JPH11112450A - Multiplex broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiplex broadcast receiver capable of using entire functions effectively and reduced in restrictions on operation. SOLUTION: A digital audio broadcast DAB receiver 1 includes a DAB front end section 4, a DAB decode section 6, an audio decode section 8, an FM.AM front end section 18, an FM.AM demodulation section 20, an RDS decode section 22 and a control section 24. The control section 24 receives the service such as an FM broadcast program with priority when the DAB service and the service of the FM broadcast or the like have the same contents and the reception quality of the FM broadcast or the like is a prescribed quality or over and the control section 24 conducts various processing on a background in the case of receiving a DAB.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a multiplex broadcast receiver capable of receiving both digital audio broadcasts and FM broadcasts.

[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, sound quality comparable to a CD can be ensured even in a moving car. There are advantages such as being able to receive many broadcast programs, being able to broadcast programs in multiple languages, being able to continuously receive weather and traffic information, and being able to receive audio and video advertisements.

[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 a plurality of broadcast programs (services) are multiplexed on each ensemble.

[0005] Some DAB programs include FM broadcasts and A broadcasts.
Some programs are duplicated with M broadcast programs. Therefore, A
In a conventional DAB receiver that can also receive M broadcast and FM broadcast, when the contents of the DAB program and the contents of the FM broadcast or AM broadcast program are the same, the DAB program is emphasized with respect to sound quality. Received preferentially.

[0006]

By the way, the above-mentioned conventional DAB receiver can perform various program search processes based on control information included in a DAB reception signal. For example, it is checked whether a program having the same content as a DAB program is included in an FM broadcast or an AM broadcast, or by designating a program type or an announcement type, various types of search mode or watch mode are specified. Search processing can be performed. However, in the conventional DAB receiver, when the contents of the DAB program and the program such as the FM broadcast are the same, the DAB program is preferentially received. The search operation could not be performed, and the operation was restricted. For example, to detect a carrier frequency that can be selected by the user, it is necessary to actually perform processing such as sweeping the reception frequency.However, the carrier frequency may be switched while any program is being received. Therefore, such a carrier frequency detection operation cannot be performed. Also, while receiving a DAB program, FM
Since the broadcast and AM broadcast reception functions are not used effectively,
The whole receiver was wasteful.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a multiplex broadcast receiver which can effectively use the functions of the entire apparatus and has less restrictions on operation. Is to do.

[0008]

In order to solve the above-mentioned problems, a multiplex broadcast receiver according to the present invention comprises a first receiving means for receiving a digital audio broadcast and a program having the same contents as the digital audio broadcast. And a second receiving unit for receiving another broadcast included therein. When a program having the same content is being broadcast, the program is preferentially received by the second receiving unit. Therefore, the first receiving means for receiving the digital audio broadcast can freely switch the carrier wave frequency, check the frequency at which various programs can be actually received, and check various control information included in a plurality of carrier waves. Various search processes and the like can be performed, and the functions of the entire receiver can be effectively used, and restrictions on various reception operations when digital audio broadcasting is used can be reduced.

In particular, it is preferable that the second receiving means can receive at least one of an AM broadcast, an FM broadcast, and a radio data system broadcast. Actually, in these various broadcasts and digital audio broadcasts, the same content program can be received redundantly. Therefore, the program of the desired content is received using the second receiving means, and in parallel with this reception operation. Thus, various reception operations and control operations can be performed by freely switching the reception frequency of the first reception means.

[0010] It is preferable that the reception of the program using the second receiving means is performed when the reception quality of the program received by the second receiving means is equal to or higher than a predetermined value.
By doing so, various operations using the first receiving means can be performed without particularly reducing the quality of the received program.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A DAB receiver according to an embodiment to which a multiplex broadcast receiver of the present invention is applied, when a program of the same content is broadcast in DAB and FM broadcast, etc. While receiving priority and outputting the sound,
It is characterized in that various processes of DAB are performed behind it. Receivable programs for DAB include both DAB services and announcements. 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 a DAB antenna 2, a DAB front end unit 4, a DAB decoding unit 6, an audio decoding unit 8, a digital-analog converter (D / A converter) 10, an amplifier 12, a speaker 14, FM / AM antenna 16, FM /
AM front end unit 18, FM / AM demodulation unit 20, R
DS (Radio Data System) decoding unit 22, control unit 2
4, a switch unit 26, an operation unit 28, and a display unit 30.

