WO2009110070A1

WO2009110070A1 - Broadcasting equipment

Info

Publication number: WO2009110070A1
Application number: PCT/JP2008/053873
Authority: WO
Inventors: 規之鈴木; 充彦山本
Original assignee: 富士通株式会社
Priority date: 2008-03-04
Filing date: 2008-03-04
Publication date: 2009-09-11
Also published as: JPWO2009110070A1; JP4894950B2

Abstract

It is made possible during broadcasting of a program to check out whether the channel being used in broadcasting suffers interference. Out of the carrier waves which constitute the channel being used, the carrier waves having predetermined frequency bands are erased, and the program is broadcast using the channel with the carrier waves having predetermined frequency bands erased. Then, the program being broadcast is received, and the amplitude level of the erased carrier waves having predetermined frequency bands is measured. When the measured amplitude level is less than the threshold value set in advance, it is determined that the channel being used suffers no interference. When the channel being used is judged suffering interference, another one channel is selected out of all the channels usable for broadcasting and the channel is switched over to that one and broadcasting of the program is continued.

Description

Broadcast equipment

The present invention relates to a broadcasting apparatus that broadcasts a program using a single channel composed of a plurality of frequency carriers.

2. Description of the Related Art Conventionally, some broadcasting apparatuses using digital OFDM (Orthogonal Frequency Division Multiplexing Modulation) technology broadcast programs using one channel selected from all channels that can be used for broadcasting. .

As a method for selecting a channel, for example, in Patent Document 1, for each channel, the amplitude level of a carrier (carrier wave) of a plurality of frequencies constituting the channel is measured, and interference is not caused based on the measured amplitude level. A method for selecting a single channel is disclosed.

Even when such a broadcasting device starts broadcasting using a channel that does not receive interference, for example, when the broadcasting device moves from place to place during broadcasting, it starts to receive interference during broadcasting. There is.

In order to detect interference that has begun to be received during broadcasting, the conventional broadcasting apparatus temporarily stops broadcasting, and then measures the amplitude level of each carrier constituting the channel used for broadcasting, and measures the measured amplitude. Based on the level, a method of determining whether or not the channel used for broadcasting is receiving interference has been studied.

However, in this determination method, since the broadcast of the program is temporarily stopped, the reception of the program by a playback device that plays back the received program (for example, a mobile phone capable of playing back the program being broadcast) is also interrupted. There was a risk of interrupting program playback.

Although there is a technology in which the playback device is equipped with a buffer and the program playback is temporarily suspended to allow the program to be continuously played even if there is a temporary interruption in the reception of the carrier, Since this is shorter than the time required to measure the amplitude level of the carrier, it has not been a practical measure.

JP-A-8-237732

By the way, the above-mentioned conventional broadcasting apparatus has a problem that it cannot be confirmed whether or not a channel being used for broadcasting is interfered with during the broadcasting of the program. That is, when a conventional broadcasting device attempts to measure the amplitude level of each carrier constituting a channel used for broadcasting during program broadcasting, the amplitude level of the carrier broadcast by the own device is reflected in the measurement result. In order to prevent the carrier broadcast by the device from being reflected in the measurement result, it is necessary to temporarily stop the broadcast of the program. Therefore, the conventional broadcasting apparatus has a problem that it is not possible to confirm whether or not the channel being used for the broadcast is interfered with during the broadcast of the program.

Therefore, this broadcasting device has been made to solve the above-described problems of the prior art, and it is possible to confirm whether or not the channel being used for broadcasting is subject to interference during the broadcasting of the program. An object is to provide a simple broadcasting apparatus.

In order to solve the above-described problems and achieve the object, the disclosed broadcasting apparatus is a broadcasting apparatus that broadcasts a program using one channel composed of carrier waves of a plurality of frequencies, and is in use. The program is broadcast using a carrier erasure unit for erasing a carrier of a part of the frequency band from among the carriers constituting the channel, and a channel in which the carrier of the part of the frequency band is erased by the carrier erasure unit. Broadcast means, amplitude level measuring means for receiving the program broadcast by the broadcast means, and measuring the amplitude level of the carrier wave in the frequency band erased by the carrier wave erasing means, and measured by the amplitude level measurement means. And determining means for determining that the channel being used is not subject to interference when the amplitude level is less than a preset threshold value. The required.

