KR20060114388A - Dab broadcast receiver apparatus - Google Patents

Abstract

A DAB broadcast receiver apparatus that can easily select services included in the ensembles other than the ensembles being received. The DAB broadcast receiver apparatus, for example when switched on, acquires information concerning services included in the ensembles being received, and actually receives all the ensembles, one by one, of the DAB broadcast within a predetermined frequency range (S13-S23), thereby storing lists of services included in some ensembles into a memory (37). Then, when a user selects a reception channel, the lists of services are read from the first memory (37), and displayed at a time by displaying means. The user selects his desired one of the services in the displayed lists, whereby he can easily perform a service selection.

Description

Digital voice broadcasting receiver {DAB BROADCAST RECEIVER APPARATUS}

1 is a block diagram showing an example of the present invention DAB broadcast receiving apparatus.

Fig. 2 is a flowchart illustrating a service list creation process in the DAB broadcast receiving device of the present invention.

3 is a diagram illustrating service information stored in the first memory 37. FIG.

4 is a flowchart showing a signal processing procedure in the channel decoder.

5 is a diagram illustrating a configuration of a transmission frame in a DAB system.

6 shows a data structure of FIG 0/2.

7 is a diagram illustrating a service configuration in DAB broadcasting.

8 is a diagram showing an embodiment of a service list display according to the present invention;

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DAB broadcast receiving apparatus for receiving digital audio broadcasting (hereinafter also referred to as DAB broadcast).

(Prior Art)

In the conventional DAB broadcast receiving apparatus, the ensemble other than the ensemble currently being received is transmitted to the ensemble currently being received so that the user (user) desired service can be easily tuned to among the services (broadcast programs) included in the ensemble. The "ensemble information" to be extracted is extracted, and a list of services that can be tuned to by the user is also included, including a service transmitted as an ensemble which is not currently received. (See, for example, Patent Document 1)

Patent Document 1: Japanese Patent Application Laid-Open No. 9-232981

In digital broadcasting, an audio information signal, an image information signal, a text information signal, and the like are compressed into a predetermined format, and information signals of a plurality of channels are multiplexed and transmitted as data signals so as to correspond to a plurality of services. As a system for transmitting and receiving data signals of the predetermined format including digital voice, for example, a DAB system conforming to the European standard (Eureka 147) has been put into practical use.

In the DAB system, one ensemble is composed of a plurality of services (broadcast programs), and each service is composed of a plurality of components.

7 is a diagram illustrating a service configuration in DAB broadcasting, but details thereof are described in the DAB standard, and description thereof is omitted.

5 is a diagram illustrating a configuration of a transmission frame in a DAB system. The transmitted DAB signal is transmitted as an 0FDM signal modulated by an orthogonal frequency division multiple modulation scheme, that is, an Orthogonal Frequency Division Multiplex (OFDM) signal, and a transmission frame shown in FIG. 5 is demodulated 0FDM demodulating the 0FDM signal. Is obtained from the signal.

As shown in FIG. 5, the transmission frame in the demodulation 0FDM signal is composed of blocks of a synchronization channel (Fyn), a fast information channel (FIC), and a main service channel (MSC). do. The FIC transmits information necessary for a reception device to tune into a broadcast program, auxiliary information for the broadcast program, and the like, and the MSC transmits a subchannel (Sub Channe1) of voice or data.

The FIC for one frame consists of three data blocks called Fast Information Blocks (FIBs), and the MSC is composed of data blocks called Common Interleaved Frames (CIFs) of 1 to 4, depending on the transmission mode. Time interleave is performed in units. A plurality of subchannels are multiplexed in the CIF, and one subchannel corresponds to one broadcast program. Therefore, when the user intends to receive one broadcast program, the user selects and selects a specific subchannel from the CIF.

In a DAB system, when an ensemble is received, information on a plurality of services and components included in the ensemble can be obtained, and it is possible to instantly switch to another service or component without changing the reception frequency.

