JP2014187592A - Radio broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a "radio broadcast receiver" for swiftly switching an object to be received from a currently received DAB service to a normally receivable FM broadcast broadcasting the same content.SOLUTION: While a DAB service being received and outputted, a seek process is repeatedly executed in which all FM broadcast frequency bands are sought in the background, and a receivable FM broadcast is thereby searched for and registered. In the background seek process, a PI check process is executed on only the frequency of an FM broadcast newly searched this time among the searched FM broadcasts and an FM broadcast which is known, by the PI check process executed in the past, to have a matching PI with the SID of the DAB service, and the PI check process is not executed on other frequencies. In the PI check process, PI and other data are received from an FM broadcast, and the reception quality high/low registration of each FM broadcast having the same PI as the received PI is updated.

Description

  The present invention relates to an FM broadcast in which, in a radio broadcast receiver that receives DAB (Digital Audio Broadcasting) and FM broadcast, the same DAB service is broadcast from the DAB service being received. It is related with the technique which switches the receiving object to the station of.

  Each DAB audio broadcast is called a service and is identified by a service identifier SID broadcast by the service. In addition, a program (program) broadcasted by FM broadcasting is a program identifier PI broadcasted by the data multiplex broadcasting when the FM broadcasting performs data multiplex broadcasting by RDS (Radio Data System). Identified by. Also, the FM broadcast that broadcasts the content broadcast by the DAB service and the PI program that matches the SID of the service broadcasts a program (program) of the same content.

  And, in a radio broadcast receiver that receives DAB and FM broadcasts, DAB's technology for switching the reception target from the receiving DAB service to the FM broadcast that broadcasts the same content as the DAB service is as follows. During service reception, search for all FM broadcast PIs that can be received in the background, search for FM broadcasts that have the same content as the DAB service, and receive DAB service. A technique for switching to an FM broadcast that has been searched for a reception target when quality deteriorates is known (for example, Patent Document 1).

JP 2012-249277 A

  According to the above-described technique, when the DAB service received by the user is switched, after the switching occurs, the PI of all FM broadcasts that can be received is searched, and the same contents as the DAB service of the switching destination We will search for FM broadcasts that are broadcasting. On the other hand, since it takes a maximum of several seconds to complete the acquisition of data such as PI from one FM broadcast, it takes a relatively long time to search for PIs of all receivable FM broadcasts.

  For this reason, when the DAB service received by the user has been switched, and the reception quality of the service of the target DAB has already deteriorated, etc. It may not be possible to immediately switch the reception target to FM broadcasting that broadcasts the same content.

  On the other hand, while receiving DAB services, in the background, search for all FM broadcast PIs that can be received, and search for FM broadcasts that are broadcasting the same content as that service for all DAB services. By doing so, by the time the DAB service received by the user is switched, it is possible to search for an FM broadcast that is broadcasting the same content as the switched DAB service.

  However, since it takes several minutes to search for all FM broadcast PIs that can be received, it is the same as the DAB service being received that was searched in response to the deterioration of the reception quality of the DAB service being received. Before switching the reception target to the FM broadcast that is broadcasting the contents, the FM broadcast reception state changes from the state when the FM broadcast search is performed, and the received DAB service being searched Even if the reception target is switched to the FM broadcast that is broadcasting the same content, there may be a case where the same content broadcast as the DAB service cannot be received normally.

  Therefore, the present invention provides a radio broadcast reception capable of promptly switching the reception target from the currently receiving DAB service to the FM broadcast that can be normally received at that time, while broadcasting the same content as the DAB service. It is an object to provide a machine.