Further, in the above broadcasting apparatus, the carrier wave erasing unit erases a carrier wave having a frequency band near the middle from all the frequency bands of the carrier wave constituting the channel being used, The amplitude level measurement means needs to measure the amplitude level of the carrier wave cut out by a filter that eliminates the carrier wave constituting the channel in use other than the carrier wave having a frequency band near the middle.

Further, in the above broadcasting apparatus, when the determining unit determines that the channel being used is subject to interference, the broadcasting unit is newly selected from all the channels usable for broadcasting. It is necessary to switch to this channel and continue broadcasting the program.

In the above broadcasting apparatus, the broadcasting means needs to select a channel having the lowest amplitude level of a carrier wave constituting the channel from all channels usable for broadcasting.

Further, in the above broadcasting apparatus, when broadcasting a program by switching channels by the broadcasting means, channel number notifying means for notifying a playback apparatus that reproduces the received program of the channel number of the channel after switching. Further preparation is required.

According to the disclosed broadcast apparatus, it is possible to confirm whether or not the channel being used for the broadcast is receiving interference during the broadcast of the program.

FIG. 1 is a diagram for explaining the outline and features of the broadcasting apparatus according to the first embodiment. FIG. 2 is a block diagram showing the configuration of the broadcast apparatus. FIG. 3 is a block diagram illustrating a configuration of the transmission unit. FIG. 4 is a block diagram showing a configuration of the OFDM circuit. FIG. 5 is a diagram for explaining processing by the carrier erasing unit. FIG. 6 is a block diagram illustrating a configuration of the receiving unit. FIG. 7 is a diagram illustrating an example of information stored in the reception information storage unit. FIG. 8 is a flowchart showing the flow of processing by the broadcasting apparatus. FIG. 9 is a block diagram illustrating the configuration of the transmission unit according to the second embodiment. FIG. 10 is a flowchart illustrating a process flow of the broadcast apparatus according to the second embodiment.

Explanation of symbols

10

Broadcasting device

21, 22, 23 Transmitter 21a OFDM (Orthogonal Frequency Division Multiplexing) circuit 21a1 Data receiver 21a2 IFFT (Inverse Fast Fourier Transform) Data 21a3 ) Circuit 21c ROM (Read Only Memory) (RAM: Random Access Memory)
21d CPU (Central Processing Unit)
21e Channel number notification unit 30 Reception unit 31 RFIF circuit 32 Filter 33 Amplitude level measurement circuit 34 Reception control unit 40 Storage unit 41 Reception information storage unit 50 Control unit 51 Reception information generation unit 52 Channel control unit

Hereinafter, embodiments of a broadcasting apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

In the following first embodiment, the outline and features of the broadcasting apparatus according to the first embodiment, the configuration of the broadcasting apparatus, the processing flow of the broadcasting apparatus will be described in order, and finally the effects of the first embodiment will be described.

[Outline and Features of Broadcasting Apparatus According to Embodiment 1]
First, the outline | summary and characteristic of the broadcasting apparatus based on Example 1 are demonstrated using FIG. FIG. 1 is a diagram for explaining the outline and features of the broadcasting apparatus according to the first embodiment.

The broadcasting apparatus according to the first embodiment outlines broadcasting a program using one channel constituted by carriers (carrier waves) of a plurality of frequencies, and the channel being used for broadcasting during the broadcasting of the program. The main feature is to check whether or not the device is receiving interference.

That is, as shown in FIGS. 1A and 1C, the broadcasting apparatus α erases carriers in some frequency bands from the carriers constituting the channel in use during the broadcast of the program. Broadcast the program using the selected channel.

Then, the broadcast device α receives the broadcast program, and measures the amplitude level of the carrier in the erased frequency band.

Here, when the measured amplitude level is less than a preset threshold, the broadcasting device α determines that the channel being used is not receiving interference.

For example, as shown in FIG. 1A, the broadcasting device α is in the case where another broadcasting device at a close position is not broadcasting a program using a channel having a carrier of the same frequency band. The program broadcast by itself is received as it is. Therefore, as shown in FIG. 1B, the broadcast device α obtains a measurement result that the amplitude level of the carrier in the measured frequency band (erased carrier) is less than a preset threshold value. It is determined that the channel inside is not interfered.

