JPH11243384A - Multiplex broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiplex broadcasting receiver by which a desired program is surely received. SOLUTION: A DAB(digital audio broadcasting) receiver 1 is constituted by including a front end part 4, a DAB decoding part 6, an audio decoding part 8, a control part 16, an operating part 20 and a buzzer 18. When a user operates the operating part 20 to instruct change-over of the program, in the case the program of changing over into the one included in an ensemble different from the ensemble in which the program being received is included, the control part 16 does not accept the instruction for change-over into the new program from the user until the program is changed over into the pertinent program.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multiplex broadcast receiver for selecting any one of a plurality of programs multiplexed on carrier waves of different frequencies.

[0002]

2. Description of the Related Art Today, digital audio is generally recognized for its excellent characteristics and ease of use, and is rapidly spreading. Against this background, digitalization of audio broadcasting has become active, and digital audio broadcasting DAB (Digital Audio Broadcasting) has been put to practical use in Europe.

[0003] Such a DAB receiver (DAB receiver) has a considerably complicated configuration as compared with a normal VHF / FM receiver, but has many advantages that can be compensated for. For example, in a moving car, sound quality comparable to a CD can be secured, many broadcast programs can be received, programs can be broadcast in multiple languages, weather and traffic information can be received continuously, and audio and video advertisements can be received. There are advantages such as.

[0004] Currently, each broadcast channel of DAB uses a vacant frequency between reception frequencies allocated to each channel of television broadcasting, and a total of 64 channels are prepared. A carrier frequency group corresponding to each broadcast channel is called an ensemble, and 6 to 8 broadcast programs (services) are multiplexed on each ensemble.

FIG. 7 is a diagram showing an example of program switching in a conventional DAB receiver. As shown in the figure, it is assumed that programs 1 to 5 are multiplexed in ensemble 1, programs 6 to 8 are multiplexed in ensemble 2, and programs 9 to 12 are multiplexed in ensemble 3. When switching the received program, for example, a remote control (remote control)
By pressing the unit's up key or down key, it is possible to switch sequentially from program 1 to program 12, and the user can multiplex each of a plurality of ensembles simply by switching programs without being aware of the ensemble. A desired program can be selected and received from the selected programs.

In the above-described DAB receiver, when a received program is switched to another program in the same ensemble (for example, when switching from program 1 to program 2 in FIG. 7), pressing the up key, for example, requires a short time. To switch the program. Therefore, within the same ensemble, the user can continuously press the up key to switch programs one after another and select a desired program. On the other hand, when the received program is switched to another program included in another ensemble (for example, from program 5 to program 6 in FIG. 7).
), The switching operation of the carrier frequency is performed. Therefore, even if the up key is pressed, the received program is not switched instantaneously, and it takes a certain time (for example, about 2 to 3 seconds).

[0007]

As described above, since the user normally operates without being aware of the ensemble, even when switching to a program included in a different ensemble, the user is switched to another program in the same ensemble. As in the case, the up key and the down key are often continuously pressed. In such a case, the switching is instructed before the receiver recognizes the program included in the ensemble to be switched to, so that the receiver may switch to the next ensemble, and the desired program may not be received. There was a possibility that it could not be done. For example, in FIG. 7, when the program 5 is switched to the program 6, the switching operation of the carrier frequency from the ensemble 1 to the ensemble 2 is performed. When the up key is pressed during the switching operation, the switching to the ensemble 3 is further performed. In some cases, the switching operation of the carrier frequency is performed, so that even if the ensemble 2 contains a desired program, it may not be possible to receive the program. If the up key is kept pressed in such a state, the ensemble may be switched one after another, and the program included in each ensemble may not be received forever.

[0008] The present invention has been made in view of the above points, and an object of the present invention is to provide a multiplex broadcast receiver capable of reliably receiving a desired program.

[0009]

In order to solve the above-mentioned problems, a multiplex broadcast receiver according to the present invention selects one of programs multiplexed on a plurality of carrier waves to select a received program. When switching between programs included in different carrier frequencies when switching, reception of a new program switching instruction is restricted until the program switching operation ends.

[0010] Specifically, the multiplex broadcast receiver described above comprises:
A program switching instruction unit, a program receiving unit, and an instruction reception restricting unit are provided, and the received program is switched between different carrier frequencies by the program receiving unit in response to a program switching instruction from the program switching instruction unit. In this case, until the program switching operation is completed, reception of a new program switching instruction is restricted by the instruction reception restricting means. As described above, when a received program is switched between different carrier frequencies, reception of a program switching instruction by a user operation is restricted, so that a new program included in the carrier frequency of the switching destination is newly identified. The user can surely receive a desired program after confirming the program included in each carrier frequency without receiving a program switching instruction and switching to the next carrier frequency.

