JP2010068157A - Squelch and relay station apparatus for broadcast - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a squelch and a relay station apparatus capable of improving reliability of broadcast by improving reliability of output shut-off control based on identification information. <P>SOLUTION: The relay station apparatus 1 for broadcast performs prescribed processing including frequency conversion to a signal for broadcast, and has a digital squelch 5 for performing output shut-off control to the signal for broadcast or an intermediate signal generated based on the signal for broadcast. The digital squelch 5 determines whether a plurality of prescribed conditions for deciding the necessity of the output shut-off control have been met, and performs output shut-off control when determining that the plurality of conditions have been met. The plurality of conditions include: a first prescribed condition for determining the necessity of output shut-off control based on identification information included in the signal for broadcast; and a second condition, where the number of times for determining that the first condition has been met has reached a prescribed number of times. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a broadcast relay station apparatus that relays a broadcast signal and a squelch provided in the broadcast relay station apparatus.

  2. Description of the Related Art Conventionally, in a broadcast system for TV broadcasting, a broadcast relay station device is used to transmit broadcast radio waves to difficult viewing areas such as mountainous areas. This broadcast relay station device is installed inside a relay station built near the top of a mountain, receives broadcast waves transmitted from the broadcast station with an antenna, and performs signal amplification and noise removal here. Then, the transmission signal is formed again and transmitted as a broadcast wave toward the target difficult viewing area.

  FIG. 6 is a block diagram showing a configuration of a conventional broadcast relay station apparatus. The broadcast relay station apparatus 100 includes a reception antenna 101, a reception conversion unit 102, a transmission conversion unit 103, a PA (Power Amp) 104, and a transmission antenna 105. The reception antenna 101 receives a broadcast wave transmitted from a broadcast station (not shown) and outputs the broadcast wave as a broadcast signal to the reception conversion unit 102. The reception conversion unit 102 converts the broadcast signal into a predetermined intermediate signal, performs noise removal and signal amplification on the intermediate signal, and then outputs the intermediate signal to the transmission conversion unit 103. The transmission conversion unit 103 converts the intermediate signal into a broadcast signal having a target frequency, and outputs the broadcast signal to the PA 104. The PA 104 amplifies the broadcast signal and outputs it to the transmission antenna 105. The transmission antenna 105 transmits the broadcast signal as a broadcast wave.

  Here, each of the reception conversion unit 102 and the transmission conversion unit 103 includes squelches 102a and 103a. These squelches 102 a and 103 a suppress noise output from the broadcast relay station device 100. That is, an AGC (Automatic Gain Control) (not shown) is provided inside the reception conversion unit 102 and the transmission conversion unit 103, and the gain is automatically controlled using this AGC, whereby the reception conversion unit 102 and the transmission conversion unit are controlled. The output level from the unit 103 is maintained at a predetermined level. For this reason, when there is no broadcast wave for reasons such as when the broadcast is suspended, it is determined that the input level to the reception conversion unit 102 or the transmission conversion unit 103 is low, and noise is amplified with the maximum gain. Noise is output from the transmission conversion unit 103 and becomes unnecessary radiation. In order to prevent this problem, the squelch 102a, 103a determines the input level for the reception conversion unit 102 and the transmission conversion unit 103. If the input level is equal to or lower than a predetermined level (hereinafter “squelch level”), AGC For example, the output of the broadcast signal is shut off by turning off the amplification function (see, for example, Patent Document 1).

JP 2004-048141 A

  However, in the conventional broadcast relay station apparatus 100, the control of AGC in the squelch 102a, 103a is performed based only on the input level. For example, when there is no broadcast wave due to the suspension of broadcasting or the like, When the broadcast wave of the same channel has jumped into the broadcast relay station device 100 at a level equal to or higher than the squelch level, the squelch 102a, 103a may continue to output the broadcast signal.

  In order to prevent such a problem, it is conceivable to control the squelches 102a and 103a based on information other than the input level. For example, identification information for identifying whether or not a predetermined broadcast wave to be relayed (hereinafter “desired wave”) is included in the broadcast wave, and the squelches 102a and 103a are based on the identification information. It is conceivable that the broadcast wave is discriminated, and if it is the desired wave, the output of the broadcast signal is continued, and if it is not the desired wave, the output of the broadcast signal is shut off.