A DAB front-end unit 4 extracts a desired reception frequency (tuning frequency) component from a signal received via the DAB antenna 2, and converts an intermediate frequency obtained by performing frequency conversion on the extracted signal. Output a signal. The DAB decoding unit 6 includes a DAB front-end unit 4
Quadrature demodulation processing on the intermediate frequency signal output from
FFT (Fast Fourier Transform) demodulation processing and decoding processing are performed to demodulate the interleaved transmission data. Further, after deinterleaving and returning to the original data sequence, error detection and correction processing is performed, and the multiplexed data is multiplexed. It outputs a high-speed information channel FIC including a service list of each ensemble indicating a symbol position of a broadcast 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 PCM audio data output from the audio decoding unit 8 into an analog signal and outputs the analog signal. Amplifier 12
Amplifies an analog audio signal output from the D / A converter 10 or an analog audio signal after FM detection or AM detection described later, and the amplified audio signal is output from the speaker 14.

The FM / AM front end section 18
A desired reception frequency (tuning frequency) component is extracted from a signal received via the AM antenna 16;
An intermediate frequency signal obtained by performing frequency conversion on the extracted signal is amplified. Further, the FM / AM front-end unit 18 outputs a received electric field strength signal obtained by AM-detecting the amplified intermediate frequency signal to the control unit 24.
The FM / AM demodulation unit 20 performs AM detection or FM detection on the intermediate frequency signal output from the FM / AM front end unit 18 and outputs an analog audio signal. Further, the FM / AM demodulation unit 20 separates the FM multiplex signal multiplexed into the FM broadcast and outputs the separated signal to the RDS decoding unit 22. The RDS decoding unit 22
The delay detection is performed on the FM multiplex signal output from the AM demodulation unit 20 to reproduce the bit clock and demodulate the bit data sequence.

The control unit 24 includes a DAB front end unit 4
The entire DAB receiver 1 is controlled by performing frequency tuning control by the FM / AM front-end section 18 and control instructions to the DAB decoding section 6 and the RDS decoding section 22. Further, the control unit 24 controls the switch unit 26 based on the received electric field strength signal input from the DAB front end unit 4 or the FM / AM front end unit 18 or control information included in a DAB data frame described later. Gives an input voice switching instruction.

The switch section 26 selectively outputs the audio signal output from the D / A converter 10 or the FM / AM demodulation section 20 to the amplifier 12 in accordance with the switching instruction output from the control section 24. I do. The operation unit 28 includes various operation keys for allowing a user to issue a program switching instruction or the like, and displays the operation status of the operation keys by the user on the control unit 2.
Send to 4. The display unit 30 displays the name given to the currently received DAB program, and displays the name of the operation unit 2 by the user.
8 is displayed.

The above-described DAB front end unit 4, DA
B decoding unit 6, audio decoding unit 8, control unit 24
Is the FM / AM front end unit 1
8, the FM / AM demodulation unit 20, the RDS decoding unit 22, and the control unit 24 correspond to the second reception unit, and the control unit 24 corresponds to the reception control unit and the program search unit.

FIG. 2 is a diagram showing a mode II frame structure of DAB employed in the DAB receiver 1.
One frame length is 24 ms, a synchronization signal SYNC of 2 symbols and 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 P used for recognizing the start point of a frame.
RS.

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 a service list 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 17 of the FIG type 0 field is represented as FIG (0/17).

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. (0/5) shows the language code used, and FIG. (1/0) and FIG. (1/1) show the ensemble names and service names displayed on the display unit 22 during program reception. The corresponding text data is included.

