JP2009130744A - Broadcast receiver and method of acquiring accompanying data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire accompanying data included in digital radio broadcasting even when reproducing analog radio broadcasting. <P>SOLUTION: A broadcast receiver is capable of receiving digital broadcasting in which accompanying data has been multiplexed and analog broadcasting corresponding to the digital broadcasting. The broadcast receiver has: a reproduction means selectively reproducing the digital broadcasting and the analog broadcasting; a digital signal strength detection means detecting a reception strength of a digital broadcasting signal corresponding to the analog broadcasting during reproduction of the analog broadcasting by the reproduction means; and an accompanying data acquisition means acquiring the accompanying data of the digital broadcasting depending on the reception strength of the detected digital broadcasting signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a broadcast receiver and method suitable for receiving a digital / analog hybrid broadcast, and more particularly, a broadcast receiver and associated data acquisition method for acquiring associated data multiplexed in a digital broadcast. It is about.

  In recent years, it has become common to process and manage audio and video in digital format in audio equipment and video equipment. The trend of digital encoding of audio and video in such audio equipment has spread to the field of radio broadcasting. For example, in the United States, a digital radio broadcasting system called IBOC (In Band On Channel) has been proposed and put to practical use by iBiquity.

  By the way, the conventional analog radio broadcast is broadcast by a carrier wave (hereinafter referred to as “analog carrier”) having a frequency distribution within a frequency band (hereinafter referred to as “channel”) assigned to each broadcasting station. Actually, in order to avoid interference between analog carriers of adjacent channels, only the central portion of the allocated frequency band is used for analog carrier transmission, and the other portions are not used.

  The IBOC system is a system that performs digital radio broadcasting using a frequency band assigned to conventional analog radio broadcasting. The IBOC system defines multiple signal formats, such as a hybrid format in which a digital radio broadcast signal is superimposed on an existing analog radio broadcast signal and an all-digital format consisting only of digital signals. It is designed so that it can gradually shift from broadcasting to multi-function, high-quality all-digital format broadcasting.

  In the IBOC system, a signal format called a hybrid format is used in a transition period from analog broadcasting to all-digital broadcasting. In the hybrid format, digital broadcast subcarriers are arranged in a frequency band (hereinafter referred to as “sideband”) that has not been used conventionally, adjacent to the center of the band in which analog carriers are arranged. That is, according to the IBOC hybrid format, the analog radio broadcast and the digital radio broadcast are transmitted simultaneously using the same channel by effectively utilizing the frequency band assigned to the existing analog radio broadcast.

  In IBOC digital radio broadcasting, accompanying data such as PSD (Program Service Data) is multiplexed with program audio data. The PSD describes various information provided to the user using ID3 tags, and specifically includes information related to the program such as program name, song name, artist name, album name, and genre name. In other words, IBOC digital radio broadcasting can provide users with various information other than audio using PSD.

For example, Patent Document 1 discloses an HD (High Definition) radio configured to be able to receive multiplexed IBOC digital radio broadcast signals. The HD radio described in Patent Document 1 displays information transmitted by PSD (hereinafter referred to as “PSD information”) on a display as well as program playback during reception of digital radio broadcast. Then, when the quality of the received radio wave deteriorates and it becomes difficult to receive the digital radio broadcast signal, the reception is automatically switched from the reception of the digital radio broadcast signal to the reception of the analog radio broadcast signal of the same channel. Since the analog radio broadcast signal does not include data corresponding to the PSD, the PSD information disappears from the display when switching to reception of the analog radio broadcast signal. For this reason, the HD radio described in Patent Document 1 stores PSD in a predetermined memory while receiving a digital radio broadcast signal, and reads the PSD stored in the memory when switching to analog radio broadcast to obtain PSD information. Is displayed on the display.
JP 2004-135219 A

  There are various user preferences, and some users prefer the sound quality of analog radio broadcasting to digital radio broadcasting. The HD radio is configured in consideration of such user preferences. Specifically, the HD radio has a function of fixing a broadcast to be reproduced to an analog radio broadcast regardless of the signal format and reception state of the reception channel.

