EP2521291A2

EP2521291A2 - Radio broadcast receiver and radio broadcast receiving method linking RDS and DAB

Info

Publication number: EP2521291A2
Application number: EP12002939A
Authority: EP
Inventors: Hidenori Hetani; Hikaru Tsuji
Original assignee: JVCKenwood Corp
Current assignee: JVCKenwood Corp
Priority date: 2011-05-02
Filing date: 2012-04-26
Publication date: 2012-11-07
Also published as: JP2012249277A; EP2521291A3

Abstract

A controller (7) sets a radio broadcast receiver to a regional on mode. A DAB receiving unit (5) receives a DAB broadcast. The controller (7) controls an RDS receiving unit (2) so that, if service linking information includes the linkage information indicating a PI code of an RDS broadcast which is the same as the DAB broadcast, the RDS receiving unit (2) ignores a regional code of the PI code indicated by the linkage information and searches for a broadcast having a PI code matching the PI code indicated by the linkage information other than the regional code.

Description

BACKGOUND OF THE INVENTION

The present invention relates to a radio broadcast receiver and a radio broadcast receiving method which are capable of receiving both digital radio broadcasting called DAB (digital audio broadcasting) and analogue FM radio broadcasting called RDS (radio data system).
In Europe, DAB as digital radio broadcasting and RDS as FM radio broadcasting are widely used, and radio broadcast receivers capable of receiving both DAB broadcasts and RDS broadcasts (hereinafter, also referred to as a hybrid radio broadcast receiver) have been released. RDS is radio broadcasting according to CENELEC standards (EN50067), and DAB is radio broadcasting according to Eureka 147 standards. On DAB and RDS, so-called simulcasting is performed to simultaneously broadcast a same program. A hybrid radio broadcast receiver normally receives broadcast waves on DAB because the sound quality of DAB is higher than that of RDS and switches to RDS if the reception of DAB is degraded.
In DAB, a broadcasting station is specified by an identification code called an SId (service identifier). In RDS, a broadcasting station is specified by an identification code called a PI (program identifier) code. The SId and PI code of simulcast stations are the same. The SId and PI code are represented by four hexadecimal digits. In a four-digit code, the first digit represents a country code; the second digit, a regional code; and the third and fourth digits, a broadcasting station code. When the SId and PI code are C201, the country code is C, the regional code is 2, and the broadcast station code is 01.
Since the SId and PI code have a same form as described above, the hybrid radio broadcast receiver can switch to the same broadcast (program) on RDS when the reception of DAB is degraded. Japanese Patent Laid-open Publication No. 2000-134119 describes about switching of a hybrid radio broadcast receiver from DAB to RDS, for example.