  In order to achieve the above object, the present invention multiplexes digital audio broadcasting that broadcasts digital audio using the service identified by the SID as a broadcast unit, and data including PI that is the identifier of the program being broadcast on the audio by RDS. Registered in a radio broadcast receiver that can receive FM broadcasts that are broadcasted to each PI, so that the frequency of each FM broadcast that broadcasts the PI can be identified so that the reception quality between the frequencies can be identified. The memory that stores the PI table and the seek process that seeks the FM broadcast frequency band in the background and searches for the receivable FM broadcast in the background while receiving and outputting the digital audio broadcast service. If the reception state deteriorates during the period of receiving and outputting the service of the digital seek broadcasting and the ground seek means, Receiving that refers to the PI table of the PI corresponding to the SID and switches the broadcast to be received and output to the FM broadcast of the frequency with the best reception quality among the FM broadcasts broadcasting the PI corresponding to the SID of the service. Broadcast switching means, and in the background seek means, in the seek process, when the searched FM broadcast is a newly searched FM broadcast, and the received output of the digital audio broadcast service Data broadcasted by the RDS from the FM broadcast only in two cases, in the case of an FM broadcast that has previously received a PI corresponding to one of the SIDs of the predetermined service including at least the service being performed PI check processing is performed to update the PI table contents of the PI included in the received data so as to match the reception status of each FM broadcast at the time It is what I did.

  Here, in such a radio broadcast receiver, the predetermined service may be any service of the digital audio broadcast. Alternatively, the predetermined service may be any service broadcast on the same frequency channel as the service that is receiving and outputting.

  Further, the radio broadcast receiver as described above stores, in the memory, an FM station list in which frequencies of receivable FM broadcasts are registered, and the background seek means searches for the FM broadcast searched in the seek process. The FM station list may be updated in a state where is registered.

  According to such radio receivers, the PI check process that takes a relatively long time to receive the data broadcast by the RDS from the FM broadcast and update the contents of the PI table is at most the digital audio. This is performed only for FM broadcasts that have received a PI corresponding to the SID of one of the broadcast services in the past, and for FM broadcasts that have been searched for newly receivable.

  Here, not all FM broadcasts have a PI that corresponds to the SID of one of the digital audio broadcast services, and relatively few FM broadcasts have a PI that corresponds to the service SID. By performing processing, the execution interval of seek processing is shortened, and as a result, the PI table contents of the PI corresponding to each service SID are maintained to be consistent with the reception status of the latest FM broadcast. Become. Therefore, when the reception status of the digital audio broadcasting service being received and output is deteriorated, the same content as the service is broadcasted with reference to the PI table of the PI corresponding to the SID of the service, and It is possible to switch the broadcast that is properly received and output to the FM broadcast that can be normally received.

  As described above, according to the present invention, the reception target is immediately switched from the currently receiving DAB service to the FM broadcast that can be normally received at that time, which is broadcasting the same content as the DAB service. It is possible to provide a radio broadcast receiver capable of performing the above.

It is a figure which shows the structure of the radio broadcast receiver which concerns on embodiment of this invention. It is a figure which shows the data which the radio broadcast receiver which concerns on embodiment of this invention stores in memory. It is a flowchart which shows the background seek process which concerns on embodiment of this invention. It is a flowchart which shows the PI check process which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows a configuration of a radio broadcast receiver according to the present embodiment.
The radio broadcast receiver according to the present embodiment is a radio broadcast receiver in which the position of the radio broadcast receiver varies, such as a radio receiver or a portable radio receiver mounted on an automobile.
As shown in the figure, the radio broadcast receiver is a DAB front-end (DAB F / E) 101, DAB decoder 102, audio decoder 103, DA converter (DA converter) as a DAB (Digital Audio Broadcasting) reception system. DAC) 104.

The radio broadcast receiver also includes an FM front end (FM F / E) 105, an FM demodulator 106, and an RDS decoder 107 as an FM broadcast receiving system.
The radio receiver includes a display unit 108, an operation unit 109, a control unit 110, a memory 111, a switch (SW) 112, an amplifier 113, and a speaker 114.
Now, in DAB, it is possible to broadcast a plurality of services each corresponding to one audio broadcast on one frequency channel, and each service is identified by a service identifier SID broadcast by the service. A collection of services broadcast on the same frequency channel is called an ensemble.

  In such a configuration, the DAB front end 101 receives the DAB of the frequency channel set as the DAB reception channel, and sends the reception data to the DAB decoder 102. The DAB decoder 102 extracts the audio data of the service set as the DAB reception service from the reception data sent from the DAB front end 101 and sends it to the audio decoder 103, and also the SID of the service set as the reception service Is extracted and sent to the control unit 110. The audio decoder 103 decodes the audio data sent from the DAB decoder 102 and sends it to the DA converter 104. The DA converter 104 converts the sent decoded audio data into an analog audio signal and outputs it to the switch 112. To do.