The high-speed information data group FIG required for the receiving operation in the present embodiment will be described below.
Fig (0 /
2) is an ensemble identification EId and a service identification S for identifying a service included in the ensemble of interest.
Id. By analyzing FIG (0/2) related to the service list in these ensembles, for example, the service identification Sid of each service included in the currently received ensemble can be known. Also, FIG (0 /
By analyzing 1), data for receiving the service can be detected.

FI related to program type (PTy)
G (0/17) is the service identification Sid, Int (Inte
rnational) code, course (Coarse) code, and fine (Fine) code. The service identification SId is an identifier given to each service. The Int code indicates a category of a basic program type such as "news" or "sports". Normally, only this Int code is transmitted from a broadcasting station, but a course code or a fine code indicating a more detailed classification may be transmitted.

FIG. (0/18) for announcement support for the currently received ensemble is:
Announcement support (Asu) flag, Number of clusters, Cluster Id
It is comprised including. The Asu flag is a flag indicating an announcement type supported by the service specified by the service identification Sid at the head. The announcement type includes emergency broadcast, road traffic information broadcast, news broadcast, weather forecast broadcast, and the like. The number of clusters indicates the number of subsequent clusters Id, and the maximum is 2
It is 3. The cluster Id is the service identification SId
Is an identifier for identifying an announcement group (announcement cluster) supported by the service indicated by.

FIG. (0/19) regarding announcement switching for the currently received ensemble
Is the cluster Id, announcement switching (A
sw) flag, new flag (New flag), region flag (Region flag), sub-channel identification (SubChI
d). The Asw flag indicates the broadcast state of the announcement cluster indicated by each cluster Id. When the announcement belonging to the cluster Id is being broadcast, the bit corresponding to the announcement type being broadcast in the Asw flag is set to “1”, and when the announcement is not being broadcast, Is the A corresponding to the cluster Id
The sw flag is all cleared to "0". The new flag indicates whether the announcement of interest has been transmitted for the first time (the flag is “1”) or a previously broadcasted one has been retransmitted (the flag is “0”). This is a flag.

FIG. On Announcement Support
By analyzing (0/18) and FIG. (0/19) related to announcement switching, it is possible to know the announcements supported by each service, and to determine whether or not the announcement is being broadcast. If it is being broadcast, it can be known whether or not it is retransmitted.

FIG. (0/6) and FIG. Regarding service and frequency information such as DAB and FM
(0/21) is the service identification SId of each service,
It is configured to include a reception frequency such as DAB or FM that can receive the service of interest. FIG
By analyzing (0/6) and FIG (0/21), it is possible to know the reception frequency of a DAB, FM, or the like that can receive a certain service.

FIG. (0/25) regarding announcement support for ensembles not currently being received
Is configured to include an announcement support (Asu) flag and an ensemble identification EId. The Asu flag is a flag indicating the announcement type supported by the service specified by the service identification Sid at the head (ensemble service not currently being received). In the ensemble identification EId, an identification code corresponding to an ensemble capable of receiving an announcement of interest is set.

FIG. (0/2) regarding announcement switching for an ensemble not currently being received
6) includes an announcement switching (Asw) flag, a new flag, a region flag, an ensemble identification EId, and the like. In the ensemble identification EId, an identification code corresponding to an ensemble capable of currently receiving the announcement of interest is set.

The DAB receiver 1 of the present embodiment has such a configuration, and the operation will be described next. FIG.
FIG. 7 is a diagram showing an operation procedure in a case where DAB and FM broadcasting or AM broadcasting are broadcasting the same service in the service switching operation by the DAB receiver of the present embodiment.