SUMMARY OF THE INVENTION

As described above, the SId and PI code of broadcasts of a same station are basically the same but are different from each other in some cases. Moreover, one SId corresponds to plural different PI codes in other cases. To be specific, the broadcasts of the same station are provided in different regions, or the second digit of the PI code is varied only in a time period when particular broadcast contents such as news are provided. Such broadcasts with plural PI codes having different regional codes at the second digits in the four digit codes are referred to as regional broadcasts.
A conventional hybrid radio broadcast receiver has two modes of searching for an RDS broadcast having a PI code corresponding to an SId code of a DAB broadcast: one is a regional on mode to search for a broadcast having a PI code perfectly matching the SId code including the regional code; and the other is a regional off mode to search for a broadcast having a PI code with the regional code ignored.
The regional off mode is effective on keeping receiving affiliated broadcast stations. At switching from an RDS station to another RDS station, to be specific, when the reception condition of the RDS broadcast being received is degraded, the radio broadcast receiver in the regional off mode automatically switches to a regional broadcast for the region where the radio broadcast receiver is located or a particular broadcast the contents of which are different from the broadcast being received, such as news. To be specific, affiliated broadcast stations having a regional relation provide almost the same contents but broadcast different contents (local news or the like) only for a particular time period of about 5 minutes in the evening, for example. Accordingly, the radio broadcast receiver set to the regional off mode automatically switches to a different broadcast by the alternative frequency (AF) function in a certain time period. Although the broadcast contents could be different at some time period in such a manner, users who want to cover all the affiliated broadcast stations select off at the regional setting.
At switching to RDS due to degradation in reception of DAB at the regional on mode, the conventional hybrid radio broadcast receiver cannot switch to RDS if there is no PI code which is the same as the SId and there is a regional broadcast of the same broadcast station but having a different regional code.
In the light of the aforementioned problem, an object of the present invention is to provide a radio broadcast receiver and a radio broadcast receiving method which are capable of switching to an RDS regional broadcast including the same broadcast contents as those of a DAB broadcast even when the radio broadcast receiver is set to a regional on mode to search for a broadcast having a PI code perfectly matching the SId including the regional code.
In order to solve the aforementioned conventional technical problems, a first aspect of the present invention provides a radio broadcast receiver including: an RDS receiving unit configured to receive an RDS broadcast appended with a PI code identifying an RDS broadcast station; a DAB receiving unit configured to receive a DAB broadcast transmitting an SId identifying a DAB broadcast and service linking information, each set of the service linking information relating an identifier number to information indicating a DAB or RDS broadcast and information indicating the SId or PI code; a mode setting unit configured to set any one of a regional on mode and a regional off mode, the regional on mode being set to search a broadcast having a PI code perfectly matching a specified PI code including the regional code included in the PI code, the regional off mode being set to ignore the regional code and search for a broadcast having a PI code matching a specified PI code other than the regional code; and a controller configured to, when the service linking information includes linkage information representing a PI code of an RDS broadcast which is the same as the DAB broadcast, control the RDS receiving unit and cause the RDS receiving unit to search for a broadcast having a PI code matching the PI code shown in the linkage information other than the regional code even if the radio broadcast receiver is set to the regional on mode by the mode setting unit.
A second aspect of the present invention provides a radio broadcast receiving method including: a reception step of receiving a DAB broadcast; a sound output step of outputting sounds of the DAB broadcast received at the reception step; an acquisition step of, based on service linking information, acquiring linkage information indicating a PI code of an RDS broadcast which is the same as the DAB broadcast, each set of the service linking information relating an identification number to information indicating a DAB broadcast or an RDS broadcast and information indicating an SId indentifying a DAB broadcast station or a PI code identifying an RDS broadcast station; a flag generation step of, if acquiring the linkage information at the acquisition step, generating a flag indicating acquisition of the linkage information; a search step of, if generating the flag at the flag generation step, ignoring a regional code of the PI code indicated by the linkage information and searching for an RDS broadcast having a PI code matching the PI code indicated by the linkage information other than the regional code even if a regional on mode is set, the regional on mode being set to search a broadcast having a PI code perfectly matching the specified PI code including the regional code included in the PI code at reception of the RDS broadcast; a determination step of determining a reception condition of the DAB broadcast received at the reception step; and a sound switching step of switching from sound outputted at the sound output step to sound of the RDS broadcast searched at the search step if it is determined that the reception condition of the DAB broadcast is degraded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a radio broadcast receiver of a first embodiment of the present invention.
FIG. 2 is a diagram showing a data format of service linking information of FIG0/6 of DAB.
FIG. 3 is a conceptual view of the service linking information.
FIG. 4 is a flowchart showing a process by which a controller 7 shown in FIG. 1 controls an RDS receiving unit 2 and a DAB receiving unit 5.
FIG. 5 is a block diagram schematically showing a radio broadcast receiver of a second embodiment of the present invention.
FIG. 6 is a flowchart showing a process by a DAB controller 72 show in FIG. 6.
FIG. 7 is a flowchart showing a process by an RDS controller 71 shown in FIG. 5.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a description is given of embodiments of a radio broadcast receiver and a radio broadcast receiving method of the present invention with reference to the accompanying drawings.