On the other hand, as shown in FIG. 1C, the broadcasting device α uses the channels in which the broadcasting device α and the broadcasting device β located in close proximity have carriers of the same frequency band to each of the individual programs. In the case of broadcasting, the broadcast device α simultaneously receives the program broadcast by the own device and the program broadcast by the broadcast device β, so that the carrier broadcast by the broadcast device β is broadcast by the own device. It is in a state of being mixed with the carrier. Therefore, as shown in FIG. 1D, the broadcast device α obtains a measurement result that the amplitude level of the carrier of the measured frequency band is equal to or higher than a preset threshold value. Judge that you are receiving.

For this reason, the broadcasting apparatus according to the first embodiment can confirm whether or not the channel being used for broadcasting is subject to interference during the broadcasting of the program, as described above. .

[Broadcaster configuration]
Next, the configuration of the broadcasting apparatus 10 shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a block diagram showing the configuration of the broadcast apparatus. FIG. 3 is a block diagram illustrating a configuration of the transmission unit. FIG. 4 is a block diagram showing a configuration of the OFDM circuit. FIG. 5 is a diagram for explaining processing by the carrier erasing unit. FIG. 6 is a block diagram illustrating a configuration of the receiving unit. FIG. 7 is a diagram illustrating an example of information stored in the reception information storage unit. As illustrated in FIG. 2, the broadcasting device 10 includes

transmission units

21, 22, and 23, a reception unit 30, a storage unit 40, and a control unit 50.

Among these, the

transmission units

21, 22, and 23 execute broadcast processing of programs stored in a server (not shown) or the like. The

transmission units

21, 22, and 23 have the same configuration. For example, the transmission unit 21 broadcasts a program with a channel number “Ch1”, and the transmission unit 22 broadcasts a program with a channel number “Ch2”. It is assumed that the same processing is executed except that the program is broadcast on the channels assigned to the

transmission units

21, 22, and 23, such as the unit 23 broadcasts the program with the channel number “Ch3”. The transmission unit 21 will be described.

As shown in FIG. 3, the transmission unit 21 includes an OFDM circuit 21a, an RFIF circuit 21b, a ROM (or RAM) 21c, and a CPU 21d. The transmitting unit 21 corresponds to “carrier wave erasing unit” and “broadcasting unit” recited in the claims.

The OFDM circuit 21a converts the program into a carrier having a plurality of frequencies. Specifically, as shown in FIG. 4, the OFDM circuit 21a includes a data receiving unit 21a1, an IFFT circuit 21a2, a carrier erasing unit 21a3, and a data output unit 21a4.

The data receiving unit 21a1 receives program data through the control unit 50, multiplexes (interleaves), convolves, and maps the program data, and inputs the data to the IFFT circuit 21a2.

The IFFT circuit 21a2 performs inverse fast Fourier transform (IFFT: Inverse Fast Fourier Transform) on the program data received from the data receiving unit 21a1 to generate one channel composed of carriers of a plurality of frequencies, and a carrier erasing unit Input to 21a3.

The carrier erasure unit 21a3 erases carriers in some frequency bands from among the carriers constituting the channel in use. More specifically, the carrier erasure unit 21a3 configures a channel received from the IFFT circuit 21a2 when erasing carriers in some frequency bands under the control of the control unit 50. Among 10 carriers (see (A) in FIG. 5), 10 carriers having a frequency band near the middle of all frequency bands of the carrier are deleted (see (B) in FIG. 5). The data is input to the data output unit 21a4.

On the other hand, when the carrier erasure unit 21a3 is not controlled by the control unit 50, the 432 carriers (see FIG. 5A) constituting the channel received from the IFFT circuit 21a2 are directly output as data. It inputs into part 21a4.

The data output unit 21a4 outputs the channel received from the carrier erasing unit 21a3 to the RFIF circuit 21b.

The RFIF circuit 21b frequency-converts and broadcasts the channel input from the OFDM circuit 21a.

Returning to the description of FIG. 3, the ROM 21c stores data and programs necessary for various processes by the CPU 21d. The CPU 21d has an internal memory for storing a control program, a program defining various processing procedures, and required data, and controls processing by the transmission unit 21. For example, the CPU 21d controls the carrier erasure unit 21a3 so as to switch whether or not to execute the process of erasing the carrier.

Returning to the description of FIG. 2, the receiving unit 30 executes a program receiving process. Specifically, as illustrated in FIG. 6, the reception unit 30 includes an RFIF circuit 31, a filter 32, an amplitude level measurement circuit 33, and a reception control unit 34.