A synchronization channel block is provided at the head of the transmission frame. In this sync channel block, a coarse synchronization NULL symbol is arranged at the head, and then a phase reference symbol (PRS) responsible for a reference phase for OFDM demodulation (for example, differential QPSK demodulation) is performed. ) Is arranged. Tuning in the DAB broadcast receiving apparatus is performed in units of ensembles, and when receiving other ensembles, the reception frequency is changed. In the change of the reception frequency, an ensemble that can be received is searched for and received by a detection operation (search operation) called ensemble up / down. In addition, even when the user starts receiving the DAB broadcast, the user can search for and receive an ensemble that can be received by a detection operation (search operation).

In the detection operation, when the user presses the up button, the search is performed from the lower frequency to the higher frequency. When the user presses the down button, the search is performed from the higher frequency to the lower frequency, and the NULL symbol is detected. When the detection is completed, the detection ends. In order to prevent the false detection, the detection is terminated as if the NULL symbol is detected when it is detected three or more times in succession. When it cannot detect three times or more consecutively, it is considered that a NULL symbol was not able to be detected.

The detection operation (search operation) for receiving a certain ensemble ends when the NULL symbol placed at the head of the transmission frame of the DAB is detected as described above.

However, if it is unclear which ensemble of the service to be received is being broadcast, the user can determine whether the ensemble being received includes a service to be received, and if not, switch to another ensemble. The tuning operation should be repeated until the ensemble containing the desired service can be received. For this reason, there is a problem that it takes a long time to select a station. In particular, the transmission frequency of the DAB has a problem that many frequencies are set in minute frequency steps, many frequencies of detection targets, and a large amount of time are required for the detection operation.

A method for solving this problem is disclosed in Japanese Patent Laid-Open No. 9-232981. In the method disclosed in this document, an identifier of a service transmitted in an ensemble other than the ensemble currently being received, based on the "other ensemble information" transmitted in the FIC (High Speed Information Channel) among the DAB transmission frames shown in FIG. (Sid) is detected and a service label corresponding to the detected service identifier (Sid) is displayed on the display means, and the user selects and receives one of the displayed services. The other ensemble information is information about an ensemble different from the ensemble currently being received.

Specifically, the FIC includes a plurality of FIG (Fast Information Group), and FIG, for example, FIG 0/21 (type 0 field for extension 21) or FIG 0/24 (type 0 field for extension 24). Or other ensemble information such as FIG 0/25 (type 0 field for extension 25).

By extracting the above-mentioned other ensemble information while receiving an ensemble, the frequency information of the ensemble which is not currently received, the service included in the ensemble which is not currently received, or the service label of the service can be known. Then, by displaying them on the display screen, the user can select a service by selecting one service from the displayed service label.

However, the above-mentioned other ensemble information, that is, information about an ensemble other than the ensemble currently being received is not necessarily broadcast, and when no other ensemble information is broadcasted, it is other than the ensemble currently being received. It is not possible to obtain information about services included in the ensemble, and to display a list of services that can be received by other ensemble.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a DAB broadcast receiving apparatus capable of easily selecting a service included in an ensemble other than a receiving ensemble in a short time.

The present invention has been made in the following configuration to achieve the above object.

The present invention provides an ensemble detection means for sequentially detecting all ensembles of DAB broadcasts within a predetermined frequency range, a first memory for storing a plurality of service identifiers included in each ensemble detected by the detection means, and a corresponding memory. And a display means for displaying a list of labels corresponding to all service identifiers stored in one memory.

The present invention, in the DAB broadcast receiving apparatus of the present invention, reads the service identifier and service label of a service included in the ensemble transmitted in FIG 0/2 and FIG 1/1 in the fast information channel (FIC). And a service identifier and a service label are stored in the first memory in association with each other.