First, using FIG. 1, a description is given of the configuration of a radio broadcast receiver of a first embodiment capable of receiving both DAB as digital radio broadcasting and RDS as analogue FM radio broadcasting. In FIG. 1, an RDS receiving unit 2 receives RDS broadcast waves inputted through an antenna 1 and supplies an intermediate frequency signal (IF signal) to an RDS signal processing unit 3. The RDS signal processing unit 3 includes a wave detector 31 and a reception condition detector 32. The wave detector 31 detects the inputted IF signal and outputs an audio signal corresponding to an RDS broadcast of a predetermined frequency (broadcast station).
The RDS broadcast wave is appended with a PI code identifying an RDS broadcast station. Specifically, the broadcast wave of a broadcast program is broadcasted with various types of additional data such as the PI code superimposed thereon. The received broadcast station can be known by the PI code.
The reception condition detector 32 detects the reception condition of the RDS broadcast based on the output from the wave detector 31. Specifically, the reception condition detector 32 detects electric field intensity, for example. A later-described controller 7 is capable of determining based on the electric field intensity whether RDS reception can be normally performed. The reception condition detector 32 may be composed of an S meter. The detection of the reception condition by the reception condition detector 32 is not limited to detection of the electric field intensity. The detection signal outputted by the reception condition detector 32 is supplied to the controller 7. The audio signal outputted from the RDS signal processing unit 3 is inputted to a terminal "a" of a switching unit 11.
On the other hand, a DAB receiving unit 5 receives DAB broadcast waves inputted through an antenna 4 and supplies intermediate wave signals (IF signals) to a DAB signal processing unit 6. The DAB signal processing unit 6 includes a demodulator 61, a reception condition detector 62, and a D/A converter 63. The demodulator 61 demodulates the inputted IF signals to output a digital audio signal corresponding to a DAB broadcast of a predetermined frequency (broadcast station). The D/A converter 63 converts the digital audio signal outputted from the demodulator 61 to an analogue signal.
A DAB broadcast wave includes an SId indentifying a DAB broadcast station and various types of additional data such as service linking information. The service linking information relates an identification number called a linkage set number to information indicating whether the broadcast station is DAB or RDS and information indicating SId or PI code. In some cases, the service linking information includes linkage information indicating a PI code of an RDS broadcast which is the same as the DAB broadcast (FM linkage information). The details of the service linking information and linkage information are described later.
The linkage set number is information included in a data format of the service linking information of FIG0/6 shown in FIG. 2 and is an identification number relating the SId of a DAB station to the PI code of an FM station. With reference to the identification number, the radio broadcast receiver can know the SId of the DAB station and the PI code of the FM station. The SId code shows the radio receiver the DAB station which is being received. Moreover, the radio broadcast receiver can know the PI codes of RDS simulcast stations based on the service linking information.
The reception condition detector 62 is configured to detect the DAB reception condition based on the output from the demodulator 61. Specifically, the reception condition detector 62 detects an error rate of the demodulated signal, for example. The controller 7 is capable of determining based on the error rate whether the DAB reception can be normally performed. The detection of the reception condition by the reception condition detector 62 is not limited to the detection of the error rate. The detection signal by the reception condition detector 62 is supplied to the controller 7. The audio signal outputted from the DAB signal processing unit 6 is inputted to a terminal "b" of the switching unit 11.
The controller 7 is configured to control each unit of the radio broadcast receiver. The controller 7 controls reception of radio broadcasts by the RDS and DAB receiving units 2 and 5. The controller 7 controls detection of RDS IF signal by the wave detector 31 and controls demodulation of DAB IF signal by the demodulator 61. The controller 7 controls switching of the terminals "a" and "b" by the switching unit 11. The controller 7 serves as a switching controller configured to control switching of audio signals by the switching unit 11. The controller 7 controls the amplification of an amplifier 12 to control the volume of sound outputted from a speaker 13. The controller 7 can be composed of a microcomputer.
The controller 7 is connected to a ROM 8 storing various kinds of software (computer programs) to operate the radio broadcast receiver. The controller 7 controls operation of the radio broadcast receiver according to the programs stored in the ROM 8. The controller 7 is further connected to an operation unit 9 and a display unit 10 composed of a liquid crystal display or the like. The operation unit 9 may include various types of operation buttons provided for the body of the radio broadcast receiver or may be composed of a remote controller. The controller 7 controls the display unit 10 so as to display various types of information, such as the name of the broadcast station which is being received, is displayed on the display unit 10.
The controller 7 normally controls the switching unit 11 to connect the switching unit 11 to the terminal "b" so that the radio broadcast receiver outputs the audio signal of the radio broadcast received by the DAB receiving unit 5. The controller 7 determines based on the detection signal from the reception condition detector 62 whether the reception of the DAB broadcast is degraded. The controller 7 may determine that the reception is degraded if the error rate exceeds the predetermined threshold. If determining that the reception of the DAB broadcast is degraded, the controller 7 controls the switching unit 11 so that the switching unit 11 switches to the terminal "a" so that the radio broadcast receiver outputs the audio signal of the radio broadcast received by the RDS receiving unit 2. The switching unit 11 selectively outputs one of the audio signal from the RDS broadcast and the audio signal from the DAB broadcast.