The control unit 24 is operated by an operation unit 28 by the user.
Is operated, and one of the "DAB reception" key, the "FM reception" key, and the "AM reception" key is operated to monitor whether reception of each broadcast service is instructed (step 101, 102). When the user presses the “DAB reception” key in such a monitoring state of the reception instruction, the control unit 24 starts the DAB reception operation (step 103). Specifically, the control unit 24
A predetermined service identification SId for the DAB decoding unit 6
Is sent from the multiplexed data. The DAB decoding unit 6 responds to an instruction sent from the control unit 24 and selects audio data (MPEG audio data) of the service corresponding to the specified service identification information from the multiplexed data included in the data field DFL. Is extracted. The extracted audio data is converted to PCM audio data by the audio decoding unit 8, and further converted to an analog audio signal by the D / A converter 10. Further, the control unit 24 outputs a switching instruction to the switch unit 26, and the analog audio signal output from the D / A converter 10 is amplified by passing through the amplifier 12 and output from the speaker 14. .

After the DAB service reception is started in this way, the control unit 24 determines whether the DAB service or announcement is being received (step 104). An affirmative determination is made immediately after the DAB service reception is started, and then the control unit 24 determines whether the service having the same content as the DAB service being received is an FM broadcast, an AM broadcast, or an RDS broadcast (hereinafter, FM broadcast or the like). It is determined whether or not it is being broadcast (step 105).

As described above, the service identification Sid of the service included in the currently received ensemble can be obtained by analyzing FIG (0/2) related to the service list in the ensemble. In addition, services and D
FI related to frequency information such as AB and FM
By analyzing G (0/6) and FIG (0/21), it is possible to obtain a reception frequency of an FM broadcast or the like corresponding to the service identification SId obtained by analyzing FIG (0/2). That is, the acquired reception frequency is a reception frequency of an FM broadcast or the like that broadcasts a service having the same content as the service currently being received.

If the service of the same content is also broadcasted by FM broadcasting or the like (Yes in step 105), the control unit 24 causes the F that broadcasts the service of the same content to be transmitted.
It is determined whether the reception quality of the M broadcast or the like is equal to or higher than a predetermined value (step 106). Specifically, the control unit 24
An instruction is issued to the FM / AM front section 18 to switch to the acquired frequency in order to make the determination in step 105. According to this instruction, FM / AM front end unit 1
8 is the extraction of the indicated reception frequency component, the frequency conversion,
AM detection is performed on the intermediate frequency signal obtained by the amplification, and the received electric field strength signal is output to the control unit 24. The control unit 24 determines the reception quality based on the received electric field strength signal. As a result, when the reception quality is equal to or higher than the predetermined value, a switching instruction is issued to the switch unit 26, and the broadcast output from the speaker 14 is output from the DAB to
Switching to M broadcast or the like (step 107).

If the service of the same content is not broadcast by FM broadcasting or the like (negative determination in step 105) or if the reception quality of the FM broadcasting or the like is not higher than a predetermined value (negative determination in step 106), , Steps 101, 10
2 to determine whether a DAB reception instruction has been issued or
It monitors whether an instruction to receive M broadcast or the like has been issued.

When the reception of the FM broadcast or the like is instructed (Yes in step 102), the control unit 24 starts the receiving operation (step 108), and the reception quality of the received FM broadcast or the like becomes a predetermined value. It is determined whether the value is equal to or more than the value (steps 104 and 109). The specific determination procedure is the same as step 106 described above. If the reception quality of the FM broadcast or the like is not equal to or more than the predetermined value, the control unit 24
It is determined whether or not a service having the same content as the service such as the FM broadcast being received is being broadcast on DAB (step 1).
10).

More specifically, first, the control unit 24
To the DAB front-end unit 4 to receive the DAB in the background. The DAB front-end unit 4 extracts a predetermined reception frequency (tuning frequency) component from the signal received via the DAB antenna 2 according to the instruction, and performs an intermediate process of performing frequency conversion on the extracted signal. Outputs a frequency signal. The DAB decoding unit 6 includes a DAB front-end unit 4
Performs a predetermined process such as a quadrature demodulation process on the intermediate frequency signal output from, demodulates transmission data, and outputs a high-speed information channel FIC to the control unit 24. Control unit 24
Analyzes the FIG (0/2) relating to the service list in the ensemble included in the high-speed information channel FIC, and obtains the service identification Sid of the service of the DAB ensemble currently received in the background. Furthermore, FIG. (0/6) and FIG. (0/2) relating to service and frequency information such as DAB and FM
By analyzing 1), DAB not currently receiving
Service identification code SId of the ensemble service
And a service identification code SId of a service such as an FM broadcast currently being received. If the service identification code SId of the currently received FM broadcast or the like matches the service identification code SId of the ensemble service of the currently received DAB or the service identification code SId of the ensemble service of the currently unreceived DAB, the service identification SId is determined. Can be determined to be broadcast on both the FM broadcast and the DAB broadcast, that is, a service having the same content as the service currently received on the FM broadcast and the like is broadcast on the DAB. .

