frame. It is preferable to use different message information formats.

  FIG. 18 shows a correlation code string (first 21 bits) of “various flags (synchronization signal)”, “emergency earthquake warning start / identification flag”, “emergency warning broadcast start flag”, and “other flags”. "Is shown in the first frame (the second frame is in parentheses) for each combination example of each flag.

  The combination of correlation code strings in FIG. 18 is based on the “various flags (synchronization signals)” in FIG. 12, and the first frame completely matches. What is important here is that the second frame uses the 21 bits of the first frame as phase inversion. Then, in the correlation calculation circuit in the receiver, the correlation calculation is performed over “various flags (synchronization signals)” of two frames shown in FIG.

  As a result, even if the “flags (synchronization signal)” in the first frame and a part of the “strong earthquake area with seismic intensity 4 or higher (prefecture unit)” completely match, this information is separated by one frame. Because the information is the same “strong earthquake area with seismic intensity of 4 or more (prefectural unit)” and does not match the phase-reversed “various flags (synchronous signals)”, at least the detected correlation coefficient value is half the peak value Can be.

  The same can be achieved when the correlation code string of FIG. 6 is used, but the case of FIG. 18 has another feature.

  FIG. 19 shows a calculation example of the “flag 1” signal in one embodiment of the correlation calculation circuit of the fifth embodiment. Here, when the 21-bit correlation code string of “various flags (synchronization signal)” is as shown in FIG. 6 (see FIG. 19A), as shown in FIG. 18 (see FIG. 19B), FIG. (Only the first frame in FIG. 18) (see FIG. 19C), the correlation coefficient for the code string pattern 1 for detecting the “emergency warning broadcast activation flag” is calculated by the sliding correlation calculation 101 ( The calculation result by “calculation over 2 frames of“ various flags (synchronization signal) ”is shown.

  Even if the correlation calculation is performed over two frames in the same manner, if the same “various flags (synchronization signals)” are transmitted for each frame in FIG. 19 (c), the “strong earthquake area with seismic intensity 4 or more (prefecture unit) It can be confirmed that a part of the symbol “” is influenced by being completely coincident with “various flags (synchronization signal)” and is a correlation coefficient for detecting a peak value in addition to the frame synchronization timing. On the other hand, when different code sequences are used in the two frames in FIG. 19A, the unnecessary peak value is not detected correctly in either case of phase inversion in the two frames in FIG. Frame synchronization timing can be detected. However, in FIG. 19B, the peak value can be detected every frame while reversing the sign (phase) of the correlation coefficient, whereas in FIG. 19A, the peak value is detected every two frames. In order to detect this frame, a correlation calculation using another correlation code string is required.

  In the fifth embodiment, a telegram information format that can transmit an emergency early warning required within each frame and one frame is adopted. Similarly, detection of “various flags (synchronization signals)” is preferably performed for each frame.

  Therefore, the feature of the correlation code string of FIG. 18 is that the correlation coefficient of “various flags (synchronization signal)” is recognized in each frame while individually recognizing the first frame and the second frame, or the odd frame and the even frame. The peak value can be detected.

  The receiver 1 according to the fifth embodiment can receive the emergency bulletin and provide information from the warning generation unit 22 at the timing of each frame in the activation flag monitoring circuit 11 of the receiver 1.

  For this reason, the components and operations of the hardware of the transmission apparatus and receiver according to the fifth embodiment of the present invention are partially different from those of the fourth embodiment in the operation of the activation flag detection circuit 15 as follows.

  The activation flag detection circuit 15 included in the receiver 1 according to the fifth embodiment includes four levels of level determiners 151, 152, 153, and 154 and three types of OR adders 155, 156, and 157. 152, 153, and 154 compare the level value or amplitude value of the input signal with a threshold value set in advance for each symbol, determine "1" and "0", and output the symbol period. The OR adders 155, 156, and 157 perform an OR operation and output the operation result.