The audio signal outputted through terminals "a" or "b" of the switching unit 11 is amplified by the amplifier 12 and is sounded out from the speaker 13.
The controller 7 receives the PI code of the RDS broadcast which is being received by the RDS receiving unit 2 from the wave detector 31. Moreover, the controller 7 receives the SId of the DAB broadcast which is being received by the DAB receiving unit 5 and the service linking information from the demodulator 61. The controller 7 also receives various additional data transmitted on DAB other than the service linking information. Such data is not directly related to the embodiment, and the description thereof is omitted.
The controller 7 can set one of the regional on mode and the regional off mode based on user's operation of the operation unit 9. At switching from DAB to RDS, in the regional on mode, the radio broadcast receiver searches for a broadcast having a PI code perfectly matching the specified SId including the regional code. In the regional off mode, the radio broadcast receiver ignores the regional code and searches for a broadcast having a PI code matching the specified PI code other than the regional code. The controller 7 serves as a mode setting unit configured to set one of the regional on mode and regional off mode when the RDS receiving unit 2 searches for an RDS broadcast. In this embodiment, the radio broadcast receiver is set to the regional on mode.
DAB is configured so that various information can be provided by data called FIG (flag information group). The correspondence relationship between the SId and PI code of simulcasts on DAB and RDS can be known by data called FIG0/6. The data of FIG0/6 describes the service linking information relating the linkage set number to the information indicating whether each broadcast station is DAB or RDS and the information indicating the SId or PI code. FIG. 2 shows the data format of FIG0/6. "0/6" in the FIG0/6 means Type 0 field for extension 6 shown n FIG. 2.
FIG. 3 conceptually shows the service linking information described in FIG0/6 of FIG. 2 for easy understanding. FIG. 3 shows just an example of the service linking information and does not show actual information. Each set of the service linking information SLI includes a linkage set number (LSN) and information indicating whether the radio broadcast having the LSN is DAB or RDS, and information indicating the SId or PI code. The lines are given reference numerals (1) to (7) to distinguish the service linking information LSI of each line.
The data set having an LSN of 1 in the first line (indicated by (1) in FIG. 3) shows that a DAB broadcast having an SId of C221 is in progress. It is assumed that the DAB receiving unit 5 is receiving the broadcast having a LSN of 1 and an SId of C221 in the first line. The data set having a LSN of 2 in the second line (indicated by (2)) shows that a DAB broadcast having an SId of C231 is in progress. The data set having an LSN of 1 in the third line (indicated by (3)) shows that an RDS broadcast having a PI code of C201 is in progress.
The data set in the first line and the data set in the third line have a same LSN of 1 and therefore represent simulcasts which are the same. In a similar manner, the data set in the fifth line (indicated by (5)) and the data set in the seventh line (indicated by (7)) have a same LSN of 1 and therefore represent simulcasts which are the same. In other words, FIG. 3 shows that the RDS broadcasts having PI codes of C201, C301, C401, and C501 are regional broadcasts and are the same as the DAB broadcast having an SId of C221. In the example of FIG. 3, the DAB broadcast with an SId of C231 in the second line is the same as the DAB broadcast with an SId of C291 in the fourth line (indicated by (4)).
In FIG. 3, the data sets in the third and fifth to seventh lines show the PI codes of RDS broadcasts (FM broadcasts) which are simulcasts of the DAB broadcast having an LSN of 1 in the first line and are referred to as FM linkage information. In FIG. 3, the FM linkage information is referred to as FMLI. The service linking information does not include the FM linkage information in some cases. To be specific, in the example of FIG. 3, the service linking information does not include the FM linking information when the data sets having LSNs of 1 in the first, third, and fifth to seventh lines are not transmitted, and only the information having LSNs of 2 in the second and fourth lines are transmitted.
The radio broadcast receiver of this embodiment is configured to search for an RDS broadcast which is the same as the received DAB broadcast based on the FM linkage information even if the radio broadcast receiver well receives the DAB broadcast after being activated. This allows for instantaneous switching to RDS when the reception of the DAB broadcast is degraded.
Next, using FIG. 4, a description is given of a process of the controller 7 controlling the RDS receiving unit 2 and DAB receiving unit 5 to search the RDS broadcast which is the same as the DAB broadcast. When the radio broadcast receiver is powered on, the process of FIG. 4 starts. In FIG. 4, in step S1, the controller 7 instructs the DAB receiving unit 5 to receive a DAB broadcast. The DAB receiving unit 5 therefore starts to receive the DAB broadcast. The controller 7 also instructs the RDS receiving unit 2 to receive an RDS broadcast, and the RDS receiving unit 2 starts to receive the RDS broadcast (not shown in the drawing).
In step S2, the controller 7 determines whether the FM linkage information which can include the aforementioned service linking information is acquired. In some cases, the FM linkage information cannot be acquired immediately after the start of reception of the DAB broadcast. It is therefore preferable that a predetermined waiting time is provided between the steps S1 and S2. If acquiring the FM linkage information in the step S2 (Yes), in step S3, the controller 7 generates an FM linkage acquisition flag indicating acquisition of the FM linkage information and stores the FM linkage acquisition flag and a PI code obtained from the FM linkage information. The FM linkage acquisition flag and the PI code may be stored in the controller 7 or may be stored in a not-shown storage connected to the controller 7.