The FM front end 105 receives the frequency channel set as the FM reception channel and sends the reception signal to the FM demodulation unit 106. The FM demodulation unit 106 demodulates the audio signal from the reception signal and sends it to the switch 112. Also, when the received signal includes a data signal that is multiplexed and transmitted with an audio signal by RDS (Radio Data System), the FM demodulator 106 sends this to the RDS decoder 107, where the RDS decoder 107 decodes data from the data signal and sends it to the control unit 110. Here, the data sent from the RDS decoder 107 to the control unit 110 includes a program identifier PI, which is an identifier of a program (program) to be FM broadcast on the frequency channel set as the FM reception channel, or the same PI as the FM reception channel. It includes an AF list that shows alternative frequencies that are the frequencies of other FM broadcasts that broadcast the program.
Now, the DAB front end 101 and the DAB decoder 102 notify the control unit 110 of information related to the reception quality of the DAB reception service, such as the reception field strength of the DAB reception channel, the SN ratio, and the error rate of the reception data. The control unit 110 calculates the reception quality of the DAB reception service from the notified information.

Further, the FM front end 105 notifies the control unit 110 of information related to the reception quality of the FM broadcast of the FM reception channel, such as the received electric field strength and the SN ratio of the FM reception channel, and the control unit 110 determines from the notified information. Calculate the reception quality of FM broadcasts.
Next, DAB ensemble data, FM station list, and PI data are stored in the memory 111 of the radio broadcast receiver.
The DAB ensemble data is data stored in advance in the memory 111, and as shown in FIG. 2a, the DAB ensemble data has an ensemble table provided corresponding to each DAB ensemble.
In each ensemble table, the ensemble name (broadcast station name) of the corresponding ensemble, the frequency channel on which the corresponding ensemble is broadcast, and the service table are registered. In the service table, an entry (each row in the figure) corresponding to each service included in the corresponding ensemble is provided. The service name of the corresponding service and the SID of the corresponding service are registered in each entry. Has been.

Next, as shown in FIG. 2b, the FM station list has entries (each row in the figure) provided corresponding to each FM broadcast that can be currently received, and each entry includes the frequency of the corresponding FM broadcast. The corresponding FM broadcast PI is registered.
As shown in FIG. 2c, the PI data has a PI table provided for each FM broadcast PI that has been received in the past, and each PI table has a corresponding PI and a corresponding PI. PS and AF frequency tables representing the program service names of the programs are registered. The AF frequency table includes an entry provided for each FM broadcast that broadcasts a PI program corresponding to the PI table, and each entry has a frequency at which the corresponding FM broadcast is broadcast. be registered. Each entry is registered in the AF frequency table in descending order of reception quality of the FM broadcast of the frequency registered in the entry.

  Note that the FM broadcast broadcasting the content of the DAB service and the PI program that matches the SID of the service broadcast the same content. Also, the content broadcast by DAB service and the number of FM broadcasts that broadcast the same content, that is, the number of FM broadcasts that broadcast a PI program that matches the SID of DAB service, It is currently limited to a small number compared to the total number of FM broadcasts.

Returning to FIG. 1, the control unit 110 receives a broadcast to be received when a request for reception of a specific DAB service via the operation unit 109 is generated by a user with an appropriate user interface using ensemble data or the like. Switch to the requested service.
In addition, the control unit 110 is requested to receive a target broadcast if a user requests to receive a specific FM broadcast via the operation unit 109 with an appropriate user interface using an FM station list or the like. Switch to FM broadcasting.
Then, when the broadcast to be received is switched, if the switching destination is a service, the control unit 110 sets the frequency channel of the ensemble including the service as the DAB reception channel in the DAB front end 101 and sets the service to As a DAB reception service, the DAB decoder 102 sets the audio signal input from the DA converter 104 to the switch 112, and the amplifier 113 amplifies the audio signal input from the switch 112 and outputs it from the speaker 114. .

Here, as a result, the audio broadcast by the DAB service requested by the user is output from the speaker 114 to the user.
In addition, when the broadcast to be received is switched, if the switching destination is an FM broadcast, the control unit 110 sets the frequency of the FM broadcast as the FM reception channel in the FM front end 105, and sets the FM demodulation unit in the switch 112. The audio signal input from 106 is output to the amplifier 113, and the amplifier 113 amplifies the audio signal input from the switch 112 and outputs it from the speaker 114.