The present invention also provides a DAB broadcast receiving apparatus according to the present invention, further comprising a second memory for storing in advance corresponding data indicating a correspondence relationship between a plurality of service identifiers and a service label, and including a fast information channel (FIC). Reads a service identifier of a service included in the ensemble, transmitted to FIG 0/2 in FIG. 0/2, and stores the service identifier in the first memory, and stores a service label corresponding to the service identifier stored in the first memory. And a service identifier read from FIG O / 2 and associated with the service label, and stored in the first memory.

In the DAB broadcast receiving device according to any one of the present invention, when the list is displayed by the display means, the service belonging to the same ensemble is displayed with the same color or the same brightness, and the service belonging to another ensemble is represented. A DAB broadcast receiving device to display in different colors or different brightness.

In addition, the present invention also provides the DAB broadcast receiving apparatus according to any one of the present invention, further comprising operation means for the user to operate the DAB receiver, wherein the display means displays one service instructed by the user through the operation means. The DAB broadcast receiving device is configured to receive an ensemble including a specific service from a list of service labels indicated by.

In the DAB broadcast receiving apparatus of the present invention, when the power supply of the receiving apparatus is turned on, information about a service included in each ensemble being received is obtained from the received signal, thereby detecting all ensembles within a predetermined frequency range. A list of services (broadcast programs) included in one ensemble is created and stored in a memory.

In the service list creation process, all ensemble of DAB broadcasts within a predetermined frequency range are actually received one by one, thereby obtaining information about a plurality of services (broadcast programs) included in the ensemble, and storing them in a memory.

Then, after detecting all the services within a predetermined frequency range, when the user performs a tuning operation, the list of services included in any one ensemble is read from the memory and displayed as a list by the display means. When the user tunes in, a desired one is indicated from the displayed list of services, the MPU recognizes and specifies the service indicated by the user, and the DAB broadcast receiving apparatus receives an ensemble in which the specified service is included. In this way, the user can easily select a desired service in a short time from the services included in any one ensemble.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

1 is a block diagram showing an example of the DAB broadcast receiving apparatus of the present invention. Hereinafter, an embodiment of the DAB broadcast receiving apparatus of the present invention will be described with reference to FIG. 1. In this DAB system, OFDM (Orthogonal Frequency Division Multiplex) is employed as the modulation method.

In Fig. 1, an instruction to start reception or an instruction to start detection in the DAB broadcast receiving apparatus is given to the MPU 31 through the operation means 33 from the user. At the time of detection or the like, the frequency information of the received DAB broadcast is sent from the MPU 31 to the PLL 14 of the front end 13 as a reception frequency setting signal.

At the front end 13, a DAB carrier of a frequency set through the antenna 11 is received, converted into a predetermined intermediate frequency signal (IF signal) capable of signal processing, and digital signal processing, thereby converting an analog / digital converter (A / D converter) 15 is output. In the A / D converter 15, an analog signal is converted into a digital information signal and supplied to the I / Q 16. The OFDM demodulator 21 is constituted by the I / Q 16, the FFT 17, and the DSP 18.

In the I / Q 16, the I signal and the Q signal are divided and supplied to the FFT 17 so that the OFDM signal can be processed later. The FFT 17 and the DSP (Digital Arithmetic Unit) 18 perform high-speed pre-free conversion and are supplied to the channel decoder 23. In the channel decoder 23, de-interleaving for returning the signal order to the original order, detection or correction of an error code, and the like are performed. In addition, the microprocessor (MPU) 31 corrects the error code and calculates a code error rate. When the code error rate is larger than a predetermined value, the decoding operation and the transmission of the decoded signal obtained by the decoding are stopped. A mute control signal is given to the MPEG decoder 27 and the D / A converter 29.

From the channel decoder 23, audio information compressed with the tuned service is supplied to the MPEG decoder 27, and in the MPEG decoder 27, the compressed audio information is decoded and decompressed, and the digital / analog converter ( D / A converter 29 is converted into analog information and output as an analog audio signal.