In the example of the service linking information SLI described in FIG. 3, all of the DAB broadcast having an SId of C221 and the RDS broadcasts having PI codes of C201, C301, C401, and C501 have LSNs of 1 and are the same. However, the service linking information is divided into plural packets to be transmitted, and the plural sets of FM linkage information FMLI cannot be always received at once. Moreover, when the controller 7 receives a set of FM linkage information FMLI with a PI code of C201, for example, the controller 7 does not know whether the service linking information includes another set of FM linkage information FMLI or how many sets of FM linkage information FMLI are included in the service linking information. Accordingly, the controller 7 is configured to generate the FM linkage acquisition flag when acquiring the first set of FM linkage information FMLI having a same LSN as that of the DAB broadcast which is being received by the DAB receiving unit 5 and hold the FM linkage acquisition flag and the PI code represented by the acquired FM linkage information FMLI.
In step S4, the controller 7 sets the search by the RDS receiving unit 2 to linkage search. When the PI code of the acquired set of FM linkage information FMLI is C201, the linkage search refers to searching for an RDS broadcast having a PI code matching C201 other than the regional code in the second digit but not searching for an RDS broadcast having a PI code perfectly matching C201.
On the other hand, if not acquiring the FM linkage information in step S2 (No), the controller 7 sets the search by the RDS receiving unit 2 to normal search in step S5. The normal search refers to searching an RDS broadcast having a PI code perfectly matching the SId of C221 received by the DAB receiving unit 5.
The process by the above steps S1 to S5 is executed even if the radio broadcast receiver is set to the regional on mode. Specifically, even if the controller 7 as the mode setting unit sets the regional on mode, the search by the RDS receiving unit 2 is forcibly set to the linkage search in the step S4 when a set of FM linkage information is acquired in the step S2.
Next, in the process after the step S5, the controller 7 causes the RDS receiving unit 2 to search for the RDS broadcast. In step S6, the controller 7 causes the RDS receiving unit 2 to set a predetermined frequency or change the frequency for search. At the first search by the RDS receiving unit 2 in the step S6, the controller 7 causes the RDS receiving unit 2 to search for the frequency preciously received by the RDS receiving unit 2. In step S7, the controller 7 determines whether the RDS reception is good. If the RDS reception is good (Yes), the controller 7 acquires the PI code in step S8. If the RDS reception is not good (No), the controller 7 returns to the step S6. The controller 7 changes the frequency in the step S6 and then executes the process after the step S6.
In step S9, the controller 7 determines whether the search is set to the linkage search. If the search is set to the linkage search (Yes), in step S10, the controller 7 determines whether the search of the entire RDS frequency band is completed. If it is determined that the search of the entire RDS frequency band is completed (Yes), in step S11, the controller 7 then determines whether the acquired PI code matches the PI code held in the step S3 other than the regional code. If it is determined that the acquired PI code matches the held PI code other than the regional code (Yes), the controller 7 terminates the search in step S13. If it is not determined that the acquired PI code matches the held PI code other than the regional code (No), the controller 7 returns to the step S6 to change the frequency and then repeats the process after the step S6.
On the other hand, if it is not determined in the step S9 that the search is set to the linkage search (No), or if the it is determined in the step S10 that the search of the entire frequency band is finished (No), the controller 7 determines whether the acquired PI code perfectly matches the SId of the broadcast which is being received by the DAB receiving unit 5. If it is determined that the acquired PI code perfectly matches the SId of the broadcast which is being received by the DAB receiving unit 5 (Yes), the controller 7 moves to the step S13 and terminates the search. If it is not determined that the acquired PI code perfectly matches the SId of the broadcast which is being received by the DAB receiving unit 5 (No), the controller 7 returns to the step S6 to change the frequency in the step S6 and then repeats the process after the step S6.
Accordingly, the search by the RDS receiving unit 2 is completed while the DAB receiving unit 5 is well receiving the DAB broadcast. If the reception of the DAB broadcast is degraded, the controller 7 controls the switching unit 11 so that the switching unit 11 switches to the terminal "a" for outputting the RDS audio signal from the RDS receiving unit 2. If acquiring from the demodulator 61 the SId the same as the PI code of the RDS broadcast which is being received by the RDS receiving unit 2, the controller 7 controls the switching unit 11 so that the switching unit 11 switches to the terminal "b" for outputting the DAB audio signal again.
According to the radio broadcast receiver and radio broadcast receiving method of the first embodiment, even if the radio broadcast receiver is set to the regional on mode, the search by the RDS receiving unit 2 is forcibly set to the linkage search when the radio broadcast receiver acquires the FM linkage information. Accordingly, the radio broadcast receiver can switch to an RDS regional broadcast which is the same as the DAB broadcast. It is therefore possible to prevent the radio broadcast receiver from becoming silent when the DAB reception is degraded. The user can continue listening to the same program on RDS that the user has listened to on DAB.