  However, when the output cutoff control based on the identification information is performed in this way, even if the broadcast wave is the desired wave, the identification information may be inconsistent even for a moment because the identification information is lost due to some interference. If it is determined, the squelch 102a, 103a executes the output cutoff control, and the broadcast is stopped. Also, depending on the situation such as fading, the state of the broadcast wave may become unstable, and the identification information may not be determined stably in the squelch 102a, 103a. There is a possibility that it will end.

  The present invention has been made in view of the above, and provides a squelch and a broadcast relay station apparatus that can improve the reliability of broadcasting by improving the reliability of output cutoff control based on identification information. For the purpose.

  In order to solve the above-described problems and achieve the object, the squelch according to claim 1 is disposed in a broadcast relay station apparatus that performs predetermined processing including frequency conversion on a broadcast signal, and the broadcast signal Alternatively, it is a squelch that performs output cutoff control of the intermediate signal generated based on the broadcast signal, and determines whether or not a plurality of predetermined conditions for determining whether or not the output cutoff control is necessary are satisfied. And a determination control means for performing the output blocking control when it is determined that the plurality of conditions are satisfied, and the plurality of conditions are required for the output blocking control based on the identification information included in the broadcast signal. It includes the predetermined first condition for determining NO and a second condition that the number of times that the first condition is determined to be satisfied has reached a predetermined number of times.

  The squelch according to claim 2 is the squelch according to claim 1, wherein the determination control means determines whether or not the first condition is satisfied at predetermined intervals, and the first condition is satisfied. It is determined that the second condition is satisfied when the predetermined number of times is continuously determined.

  The squelch according to claim 3 is the squelch according to claim 1 or 2, wherein the plurality of conditions satisfy the first condition within a predetermined time after it is determined that the second condition is satisfied. It includes a third condition that the state does not change.

  The squelch according to claim 4 is the squelch according to any one of claims 1 to 3, wherein the determination control means is determined after the determination of the first condition among the plurality of conditions. Information on the condition determination result is transmitted to a predetermined external device.

  The broadcast relay station apparatus according to claim 5 is a broadcast relay station apparatus that performs predetermined processing including frequency conversion on a broadcast signal, and the broadcast relay station apparatus according to any one of claims 1 to 3. A squelch is provided.

  According to the squelch according to claim 1 or the broadcast relay station device according to claim 5, the first condition for determining whether or not the output cutoff control is necessary based on the identification information, and the first condition is satisfied The second condition, which is that the number of times determined to have reached the predetermined number of times, is determined to determine whether or not to shut off the output. Therefore, when the identification information is lost due to some kind of obstruction, or because of fading effects, etc. Even when the wave becomes unstable, it is possible to reliably determine whether or not to shut off the output and improve the reliability of broadcasting.

  According to the squelch according to claim 2, the first condition is satisfied for some reason by determining that the second condition is satisfied when it is determined that the first condition is satisfied a predetermined number of times continuously. Even if it is mistakenly determined, the output is not shut off immediately, but the necessity of the output shut-off is determined after determining whether the first condition is satisfied, so that the reliability of broadcasting can be improved. it can.

  According to the squelch according to claim 3, since the third condition is that the satisfaction state of the first condition does not change within a predetermined time after it is determined that the second condition is satisfied, the second condition Even if it is determined that the condition is satisfied, if the first condition is not satisfied within the predetermined time thereafter, the output is not shut off, and the identification information is not detected temporarily. Thus, it is possible to prevent the broadcast from being stopped, and to improve the reliability of the broadcast.

  According to the squelch according to claim 4, in order to transmit the information about the determination result of the condition determined after the determination of the first condition to the predetermined external device, the determination result of the first condition is transmitted one by one. Compared to the case, it is possible to reduce the number of times of transmission of the determination result, for example, it is possible to extend the life of the relay for signal transmission, and since the determination state of the broadcast relay station device can be confirmed stably over a long period of time, Broadcast reliability can be improved.

  Hereinafter, an embodiment of a squelch and a broadcast relay station apparatus according to the present invention will be described in detail with reference to the accompanying drawings. [I] First, the basic concept of the present embodiment will be described, then [II] the specific contents of the present embodiment will be described, and [III] Finally, a modification to the present embodiment will be described. However, the present invention is not limited by the present embodiment.

