JP3830067B2 - Digital broadcasting receiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital broadcast receiver that receives digital broadcasts such as DAB (Digital Audio Broadcasting), and more particularly to a digital broadcast receiver equipped with a service preset function.
[0002]
[Prior art]
DAB is attracting attention as a radio broadcast format that can cope with the deterioration of sound quality due to interference caused by the multi-station of FM broadcasts and the difficulty of high-quality reception on mobiles. DAB has been developed by Eureka (Europe: European Advanced Technology Development Plan), and its specifications have already been determined. As a modulation method, π / 4 shift DQPSK-OFDM (Differential Quadrature Phase Shifting Frequency Quantitative Frequency: (Orthogonal Frequency Division Multiplexing) is adopted, and it has the feature that it is hardly affected by fading and multipath, and MPEG layer II of high-efficiency speech coding is used for speech coding, with a transmission bandwidth of 1.5 MHz. Many stereo broadcasts and data broadcasts are possible.
[0003]
In DAB, a plurality of services are collected into one ensemble and transmitted by an orthogonal frequency division multiplexing modulation system. A DAB car radio or the like has a service preset function, and a user presses a preset key or a service up / down key to output a service from a speaker (specifically, among the service components included in a plurality of services, the primary As the only existing audio service component). The service switching by the conventional preset function can be freely switched between arbitrary services of arbitrary ensembles, that is, free switching to services between different ensembles.
[0004]
[Problems to be solved by the invention]
In the same region, multiple ensembles can be received, and since one ensemble includes 6 to 10 services, the total number of services of all ensembles reaches 20th, In order to assign a preset key to the total number of preset keys, the number of preset keys becomes excessive, and the arrangement space of the preset keys in the DAB car radio is hindered. In the case of the service up / down key, the number of service up / down keys does not increase in spite of an increase in preset services. Output is interrupted, which makes the user uncomfortable.
[0005]
An object of the present invention is to provide a digital broadcast receiver capable of overcoming the above-mentioned problems.
[0006]
[Means for Solving the Problems]
The digital broadcast receiver (10) of the present invention receives a digital broadcast in which a plurality of services are collected into one ensemble and transmitted by an orthogonal frequency division multiplex modulation system. This digital broadcast receiver (10) is an ensemble selection operation unit (40) operated for selecting an ensemble, and during operation, it is a service belonging to the ensemble selected by the ensemble selection operation unit (40). Only the service selection operation unit (41, 42) for switching the service and allowing the user to select the service is provided.
[0007]
In the operation of the service selection operation unit (41, 42), the service is switched and selected by being limited to the services within the service belonging to the ensemble selected by the ensemble selection operation unit (40). Therefore, when switching services, the output from the speaker or the like is not interrupted, and quick switching is possible.
[0008]
According to the digital broadcast receiver (10) of the present invention, the service selection operation units (41, 42) are provided in common to all ensembles.
[0009]
Thus, the common service selection operation unit (41, 42) enables selection of all ensemble services, and the arrangement of the service selection operation unit (41, 42) in the entire digital broadcasting receiver (10). Space can be reduced.
[0010]
According to the digital broadcast receiver (10) of the present invention, the service selection operation unit (41, 42) switches the service only among the services belonging to the ensemble selected by the ensemble selection operation unit (40). In addition to the first mode that allows the user to select, a second mode that allows the user to select by switching to an arbitrary ensemble service is provided.
[0011]
By switching between the first mode and the second mode, the user can select between quick switching of services and free switching of desired services between arbitrary ensembles.
[0012]
According to the digital broadcast receiver (10) of the present invention, in the automatic service presetting, the service selection operation unit (41, 42) can be used in the first mode, and data necessary for the output of each service is obtained. Remember.
[0013]
According to the digital broadcast receiver (10) of the present invention, the ensemble selection operation unit (40) is assigned with one ensemble and is operated when selecting the assigned ensemble. 40).
[0014]
Since the number of ensembles that can be received is small, the number of preset keys (40) is small.
[0015]
According to the digital broadcast receiver (10) of the present invention, the ensemble selection operation unit includes a first ensemble cyclic key that sequentially switches the ensemble cyclically in the first cyclic direction and allows the user to select the ensemble. And a second ensemble cyclic key that causes the user to select the ensemble cyclically in a cyclic direction opposite to the first ensemble cyclic key.
[0016]
The first and second cyclic directions are, for example, an upper direction and a lower direction. For the ensemble, whether it is higher or lower can be set, for example, from the first to the highest in the preset order, or can be set by appropriately changing the order of the user (the same applies to the upper and lower levels of services described later). .) Cyclic means, for example, that when the highest level is reached in the upper direction, the next level is returned to the lowest level, and when the lowest level is reached in the lower level direction, the next level is returned to the highest level.
[0017]
In this way, even if the number of ensembles that can be received increases, it is possible to switch between all ensemble selection operation units with two of the first and second ensemble cyclic keys, and the necessary space for the ensemble selection operation unit. Can be reduced.