The RFIF circuit 31 converts the frequency of the received channel and inputs it to the filter 32. The filter 32 includes a filter that eliminates carriers other than the predetermined frequency band, cuts out a carrier for measuring the amplitude level from the channel received from the RFIF circuit 31, and inputs the carrier to the amplitude level measuring circuit 33.

Specifically, the filter 32 generates reception information under the control of the reception information generation unit 51 described later (in other words, the amplitude level of the carrier constituting the channel for each of all channels usable for broadcasting). Is measured), for each channel that can be used for broadcasting, a process of cutting out a plurality of frequency carriers constituting the channel from the channel received from the RFIF circuit 31 is executed.

Further, the filter 32 is controlled by a channel control unit 52 described later to determine whether or not the channel being used is receiving interference (in other words, the frequency band carrier erased by the carrier erasing unit 21a3). When measuring the amplitude level), a process of cutting out the carrier of the frequency band erased by the carrier erasure unit 21a3 from the channel received from the RFIF circuit 31 is executed. The filter 32 corresponds to “amplitude level measuring means” recited in the claims.

The amplitude level measurement circuit 33 measures the amplitude level of the carrier input from the RFIF circuit 31. The amplitude level measuring circuit 33 corresponds to “amplitude level measuring means” recited in the claims.

The reception control unit 34 has an internal memory for storing a control program, a program defining various processing procedures, and necessary data, and controls various processes by the reception unit 30. For example, the reception control unit 34 controls the filter 32 to switch the frequency band of the carrier to be cut out.

Returning to the description of FIG. 2, the storage unit 40 stores data and programs necessary for various processes by the control unit 50. Particularly as closely related to the present invention, the storage unit 40 includes a reception information storage unit 41.

As shown in FIG. 7, the reception information storage unit 41 stores channel information and an amplitude level in association with the channel number. Here, “channel information” is information indicating whether or not the channel is not subject to interference. For example, “◯” means that the channel is not subject to interference, and “×” indicates that the channel is not subject to interference. Means that the channel is subject to interference. “(DB)” is a unit (decibel) representing the magnitude of the amplitude level.

The control unit 50 has an internal memory for storing a control program, a program that defines various processing procedures, and necessary data, and controls various processes performed by the broadcasting apparatus 10 using these. In particular, as closely related to the present invention, the control unit 50 includes a reception information generation unit 51 and a channel control unit 52.

The reception information generation unit 51 generates reception information for selecting one channel from all channels usable for broadcasting. Specifically, when the reception information generation unit 51 receives a broadcast start instruction from the user or receives a request for updating reception information from the channel control unit 52, the reception information generation unit 51 sets a channel for each of all channels that can be used for broadcasting. The receiving unit 30 is controlled so as to measure the amplitude level of the carrier to be configured.

Subsequently, the reception information generation unit 51 reads the measurement result of the amplitude level of the carrier constituting each channel from the reception unit 30, and is a channel that does not receive interference based on a preset threshold value for each channel. It is determined whether or not. More specifically, the reception information generation unit 51 determines that a channel whose measured amplitude level is less than the threshold is a channel that does not receive interference, and performs interference for a channel whose measured amplitude level is greater than or equal to the threshold. It is determined that it is a channel that receives

Then, the reception information generation unit 51 generates reception information in which channel information and amplitude levels are stored in association with channel numbers for each of the channels that can be used for broadcasting, and the reception information storage unit 41 stores the reception information. Store.

The reception information generation unit 51 receives a request for updating reception information from the channel control unit 52, and when receiving information is generated again, the reception information generation unit 51 is a channel that is interfered with channel information of a channel that is broadcasting a program. It is assumed that “x” which means that is stored.

The channel control unit 52 determines that the channel in use is not receiving interference when the measured amplitude level is less than a preset threshold value. The channel control unit 52 corresponds to “broadcast means” and “determination means” recited in the claims.

Specifically, the channel control unit 52, based on the reception information generated by the reception information generation unit 51 (see FIG. 7), channel numbers (for example, Ch1 to Ch5,...) Of all channels that can be used for broadcasting. The channel number (for example, Ch2) having the lowest amplitude level of the carrier constituting the channel is selected from (.).

Subsequently, the channel control unit 52 controls the transmission unit corresponding to the selected channel number (for example, the transmission unit 22 corresponding to Ch2) to start broadcasting the program.