[0011] Further, when the received program is switched between the different carrier frequencies as described above, there is a case where the user may want to intentionally switch to the next carrier frequency. After outputting some information that the switching operation of the received program is performed between the frequencies (for example, after sounding a buzzer), only when the user repeatedly performs a predetermined operation within a predetermined time, or It is preferable to perform the operation only when the user performs a predetermined operation for instructing the switching of the carrier frequency. As described above, even when the reception of the program switching instruction is restricted, when a specific operation is performed by the user, the received program is quickly switched by further switching to the next carrier frequency. Thus, the time until a desired program is received can be reduced.

When the multiplex broadcasting receiver is for digital audio broadcasting, the instruction reception restricting means restricts reception of a program switching instruction based on information included in the high-speed information channel of the received signal frame. Is preferably determined. Since the high-speed information channel includes the configuration information of the program (service) of each carrier frequency and the like, by analyzing this, it is possible to determine whether the next program to be switched is included in the same carrier frequency, It can be easily determined whether the reception restriction is necessary.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A DAB receiver according to an embodiment to which the multiplex broadcast receiver of the present invention is applied, when switching a received program, uses another ensemble included in an ensemble different from the ensemble containing the program currently being received. When switching to a program, it is characterized in that a program switching instruction from a user is not accepted until the switching operation is completed.
Hereinafter, a DAB receiver according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a D according to an embodiment of the present invention.
It is a figure showing the composition of AB receiver. The DAB receiver 1 shown in FIG. 1 includes an antenna 2, a front end unit (F / E)
4. DAB decoding section 6, audio decoding section 8, digital-analog converter (D / A converter) 10, amplifier 12, speaker 14, control section 16, buzzer 18, operation section 20, display section 22 Have been.

The front end unit 4 extracts a desired reception frequency (tuning frequency) component from the signal received via the antenna 2 and converts an intermediate frequency signal obtained by performing frequency conversion on the extracted signal. Output. Further, the front end unit 4 outputs a reception electric field strength signal obtained by AM-detecting the intermediate frequency signal to the control unit 16. The DAB decoding unit 6 subjects the intermediate frequency signal output from the front end unit 4 to quadrature demodulation processing, FFT
(Fast Fourier Transform) Performs demodulation processing and decoding processing, demodulates interleaved transmission data, deciphers this interleaving and returns to the original data string, and then performs error detection and correction processing to perform multiplexed broadcasting. It outputs a high-speed information channel FIC including a service list of each ensemble indicating the symbol position of the program and a data frame composed of decoded data (MPEG audio data).

The audio decoding unit 8 performs a decompression process for restoring the decoded data (MPEG audio data) output from the DAB decoding unit 6, and outputs decompressed PCM audio data. The D / A converter 10 converts the PCM audio data output from the audio decoding unit 8 into an analog signal and outputs the analog signal. This analog audio signal is amplified by the amplifier 12 and output from the speaker 14.

The control section 16 controls the entire DAB receiver 1 by performing frequency tuning control by the front end section 4 and designating a program for the DAB decoding section 6. Further, when switching the program being received to a program included in a different ensemble, the control unit 16 controls the operation unit until the switching operation is completed (until the reception of a new program is started). Even if the user operates 20 to instruct the program switching, control is performed so that the instruction is not accepted. The control unit 16 controls a buzzer 18 that sounds when the ensemble is switched.

The operation unit 20 includes various operation keys for giving a user a program switching instruction or the like, and sends an operation state of the operation keys by the user to the control unit 16. The display unit 22 displays a simple content display of the program currently being received and the operation status of the operation unit 20 by the user.

The above-mentioned operation unit 20 provides the front end unit 4 and the DA switching instruction unit with the program switching instruction unit and the frequency switching instruction unit.
The B decoding unit 6, the audio decoding unit 8 and the control unit 16 correspond to the program receiving unit, the control unit 16 corresponds to the instruction reception restricting unit, and the control unit 16 and the buzzer 18 correspond to the switching information output unit.