Here, as a result, the sound broadcast on the FM broadcast requested by the user is output from the speaker 114 to the user.
In addition, during a period in which the reception target broadcast is an FM broadcast, the control unit 110 broadcasts the same content as the FM broadcast that is the reception target broadcast if the reception quality of the FM broadcast that is the reception target broadcast has deteriorated by a predetermined level or more. A process of switching the reception target broadcast to another broadcast is performed. Here, other broadcasts to be switched to are the DAB service with the SID that matches the PI of the FM broadcast that is the reception target broadcast before switching obtained by referring to the DAB ensemble data, or the PI data before switching Registered at the highest of the frequencies other than the frequency other than the FM broadcast that is the target broadcast before switching, registered in the AF frequency table of the PI table where the PI of the FM broadcast that is the target broadcast is registered Has been the FM broadcast of the frequency (the best reception quality).

  In addition, during the period when the reception target broadcast is a DAB service, the control unit 110 broadcasts the same content as the service being received if the reception quality of the service that is the reception target broadcast deteriorates by a predetermined level or more. The process of switching the reception target broadcast to the broadcast of Here, the other broadcasts to be switched to are registered at the top of the frequencies registered in the AF frequency table of the PI table in which the PI that matches the SID of the service that is the reception target broadcast before switching is registered. It is FM broadcast with the frequency (best reception quality).

Note that the control unit 110 may perform processing for updating the above-described FM station list and PI data by an appropriate method during reception of the FM broadcast.
Hereinafter, in such a radio broadcast receiver, the control unit 110 uses the FM broadcast reception system to update the FM station list and PI data during the period when the target broadcast is a DAB service. A background seek process performed at the ground will be described.

FIG. 3 shows the procedure of the background seek process.
As shown in the figure, in this process, the control unit 110 first sets a lower limit frequency of a frequency band in which FM broadcast is performed as an FM reception channel in the FM front end 105 (step 300).
Then, the reception quality of the FM reception channel is calculated (step 302), and it is checked whether or not the calculated reception quality exceeds a predetermined threshold value Th (step 304). Here, the threshold value Th is set in advance as a lower limit value of reception quality at which FM broadcasting can be normally received.
If the reception quality of the FM reception channel does not exceed the predetermined threshold Th (step 304), it is determined whether or not the frequency of the FM reception channel is registered in the FM station list (step 306). If not, the process proceeds to step 310. If the FM reception channel is registered, the FM reception channel cannot be received at present, so the frequency of the registered FM reception channel is deleted from the FM station list (step 308), and the process proceeds to step 310. .

  On the other hand, if the reception quality of the FM reception channel exceeds a predetermined threshold Th (step 304), it is determined whether or not the frequency of the FM reception channel is registered in the FM station list (step 314). If yes, go to Step 316. In step 316, it is checked whether the PI registered in the FM station channel frequency entry in the FM station list matches the SID registered in any ensemble table of the DAB ensemble data. If not, the process proceeds to step 310, and if they match, the process proceeds to step 318.

  On the other hand, if the reception quality of the FM reception channel exceeds the predetermined threshold Th (step 304) and the frequency of the FM reception channel is not registered in the FM station list (step 314), a new one is added to the FM station list. A new entry is created, the frequency of the FM reception channel is registered in the created entry (step 320), and the process proceeds to step 318.

Next, when the process proceeds from step 316 or step 320 to step 318, the FM reception channel PI check process is executed, and the process proceeds to step 310. Here, the PI check process performed in step 318 will be described in detail later.
If the process proceeds from step 308, 316, or 318 to step 310 as described above, it is checked whether the FM reception channel has reached the upper limit frequency of the frequency band in which FM broadcast is performed. If not, the FM reception channel is increased by a predetermined frequency step FSTP (for example, FSTP = 100 kHz) (step 312), the process returns to step 302, and the above processing is performed for the FM reception channel increased by FSTP.