  This operation is not different from the fourth embodiment. That is, the actual correlation coefficient detects two types of values “1” and “−1” when detecting the peak value. However, since the message information is the same in each frame, it is not necessary to distinguish this. That is, the absolute value is obtained, and “1” and “−1” can be set to the same “1”.

  On the other hand, the correlation code string of FIG. 18 can also be applied to the first embodiment, and in this case, different telegram information is transmitted between the first frame and the second frame, so the activation of the first embodiment. A function for detecting the phase difference between “1” and “−1” and detecting the first frame and the second frame separately is added to the level determiners 151, 152, 153, and 154 of the flag detection circuit 11. It is suitable to use.

  According to the fifth embodiment, the receiver 1 promptly and reliably notifies the emergency early warning including the information “how much the maximum seismic intensity earthquake occurs in which region” that the user of the receiver needs. Be able to get.

  If the receiver 1 has no means for knowing or correcting the current time, instead of sending the “earthquake occurrence time” as in the message information format of the third embodiment on the transmission side, The same effect can be obtained by sending the “current time” and the “elapsed time” since the occurrence of the earthquake.

  As described above, according to the fifth embodiment, the user of the receiver 1 can quickly and reliably obtain the emergency bulletin.

  In the above explanation, “maximum predicted seismic intensity” is used as the data of the magnitude of the earthquake, and “emergency earthquake bulletin (Meteorological Agency): ● Hour ▲ minutes × seconds, earthquake occurred in XX prefecture. Seismic intensity △ is predicted. We were wary of strong shaking in the following areas: △△ prefecture, □□ prefecture, ... ", but instead of" maximum predicted seismic intensity ", we sent" Magnitude "and" Earthquake Early Warning (Japan Meteorological Agency): ● Magnitude △ earthquake occurred in XX prefecture at hour ▲ minute x second. Be wary of strong shaking in the following areas: △△ prefecture, □□ prefecture,… ”. Here, “Magnitude” is the same as “Magnitude” described in the message information format of FIGS. 11 and 14 used in the second and third embodiments.

  Next, a transmission device and a receiver according to Embodiment 6 of the present invention will be described.

(Example 6)
The components of the hardware of the transmission apparatus and receiver according to the sixth embodiment of the present invention are the same as those of the fourth and fifth embodiments, and detailed description thereof is omitted. In the sixth embodiment, still another message information format is used. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  An example of the message information format of the sixth embodiment is shown in FIG. This is an example of the case where the receiver 1 presents a necessary minimum earthquake message close to the current emergency earthquake bulletin, particularly the emergency earthquake bulletin among the emergency bulletins based on the same concept as in the fifth embodiment. . In other words, the information is sent from the sender only to “Information number”, “Earthquake name code”, and “Strong earthquake area with seismic intensity 4 or higher (prefecture unit)”, and the receiver uses the information to send the information to the user This is a case where the message “Earthquake Early Warning (Meteorological Agency): An earthquake occurred in XX prefecture. Be wary of strong shaking in the following areas: △△ prefecture, □□ prefecture,.

  The “seismic place name code” and the “strong earthquake area having a seismic intensity of 4 or more (prefecture unit)” are the same as those in the fifth embodiment, and detailed description thereof is omitted.

  The “information number” is a number that is inserted instead of the earthquake identification number (ID number) of the emergency earthquake bulletin and is incremented by one each time an emergency earthquake bulletin regarding a different earthquake is announced. The earthquake early warning published by the Japan Meteorological Agency has an earthquake identification number that starts with “ND” and is created by arranging (year), month, day, hour, minute, and second. In the message information formats described in the first to fifth embodiments so far, the “earthquake occurrence time” or “predicted arrival time” in a certain area is described, and the earthquake identification number can be estimated. Therefore, even if a follow-up report or a cancel report is generated, it is possible to distinguish the earthquake from other earthquakes.