FIG. 2 is a diagram showing a mode II frame structure employed in the DAB receiver 1. One frame length is 24 ms, and a two-symbol synchronization signal SYN
C, a high-speed information channel FIC of 3 symbols, and a data field DFL of 72 symbols. The synchronization signal SYNC includes a null symbol and a phase reference symbol PRS used to recognize the start point of the frame.

The high-speed information channel FIC is composed of three high-speed information blocks FIB. The data field DFL is divided into 72 data fields, and a broadcast signal of a predetermined service and announcement is inserted in each data field, so that 6 to 8 services can be received simultaneously from one broadcast wave. Has become. Which service corresponds to which data field is specified by array data of services included in the high-speed information channel FIC.

The high-speed information block FIB is composed of a plurality of high-speed information groups FIG. Each high-speed information group FIG includes a FIG header and a FIG data field. The FIG header is composed of "FIG type" indicating the type of data included in the FIG data field, and "length" indicating the byte length of the FIG data field. The first byte of the FIG data field has different contents for each FIG type, and an extension is included in a part thereof.

For example, in the case of a type 0 field,
In the first byte of the FIG data field, a C / N (Current / Next) flag and an OE (Other En
semble) flag, P / D flag, and extension. The contents of the detailed data included in the FIG data field are defined by the FIG type and the extension. Hereinafter, for example, a data field corresponding to the extension 3 of the FIG type 0 field is represented as FIG (0/3).

The area excluding the first byte of the FIG data field contains various data specified by the FIG type and the extension. By reading this data, various reception controls can be performed. . For example, FIG (0/17) includes a program type PTy corresponding to each multiplexed service. In FIG. (0/2) and FIG. (0/3), the service list in each ensemble includes FIG.
In 3), the service identification code SId is shown in FIG.
In 5), the language code used is fig (1/0)
And FIG. (1/1) include text data corresponding to each ensemble name or service name displayed on the display unit 22 during program reception.

The DAB receiver 1 of this embodiment has such a configuration, and its operation will be described next.

FIG. 3 is a flow chart showing an operation procedure at the time of program switching by the DAB receiver 1 of the present embodiment, and shows an operation at the time of received program switching under the control of the control unit 16. Note that one of the programs is currently being received,
After that, the “Up” key or “Down” key on the operation unit 20
It is assumed that the key is pressed and the program is switched in a predetermined order. In addition, the program switching is performed as shown in FIG.
It is assumed that the order follows the service identification SId included in 3).

The control unit 16 constantly monitors whether the "up" key or the "down" key provided on the operation unit 20 has been pressed. It is determined whether or not an instruction has been given (step 100). When any key is pressed, the control unit 1
6 judges whether the next program to be switched is in the same ensemble (step 101). More specifically, the control unit 16 determines that FIG (0/2) and FIG (0 /
3), a service list, which is a list of programs multiplexed in the ensemble being received, is extracted, the service identification SId of each program included in the service list is read, and the service ID corresponding to each of these programs is read. The service identification SId is compared with the service identification Sid corresponding to the currently received program. For example, when the “up” key of the operation unit 20 is pressed, the control unit 16 determines whether there is another program corresponding to the service identification Sid having a value larger than the service identification Sid of the currently received program. If there is a corresponding program, it is determined that the next program to be switched exists in the same ensemble. Conversely, when the “down” key of the operation unit 20 is pressed, the control unit 16 determines that the service identification SId is smaller than the service identification Sid of the program currently being received.
It is checked whether or not there is another program corresponding to the above. If there is such a program, it is determined that the next program to be switched exists in the same ensemble.

When another program to be switched is in the same ensemble, the control unit 16 switches the program being received in response to the operation of the “up” key or the “down” key of the operation unit 20. Is performed (step 102).
For example, when the “up” key of the operation unit 20 is pressed to instruct to switch the program, the control unit 16
An instruction is sent to the B decoding unit 6 to separate a program having a service identification SId next to the service identification SId of the currently received program from the multiplexed data. D
The AB decoding unit 6 responds to an instruction sent from the control unit 16 and selects audio data (MPEG audio data) of a program corresponding to the specified service identification Sid from the multiplexed data included in the data field DFL. Is extracted. The extracted audio data is converted into PCM audio data by the audio decoding unit 8,
Further, the signal is converted into an analog signal by the D / A converter 10 and output from the speaker 14. Thus, the switching operation of the program being received is performed.