On the other hand, when the FM reception channel has reached the upper limit frequency at which FM broadcast is performed (step 310), the process returns to step 300 and the above processing is repeated from the lower limit frequency at which FM broadcast is performed.
The procedure for the background seek process performed by the control unit 110 has been described above.
Next, the PI check process performed in step 318 of the background seek process as described above will be described.
FIG. 4 shows the procedure of this PI check process.
As shown in the figure, in this PI check process, the control unit 110 first checks whether or not data broadcasting by RDS is performed on the FM reception channel (step 400). If not, the PI check process is performed as it is. finish.
On the other hand, if data broadcasting by RDS is being performed on the FM reception channel (step 400), reception of PI or PI and AF list from the FM reception channel is waited (step 402). It is checked whether the PI matches the PI registered in the FM reception channel frequency entry of the FM station list (step 404). Here, even when the PI is not registered in the frequency entry of the FM reception channel in the FM station list, the determination in step 404 is inconsistent.

  If the received PI matches the PI registered in the frequency entry of the FM reception channel in the FM station list, the process proceeds to step 408. If not, the FM reception in the FM station list is performed. After updating the PI of the channel frequency entry to the received PI (step 406), the process proceeds to step 408.

  If the process proceeds to step 408, it is checked whether or not the PI table in which the received PI is registered exists in the PI data. If it exists, the process proceeds to step 412. If not, the received PI is registered. The PI table is created (step 410), and the process proceeds to step 412.

  Then, when the process proceeds to step 412 in this way, the AF frequency table of the PI table in which the received PI is registered is displayed, and the state of the AF frequency table is broadcasting the received PI program. The frequency is updated so as to be registered in the order of good reception quality, and the PI check process is terminated.

Here, several methods can be taken to update the AF frequency table of the PI table in which the received PI is registered.
For example, the AF frequency table can be updated as follows.
That is, when the frequency of the FM reception channel is not registered in the AF frequency table, the frequency of the FM reception channel is additionally registered in the AF frequency table.
Then, the entries in the AF frequency table are rearranged in the order of the reception quality of the frequencies registered in the entries. Here, as the reception quality of the frequency registered in each entry, the reception quality finally calculated for the frequency in step 302 of the background seek process shown in FIG. 3 can be used. However, within the PI check process, the reception quality of each frequency is checked and used while changing the FM reception channel set in the FM front end 105 to each frequency registered in each entry of the F frequency table. Good.

Alternatively, the AF frequency table can be updated as follows.
That is, in step 402, the AF list is received, and among the frequencies of the FM reception channel and the frequencies included in the AF list, frequencies that are not registered in the AF frequency table are additionally registered in the AF frequency table.
Then, the entries in the AF frequency table are rearranged in the order of the reception quality of the frequencies registered in the entries. The reception quality of the frequency registered in each entry can be obtained as described above.
Alternatively, the AF frequency table can be updated as follows.
That is, in step 402, the AF list is received, and the AF frequency table of the PI table in which the received PI is registered is replaced with the AF frequency table in which the frequency of the FM reception channel and each frequency included in the AF list are registered.
Then, the entries in the AF frequency table are rearranged in the order of the reception quality of the frequencies registered in the entries. The reception quality of the frequency registered in each entry can be obtained as described above.
The PI check process performed by the control unit 110 has been described above.
As described above, according to the present embodiment, the PI check process is performed in the FM broadcast that has received a PI corresponding to the SID of one of the DAB services in the past, and the FM broadcast that has been searched for newly receivable. Only done about.
Here, as described above, not all FM broadcasts have a PI corresponding to the SID of one of the DAB services, but relatively few FM broadcasts have a PI corresponding to the service SID. By performing the PI check process in a limited manner as described above, the execution interval of the process of seeking all the frequencies of the FM broadcast (the process from steps 300 to 312 of the background seek process) is shortened. As a result, each service The content of the PI table corresponding to the SID of the SID is maintained to be consistent with the reception status of the latest FM broadcast. Therefore, when the reception status of the digital audio broadcasting service being received and output is deteriorated, the same content as the service is broadcasted with reference to the PI table of the PI corresponding to the SID of the service, and It is possible to switch the broadcast that is properly received and output to the FM broadcast that can be normally received. Also, immediately after switching the broadcast to be received and output to FM broadcast, even if the reception quality of the FM broadcast deteriorates, refer to the PI table and broadcast to other FM broadcasts that broadcast the same content. Can be switched more appropriately.