The operation means 33, the display means 35, the first memory 37, the ensemble detection means 39, and the second memory 41 are connected to the MPU 31. The operation means 33 is an apparatus for the user to operate the DAB broadcast reception device 10, and is used to designate a service to be received from a list of services displayed on the display means 35, for example. The display means 35 is display means for displaying a list of all services included in any one of the plurality of ensemble. The first memory 37 is a memory that stores a list of services included in any one of the plurality of ensembles, and the second memory 41 stores corresponding data between the service identifier and the service label for a plurality of services. It is memory to save, but it may be necessary to do it without it. The ensemble detecting means 39 is means for sequentially detecting an ensemble within a range of a predetermined frequency when the DAB broadcast receiving apparatus is powered on or when the user instructs it.

The first memory 37 and the second memory 41 may be configured as one memory.

4 is a flowchart showing a signal processing procedure in the channel decoder 23. In FIG. 4, in step S41, the demodulated OFDM signal output from the OFDM demodulator 21 of FIG. 1 is processed. That is, in step S41, first, the deinterleaving which cancels the frequency interleaving made to randomize the error on the frequency axis and returns it is performed, and the transmission frame shown in FIG. 5 is obtained.

Next, the FIC and the MSC are separated in step S43. In step S45, Viterbi decoding is performed on the data of the FIC, and at the same time, the sign error rate is calculated in step S47. The steps S45 and S47 are actually performed by the MPU 31 at substantially the same time, and when the code error rate is larger than a predetermined value, the mute control signal for stopping decoding of the MPEG audio signal and transmitting the decoded signal. Is given to the D / A converter 29. The calculation of the code error rate in step S47 is performed by comparing the data corrected by Viterbi decoding in step S45 with the data before error correction. Next, scramble is released (descrambled) in step S49, and a CRC check is performed in step S51, and is supplied to the microprocessor (MPU) 31 as a control signal.

In step S55, the data of the subchannels corresponding to the broadcast program selected by the user among the plurality of subchannels are separated based on the broadcast program designation signal given from the MPU 31. Next, in step S57, time deinterleaving is performed to release time interleave for randomizing errors on the time axis. In that regard, no time deinterleave is performed for the FIC. Then, in step S59, Viterbi decoding and descrambling are performed in step S61, and a DAB audio frame is output to the MPEG decoder 27 of FIG. In step S59, the same as in the case of the FIC, the detection and correction of the sign error for the convolutional encoded data is performed by Viterbi decoding.

When the DAB broadcast receiving device 10 is powered on or instructed by the user, the ensemble detecting means 39 sequentially detects all ensemble within a predetermined frequency range.

Specifically, the operation at the time of detection is as follows. That is, when detection is instructed, the received frequency is tuned in the order of the frequencies of each ensemble stored in a storage means (not shown) built in the MPU, and detection is temporarily performed when a NULL symbol is detected at a certain reception frequency. Stops, the frequency adjustment is performed by the automatic frequency adjusting means, the ensemble is received, and detection is continued if a NULL symbol is not detected. The NULL symbol detecting means for detecting the NULL symbol is constituted by the FFT 17 and the DSP 18 of the 0FDM demodulator 21.

When the NULL symbol is detected and the ensemble can be received, the MPU 31 extracts data of FIG 0/2 (type 0 field for extension 2) transmitted to the FIC and includes a plurality of ensemble data. The service identifier (SId) of the service of is stored in the first memory 37.

6 shows a data structure of FIG 0/2. As shown in the figure, FIG 0/2 includes information on service identifiers (Sid) of a plurality of services belonging to the ensemble currently being received.

Next, data of FIG 0/1 (type 0 field for extension 2) is extracted. Since FIG 0/1 includes service label information of a plurality of services belonging to the ensemble currently being received, the service label is associated with the service Id obtained from FIG 0/2, and the frequency information of the ensemble is also included. Correspondingly, it is stored in the first memory 37.