On the other hand, if there is no other program to be switched in the same ensemble, the control unit 16 stops accepting a new program switching instruction from the user (step 103) and operates the operation unit 20. The ensemble switching operation is started in accordance with the operation state of the "up" key or the "down" key (step 104), and it is monitored whether the switching operation is completed (step 10).
5). For example, when the “up” key of the operation unit 20 is pressed to instruct to switch the program, the control unit 16
Issues an ensemble switching instruction to the front-end unit 4, starts the switching operation of the carrier frequency, monitors the received electric field strength signal output from the front-end unit 4, and monitors the ensemble corresponding to the new carrier frequency. It is determined whether or not the switching has been completed.

When the ensemble switching operation is completed, the control unit 16 switches the received program to a predetermined program included in the switched ensemble. (Step 1
06). Specifically, the control unit 16 sends an instruction to the DAB decoding unit 6 to separate a program having the smallest service identification SId from a plurality of programs included in the switched ensemble. The DAB decoding unit 6 includes a control unit 16
Data field DF according to the instruction sent from
The audio data (MPEG audio data) of the program corresponding to the specified service identification SId is extracted from the multiplexed data included in L. The extracted audio data is converted to PCM audio data by the audio decoder 6, further converted to an analog signal by the D / A converter 10, and output from the speaker 14.
In this way, the operation of switching the received program between different ensembles is performed.

Next, the control unit 16 cancels the suspension of reception of the program switching instruction performed in step 103 (step 107), and again determines whether or not a program switching instruction has been issued (step 100). The operation is performed.

FIG. 4 is a diagram showing an example of the program switching operation of the DAB receiver 1. As shown in the figure, ensemble 1 has programs 1 to 5, and ensemble 2 has programs 6 to 5.
8, programs 9 to 12 are multiplexed in the ensemble 3, and the service identification SId increases in the order of programs 1 to 5, program 6 to 8, and program 9 to 12 in each ensemble. For example, if the “up” key of the operation unit 20 is pressed while receiving the program 1 of the ensemble 1, the control unit 16 switches to the program 2 in a short time without stopping the reception of the program switching instruction. While receiving program 5 of ensemble 1, "up" of operation unit 20 by the user
When the key is pressed, the user may newly instruct the program switching by pressing the “up” key of the operation unit 20 until the carrier frequency is switched and the program is switched to the program 6 of the ensemble 2. , Does not perform the program switching operation corresponding to the instruction.

As described above, the DAB receiver 1 of the present embodiment
Is included in an ensemble different from the ensemble containing the program currently being received when the user presses the “up” key or the “down” key provided on the operation unit 20 to give an instruction to switch the received program. When switching to another program, the program switching operation is completed in consideration of the fact that it takes a predetermined time (for example, 2 to 3 seconds) to switch the carrier frequency and recognize a program included in a new ensemble. Until a new program switching instruction from the user is accepted. Therefore, since the switching instruction is not performed again before recognizing the program included in the new ensemble corresponding to the switching destination carrier frequency, and the switching to the next ensemble is not performed, the user can receive. It is possible to confirm the contents of the programs included in all the ensembles, and it is possible to reliably receive a desired program.

By the way, in the operation procedure shown in FIG. 3, when switching to a program of a different ensemble, in principle, a program switching instruction from a user is not accepted until this switching operation is completed. If a buzzer or the like is sounded to notify that a switching operation to a program of a different ensemble is in progress and a program switching instruction is repeatedly made, the ensemble switching operation is performed by switching the carrier frequency as in the related art. You may.

FIG. 5 is a flowchart showing a modification of the program switching operation by the DAB receiver 1 of the present embodiment. The operations in steps 200 to 204 shown in FIG. 10 correspond to the operations in steps 100 to 104 shown in FIG. 3, and the operation after the start of the ensemble switching operation in step 204 will be described.

After the control unit 16 sounds the buzzer 18 at the start timing of the ensemble switching operation (step 205), the "up" key or the "down" key provided on the operation unit 20 is depressed and the program is started. It is determined whether switching has been instructed (step 20).
6).

When any one of the keys is pressed to instruct the program switching (when the first program switching is instructed), the control unit 16 does not perform the program switching operation according to this instruction. Next, it is determined whether or not a second program switching instruction has been issued before a predetermined time (for example, 0.5 seconds) has elapsed from the time when the program switching instruction was issued (step 207). If the instruction to switch the program is issued again within the predetermined time, the control unit 16 starts the operation of switching to the next ensemble (step 208). For example, in the case where the program switching operation is performed in the order shown in FIG. 4, when the user instructs the program switching while receiving the program 5 included in the ensemble 1, the switching operation from the ensemble 1 to the ensemble 2 is performed. Is started. Thereafter, when the program switching instruction is repeated twice within a predetermined time, in step 208,
Further, the switching operation from ensemble 2 to ensemble 3 is started. When the switching operation to the ensemble 3 is started, the operation after the buzzer sound output (step 205) is repeated again.