  On the other hand, in the sixth embodiment, time information is not transmitted. Therefore, another number for identifying the earthquake is necessary, and the “information number” serves the purpose. Here, 4 bits are allocated, and earthquake early warnings are issued in order from “0001” to “0010”, “0011”, “0100”,..., “1111”, “0000”, “0001”. The same number is repeatedly used again in the 16th cycle.

  The 4-bit value of “information number” can be changed based on the operation. In addition, when a specific operation can be assumed, such as not using “cancel” in “various flags (synchronization signal)”, the “information number” may be omitted.

  The “phase reference”, “various flags (synchronization signal)”, and “parity bit” corresponding to the data state are the same as the telegram information format of the fifth embodiment so far, and the description thereof is omitted. It is always transmitted regardless of the presence of emergency bulletin.

  In the sixth embodiment, “information number” is added, but information on “earthquake occurrence time” and “maximum predicted seismic intensity” or “magnitude” is not transmitted. It can be transmitted in capacity. For this reason, there is future expansion of the number of regions. Further, another control signal can be transmitted by expanding the “various flags (synchronization signal)”. Furthermore, the transmission performance can be enhanced by expanding the “parity bit” and other error correction codes.

  The message information format of the sixth embodiment using the message information format of FIG. 20 is also the AC carrier in the partial reception segment (segment number # 0) of the ISDB-T terrestrial digital television broadcast wave, for example, synchronous modulation in mode 3 In the case of a copy, the same information is copied to each of eight 204 symbols and one frame of carrier numbers # 7, # 89, # 206, # 209, # 226, # 244, # 377 and # 407, respectively. And transmit.

  According to the sixth embodiment, the receiver 1 promptly informs the user of the receiver that the emergency bulletin including the information “where an earthquake to be warned and where the strong shaking occurs” is included, And it becomes possible to obtain reliably.

  Next, a transmission device and a receiver according to Embodiment 7 of the present invention will be described.

(Example 7)
The components of the hardware of the transmission apparatus and receiver according to the seventh embodiment of the present invention are the same as those of the fourth to sixth embodiments, and detailed description thereof is omitted. In the seventh embodiment, still another message information format is used. Also in the description of the present embodiment, a case will be described in which all AC information carried by the mode 3 AC carrier in ISDB-T terrestrial digital television broadcasting is used, but it is also applicable to other modes. To do.

  In Example 7, both the message information format of FIG. 15 shown in FIG. 15 or Example 6 shown in Example 5 and the message information format of FIG. 11 shown in Example 2 are transmitted from the transmitter.

  An AC carrier in a partial reception segment (segment number # 0) of an ISDB-T terrestrial digital television broadcast wave, for example, in the case of mode 3 synchronous modulation, carrier numbers # 7, # 89, # 206, # 209, # These two types of information are stored and transmitted in any of 204 symbols, one frame, and eight symbols 226, # 244, # 377, and # 407, respectively.

  In order to improve reception sensitivity by diversity, the transmitter assigns and transmits the message information formats of both FIG. 15 (or FIG. 20) and FIG. 11 to each of the four AC carriers. For example, the message information format of FIG. 11 is set to carrier numbers # 7, # 206, # 226, and # 377, and the message information format of FIG. 15 (or FIG. 20) is changed to carrier numbers # 89, # 209, and # 244. , And # 407 for transmission.

  On the receiver 1 side, the information processing circuit 18 is configured to be able to select each piece of telegram information according to the setting of the user of the receiver 1, so that the user of the receiver 1 can perform the operation of the fifth embodiment or the second embodiment. It becomes possible to select and use one of the methods for receiving emergency bulletins.

  When the receiver 1 cannot acquire the current time, the message information format shown in FIG. 14 may be used instead of the message information format shown in FIG. When the message information format of FIG. 15 is used, the “current time” and “elapsed time” from the occurrence of the earthquake may be sent instead of the “earthquake occurrence time” of the message information format of FIG. Alternatively, it may be a format that sends both “current time” and “elapsed time”.