Similarly, if all ensembles in a predetermined frequency range are detected in sequence, and the service information extracted from each ensemble is stored in the first memory 37, the first memory 37 contains a plurality of service information, i.e., service Id. , The service label, the frequency of the ensemble to which the service belongs, and the like are stored in association with each other.

3 is a diagram illustrating service information stored in the first memory 37. In Fig. 3, No is a number assigned in the order of storing service information. For example, No3 corresponds to a service identifier SIdc extracted from an ensemble whose frequency is fa, and a service label SLc corresponding to this SIDc. Is stored. In addition, as an item to be stored in the first memory 37, an ensemble label and a program type corresponding to the service Id may be stored in association with each other.

The list of service information stored in the first memory 37 is displayed by the display means 35 when the user starts the tuning operation. In this list display, all items stored in the first memory 37 as shown in FIG. 3 may be displayed, but only a part of the items may be displayed, for example, only service labels. . In addition, color classification may be performed for each ensemble so that services belonging to the same ensemble may be easily recognized, or the brightness may be changed for each ensemble. In the case of displaying the program type in the DAB, the brightness and the color may be changed for each program type.

8 is a diagram showing an embodiment of a service list display according to the present invention. FIG. 8A is a list of services displayed when a certain ensemble E1 is being received, and the round circle display service represents a currently selected service. In addition, the diagonally drawn service represents a service belonging to the same ensemble as the currently selected service, and is highlighted by brightness enhancement, color conversion, blinking, or the like. FIG. 8B is a list of services displayed when receiving an ensemble E2 which is different from a certain ensemble E1. The round circle display service represents a service currently selected. In addition, the diagonally drawn service represents a service belonging to the same ensemble as the currently selected service.

When the user tunes in, tuning is performed by designating one service by the operation means 33 from the list of service information displayed by the display means 35. The MPU 31 refers to the service list of the first memory 37 and supplies the front end 13 with the reception frequency of the ensemble including the service designated by the user, so that the ensemble containing the service selected by the user is received. do. The channel decoder 23 separates the service selected by the user from the received ensemble and gives it to the MPEG decoder 27.

Fig. 2 is a flowchart illustrating a service list creation process in the DAB broadcast receiving device of the present invention. The process shown in FIG. 2 is started when the DAB broadcast receiving device 10 is powered on or by a request from a user.

In FIG. 2, in step S11, a mute signal is sent to the MPEG decoder 27 and the D / A 29 so that noise is not output, and it mutes ON, and it progresses to step S13. In step S13, the frequency of the next detected ensemble is read from the ensemble frequency data stored in the MPU 31, and the flow advances to step S15. In step S15, the read frequency data is sent to the PLL 14 of the front end 13 as received frequency data, and the flow proceeds to step S17. In addition, the detection of the ensemble is performed sequentially from the lower side to the higher side, or vice versa.

In step S17, the demodulation start of the OFDM instruction is instructed, and the procedure proceeds to step S19. In step S19, it is determined whether or not the NULL symbol is detected. In step S21, it is determined whether the demodulator has been synchronized, and if yes, the flow goes to step S23, and if negative, the flow goes to step S13. In step S23, FIG 0/2 and FIG 1/1 are extracted, the service identifier SId of the service belonging to the ensemble being received and the service label are read out, and the frequencies of the service Id, the service label, and the ensemble are correlated. 1 is stored in the memory 37, and the flow proceeds to step S25.

In step S25, it is determined whether all of the predetermined frequency ranges (bands) have been detected (searched), and if yes, the flow goes to step S27, and if negative, the flow goes to step S13. In step S27, the mute 0FF signal is sent to the MPEG decoder 27 and the D / A 29, and the flow proceeds to step S29. In step S29, the list of the service information stored in the first memory 37 is displayed by the display means 35. In this display, it is not necessary to display all of the service information stored in the first memory 37, and only a part of the items may be displayed, for example, No, service ID, and the service label in association with each other. Thereby, all the services (broadcast programs) included in any one ensemble in the predetermined frequency range are displayed and displayed by the display means 35.