  In this way, users who like the sound quality of analog radio broadcasts have a desire to know the names of songs and artists that are being played in the program. However, the existing HD radio cannot acquire PSD during analog radio broadcast reproduction, and cannot display PSD information on a display. Moreover, although the HD radio described in Patent Document 1 can display PSD information on a display during analog radio broadcast reproduction, it cannot newly acquire the PSD itself, like other existing HD radios. Therefore, even if a new song flows after switching to the analog radio broadcast, PSD information corresponding to the song is not displayed on the display unless the digital radio broadcast is switched.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a broadcast receiver capable of acquiring accompanying data included in a digital radio broadcast even when an analog radio broadcast is reproduced, and an accompanying It is to provide a data acquisition method.

  A broadcast receiver according to an embodiment of the present invention that solves the above problem is a broadcast receiver that can receive a digital broadcast in which accompanying data is multiplexed and an analog broadcast corresponding to the digital broadcast. And a reproduction means for selectively reproducing the analog broadcast, and a digital signal strength detection means for detecting the reception intensity of the digital broadcast signal corresponding to the analog broadcast while the analog broadcast is reproduced by the reproduction means, and the detected And an accompanying data acquisition means for acquiring the accompanying data of the digital broadcast according to the reception intensity of the digital broadcast signal.

  According to such a configuration, the accompanying data of the digital broadcast can be acquired even during the reproduction of the analog broadcast. For example, a user who fixes the broadcast to be reproduced to the analog broadcast can refer to the information of the accompanying data.

  Such a broadcast receiver may be configured to further include status information generating means for generating status information regarding the digital broadcast based on the received signal of the digital broadcast. In this case, the digital signal strength detection means detects the strength of the received signal of the digital broadcast signal based on the generated status information, for example, DAAI (Digital Audio Availability Indicator) included in the status information.

  The broadcast receiver may further include a display unit that processes and displays the accompanying data acquired by the accompanying data acquisition unit.

  Here, the accompanying data includes, for example, at least one of PSD and SIS (Station Information Service).

  In addition, the digital broadcast and the analog broadcast here may be broadcasts transmitted in, for example, an IBOC signal format.

  Moreover, as an example of such a broadcast receiver, for example, one attached to a moving body can be cited.

  An accompanying data acquisition method according to an aspect of the present invention that solves the above problem is a method for acquiring accompanying data multiplexed in a digital broadcast, and reproducing analog broadcast corresponding to the digital broadcast; An intensity detection step for detecting the reception intensity of a digital broadcast signal corresponding to the analog broadcast during analog broadcast reproduction, and accompanying data acquisition for acquiring the accompanying data of the digital broadcast according to the detected reception intensity of the digital broadcast signal Steps.

  According to such a method, accompanying data of a digital broadcast can be acquired even during playback of an analog broadcast. For example, a user who fixes a broadcast to be played back to an analog broadcast can refer to the information of the accompanying data.

  Such an accompanying data acquisition method may further include a status information generation step of generating status information regarding the digital broadcast based on the received signal of the digital broadcast. In this case, in the intensity detection step, the reception intensity of the digital broadcast signal is detected based on the generated status information, for example, DAAI included in the status information.

  The accompanying data acquisition method may further include a display step of processing and displaying the accompanying data acquired in the accompanying data acquisition step.

  The accompanying data in such an accompanying data acquisition method includes at least one of PSD and SIS.

  In such an accompanying data acquisition method, the digital broadcast and the analog broadcast may be broadcasts transmitted in, for example, an IBOC signal format.

  According to the broadcast receiver and the accompanying data acquisition method according to the present invention, the accompanying data of the digital broadcast can be acquired even during the reproduction of the analog broadcast. Information can be referred.

  Hereinafter, an HD radio according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of HD radio 100 according to the embodiment of the present invention. The HD radio 100 is attached to, for example, a vehicle that is a moving body. The HD radio 100 is designed to be compatible with IBOC radio broadcasting, and is configured to receive and process broadcast signals in the signal format of the system.

  The HD radio 100 includes an antenna 1, a tuner 2, an IF (Intermediate Frequency) amplifier 6, a separator SEP, an IF filter 7, an A / D converter 8, a DSP (Digital Signal Processor) 9, an audio signal processing unit 10, and a D / A converter. 11, power amplifier 12, speaker 13, PLL (Phase Locked Loop) circuit 14, microcomputer 15, IDM (IBOC Digital Module) 16, light receiving unit 17, remote controller (hereinafter referred to as “remote controller”) 18, display control circuit 19 and a display 20.