(Second Embodiment)

In the aforementioned first embodiment, the units on the RDS receiving unit 2 side and the units on the DAB receiving unit 5 side are controlled by the single controller 7. The second embodiment is configured to separately provide a controller to control the units on the RDS receiving unit 2 side and a controller to control the units on the DAB receiving unit 5 side for controlling the entire radio broadcast receiver through the both controllers.
FIG. 5 conceptually shows a radio broadcast receiver of the second embodiment. In FIG. 5, the same portions as those of FIG. 1 are given the same reference numerals, and the description thereof are properly omitted. As shown in FIG. 5, an RDS controller 71 controls at least the RDS receiving unit 2 and the RDS signal processing unit 3. The DAB controller 72 controls at least the DAB receiving unit 5 and DAB signal processing unit 6. The RDS controller 71 and the DAB controller 72 are composed of separate bodies and are connected to each other. Each of the RDS controller 71 and DAB controller 72 may be composed of a microcomputer.
The units shown in FIG. 1 but not in FIG. 5 may be controlled by any one of the RDS and DAB controllers 71 and 72 or may be controlled by another controller. Each of the mode setting unit setting the regional on mode or regional off mode and the switch controller controlling the switching unit 11 may be composed of any one of the RDS controller 71 and DAB controller 72 or may be another controller.
In the second embodiment shown in FIG. 5, the RDS controller 71 and DAB controller 72 are configured to execute a process in cooperation to search for an RDS broadcast which is the same as the DAB broadcast.
First, a description is given of a process by the DAB controller using FIG. 6. In FIG. 6, some of the same portions as those of FIG. 4 are not described. When the radio broadcast receiver is powered on, the process of FIG. 6 starts. In FIG. 6, the DAB controller 72 instructs the DAB receiving unit 5 to receive a DAB broadcast in step S21. The DAB receiving unit 5 therefore starts to receive the DAB broadcast.
In step S22, the DAB controller 72 determines whether the FM linkage information is acquired. If acquiring the FM linkage information in the step S22 (Yes), in step S23, the DAB controller 72 generates an FM linkage acquisition flag indicating acquisition of the FM linkage information and transfers the FM linkage acquisition flag and the PI code obtained from the FM linkage information to the RDS controller 71. The FM linkage acquisition flag and the PI code are stored in the RDS controller 71. In step S24, the DAB controller 72 instructs the RDS controller 71 to set the search by the RDS receiving unit 2 to the linkage search and then terminates the process.
On the other hand, if not acquiring the FM linkage information in step S22 (No), the DAB controller 72 instructs the RDS controller 71 to set the search by the RDS receiving unit 2 to normal search in step S25 and then terminates the process.
The process by the above steps S21 to S25 is executed even if the radio broadcast receiver is set to the regional on mode. Specifically, even if the mode setting unit sets the regional on mode, the search by the RDS receiving unit 2 is forcibly set to the linkage search in the step S24 when the FM linkage information is acquired in the step S22.
Next, a description is given of a process by the RDS controller 71 using FIG. 7. Some of the same portions in FIG. 7 as those of FIG. 4 are not described. In FIG. 7, the RDS controller 71 determines in step S31 whether an instruction to search is received. If the instruction to search is not received, the RDS controller 71 returns to the step S31 and then repeats the processing of the step 31. If it is determined in the step S32 that the instruction to search is received (Yes), the RDS controller 71 causes the RDS receiving unit 2 in the step S32 to set a predetermined frequency or changes the frequency for searching. At the first search by the RDS receiving unit 2 in the step S32, the RDS controller 71 causes the RDS receiving unit 2 to search for a frequency which the RDS receiving unit 2 has previously received.
Steps S33 and S34 are the same as the steps S7 and S8 of FIG. 4, respectively. In step S35, the RDS controller 71 determines whether the RDS controller 71 receives an instruction to perform the linkage search. If it is determined that the RDS controller 71 receives an instruction to perform the linkage search (Yes), the RDS controller 71 moves the process to the step S36. If it is not determined that the RDS controller 71 receives an instruction to perform the linkage search (No), the RDS controller 71 moves the process to step S38. The steps S33 to S39 are the same as the steps 7 to 13 of FIG. 4, respectively.