[I] Basic concept of the present embodiment First, the basic concept of the present embodiment will be described. The broadcast relay station apparatus according to the present embodiment has a function of receiving a broadcast radio wave as an input signal and performing a process including frequency conversion on the broadcast radio broadcast system to generate an output signal. . In this type of broadcast relay station apparatus, an input signal is mixed with a signal having a predetermined frequency from an oscillator, and once converted into an intermediate signal for processing. In this state, signal noise is removed by the filter circuit, and necessary signal amplification or the like is performed. The intermediate signal that has undergone these processes is converted again and output to the same frequency as the input signal or an arbitrary frequency.

  A typical example of the broadcast relay station apparatus according to the present invention is a TV broadcast relay station apparatus. The broadcast relay station device is for relaying broadcast radio waves to difficult viewing areas such as mountainous areas in a TV broadcast system. In particular, the present invention relates to a broadcast signal that is intermediate between predetermined frequencies. A broadcast relay station device having a signal conversion function of converting the intermediate signal into a broadcast signal having a predetermined frequency after conversion to a signal. In the broadcast relay station apparatus to which the present embodiment is applied, a receiving station that receives broadcast radio waves and a transmitting station that transmits radio waves to difficult-to-view areas are separated and connected by a transmission path such as an optical fiber. It does not matter whether the separation type is a non-separation type in which the receiver and the transmitter are in one place. In the following embodiments, the broadcast relay station apparatus for relaying the broadcast radio wave will be described as an example. The configuration of the broadcast relay station apparatus can be roughly classified into a single channel power amplifier (SCPA) and a multi channel power amplifier (MCPA) according to a demultiplexing method, and the present invention can be similarly applied to any configuration. Hereinafter, an example of SCPA will be described.

  In addition, as a typical example of the broadcast relay station apparatus according to the present invention, there is a common level controller. The level controller for common hearing is provided as a receiving-side device in an apartment house, and adjusts gain variation for each reception channel to output a stable output signal to each dwelling unit via a coaxial cable or the like. . Even in the level controller for common hearing, the broadcast radio wave as an input signal is demultiplexed for each channel, and then an oscillator is temporarily used to remove an undesired frequency component by a SAW filter (surface acoustic wave filter) or the like. Are mixed with a predetermined frequency signal from the signal and converted into a predetermined intermediate frequency signal.

[II] Specific contents of the present embodiment Next, specific contents of the present embodiment will be described. First, the configuration of the squelch and the broadcast relay station apparatus according to the present embodiment will be described, and then various processes performed using the broadcast relay station apparatus will be described.

(Constitution)
FIG. 1 is a block diagram showing a configuration of a broadcast relay station apparatus according to the present embodiment. The broadcast relay station apparatus 1 is generally configured to include a reception antenna 2, a reception conversion unit 3, a transmission conversion unit 4, a digital squelch 5, a PA 6, and a transmission antenna 7.

  The receiving antenna 2 receives a broadcast wave transmitted from a broadcast station and outputs it as a broadcast signal to the reception conversion unit 3. The reception conversion unit 3 is an intermediate signal conversion unit that converts a broadcast signal into a predetermined intermediate signal and outputs the signal to the transmission conversion unit 4. The transmission conversion unit 4 is broadcast signal conversion means for converting an intermediate signal into a broadcast signal having a target frequency. In the reception conversion unit 3 and the transmission conversion unit 4, noise removal and signal amplification are performed on the intermediate signal. The digital squelch 5 will be described later. The PA 6 is an amplifying unit that amplifies the broadcast signal and outputs it to the switching unit. The transmission antenna 7 transmits a broadcast signal as a broadcast wave. Note that the reception antenna 2, the reception conversion unit 3, the transmission conversion unit 4, the PA 6, and the transmission antenna 7 can be configured in the same manner as in the prior art, and the details thereof are omitted.

(Configuration-Digital squelch)
Next, the configuration of the digital squelch 5 will be described in detail. The digital squelch 5 is for performing output cutoff control of a broadcast signal or an intermediate signal generated based on the broadcast signal, and corresponds to the squelch in the claims. FIG. 2 is a block diagram showing a configuration of the digital squelch 5 of FIG. The digital squelch 5 includes an input terminal 5a, an output terminal 5b, a demodulation unit 5c, a NIT acquisition unit 5d, a NIT determination unit 5e, a squelch control unit 5f, an input / output interface (hereinafter referred to as “input / output I / F”) 5g, and a channel indicator. 5h, channel setting SW 5i, synchronization indicator lamp 5j, NIT reception indicator lamp 5k, NIT setting SW 5m, squelch indicator lamp 5n, and control switch 5p.