If the service having the same content is being broadcast by DAB, the control section 24 starts the DAB service receiving operation (step 111). This receiving operation is performed as follows. First, in the determination operation of step 110, when the service identification code SId of the currently received FM broadcast or the like matches the service identification Sid of the service included in the ensemble of the currently received DAB, the current reception of the DAB is determined. Since the service included in the ensemble has the same contents as the service such as the FM broadcast currently being received, the control unit 24 outputs the service identification information of this service to the DAB decoding unit 6 and The unit 6 inputs the MPEG audio data of the service corresponding to the service identification information to the audio decoding unit 8. The MPEG audio data is converted to PCM audio data by the audio decoding unit 8 and further converted to an analog audio signal by the D / A converter 10. Control unit 2
4 outputs a switching instruction to the switch unit 26,
An analog audio signal output from the D / A converter 10 is amplified by passing through an amplifier 12 and is amplified by a speaker 14.
Output from

On the other hand, if the service identification code SId of the currently received FM broadcast or the like matches the service identification Sid of the service included in the ensemble of the DAB that is not currently being received, it is included in the ensemble of the DAB that is not currently being received. Since the service has the same content as the service such as the FM broadcast currently being received, the control unit 24
Are FIG. (0/6) and FIG. (0/2) related to services and frequency information such as DAB and FM.
By analyzing 1), DAB broadcasting a service with the same content as the service currently being received in FM broadcast etc.
Extract the carrier frequency corresponding to the ensemble of
An instruction to switch the reception frequency is issued to the B front end unit 4. DAB front-end unit 4 switches the reception frequency according to this instruction, and outputs an intermediate frequency signal to DAB decoding unit 6. The DAB decoding unit 6 performs a predetermined process on the intermediate frequency signal and outputs a data frame including FIC and decoded data (MPEG audio data). Thereafter, as in the case where the service detected by the search is included in the currently received ensemble, the MPEG audio data of the corresponding service is extracted and converted into PCM audio data. The signal is converted into an analog signal by 10 and output from the speaker 14. When the DAB service receiving operation is started, the control unit 24 proceeds to steps 101 and 1.
Returning to 02, it is monitored whether or not a DAB reception instruction has been issued, or whether or not an FM broadcast reception instruction has been issued.

When the reception quality of the FM broadcast or the like is equal to or higher than a predetermined value (Yes at step 109), the service whose reception quality is equal to or lower than the predetermined value but has the same content as the service of the FM broadcast or the like being received is provided. Is not broadcast on DAB (Yes at step 110), the control unit 24 determines whether the program type PTy for search is set by the user, that is, the service to be preferentially received is set. (Step 11)
2). If the program type PTy is set, the control unit 24 determines whether a service corresponding to the set program type PTy is being broadcast in any DAB ensemble (step 113). If it is being broadcast, a reception operation for receiving the service is performed (step 114).

The specific operation of steps 113 and 114 will be described below. If the reception quality of the FM broadcast or the like is equal to or higher than the predetermined value (Yes in step 109), the DAB is not received in the background, so that the DAB is first received in the background as in step 110. Assumed to be performed.