In the above embodiment, in the service list creation process shown in Fig. 2, the service identifier and the service of the service included in the ensemble from FIG 0/2 and FIG 1/1 in the fast information channel (FIC). Although a label is read and a service identifier is associated with a service label and stored in the first memory 37, label information may not be transmitted in FIG 1/1, so that a plurality of service identifiers and Data representing the correspondence with the service label may be stored in the second memory 41.

That is, as shown in Fig. 1, a second memory 41 for storing data representing the correspondence between the plurality of service identifiers and the service label in advance is provided, and the correspondence relation between the plurality of service identifiers and the service label is provided. Is stored in the second memory 41 in advance.

In the service list creation process, the service identifier of the service included in the ensemble transmitted in FIG 0/2 in the fast information channel (FIC) is read out and stored in the first memory 37. The service label corresponding to the service identifier stored in the first memory 37 is retrieved by the corresponding data stored in the second memory 41, and the service identifier read from FIG 0/2 is associated with the service label. It may be stored in the first memory 37.

Next, a case where the DAB broadcast is received by the DAB broadcast reception device 10 will be described.

When the detection of all ensembles in the service list creation process shown in FIG. 2 is finished or when the user starts a channel selection operation, the list of services stored in the first memory 37 is displayed on the display means 35. .

The user designates the desired service to be received through the operation means 33 among the displayed services. The MPU 31 recognizes and specifies one service designated by the user, and sends the frequency of the ensemble in which the service is included to the PLL 14 of the front end 13 as a reception frequency setting signal. The front end 13 receives the ensemble of the given reception frequency, and the channel decoder 23 extracts the service designated by the user from the received ensemble and sends it to the MPEG decoder 27.

As described in detail above, according to the embodiment to which the present invention is applied, the ensemble being received by actually receiving all the ensembles of the DAB broadcast within a predetermined frequency range, such as when the DAB broadcast receiving apparatus is powered on, one by one. Obtain information about the services included in and store them in memory. In this way, all ensembles in the predetermined frequency range are detected, and the service identifiers of all the services included in any one ensemble are stored in the memory.

When the user performs the tuning operation, the service list stored in the memory is displayed on the display means, and the user can easily tune in a short time by selecting one service to be received from the displayed list of services. have.

In other words, in the channel selection, the user can select among the services (broadcast programs) included in any one of the plurality of ensembles without manually repeatedly switching the receiving ensemble even if the service to be received is not included in the ensemble. The desired service can be easily selected in a short time.

Claims (2)

Ensemble detection means for sequentially detecting all receivable ensembles of DAB broadcast within a predetermined frequency range in response to an instruction to start detection, the detection means, and a plurality of current broadcasts included in each of the ensembles detected by the detection means. A DAB broadcast receiving device comprising: a first memory for storing a service identifier of a; and display means for listing a service label corresponding to all service identifiers stored in the first memory, respectively; When displaying the list by the display means, services belonging to the same ensemble are displayed with the same color or the same brightness, and services belonging to different ensemble are displayed with different colors or different brightness, Displays the service belonging to the ensemble currently being received with a specific color or brightness to distinguish it from the service belonging to the non-receiving ensemble, and whenever the receiving ensemble changes, converts the service belonging to the ensemble under reception to the indication of that particular color or brightness. , Operation means for selecting one of a desired service from a list of corresponding service labels; And a reception frequency of an ensemble belonging to the selected service to the front end of the receiver device in response to the service selected by the corresponding user. The method of claim 1, And a DAB broadcast receiving device correspondingly displaying a program type of a service.

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