  The input terminal 5a is an input unit that receives an input of a broadcast signal from a preceding device (here, the transmission conversion unit 4). The output terminal 5b is output means for outputting a broadcast signal to a subsequent device (PA6 in this case). The demodulator 5c acquires a broadcast signal from the line from the input terminal 5a to the output terminal 5b, demodulates the acquired broadcast signal, and outputs the demodulated signal to the NIT acquisition unit 5d.

  The NIT acquisition unit 5d is a NIT acquisition unit that acquires a Network Information Table (NIT) multiplexed on a broadcast signal and outputs the NIT (Network Information Table) to the NIT determination unit 5e. NIT is identification information for identifying a broadcast signal to be relayed by the broadcast relay station apparatus 1. However, the specific type of identification information is arbitrary, and instead of NIT, it includes SDT (Service Description Table), BIT (Broadcaster Information Table), EIT (Event Information Table), CDT (Common Data Table, optional Data Table). Information can be used.

  The NIT determination unit 5e is identification information determination means for determining whether or not the broadcast signal input through the input terminal 5a is a broadcast signal to be relayed by the broadcast relay station device 1. For example, the NIT determination unit 5e holds in advance the NIT of the broadcast signal to be relayed by the broadcast relay station device 1, and the NIT and the NIT acquired by the NIT acquisition unit 5d match each other. It is determined whether or not the broadcast signal is appropriate by determining whether or not to do so. The determination result of the NIT determination unit 5e when these two NITs match each other is referred to as “NIT match”, and the determination result of the NIT determination unit 5e when they do not match each other is referred to as “NIT mismatch”. The NIT determination result includes a case where the NIT could not be acquired (no NIT) and a case where there was some error in the NIT (NIT error). In any of these cases, for example, NIT match judge.

  The squelch control unit 5f is a squelch control unit that determines whether or not a plurality of predetermined conditions for performing output cutoff control are satisfied, and performs output cutoff control when the plurality of conditions are satisfied. Here, the predetermined conditions are roughly classified into three categories: “basic conditions”, “continuous conditions”, and “delay conditions”.

  The “basic condition” corresponds to the first condition in the claims, and for example, “the determination result of the NIT determination unit 5e is NIT mismatch”. In particular, the squelch control unit 5f determines whether or not the basic condition is satisfied at a predetermined interval. Specifically, since the NIT is included in the broadcast signal at an interval of once per second, the squelch control unit 5f determines whether the basic condition is satisfied each time this NIT is included.

  The “continuous condition” corresponds to the second condition in the claims, and is, for example, “the number of times that the basic condition has been satisfied has reached a predetermined number of times”. Although the setting of the predetermined number of times is arbitrary, the following description will be made assuming that the predetermined number of times = 2. The interval for counting the predetermined number of times is also arbitrary. When the number of times that the basic condition is satisfied within a predetermined time (for example, 10 seconds) reaches the predetermined number of times, it is determined that the continuous condition is satisfied. May be. However, in the following, when it is determined that the basic condition is satisfied for a predetermined number of times, it is determined that the continuous condition is satisfied. That is, even if it is determined that the basic condition is satisfied when the NIT arrives, if it is determined that the basic condition is not satisfied when the next NIT arrives one second later, the NIT Even if it is determined that the basic condition is satisfied when it arrives, the non-satisfied determination results of these two basic conditions are not continuous, so it is determined that the continuous condition is not satisfied.

  The “delay condition” corresponds to the third condition in the claims. For example, “the satisfaction condition of the basic condition does not change within a predetermined time after it is determined that the continuous condition is satisfied”. It is. Although the setting of the predetermined time (hereinafter “delay time”) is arbitrary, the following description will be made assuming that the delay time = 2 seconds. That is, even if it is determined that the continuous condition is satisfied, the delay condition is not satisfied if the basic condition is not satisfied when the NIT arrives within the next 2 seconds. Judge that it is.