When the second program switching instruction is not issued within a predetermined time after the first program switching instruction is issued (when a negative determination is made in step 207), the control unit 16 switches the ensemble. It is determined whether or not the operation has been completed (step 209), and this determination operation is repeated until the switching operation is completed.

If the first program switching instruction is not issued after the buzzer sound is output in step 205 (if a negative determination is made in step 206), the control unit 16 determines whether the ensemble switching operation has been completed. It is determined whether or not the switching operation has not been completed (step 210). If the switching operation has not been completed, the operation from the determination as to whether or not the first program switching instruction has been issued (step 206) is repeated.

When the ensemble switching is completed, the control section 16 switches the program (step 211) and cancels the suspension of the reception of the program switching instruction (step 21).
Perform 2).

As described above, the DAB receiver 1 of the present embodiment
When switching to another program included in an ensemble different from the ensemble containing the currently received program when the program switching is instructed, the ensemble switching operation is started, and a buzzer sound is given to that effect. If the user instructs to switch the program twice consecutively within a predetermined time thereafter, the switching operation to the next ensemble is started. Therefore, if you know in advance which ensemble contains the desired program,
By instructing program switching twice consecutively after the buzzer sounds, the ensemble can be switched continuously, so that it is possible to quickly select a desired program and listen to its contents. In addition, since the ensemble is switched only when a program switching instruction is given twice consecutively, it is possible to prevent the ensemble from being erroneously switched due to an operation error or the like.

In the operation procedure shown in FIG. 5, when switching to a program of a different ensemble, in principle, a program switching instruction from the user is not accepted until this switching operation is completed. When a program switching instruction is issued again after notifying the user by sounding a buzzer that the switching operation is being performed, the ensemble switching operation is performed by switching the carrier frequency as in the related art, When the user performs a predetermined key operation, a conventional ensemble switching operation may be performed.

FIG. 6 is a flowchart showing another modification of the program switching operation by the DAB receiver 1 of the present embodiment.
It is assumed that the operation unit 20 has an “ensemble switching” key for instructing the user to switch the ensemble. Step 3 shown in FIG.
The operations of 00 to 304 correspond to steps 100 to 304 shown in FIG.
The operation after the start of the ensemble switching operation in step 304 corresponding to the operation of step 104 will be described.

The control section 16 determines whether or not the "ensemble switching" key provided on the operation section 20 has been pressed to instruct ensemble switching (step 30).
5). If the switching of the ensemble has been instructed, the control unit 16 starts the operation of switching to the next ensemble according to the instruction (step 306).

For example, in the case where the program switching operation is performed in the order shown in FIG. 4, if the user instructs to switch the program while receiving the program 5 included in the ensemble 1, the ensemble 1 is switched to the ensemble 2. Is started (step 304), and if the “ensemble switching” key of the operation unit 20 is further pressed to instruct switching to the next ensemble (affirmative determination in step 305), step At 306, an operation of switching from ensemble 2 to ensemble 3 is further started. When the switching operation to the ensemble 3 is started, the control unit 16 determines whether the switching of the ensemble is instructed again (Step 305).
I do.

If ensemble switching is not instructed (if a negative determination is made in step 305), the controller 16 determines whether or not the ensemble switching operation has been completed (step 307). Is completed, the program is switched (step 30).
8) and release of the suspension of reception of the program switching instruction is performed (step 309). When the ensemble switching operation has not been completed (when a negative determination is made in step 307), the control unit 16 determines again whether the ensemble switching has been instructed (step 305) and thereafter. Do.

As described above, the DAB receiver 1 of the present embodiment
If a program switching instruction is issued and the user switches to another program included in an ensemble different from the ensemble containing the currently received program, a new program from the user is required until the program is switched. Although the switching instruction is not accepted, if the “ensemble switching” key is pressed, an operation of switching to another ensemble is performed. Therefore, in the case where the user knows in advance which ensemble contains the desired program, the user issues a further instruction to switch the next ensemble during the operation of switching the ensemble,
Because you can switch ensembles continuously,
It is possible to quickly select a desired program and listen to its contents.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, when the ensemble is switched, reception of a new program switching instruction is stopped until switching to any program included in the ensemble of the switching destination. The control unit 16 stores the number of times the switching instruction is issued, that is, the number of times the “up” key or the “down” key of the operation unit 20 is pressed, and after the ensemble is switched, the program is stored by the stored number. A switching operation or an ensemble switching operation may be performed.