As described above, when the DAB controller 72 acquires the FM linkage information, the DAB controller 72 transfers the FM linkage acquisition flag and the PI code acquired from the FM linkage information to the RDS controller 71. The RDS controller 71 can therefore cause the RDS receiving unit 2 to perform the linkage search. The search by the RDS receiver 2 is therefore completed while the DAB receiving unit 5 is well receiving the DAB broadcast. If the DAB reception is degraded, the switching controller controls the switching unit 11 so that the switching unit 11 switches to the terminal "a" for outputting the RDS audio signal from the RDS receiving unit 2.
According to the radio broadcast receiver and radio broadcast receiving method of the second embodiment, even if the radio broadcast receiver is set to the regional on mode, the radio broadcast receiver can switch to an RDS regional broadcast which is the same as the DAB broadcast. According to the radio broadcast receiver and radio broadcast receiving method of the second embodiment, even in the configuration where the controller controlling the RDS receiving unit 2 and the controller controlling the DAB receiving unit 5 are separately provided, switching to the RDS regional broadcast can be implemented.
The operation of receiving radio broadcasts (the radio broadcast reception method) which is executed by the radio broadcast receiver of the first and second embodiment described above is described once again. After the radio broadcast receiver is powered on, the RDS receiving unit 2 receives an RDS broadcast, and the DAB receiving unit 5 receives a DAB broadcast (reception step). The switching unit 11 is switched to the terminal "b" at the initial state to supply the audio signal of the DAB broadcast to the speaker 13, and the speaker 13 outputs sounds (sound output step). The controller 7 or DAB controller 72 acquire the linkage information based on the service linking information when the service linking information includes the linkage information (acquisition step).
The controller 7 generates a flag indicating acquisition of the linkage information (flag generation step). The controller 7 may be composed of the DAB controller 72 as a first controller and the RDS controller 71 as a second controller different from the DAB controller 72. In such a case, the DAB controller 72 generates the flag and transfers the flag to the RDS controller 71 (transfer step). If the flag is generated, the RDS receiving unit 2 ignores the regional code and searches for an RDS broadcast having the PI code matching the PI code included in the linkage information other than the regional code (search step). The search step is executed under control by the controller 7 or the RDS controller 71. This search step is executed even when the radio broadcast receiver is set to the regional on mode.
The reception condition detector 62 detects the reception condition of the DAB broadcast received in the reception step, and the controller 7 or DAB controller 72 determines the reception condition of the DAB broadcast based on the detection signal from the reception condition detector 62 (determination steps). If the controller 7 or DAB controller 72 determines that the reception of the DAB broadcast is degraded, the controller 7 or DAB controller 72 switches the switching unit 11 to the terminal "a" for switching to the sound of the RDS broadcast searched in the search step (sound switching step).
As described above, according to the radio broadcast receiver and radio broadcast receiving method of the first and second embodiments, even if the radio broadcast receiver is set to the regional on mode to search for a broadcast having a PI code perfectly matching the SId including the regional code, the DAB broadcast can be switched to the regional broadcast which is the same as the DAB broadcast. According to the radio broadcast receiver and radio broadcast receiving method of the first and second embodiments, it is therefore possible to prevent the radio broadcast receiver from becoming silent when the DAB reception is degraded.
The present invention is not limited to the above-described first and second embodiments and can be variously changed without departing from the spirit of the present invention.