Here, the channel control unit 52 controls the transmitting unit that is broadcasting the program so as to erase the carriers in some frequency bands every time a certain time elapses, and sets the amplitude level of the carriers in the erased frequency bands. The receiving unit 30 is controlled to measure.

Subsequently, the channel control unit 52 reads the measurement result of the amplitude level of the carrier in the frequency band erased by the carrier erasing unit 21a3 from the receiving unit 30, and whether or not the measured amplitude level is less than a preset threshold value. By determining whether or not the channel being used is receiving interference.

Here, if the channel control unit 52 determines that the channel being used is not subject to interference, the channel control unit 52 controls the transmission unit that is broadcasting the program so as to continue broadcasting the program on the channel being used.

On the other hand, the channel control unit 52 requests the reception information generation unit 51 to update the reception information when determining that the channel being used is subject to interference.

Based on the reception information updated by the reception information generation unit 51, the channel control unit 52 again selects one channel number from the channel numbers that are not subject to interference, and stops broadcasting the program. The transmitter that is broadcasting the program is controlled, and the transmitter corresponding to the newly selected channel number is controlled to continue broadcasting the program. In other words, if it is determined that the channel being used is subject to interference, the channel for broadcasting the program is changed to a channel that is not subject to interference.

[Processing by broadcasting equipment]
Next, the process by the broadcast apparatus 10 is demonstrated using FIG. FIG. 8 is a flowchart showing the flow of processing by the broadcasting apparatus. Note that the processing by the broadcasting device 10 ends when the driving of the broadcasting device 10 is stopped.

As shown in FIG. 8, when receiving a broadcast start instruction from the user (Yes in step S1001), the broadcasting device 10 associates channel information, amplitude levels, and channel numbers with respect to all channels that can be used for broadcasting. Is stored (step S1002), and broadcast of the program is started using one channel selected from the channels not subject to interference (step S1003).

After that, when a certain time has elapsed (Yes in step S1004), the broadcasting device 10 deletes carriers in some frequency bands from the carriers constituting the channel being used (step S1005), and the deleted frequency band is deleted. The carrier amplitude level is measured (step S1006), and it is determined whether the channel being used is receiving interference (step S1007).

Here, if the broadcasting device 10 determines that the channel being used is not subject to interference (Yes at step S1007), the broadcasting device 10 continues to broadcast the program on the channel being used again until a predetermined time has elapsed (step S1007). S1004).

On the other hand, if it is determined that the channel being used is subject to interference (No at step S1007), the broadcast device 10 updates the received information (step S1008), and the program is set to the newly selected channel. The broadcast channel is changed (step S1009), and the broadcast of the program is continued until a predetermined time passes again (step S1004).

[Effect of Example 1]
As described above, according to the first embodiment, during the broadcast of a program, it is possible to confirm whether or not the channel being used for the broadcast is subject to interference. That is, since the broadcasting apparatus 10 according to the first embodiment measures the amplitude level of the carrier in the frequency band erased from the carriers constituting the channel used for broadcasting, the amplitude level of the carrier broadcast by the own apparatus is determined. Without being reflected in the measurement result, it is possible to confirm whether or not the channel being used for the broadcast is receiving interference during the broadcast of the program.

In addition, according to the first embodiment, since the carrier whose frequency band is located near the center is deleted from the carriers constituting the channel in use, it is determined whether or not the channel being used for broadcasting is subject to interference. It is possible to determine clearly.

Further, according to the first embodiment, it is possible to continue broadcasting the program even when it is determined that the channel being used is receiving interference.

By the way, in the first embodiment, when the broadcasting device 10 changes the channel for broadcasting the program, in order for the playback device that was playing the program being broadcast to continue playing the program, You need to get the channel number of the channel.

Therefore, in the second embodiment, a case will be described in which the broadcasting device 10 notifies the channel number after switching. In the second embodiment, the configuration of the broadcasting device according to the second embodiment and the flow of processing by the broadcasting device will be described, and then the effects of the second embodiment will be described.

[Configuration of Broadcasting Apparatus According to Second Embodiment]
First, the configuration of the broadcasting apparatus 10 according to the second embodiment will be described with reference to FIG. FIG. 9 is a block diagram illustrating the configuration of the transmission unit according to the second embodiment. The configuration of the broadcasting device 10 according to the second embodiment is different from the broadcasting device 10 according to the first embodiment in the following points, except that a channel number notification unit 21e is newly provided.