  The remote controller 18 is provided with operation keys for operating the HD radio 100. When the user operates the remote controller 18, a control pulse corresponding to the operation is output from the remote controller 18. The control pulse output at this time is, for example, a signal conforming to the IrDA standard. When the light receiving unit 17 receives this control pulse output from the remote controller 18, it passes it to the microcomputer 15.

  The microcomputer 15 controls the overall HD radio 100. Various control programs are installed in the microcomputer 15, and the control programs are executed based on the control pulses received from the light receiving unit 17 to control each element in the HD radio 100.

  The HD radio 100 reproduces a radio broadcast signal as follows. That is, when the antenna 1 receives a radio wave and outputs it to the tuner 2, the tuner 2 extracts an RF (Radio Frequency) signal of the selected channel from the received radio wave by control via the PLL circuit 14 by the microcomputer 15. Thus, frequency conversion to an intermediate frequency suitable for signal processing such as filtering is performed. The IF signal obtained by the frequency conversion of the RF signal is then input to the IF amplifier 6.

  Note that the above channel selection channel is determined according to the channel selection operation by the user using the remote controller 18 or the like. Information on the channel selected last (hereinafter referred to as “last channel”) is stored in an internal memory of the microcomputer 15 or a flash ROM (not shown). Immediately after the HD radio 100 is powered on, the microcomputer 15 controls the tuner 2 so that the last channel stored in the internal memory or the like is tuned.

  The IF amplifier 6 amplifies the input IF signal and outputs it to the separator SEP. Note that the amplification factor of the IF amplifier 6 is adjusted by feedback control so that the output signal from the IF amplifier 6 has a set intensity regardless of the intensity of the input signal to the IF amplifier 6. The separator SEP separates the input IF signal into two signal components. One of the signal components to be separated is a signal component obtained by converting an analog carrier wave to an IF signal, and the other is a signal component obtained by converting a sideband subcarrier to an IF signal. is there. For convenience of explanation, the former signal component is referred to as an “analog IF signal”, and the latter signal component is referred to as a “digital IF signal”. The separator SEP outputs the analog IF signal to the IF filter 7 and the digital IF signal to the A / D converter 8.

  The above description is based on the premise that the channel selection channel is a channel in a hybrid format. Of course, when only analog radio broadcast (or digital radio broadcast) is broadcast on the selected channel, the digital IF signal (or analog IF signal) separated by the separator SEP does not contain a valid signal component and is just noise. Absent.

  The IF filter 7 filters the input analog IF signal to remove unnecessary frequency components, and outputs the analog IF signal to the A / D converter 8. The A / D converter 8 includes separate A / D conversion processing circuits for analog IF signals and digital IF signals. Then, the input analog IF signal and digital IF signal are A / D converted by the corresponding A / D conversion processing circuit and output to the DSP 9.

  The DSP 9 includes a detection circuit 9a, a noise canceller 9b, and a weak electric field processing circuit 9c. The analog IF signal input to the DSP 9 is output to the detection circuit 9a, and the digital IF signal is output to the IDM 16.

  The analog IF signal is demodulated into an audio signal by the detection circuit 9a, and then noise is removed by the noise canceller 9b. Then, the signal after noise removal is subjected to processing (mute, high cut, separation control, etc.) according to the reception state of the selected channel by the weak electric field processing circuit 9c and output to the audio signal processing unit 10 as an analog audio signal. Is done.

  The IDM 16 is a module designed exclusively for IBOC digital radio broadcast signal processing. The IDM 16 demodulates the digital IF signal input from the DSP 9, decodes the demodulated signal, performs predetermined error correction processing, and separates the resulting data into program audio data and accompanying data . The separated program audio data, that is, the digital radio broadcast audio signal (hereinafter, “digital audio signal”) is output to the audio signal processing unit 10.

  The IDM 16 measures the quality of the received signal (digital radio broadcast signal) based on the CN ratio and SN ratio of the signal obtained by the demodulation process, the error bit rate of the data obtained by the decoding process, and the like, and based on the quality. To generate a blend signal and status information. The generated blend signal is output to the audio signal processing unit 10 and the status information is output to the microcomputer 15.