  Here, the squelch control unit 5f performs the output cutoff control only when all of the basic condition, the continuous condition, and the delay condition are satisfied, and performs the output cutoff control when any one is not satisfied. Continue to output broadcast signals without doing so. For this reason, even when the identification information is lost due to some kind of interference, it is possible to reliably determine whether or not to shut off the output. The NIT determination unit 5e and the squelch control unit 5f correspond to the determination control means in the claims.

  The input / output I / F 5g is an input / output means for communicating with an external device by wire or wireless. For example, a remote monitoring device is assumed as the external device. The remote monitoring device is a device that is disposed in a broadcasting station, for example, and when it is difficult to directly operate the broadcasting relay station device 1 installed in a mountainous area, a control signal in a predetermined format is relayed for broadcasting. This is a device for remotely operating the broadcast relay station device 1 by transmitting to the station device 1.

  The channel indicator 5h is a display means for displaying the channel number of the broadcast signal to be relayed by the broadcast relay station device 1, and is constituted by, for example, a 7-segment indicator. The channel setting SW 5i is an input switch for setting a channel number of a broadcast signal to be relayed. The synchronization indicator lamp 5j is a display means for indicating the synchronization state with the broadcast signal, the NIT reception indicator lamp 5k is a display means for indicating the acquisition state of the NIT from the broadcast signal, and the squelch indicator lamp 5n is the output cutoff control state. These display means are configured using, for example, an LED (Liquid Emitting Diode). The NIT setting SW 5m is an input switch for setting the NIT of a broadcast signal to be relayed.

  The control switch 5p is instruction means for outputting the broadcast signal to the output terminal 5b in a so-called through state by automatically canceling the output cutoff control. When the control switch 5p is pressed, the control switch 5p The pressed state is mechanically held until the switch 5p is pressed again, and while the pressed state is held, the output cutoff control is released regardless of whether the basic condition and the continuous condition are satisfied.

(processing)
Next, various processes performed in the digital squelch 5 of the broadcast relay station apparatus 1 will be described. This process is roughly divided into a setting process for setting a channel and NIT in the broadcast relay station apparatus 1 and a relay process for relaying a broadcast signal.

(Processing-Setting processing)
First, the setting process will be described. FIG. 3 is a flowchart of the setting process. This setting process is started at an arbitrary timing prior to the relay process, and is started when the operator presses the channel setting SW 5i while a broadcast signal is being input to the input terminal 5a. When the channel setting SW 5i is pressed, the NIT acquired by the NIT acquisition unit 5d from the broadcast signal demodulated by the demodulation unit 5c and the channel number specified by a predetermined method based on the frequency of the broadcast signal are Displayed on the channel display. For example, the NIT and the channel number are alternately displayed. When the number of digits of the NIT is larger than the number of digits displayed on the channel display unit, the NIT is divided into a plurality of pieces and sequentially displayed (SA1). The operator confirms these channel numbers and NIT display contents, and if they match the desired wave channel number and NIT contents, the NIT setting SW5m is pressed to instruct NIT setting (SA2). . Receiving this instruction, the NIT determination unit 5e (SA2, Yes) holds the NIT displayed on the channel display unit at that time (SA3). At this time, synchronization processing is performed to match the arrival timing of the NIT with the acquisition / determination timing of the NIT. This completes the setting process.

(Processing-Relay processing)
Next, the relay process will be described. FIG. 4 is a flowchart of the relay process. The NIT determination unit 5e first determines basic conditions. In other words, the NIT determination unit 5e determines whether or not the NIT acquired by the NIT acquisition unit 5d from the broadcast signal demodulated by the demodulation unit 5c and the NIT held internally by the setting process match each other. Is determined (SB1). Then, when the NIT matches (when the determination result is OK) (SB1, Yes), the NIT determination unit 5e assumes that the basic condition is not satisfied, and performs the output cutoff control by the squelch control unit 5f. Continue relaying.

  On the other hand, when the NITs do not match (in the case of the determination result NG) (SB1, No), the NIT determination unit 5e determines the continuous condition as the basic condition is satisfied. That is, the NIT determination unit 5e counts the number of times the determination result is NIT mismatch, and determines whether this number has reached 2 (SB2). If the determination result is determined to be NIT match before the number of times reaches 2, the count is reset assuming that the continuous condition is not satisfied (SB3).