In the above-described embodiment, the operation unit 20
Is provided with an "up" key and a "down" key, and when these are pressed, the service identification code SId is switched in the order of the value of the program multiplexed in the same ensemble. The types of keys operated to issue a program switching instruction and the order of programs switched within the same ensemble can be changed as appropriate.

In the operation procedure shown in FIG. 5, the buzzer 18 sounds at the time of switching the ensemble. However, if the user can be notified of the switching of the ensemble, another sound may be output. Guidance voice such as "Ensemble is switching" is output from the speaker 14.
May be output.

[0051]

As described above, according to the present invention, when one of the programs multiplexed on each of a plurality of carriers is selected and the received program is switched, it is included in a different carrier frequency. When switching between programs to be performed, reception of a new program switching instruction is restricted until the program switching operation ends. Therefore, when a received program is switched between different carrier frequencies, a new program switching instruction is issued before a program included in the carrier frequency of the switching destination is identified, and further switching to the next carrier frequency is performed. Therefore, the user can reliably receive a desired program after confirming a program included in each carrier frequency.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a DAB receiver according to an embodiment to which the present invention has been applied.

FIG. 2 is a diagram illustrating a frame structure used in a DAB receiver.

FIG. 3 is a flowchart showing an operation procedure of a program switching operation in the DAB receiver.

FIG. 4 is a diagram showing an example of a program switching order.

FIG. 5 is a flowchart showing a modification of the program switching operation in the DAB receiver.

FIG. 6 is a flowchart showing another modification of the program switching operation in the DAB receiver.

FIG. 7 is a diagram showing an example of a program switching order of a conventional DAB receiver.

[Explanation of symbols]

 Reference Signs List 1 DAB receiver 4 Front end unit 6 DAB decoding unit 8 Audio decoding unit 16 Control unit 18 Buzzer 20 Operation unit 22 Display unit

Claims (6)

[Claims] 1. A multiplex broadcast receiver for selecting one of programs multiplexed on a plurality of carrier waves having different frequencies to switch a received program, wherein the multiplexed broadcast receiver includes a plurality of programs multiplexed on different carrier frequencies. A multiplex broadcast receiver that limits reception of a new program switching instruction until the program switching operation is completed when the switching is performed in (1). 2. A multiplex broadcasting receiver for selecting one of programs multiplexed on a plurality of carrier waves having different frequencies to switch a received program, wherein the received program is switched in accordance with a predetermined operation. A program switching instructing means for instructing the switching of a received program, and selecting and receiving any one of the plurality of programs, and receiving a program to be received when the program switching instructing means instructs to switch a received program. A program receiving unit for performing switching of received programs, and, when a received program is switched between different carrier wave frequencies by the program receiving unit according to a received program switching instruction by the program switching instruction unit, the program receiving unit corresponds to the predetermined operation. And a command reception restricting means for restricting the reception of the switching instruction of the received program after the reception. 3. The method according to claim 2, wherein the instruction reception restricting unit does not receive an instruction to switch the next received program until the operation of switching the received program by the program receiving unit ends. Multiplex broadcast receiver. 4. The instruction receiving means according to claim 2, further comprising: switching information output means for outputting information that a switching operation of a received program is performed between different carrier frequencies by said program receiving means. The multiplex broadcast receiver according to claim 1, wherein when the predetermined operation is repeatedly performed within a predetermined time after the information is output by the switching information output unit, the restriction on reception of the switching instruction is released. 5. The apparatus according to claim 2, further comprising frequency switching instruction means for instructing switching of a carrier frequency according to a predetermined operation, wherein said program receiving means performs an operation of switching a received program between different carrier frequencies. A multiplex broadcast receiver, further comprising: when a carrier frequency switching instruction is given by the frequency switching instruction means while the program is being performed, switching to a program included in the next carrier frequency. 6. The instruction reception restricting unit according to claim 2, wherein the instruction reception restricting unit restricts reception of the switching instruction based on information included in a high-speed information channel of a received signal frame for digital audio broadcasting. A multiplex broadcast receiver, which determines whether or not the multiplex broadcast is received.