  The status information generated by the IDM 16 includes DAA (Digital Audio Acquired) which is a code indicating whether or not digital broadcasting is being performed on the selected channel. The DAA does not include a decodable digital broadcast signal in the channel selection channel signal, and “0x00” if it is determined that the digital broadcast is not being performed. When it is determined that the broadcast is being performed, “0x01” is set.

  Further, when it is set to reproduce only the analog radio broadcast by a user operation using the remote controller 18 or the like, the IDM 16 is set as DAA even if a digital signal that can be decoded is included in the channel selection channel signal. “0x00” is output.

  The audio signal processing unit 10 includes a blend circuit 10a and an audio processing circuit 10b. The blend circuit 10a performs blend processing on the analog audio signal from the DSP 9 and the digital audio signal from the IDM 16 based on the input blend signal. Specifically, when the quality level of the received radio wave is equal to or higher than a predetermined level, the blend circuit 10a attenuates the analog audio signal based on the blend signal so that substantially only the digital audio signal is output. Further, when the quality level of the received radio wave is less than a predetermined level, or when the radio broadcast to be reproduced by the user operation is fixed to the analog radio broadcast, the blend circuit 10a is substantially analog based on the blend signal. Attenuate the digital audio signal so that only the audio signal is output. Further, when the quality level of the received radio wave changes over a predetermined level, the blend circuit 10a performs correction in consideration of the delay amount, quality difference, etc. between the analog audio signal and the digital audio signal based on the blend signal. While mixing the signals, the audio signal to be output is switched so that the sound is smoothly connected. The audio signal output from the blend circuit 10a is input to the audio processing circuit 10b, subjected to predetermined processing by the audio processing circuit 10b, and then output to the D / A converter 11.

  The audio signal input to the D / A converter 11 is D / A converted and then input to the power amplifier 12. The audio signal input to the power amplifier 12 is amplified according to the user's volume operation and output from the speaker 13. Through the above signal processing, the radio broadcast of the selected channel is reproduced.

  Each time the microcomputer 15 receives status information from the IDM 16, the microcomputer 15 performs the PSD acquisition process shown in FIG. According to FIG. 2, the microcomputer 15 first determines whether or not the DAA included in the status information is “0x01” (step 1, step is abbreviated as “S” in the following specification and drawings). . When DAA is “0x01” (S1: YES), the reception state of the digital radio broadcast signal is good as described above, and the state is suitable for reproduction of the digital audio signal. Accordingly, the microcomputer 15 determines that the accompanying data can be acquired, outputs a GET command to the IDM 16 to request the accompanying data (in this case, PSD), acquires this (S2), and ends the PSD acquisition process. To do.

  Next, the microcomputer 15 interprets the acquired PSD and outputs the interpretation result to the display control circuit 19. Then, the display control circuit 19 performs a predetermined process on the input interpretation result and outputs it to the display 20. Through the above processing, PSD information is displayed on the display 20.

  By the way, when the digital radio broadcast is not performed or the reception state of the digital radio broadcast signal is poor and the digital audio signal cannot be reproduced, the DAA output from the IDM 16 to the microcomputer 15 is “0x00”. For this reason, the conventional HD radio determines that when the DAA is “0x00”, the reception state of the digital radio broadcast signal is poor and the IDM 16 is in a state where the digital radio broadcast signal including the accompanying data cannot be decoded. The process corresponding to the PSD acquisition process 2 was completed at this stage. For this reason, when DAA is “0x00”, the PSD is not acquired, and the PSD information cannot be displayed on the display.

  However, as described above, when it is set to reproduce only the analog audio signal, the DAA becomes “0x00” even if the reception state of the digital radio broadcast signal is good. That is, even if DAA is “0x00”, accompanying data such as PSD may be decoded. Therefore, in the HD radio 100 of this embodiment, when DAA is “0x00” (S1: NO), whether or not PSD acquisition is possible using data different from DAA included in the status information. When the information can be acquired, the PSD information can be displayed on the display 20. Specifically, the microcomputer 15 determines whether or not the PSD can be acquired by using DAAI (Digital Audio Availability Indicator) included in the status information. DAAI is data obtained by quantifying the reception intensity of a digital radio broadcast signal, and is normally used as an indicator of the reception intensity displayed on a display.

  When DAAI is “0” (S3: NO), the reception intensity of the digital radio broadcast signal is extremely weak and the IDM 16 cannot decode the accompanying data. Therefore, the microcomputer 15 ends the PSD acquisition process without acquiring PSD information.