  Further, every time the NIT determination unit 5e determines the continuous condition as described above, the NIT determination unit 5e transmits a signal indicating the determination result to the remote monitoring device via the input / output I / F 5g (SB4, 5). That is, every time the basic condition is determined (every time NIT match / mismatch is determined), a signal indicating the determination result may be transmitted to the remote monitoring device. The NIT is, for example, once per second. Since broadcasts are made at regular intervals, especially when signal transmission is performed by the contact operation of a relay provided in the digital squelch, the number of relay contact operations becomes enormous and the life of the relay is shortened. is there. For this reason, in this embodiment, the signal transmission frequency to the remote monitoring device is not performed every time the basic condition is determined, but is performed every time the continuous condition is determined. To extend the life of the relay. Specifically, for example, the output to the remote monitoring device is a relay contact output, the contact is open during normal times (when the basic conditions are not satisfied or during a power failure), and the contacts are open when the basic conditions and continuous conditions are satisfied. By setting it to Close, signal transmission is performed.

  When it is determined in SB2 that the number of times has reached 2 (SB2, Yes), the NIT determination unit 5e determines the delay condition as the continuous condition is satisfied. That is, the NIT determination unit 5e uses a timer (not shown) to determine whether or not the delay time of 2 seconds has elapsed after the number of times the determination result has become NIT mismatch reaches two (SB6). . If the determination result is determined to be NIT match before the delay time elapses (SB1, Yes), it is determined that the delay condition is not satisfied, and the count of the continuous condition is reset in SB3 and the timer is Reset (SB3). On the other hand, when the delay time has elapsed (SB6, Yes), the NIT determination unit 5e executes output cutoff control assuming that the delay condition is satisfied (SB7). That is, the NIT determination unit 5e outputs a control signal that instructs the squelch control unit 5f to shut off the output, and the squelch control unit 5f that receives this control signal cuts off the output of the broadcast signal to the output terminal 5b. To do. By such processing, output cutoff control is performed only when all three of the basic condition, the continuous condition, and the delay condition are satisfied.

  Thereafter, the NIT determination unit 5e monitors the fulfillment state of the basic condition (SB8), and when the basic condition is not satisfied (SB8, No), determines to cancel the output cutoff control. Then, a control signal for instructing the squelch control unit 5f to cancel the output cutoff is output (SB9).

  FIG. 5 is a timing chart showing the NIT determination result by the NIT determination unit 5e and the output cutoff control state by the squelch control unit 5f. The basic condition is satisfied by determining that the NIT does not match at the time t1, but since the next NIT determination result at the time t2 is NIT matching, the continuous condition is not satisfied and the output cutoff control is not executed (FIG. 5 OFF). After that, the NIT mismatch is continuous twice at time t3, and the continuous condition is satisfied. However, because the next NIT determination result at time t4 is NIT match, the delay condition is not satisfied and the output cutoff control is executed. Not. Further, after that, the NIT mismatch is continued twice at time t5 and the continuous condition is satisfied, and the delay condition is satisfied at time t6, whereby the output cutoff control is executed (ON in FIG. 5). Thereafter, the determination result of the next NIT at the time t7 is NIT match, so the basic condition is not satisfied, and the output cutoff control is released (OFF in FIG. 5).

(effect)
As described above, according to the present embodiment, the basic condition for determining whether or not the output cutoff control is necessary based on the NIT, and the continuous condition that the number of times that the basic condition has been satisfied has reached a predetermined number of times. Therefore, even if the identification information is missing due to some interference or the broadcast wave becomes unstable due to fading, etc. It is possible to reliably determine whether or not it is necessary and improve the reliability of broadcasting.

  In addition, when it is determined that the basic condition is satisfied for a predetermined number of times, it is determined that the continuous condition is satisfied, so that even if it is erroneously determined that the basic condition is satisfied for some reason, it is output immediately. Instead of blocking, it is further determined whether the output blocking is necessary after determining whether or not the basic condition is satisfied, so that the reliability of broadcasting can be improved.

  In addition, even if it is determined that the continuous condition is satisfied because it includes a delay condition that the satisfaction state of the basic condition does not change within a predetermined time after it is determined that the continuous condition is satisfied. If the basic conditions are not satisfied within a predetermined time after that, the output is not shut down, so that it is possible to prevent the broadcast from being stopped when the identification information is not detected temporarily. Reliability can be improved.