  As described above, according to the seventh embodiment, the user of the receiver 1 can quickly and reliably obtain the emergency bulletin. Furthermore, the user of the receiver 1 has a function of correcting the time according to the message information format received by the receiver 1, and can accurately know the contents of the emergency bulletin based on the received emergency bulletin. .

(Additional examples of correlation code string patterns)
In the above-described embodiment, the N-bit correlation code string constituting the main part of the present invention is divided into three main flags, “emergency warning broadcast activation flag”, “emergency earthquake warning activation / identification flag” and “others”. A fixed, for example, 7-bit code sequence is assigned to “flag”, and “1” and “0” are described as non-inversion and inversion of the phase of the code sequence, respectively (Example 1). Also, a series of N-bit pseudo-random code sequences are divided into three and assigned to three flags, and “1” and “0” are described as non-inversion and inversion of the phase of the code sequence, respectively (Example 2) .

  Further, an example in which different code sequences (including six divisions of a series of 2N-bit pseudorandom codes) are used to distinguish between odd frames and even frames (first frame and second frame) will be described. did. Further, the code string of the even frame (second frame) has been described as the phase inversion of the odd frame (first frame) (Example 5).

  Here, another example of the correlation code string will be described.

  The total combination pattern in the transmission of three flags and three-bit information is 2 3 = 8 patterns. An example is an example of using a code string obtained by assigning an orthogonal code having a combination of 8 patterns or more to an N-bit code string and performing multiplication or bit operation.

For example, Hadamard code
+ + + + + + + +
+ − + − + − + −
+ + − − + + − −
+ − − + + − − +
＋ ＋ ＋ ＋ − − − − −
+ − + − − + − +
+ +----+ +
+ − − + − + + −
Are previously associated with combinations of the states (“1” or “0”) of the three flags. Note that “+” is “1” or bit non-inversion, and “−” is “−1” or bit inversion.

  This Hadamard code is applied to a basic code string, for example, a 24-bit pseudo-random code string “0011101001000010101110110” to obtain eight types of orthogonal code strings, which are used as combinations of corresponding flags. One bit of Hadamard code corresponds to 3 bits of pseudorandom code string.

  FIG. 21 and FIG. 22 show examples of combinations of the three flags thus created, “emergency warning broadcast activation flag”, “emergency earthquake early warning activation / identification flag”, and “other flags” and correlation code strings. .

  FIG. 21 shows an example in which the second frame is phase-inverted from the first frame, and FIG. 22 shows the first half and the second half of a continuous 48-bit pseudo-random code sequence of the basic code sequence of the first frame and the second frame. This is a case study.

  The operation of each of the correlation code strings disclosed in FIGS. 21 and 22 is verified based on an example applied to the calculation of the “flag 1” signal in the correlation calculation circuit of the fifth embodiment.

  FIG. 23 and FIG. 24 are examples of this result. Here, FIG. 23A shows code sequence pattern 1 (“flag 1”) in the correlation code sequence of FIG. 21 for the AC signal transmitted with “emergency warning broadcast activation flag” set to “1”. FIG. 23B shows the result of the sliding correlation calculation calculated by using the code sequence pattern 1 (“flag 1”) of the correlation code sequence of FIG. 21 for the AC signal transmitted in normal time. It is the result of the calculated sliding correlation calculation. FIG. 24A uses code string pattern 1 (“flag 1”) of the correlation code string of FIG. 22 for the AC signal transmitted with “emergency warning broadcast activation flag” set to “1”. FIG. 24 (b) shows the result of the sliding correlation calculation calculated in FIG. 24, using the code string pattern 1 (“flag 1”) of the correlation code string of FIG. 22 for the AC signal transmitted in normal time. This is the result of the sliding correlation calculation.