That is, when the transmission unit corresponding to the newly selected channel number is controlled to continue broadcasting the program, the channel control unit 52 broadcasts the channel number to the channel number notification unit 21e provided in the transmission unit. Control to do.

The channel number notification unit 21e notifies the channel number after switching to the playback device that plays back the received program. Specifically, the channel number notification unit 21e broadcasts the channel number assigned to the transmission unit 21 via the RFIF circuit 21b when receiving control from the channel control unit 52 to continue broadcasting the program. Then, the channel number after switching is notified to the playback device. Here, the method of notifying the channel number is not limited to the present invention, and the program may be broadcast with the channel number superimposed on the program, or may be notified using another application such as e-mail. It may be.

[Processing by Broadcast Apparatus According to Second Embodiment]
Next, processing performed by the broadcasting apparatus according to the second embodiment will be described with reference to FIG. FIG. 10 is a flowchart illustrating a process flow of the broadcast apparatus according to the second embodiment. In the following, differences from the processing by the broadcasting apparatus according to the first embodiment will be described in detail.

As shown in FIG. 10, when the broadcasting apparatus 10 determines that the channel being used is subject to interference (No at Step S2007), it updates the received information (Step S2008) and reselects one channel. The channel for broadcasting the program is changed (step S2009).

Then, the broadcasting device 10 notifies the playback device of the channel number after switching (step S2010), and continues broadcasting until a predetermined time has passed again (step S2004).

[Effect of Example 2]
As described above, according to the second embodiment, it is possible to continuously reproduce the program being broadcast on the playback device that was playing the program being broadcast.

The embodiments 1 and 2 have been described so far, but the present invention may be implemented in various different forms other than the embodiments described above. Therefore, another embodiment will be described below as a third embodiment.

For example, in the second embodiment, the case where the channel number notification unit 21e of the transmission unit corresponding to the newly selected channel number broadcasts the channel number has been described. However, the present invention is not limited to this, for example, the channel number A dedicated number transmission unit may be provided, or a channel number selected again by the transmission unit that is broadcasting the program may be broadcast.

Further, the processing procedure, control procedure, specific name, information including various data and parameters shown in the document and drawings (for example, the channel information shown in FIG. 7 and the number of carriers to be erased by the carrier erasing unit 21a3) ) Can be changed arbitrarily unless otherwise specified.

Also, each component of each illustrated apparatus is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. For example, the reception control unit 34 shown in FIG. 6 can be integrated with the control unit 50 shown in FIG.

Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

Note that the processing by the broadcasting apparatus 10 described in the present embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program can be distributed via a network such as the Internet. The program can also be executed by being recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, and a DVD and being read from the recording medium by the computer.

Claims

A broadcasting device that broadcasts a program using one channel composed of carrier waves of a plurality of frequencies,
A carrier wave erasing means for erasing a carrier wave in a part of the frequency band from among the carrier waves constituting the channel in use;
Broadcasting means for broadcasting a program using a channel in which carrier waves in some frequency bands are erased by the carrier wave erasing means;
Amplitude level measuring means for measuring an amplitude level of reception of a carrier wave in a frequency band erased by the carrier wave erasing means in a frequency band of a channel broadcast by the broadcasting means;
A determination unit that determines that the channel being used is not receiving interference when the amplitude level measured by the amplitude level measurement unit is less than a preset threshold;
A broadcasting apparatus comprising:
The carrier wave erasing means erases a carrier wave having a frequency band near the middle of all the frequency bands of the carrier wave from among the carrier waves constituting the channel in use,
The amplitude level measuring means measures an amplitude level of a carrier wave cut out by a filter that eliminates a carrier wave constituting a channel in use other than a carrier wave having a frequency band near the middle. 1. The broadcasting device according to 1.
When the determining means determines that the channel being used is subject to interference, the broadcasting means switches to all the channels that can be used for broadcasting, and broadcasts the program again. The broadcasting apparatus according to claim 1, wherein the broadcasting device is continued.
4. The broadcasting apparatus according to claim 3, wherein the broadcasting means selects a channel having a lowest amplitude level of a carrier wave constituting the channel from all channels usable for broadcasting.
In the case of broadcasting a program by switching channels by the broadcasting means, the apparatus further comprises channel number notifying means for notifying a playback apparatus that plays back the received program of the channel number of the channel after switching. The broadcasting device according to claim 3.