  In addition, in order to transmit the information regarding the determination result of the continuous condition determined after the determination of the basic condition to the remote monitoring device, the number of transmissions of the determination result is smaller than when the determination result of the basic condition is transmitted one by one. Thus, the life of the relay for signal transmission can be extended, and the determination state of the broadcast relay station apparatus can be confirmed stably over a long period of time, so that the reliability of broadcasting can be improved.

[III] Modifications to Embodiments Although the embodiments of the present invention have been described above, the specific configuration and means of the present invention are within the scope of the technical idea of each invention described in the claims. Can be arbitrarily modified and improved. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved.

(About the configuration of the broadcast relay station device)
Further, in the present embodiment, the arrangement position of the digital squelch 5 inside the broadcast relay station device can be arbitrarily changed, and may be provided, for example, before the transmission conversion unit 4. Moreover, the specific method of output interruption | blocking control can also be changed, and it is good also as turning off the power supply of PA6, for example instead of interrupting | blocking the output to the output terminal 5b. Alternatively, the function of the digital squelch 5 may be built in the reception conversion unit 3, the transmission conversion unit 4, or the PA 6.

(Basic conditions, continuous conditions, and delay conditions)
Whether or not the output cutoff control is necessary may be determined by omitting one of the continuous condition and the delay condition. Alternatively, in addition to the basic condition, the continuous condition, and the delay condition, the output cutoff control may be performed on condition that an arbitrary additional condition is satisfied.

(About sending judgment results to a remote monitoring device)
A signal indicating this determination result may be transmitted to the remote monitoring apparatus via the input / output I / F 5g each time the delay condition is determined instead of every time the continuous condition is determined. In addition, when transmitting a signal every time the delay condition is determined in this way, the signal transmission is not performed unless the delay condition is determined (unless the basic condition and the continuous condition are satisfied). When the basic condition and the continuous condition are not satisfied a predetermined number of times or a predetermined time or more, a signal indicating that may be transmitted.

It is a block diagram which shows the structure of the broadcast relay station apparatus which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the digital squelch of FIG. It is a flowchart of a setting process. It is a flowchart of a relay process. It is a timing chart which shows the NIT determination result by a NIT determination part, and the output cutoff control state by a squelch control part. It is the block diagram which showed the structure of the conventional broadcast relay station apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Broadcast relay station apparatus 2,101 Reception antenna 3,102 Reception conversion part 4,103 Transmission conversion part 5 Digital squelch 5a Input terminal 5b Output terminal 5c Demodulation part 5d NIT acquisition part 5e NIT determination part 5f Squelch control part 5g Input / output I / F
5h Channel indicator 5i Channel setting SW
5j Sync indicator 5k NIT reception indicator 5m NIT setting SW
5n Squelch indicator light 5p Control switch 6, 104 PA
7, 105 Transmitting antenna 102a, 103a Squelch

Claims (5)

A squelch that is disposed in a broadcast relay station apparatus that performs predetermined processing including frequency conversion on a broadcast signal, and that performs output cutoff control of the broadcast signal or an intermediate signal generated based on the broadcast signal. ,
Determination control means for determining whether or not a plurality of predetermined conditions for determining whether or not the output cutoff control is necessary is satisfied, and performing the output cutoff control when it is determined that the plurality of conditions are satisfied With
The plurality of conditions include the predetermined first condition for determining whether or not the output cutoff control is necessary based on identification information included in the broadcast signal, and a predetermined number of times that the first condition is determined to be satisfied. Including a second condition that has been reached
A squelch characterized by The determination control means determines whether or not the first condition is satisfied at a predetermined interval, and the second condition is satisfied when it is determined that the first condition is satisfied and the predetermined number of times continuously. To determine,
The squelch according to claim 1. The plurality of conditions include a third condition in which a satisfaction state of the first condition does not change within a predetermined time after it is determined that the second condition is satisfied,
The squelch according to claim 1 or 2, wherein The determination control means transmits information related to a determination result of a condition determined after the determination of the first condition among the plurality of conditions to a predetermined external device;
The squelch according to any one of claims 1 to 3, wherein A broadcast relay station apparatus that performs predetermined processing including frequency conversion on a broadcast signal,
The squelch according to any one of claims 1 to 3,
A broadcast relay station apparatus comprising:

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