  In the above embodiment, the PI registered in the frequency entry of the FM reception channel in the FM station list in step 316 of the background seek processing shown in FIG. 3 is one of the ensemble tables of DAB ensemble data. If it does not match, the process proceeds to step 310, and if it matches, the process proceeds to step 318. In step 316, this is done in the FM station list FM. Check if the PI registered in the frequency entry of the receiving channel matches one of the SIDs registered in the ensemble table of the ensemble containing the service currently being received. If it matches, go to step 318. It may be.

  In this way, when the DAB service to be received by the user is switched to a service belonging to a different ensemble from the service before switching, the reception quality of the service of the switching destination DAB deteriorates. If this is the case, it may not be possible to switch the broadcast that is properly received and output to the FM broadcast that can be normally received, but the execution interval of the process of seeking all the frequencies of the FM broadcast can be shortened. In other cases, it is possible to switch the broadcast to be received and output to an FM broadcast that can be properly received normally, using the PI table reflecting the reception state of the latest FM broadcast.

  Also, in the background seek processing step 316 shown in FIG. 3 of the above embodiment, the PI registered in the frequency entry of the FM reception channel in the FM station list is the service currently being received. It can be determined whether or not the SID matches, and if not, the process proceeds to step 310, and if matched, the process proceeds to step 318.

  In this way, when the DAB service to be received is switched by the user and the reception quality of the DAB service of the switching destination is deteriorated, the FM broadcast can be received normally. Although it becomes impossible to switch the broadcast that is received and output properly, the execution interval of the process of seeking all the frequencies of FM broadcast can be shortened, so in other cases, the reception status of the latest FM broadcast can be further reduced. Using the reflected PI table, the broadcast to be received and output can be switched to an FM broadcast that can be properly received normally.

  DESCRIPTION OF SYMBOLS 101 ... DAB front end, 102 ... DAB decoder, 103 ... Audio decoder, 104 ... DA converter, 105 ... FM front end, 106 ... FM demodulation part, 107 ... RDS decoder, 108 ... Display part, 109 ... Operation part, 110 ... Control unit, 111, memory, 112, switch, 113, amplifier, 114, speaker.

Claims (4)

Digital audio broadcasting that broadcasts digital audio using the service identified by SID as a broadcast unit, and FM broadcast that broadcasts data including PI, which is the identifier of the program being broadcast, multiplexed with RDS can be received A radio broadcast receiver,
A memory provided for each PI, storing a PI table in which the frequency of each FM broadcast broadcasting the PI is registered so that the reception quality between the frequencies can be identified,
During the period in which the digital audio broadcast service is received and output, a background seek unit that repeatedly performs seek processing to search for an FM broadcast that can be received by seeking the frequency band of the FM broadcast in the background;
When the reception state deteriorates during the period of receiving and outputting the digital audio broadcasting service, the PI table corresponding to the SID of the service is referred to by referring to the PI table of the PI corresponding to the SID of the service. Receiving broadcast switching means for switching the broadcast to be received and output to the FM broadcast having the best reception quality among the FM broadcasts being broadcast,
The background seek means includes at least a service that is received and output among the newly searched FM broadcasts and the digital audio broadcast services in the seek process when the searched FM broadcast is a newly searched FM broadcast. Received and received data broadcasted by the RDS from the FM broadcast only in two cases, when the FM broadcast has received a PI corresponding to one of the SIDs of the predetermined service in the past. A radio broadcast receiver that performs PI check processing for updating the contents of a PI table of PI included in data so as to match the reception state of each FM broadcast at the time. The radio broadcast receiver according to claim 1,
The radio broadcast receiver according to claim 1, wherein the predetermined service is one of the services of the digital audio broadcast. The radio broadcast receiver according to claim 1,
The radio broadcast receiver according to claim 1, wherein the predetermined service is any service broadcast on the same frequency channel as that of the service being received and output. The radio broadcast receiver according to claim 1, 2, or 3,
In the memory, an FM station list in which frequencies of receivable FM broadcasts are registered is stored.
The background seek means updates the FM station list so that the searched FM broadcast is registered in the seek process.