Claims

A radio broadcast receiver, comprising:
an RDS receiving unit (2) configured to receive an RDS broadcast appended with a PI code identifying an RDS broadcast station;

a DAB receiving unit (5) configured to receive a DAB broadcast transmitting an SId identifying a DAB broadcast and service linking information, each set of the service linking information relating an identifier number to information indicating a DAB or RDS broadcast and information indicating the SId or PI code;

a mode setting unit (7, 71, 72) configured to set any one of a regional on mode and a regional off mode, the regional on mode being set to search a broadcast having a PI code perfectly matching a specified PI code including the regional code included in the PI code, the regional off mode being set to ignore the regional code and search for a broadcast having a PI code matching a specified PI code other than the regional code; and

a controller (7, 71, 72) configured to, when the service linking information includes linkage information representing a PI code of an RDS broadcast which is the same as the DAB broadcast, control the RDS receiving unit (2) and cause the RDS receiving unit (2) to search for a broadcast having a PI code matching the PI code shown in the linkage information other than the regional code even if the radio broadcast receiver is set to the regional on mode by the mode setting unit (7, 71, 72).
The radio broadcast receiver according to claim 1, wherein the controller (7, 71, 72) generates and holds a flag indicating acquisition of the linkage information when acquiring the linkage information, and the controller controls the RDS receiving unit (2) to search for a broadcast having the PI code matching the PI code represented by the linkage information other than the regional code if the flag is held.
The radio broadcast receiver according to claim 2, wherein the controller (7, 71, 72) generates the linkage acquisition flag when acquiring the first set of the linkage information.
The radio broadcast receiver according to claim 2 or 3, wherein
the controller (71, 72) includes an RDS controller (71) configured to control the RDS receiving unit (2) and a DAB controller (72) configured to control the DAB receiving unit (5) and generate the flag when acquiring the linkage information, the DAB controller (72) being composed of a different body from the RDS controller (71), and
the DAB controller (72) transfers the flag to the RDS controller (71), and the RDS controller (72) controls the RDS receiving unit (2) to search for a broadcast having a PI code matching the PI code represented by the linkage information other than the regional information.
A radio broadcast receiving method, comprising:
a reception step of receiving a DAB broadcast;

a sound output step of outputting sounds of the DAB broadcast received at the reception step;

an acquisition step of, based on service linking information, acquiring linkage information indicating a PI code of an RDS broadcast which is the same as the DAB broadcast, each set of the service linking information relating an identification number to information indicating a DAB broadcast or an RDS broadcast and information indicating an SId indentifying a DAB broadcast station or a PI code identifying an RDS broadcast station;

a flag generation step of, if acquiring the linkage information at the acquisition step, generating a flag indicating acquisition of the linkage information;

a search step of, if generating the flag at the flag generation step, ignoring a regional code of the PI code indicated by the linkage information and searching for an RDS broadcast having a PI code matching the PI code indicated by the linkage information other than the regional code even if a regional on mode is set, the regional on mode being set to search a broadcast having a PI code perfectly matching the specified PI code including the regional code included in the PI code at reception of the RDS broadcast;

a determination step of determining a reception condition of the DAB broadcast received at the reception step; and

a sound switching step of switching from sound outputted at the sound output step to sound of the RDS broadcast searched at the search step if it is determined that the reception condition of the DAB broadcast is degraded.
The radio broadcast receiving method according to claim 5, wherein
the flag generation step is executed by a first controller (72), the method further comprising:
a transfer step of transferring the flag generated by the first controller to a second controller (71) which is composed of a different body from the first controller, wherein

the search step is executed under control by the second controller (71).