  In FIG. 23 (a) and FIG. 24 (a), peak values of the “emergency warning broadcast activation flag” are observed every frame and every two frames, respectively, while FIGS. 23 (b) and 24 (b) It can be confirmed that no special peak value is observed.

  It can be seen that a code string pattern using a pseudo-random code string to which an orthogonal code is applied is also suitable as “various flags (synchronization signals)” used for transmission of emergency warning information disclosed by the present invention.

  Although the specific coding scheme has been described as a representative example for the above-described embodiments, it will be apparent to those skilled in the art that many variations and substitutions can be made within the spirit and scope of the invention. For example, in the above-described embodiment, in order to facilitate understanding of the present invention, it has been described that the receiver according to the present invention can be provided in, for example, a mobile phone. In addition, the function of the receiver according to the present invention can be integrated into the decoding function. For example, when the mobile phone is in the standby mode, it can be operated in the same manner as in the above-described embodiment. Alternatively, when the mobile phone is in the normal operation mode, the flag value in the telegram information is set. Depending on the determination, the emergency early warning may be decoded without performing power supply control, the seismic intensity of the area where the mobile phone is located and the prediction information of the predicted arrival time may be calculated and a warning may be issued. Accordingly, the invention should not be construed as limited by the above-described embodiments, but only by the claims.

  The receiver and the transmission device according to the present invention can transmit emergency early warnings such as emergency warning broadcasts and emergency earthquake warnings promptly and reliably regardless of the establishment of frame synchronization, and therefore use predetermined transmission control signals. Useful for transmission system applications.

It is the schematic explaining the principle which transmits / receives only the starting flag for emergency warning broadcasting in the transmission apparatus and receiver of each Example by this invention. It is a figure which shows the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 1 by this invention. It is a figure which shows the example of a format of the various flags (synchronization signal) in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 1 by this invention. It is a figure which shows the example of the area code in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 1 by this invention. It is a block diagram of the receiver of Example 1 by this invention. It is a figure which shows the example of a combination of each flag in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 1 by this invention. It is a block diagram of the correlation calculation circuit in the receiver of Example 1 by this invention. It is a figure which shows operation | movement of the sliding correlation calculating means of the correlation calculating circuit in the receiver of Example 1 by this invention. It is a figure which shows the example of calculation of the "flag 1" signal in one Example of the correlation calculating circuit in the receiver of Example 1 by this invention. It is a block diagram of the starting flag detection circuit in the receiver of Example 1 by this invention. It is a figure which shows the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 2 by this invention. It is a figure which shows the format example of the various flags (synchronization signal) in the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 2 by this invention. It is a figure showing the relationship between the measured seismic intensity I _INSTR used for the calculation of the information processing circuit in the receiver of one Example by this invention, and a seismic intensity class. It is a figure which shows the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 3 by this invention. It is a figure which shows the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 5 by this invention. It is a figure which shows the example of the epicenter name code in the format of the message | telegram information transmitted / received by the transmitter and receiver of Example 5 by this invention. It is a figure which shows an example of the "strong earthquake area of seismic intensity 4 or more" in the format of another message | telegram information transmitted / received by the transmission apparatus and receiver of Example 5 by this invention. It is a figure which shows the example of a combination of each flag in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 5 by this invention. It is a figure which shows operation | movement of the sliding correlation calculating means of the correlation calculating circuit in the receiver of Example 5 by this invention. It is a figure which shows the format of the message | telegram information transmitted / received in the transmission apparatus and receiver of Example 6 by this invention. It is a figure which shows the example of a combination of each flag in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 6 by this invention. It is a figure which shows the example of another combination of each flag in the format of the message | telegram information transmitted / received by the transmission apparatus and receiver of Example 6 by this invention. It is a figure which shows operation | movement of the sliding correlation calculating means of the correlation calculating circuit at the time of using the code sequence of FIG. It is a figure which shows operation | movement of the sliding correlation calculating means of the correlation calculating circuit at the time of using the code sequence of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Receiver 2 AC receiving part 3 AC information analysis part 4 Synchronization holding | maintenance and power supply control part 5 Antenna 6 Frequency conversion circuit 7 AD conversion circuit 8 FFT
9 AC Extraction Circuit 10 Correlation Operation Circuit 11 Activation Flag Detection Circuit 12 Frame Synchronization Detection Circuit 13 Frame Synchronization Holding Circuit 14 Timing Control Circuit 15 Activation Flag Monitoring Circuit 16 Error Correction Circuit 17 AC Decoding Circuit 18 Information Processing Circuit 19 First Power Switch 20 Second power switch 21 Power supply circuit 22 Warning generating means 101, 102, 103, 104 Sliding correlation calculating means 101a, 102a, 103a, 104a Memory 151, 152, 153, 154 Level determiners 155, 156, 157 OR adders 200, 200 ′, 201, 202 Code sequence