As described above, FIG. (0/17) relating to the program type includes an I representing the type of each service.
An nt code is included, and by using this Int code, it can be checked whether or not each service matches the service to be searched. When the service to be searched is detected, the control unit 24 acquires the service identification SId of the detected service by referring to FIG (0/17) related to the program type, and further obtains the service identification SId in the ensemble. By analyzing FIG (0/2) related to the service list, it is determined whether or not the service detected by the search is included in the currently received ensemble. If the service is included in the currently received ensemble, the control unit 24 outputs the service identification information of the service to the DAB decoding unit 6, and the DAB decoding unit 6 outputs the MPEG of the service corresponding to the service identification information. The audio data is input to the audio decoding unit 8. The MPEG audio data is converted to PCM audio data by the audio decoding unit 8 and further converted to an analog audio signal by the D / A converter 10. Further, the control unit 24 includes the switch unit 2
A switching instruction is output to the speaker 6, and the analog audio signal output from the D / A converter 10 is amplified by passing through the amplifier 12 and output from the speaker 14.

On the other hand, if the service detected by the search is not included in the currently received ensemble, the control unit 24 sets the FIG. (0/6) and FIG. Regarding the service and the frequency information such as DAB and FM.
By analyzing (0/21), the carrier frequency corresponding to this service is extracted, and an instruction to switch the reception frequency is issued to the DAB front-end unit 4. DAB front end part 4
Switches the receiving frequency according to this instruction, and
The intermediate frequency signal is input to the decoding unit 6. The DAB decoding unit 6 performs a predetermined process on the intermediate frequency signal, and performs FIC and decoded data (MPEG audio data).
Output a data frame consisting of Thereafter, as in the case where the currently detected ensemble includes the service detected by the search, the MP
After the EG audio data is extracted and converted to PCM audio data, it is converted to an analog audio signal by the D / A converter 10 and output from the speaker 14. Further, the control unit 24 outputs a switching instruction to the switch unit 26, and the analog audio signal output from the D / A converter 10 is amplified by passing through the amplifier 12 and output from the speaker 14. . When the receiving operation of the service of the set program type PTy is started,
The control unit 24 returns to steps 101 and 102,
It monitors whether a reception instruction has been made or whether a reception instruction for FM broadcasting or the like has been made.

When the user has not set the program type PTy (No in step 112), or when the service corresponding to the program type PTy set by the user has not been broadcast in any ensemble (step 112). 113), the control unit 24
Returns to steps 101 and 102, and monitors whether a DAB reception instruction has been issued or an instruction to receive FM broadcast or the like has been issued.

As described above, when the same service is broadcasted in the DAB broadcast and the FM broadcast, and the reception quality of the FM broadcast or the like is equal to or higher than a predetermined value, the FM broadcast or the like is preferentially output. Since the DAB is frequently received in the background, processing such as searching for a service set by the user can be performed quickly. Further, since the DAB operates in the background, the reception frequency is changed to check the frequency at which various services can be actually received, and various search processes using various control information included in a plurality of ensembles are performed. Etc. become possible.

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 a service to receive preferentially is set by the user, the DAB is received in the background to search for the set service, but the announcement is given priority. May be set to be received.

The procedure for determining whether or not an announcement belonging to the announcement type set by the user is being broadcast and receiving the announcement is as follows. For determining whether or not an announcement belonging to the set announcement type is being broadcast, first, the control unit 24 sets the FIG. (0/18) and FIG.
By using the Asu flag indicating the announcement type included in the announcement, it is checked whether or not each announcement matches the announcement to be searched. When the announcement to be searched is detected, the control unit 24 analyzes the FIG. (0/19) and FIG. (0/26) related to the announcement switching, and returns the detected announcement. It is determined whether or not the broadcast is currently being broadcast on the ground. If the broadcast is currently being broadcast, the announcement is switched to and the corresponding audio is output.