  On the other hand, when DAAI is a value greater than “0” (S3: YES), the digital radio broadcast signal has sufficient reception strength to decode the accompanying data, and IDM 16 normally decodes the accompanying data. It can be carried out. Therefore, the microcomputer 15 outputs a GET command to the IDM 16 to request a PSD, then acquires the PSD from the IDM 16 (S2), and ends the PSD acquisition process. As a result, PSD information is displayed on the display 20, and the user who fixes the radio broadcast to be played back to the analog radio broadcast can check the name of the currently playing song and the artist name on the display 20.

  The above is the embodiment of the present invention. The present invention is not limited to these embodiments, and various modifications are possible within the scope of the technical idea of the present invention. For example, the threshold employed in the process of S3 is not limited to “0”, and is appropriately selected according to the specifications of the HD radio 100.

  In addition, for example, data to be acquired in the PSD acquisition process of FIG. 2 is not limited to PSD, but may be SIS (Station Information Service) including information such as a short name and long name of a radio station.

It is a block diagram which shows the structure of HD radio of embodiment of this invention. It is a flowchart which shows the PSD acquisition process performed in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Tuner 6 IF amplifier 7 IF filter 8 A / D converter 9 Analog signal processing circuit 10 Audio signal processing part 11 D / A converter 12 Power amplifier 13 Speaker 14 PLL circuit 15 Microcomputer 16 IDM
17 Photosensitive unit 18 Remote control 19 Display control circuit 20 Display 100 HD radio SEP Separator

Claims (13)

In a broadcast receiver capable of receiving a digital broadcast in which accompanying data is multiplexed and an analog broadcast corresponding to the digital broadcast,
Playback means for selectively playing back the digital broadcast and the analog broadcast;
Digital signal strength detection means for detecting the reception strength of a digital broadcast signal corresponding to the analog broadcast while the analog broadcast is played back by the playback means;
A broadcast receiver comprising: accompanying data acquisition means for acquiring accompanying data of the digital broadcast according to the detected reception intensity of the digital broadcast signal. Further comprising status information generating means for generating status information regarding the digital broadcast based on the received signal of the digital broadcast;
The broadcast receiver according to claim 1, wherein the digital signal strength detection unit detects the reception strength of the digital broadcast signal based on the generated status information.   3. The broadcast receiver according to claim 2, wherein the digital signal strength detection means detects the reception strength of the digital broadcast signal based on DAAI (Digital Audio Availability Indicator) included in the status information.   4. The broadcast receiver according to claim 1, further comprising display means for processing and displaying the accompanying data acquired by the accompanying data acquiring means.   The broadcast receiver according to any one of claims 1 to 4, wherein the accompanying data includes at least one of PSD (Program Service Data) and SIS (Station Information Service).   The broadcast receiver according to any one of claims 1 to 5, wherein the digital broadcast and the analog broadcast are broadcasts transmitted in an IBOC signal format.   The broadcast receiver according to any one of claims 1 to 6, wherein the broadcast receiver is attached to a moving body. In the accompanying data acquisition method for acquiring accompanying data multiplexed in digital broadcasting,
Reproducing analog broadcast corresponding to the digital broadcast;
During the analog broadcast reproduction, an intensity detection step of detecting the reception intensity of the digital broadcast signal corresponding to the analog broadcast;
An accompanying data acquisition method comprising: an accompanying data acquisition step of acquiring accompanying data of the digital broadcast according to the detected reception intensity of the digital broadcast signal. A status information generating step of generating status information about the digital broadcast based on a received signal of the digital broadcast;
9. The incidental data acquisition method according to claim 8, wherein in the intensity detection step, the reception intensity of the digital broadcast signal is detected based on the generated status information.   10. The incidental data acquisition method according to claim 9, wherein in the intensity detection step, the intensity of the received signal is detected based on DAAI included in the status information.   The incidental data acquisition method according to any one of claims 8 to 10, further comprising a display step of processing and displaying the incidental data acquired in the incidental data acquisition step.   12. The incidental data acquisition method according to claim 8, wherein the incidental data includes at least one of PSD and SIS.   13. The accompanying data acquisition method according to claim 8, wherein the digital broadcast and the analog broadcast are broadcasts transmitted in an IBOC signal format.

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