Claims (5)

A receiver for receiving an AC signal from a terrestrial digital television broadcast wave,
The telegram information storing the flag that also serves as the synchronization signal and the emergency early warning including emergency warning broadcast or emergency earthquake early warning information is transmitted as an AC signal having the same frame length as that of the TMCC signal from the transmitting device by the AC carrier. Pre-defined so that
In order to identify the presence or absence of emergency warning broadcasting and the presence or absence of emergency earthquake warning, the flag has N bits (N is a code string pattern of a plurality of flags including an emergency warning broadcasting flag and an emergency earthquake warning flag. A positive integer)
Storage means for storing in advance a pattern sequence corresponding to the plurality of code sequence patterns;
AC extraction means for receiving a terrestrial digital television broadcast wave and extracting an AC signal;
Correlation calculation means for executing a sliding correlation calculation on the extracted AC signal based on the pattern string read from the storage means, and generating a correlation coefficient as a result of the correlation calculation corresponding to the code string pattern of each system When,
Flag detection means for separating the peak value of the correlation coefficient corresponding to the code string pattern of each system into a signal representing the state of each flag and a signal for frame synchronization;
Flag monitoring means for identifying the presence / absence of an emergency warning broadcast and the presence / absence of an emergency earthquake warning from the state of each of the separated flags,
Frame synchronization detection means for detecting frame synchronization timing from the separated frame synchronization signal;
When it is identified by the flag monitoring means that there is an emergency warning broadcast, or there is an emergency earthquake warning, the contents of the emergency warning broadcast or the contents of the emergency warning broadcast in synchronization with the frame synchronization timing detected by the frame synchronization detection means AC information analysis means for analyzing the contents of the earthquake early warning ,
The receiver according to claim 1, wherein the correlation calculation unit individually identifies odd-numbered frames and even-numbered frames in the received AC signal, detects a peak value of a correlation coefficient, and determines a state of the flag . The flag, characterized in that the odd and even frames in a received AC signal, ing from the bit stream obtained by phase-inverted with respect to each other, the receiver of claim 1. The telegram information is specified in advance so that the emergency information of the same content is transmitted as eight AC signals in the synchronous modulation mode of mode 3 in the partial reception segment of the ISDB-T digital terrestrial television broadcast wave. And
The correlation calculating means includes means for performing diversity combining on the eight AC signals in order to obtain diversity gain, and performing the sliding correlation calculation on the AC signals after diversity combining. The receiver according to claim 1 or 2.   When the flag monitoring means identifies that there is an emergency warning broadcast or the presence of an emergency earthquake warning, the flag monitoring means comprises warning generating means for issuing a warning based on the content analyzed by the AC information analyzing means. The receiver according to any one of claims 1 to 3. The telegram information includes a predetermined difference set cyclic code parity bit,
5. The AC information analysis unit includes a decoding unit that performs error correction based on the differential cyclic code system and decodes the emergency bulletin, according to claim 1. Receiving machine.

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