Specifically, when an announcement having an Asw flag to be searched is detected from FIG. (0/19) related to announcement switching of an ensemble currently being received in the background, the control unit 24 sets , And analyzes the FIG. (0/19), and outputs identification information of the announcement to the DAB decoding unit 6. DAB decoding section 6 outputs the MP of the announcement corresponding to the output identification information.
EG audio data is extracted and input to the audio decoding unit 8. The MPEG audio data is converted to PCM audio data by the audio decoding unit 8 and further converted to an analog audio signal by the D / A converter 10. Further, the control unit 24 outputs a switching instruction to the switch unit 26, and the D / A converter 1
The analog audio signal output from 0 is amplified by passing through the amplifier 12 and output from the speaker 14.

If the announcement having the Asw flag to be searched is detected from the FIG. (0/26) relating to the announcement switching for the ensemble not currently being received in the background, the control unit 24 causes the announcement to be performed. The identification information of the ensemble broadcasting the announcement and the announcement is detected, and FIG (0/6) and FIG (0/2) relating to the service and frequency information such as DAB and FM are detected.
By analyzing 1), the carrier frequency corresponding to the announcement of the switching destination is obtained, and the DAB front end unit 4 is instructed to switch the receiving frequency. The DAB front end unit 4 switches to the corresponding frequency according to the instruction and inputs the intermediate frequency signal to the DAB decoding unit 6. D
The AB decoder 6 performs a predetermined process on the intermediate frequency signal, and outputs a data frame including FIC and decoded data (MPEG audio data). Next, the control unit 24 analyzes the FIG. (0/19) relating to the announcement switching for the currently received ensemble corresponding to the detected cluster Id, and
The identification information of the announcement corresponding to the detected cluster Id is output to the decoding unit 6. The DAB decoding unit 6 extracts the MPEG audio data of the announcement corresponding to the output identification information and inputs the extracted audio data to the audio decoding unit 8. The MPEG audio data is converted to PCM audio data by the audio decoding unit 8 and further converted to an analog audio signal by the D / A converter 10. Further, the control unit 24 outputs a switching instruction to the switch unit 26, and the analog audio signal output from the D / A converter 10 is amplified by passing through the amplifier 12 and output from the speaker 14. .

[0052]

As described above, according to the present invention, the first receiving means for receiving a digital audio broadcast and the second receiving means for receiving another broadcast including a program having the same contents as the digital audio broadcast are provided. Receiving means, and when a program with the same content is being broadcast, the
, And the first receiving means can freely switch the carrier frequency to receive various programs. Therefore, the frequency of various programs that can be actually received can be checked. It is possible to perform various search processes using various control information included in the carrier wave, effectively use the functions of the entire receiver, and restrict various reception operations when using digital audio broadcasting. Can be reduced.

It is preferable that the reception of the program using the second receiving means is performed when the reception quality of the program received by the second receiving means is equal to or higher than a predetermined value.
In this manner, various operations using the first receiving unit can be performed while maintaining the quality of the received program.

[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 when DAB and FM broadcasting or AM broadcasting are broadcasting the same service.

[Explanation of symbols]

 Reference Signs List 1 DAB receiver 4 DAB front end section 6 DAB decoding section 8 Audio decoding section 18 FM / AM front end section 20 FM / AM demodulation section 22 RDS decoding section 26 Switch section 28 Operation section

Claims (4)

[Claims] 1. A first method for receiving digital audio broadcasting.
Receiving means, a second receiving means for receiving another broadcast including a program having the same content as the digital audio broadcast, and a program having the same content being broadcast in the digital audio broadcast and the other broadcast At the same time, the program having the same content is received by the second receiving means,
And a reception control means for causing the receiving means to receive a program other than the program having the same content. 2. The method according to claim 1, wherein the other broadcast received by the second receiving means is:
A multiplex broadcast receiver, which is at least one of an AM broadcast, an FM broadcast, and a radio data system broadcast. 3. The reception control unit according to claim 1, wherein the reception control unit transmits the same content to the second reception unit when a reception quality of a broadcast received by the second reception unit is equal to or higher than a predetermined value. A multiplex broadcast receiver characterized by receiving a program. 4. The search for a predetermined program receivable by the first receiving means when the program having the same content is being received by the second receiving means according to claim 1. A multiplex broadcast receiver further comprising program search means for performing processing in parallel.