[0018]
According to the digital broadcast receiver (10) of the present invention, the service selection operation unit (41, 42) is configured to sequentially switch the service in the upper direction and allow the user to select the upper direction service selection sequential switching key (42). And a lower-order service selection sequential switching key (42) for sequentially switching the services in the lower direction and allowing the user to select them.
[0019]
The upper direction service selection sequential switching key (42) and the lower direction service selection sequential switching key (42) are not necessarily limited to cyclic keys. Even if the number of services in one ensemble increases, the service can be switched by using the upper direction service selection sequential switching key (42) and the lower direction service selection sequential switching key (42). The required space for the service selection operation unit (41, 42) can be reduced.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a system configuration diagram of a DAB car radio 10. The DAB car radio 10 is equipped with a main body 12 and a DAB control microcomputer 26 that is separate from the main body 12. In the main body 12, the DAB system microcomputer 14 has a memory 16, and a plurality of ensembles (each ensemble is transmitted by radio broadcast radio waves modulated by DQPSK-OFDM, and one ensemble has a bandwidth of about 1. 5 MHz, which normally includes 6 to 10 services), and designates one ensemble from among them, and sends the frequency data of the designated ensemble to the RF block 18. The RF block 18 extracts an RF (Radio Frequency) signal of the ensemble designated from the DAB system microcomputer 14 and sends it to the demodulation block 20. The demodulation block 20 demodulates the RF signal from the RF block 18 as DAB data, and the channel decoding block 22 decodes the demodulated signal related to the corresponding channel from the demodulation block 20 based on the channel information from the DAB system microcomputer 14. . Thus, the data of the necessary channel in the ensemble designated by the DAB system microcomputer 14 to the RF block 18 is decoded in the channel decoding block 22. Among the digital signals decoded in the channel decoding block 22, the audio data is sent from the channel decoding block 22 to the audio decoding block 24, and FIG data such as a program type other than the audio data (FIG. Will be described later) is the channel decoding block 22. To the DAB system microcomputer 14. The audio decoding block 24 decodes the audio data of the subchannel instructed from the DAB system microcomputer 14 among the audio data input from the channel decoding block 22 and sends it to the left and right speakers (not shown). The DAB control microcomputer 26 includes a memory 28 and exchanges data with the DAB system microcomputer 14 of the main body 12. The DAB control microcomputer 26 receives an instruction from the user via the key 30 and outputs data such as data service to the display 32 to display information and notify the user.
[0021]
In the following, the communication protocols of various elements of DAB such as transmission frames are described as appropriate in FIG. 2 to FIG. 6, but the details are described in the European Telecommunications Standards (European Telecommunications Standards Institute). (European Telecommunications Standard).
[0022]
FIG. 2 shows the structure of a DAB transmission frame. A transmission frame (Transmission frame) has a synchronization channel, FIC (Fast Information Channel), and MSC (Main Service Channel) in order from the front. The FIC further includes a plurality of FIBs (Fast Information Blocks), and the MSC further includes a plurality of CIFs (Common Interleaved Frames). The specifications of DAB are determined from mode 1 to mode 4, and the transmission frame duration and the number of FIBs and CIFs in one transmission frame are different for each mode. For example, in mode 1, the time of one transmission frame is 96 ms, and the number of FIBs and CIFs in one transmission frame is 12 and 4, respectively.
[0023]
FIG. 3 is an exemplary diagram of a DAB service structure. The ensemble label (ensemble name) is DAB ENSEMBLE ONE, and the service labels are alpha 1 radio (ALPHA1 RADIO), beta radio (BETA RADIO), alpha 2 radio (ALPHA2 RADIO), etc. A plurality of services (Services) are included. The user listens to the selected service from the DAB car radio 10.
[0024]
The alpha 1 radio has one primary service component (Service component) and two secondary service components. The primary service component is audio (Audio), and the secondary service component is a traffic message channel: TMC (Traffic Message Channel) and service information: SI (Service Information). The audio component and the SI are transmitted on separate subchannels (SubCh) in the MSC, and the TMC is transmitted on a FIDC (Fast Information Data Channel) in the FIC.
[0025]
Beta radio has two service components. Audio and secondary audio components, both of which are placed on the MSC subchannel.
[0026]
The alpha 2 radio has the same TMC and SI as the alpha 1 radio, and depending on the switch, the audio may be the same as the alpha 1 radio.
[0027]
FIG. 4 is a structural diagram of the FIB. The FIB consists of 256 bits as a whole, and consists of a front 30-byte FIB data field (FIB data field) and a rear 16-bit CRC (Cyclic Redundancy Check word). The FIB data area further includes a plurality of FIGs (Fast Information Group), one end marker (End marker), and one padding (the remaining bits for aligning the FIB data area with bytes) in order from the front. 0). The FIG portion constitutes a useful data field. Each FIG comprises, in order from the front, a FIG type, Length (length: represents the bit length of the subsequent FIG data area), and FIG data field (FIG data field). The FIG type and Length constitute the FIG header.
[0028]
FIG. 5 is a structural diagram of a FIG data area in which the FIG type of FIG. 4 is 0 (000 in 3-bit binary display). The FIG data area further includes C / N (Current / Next), OE (Other Ensemble), P / D (Program / Data), Extension, and a type 0 area (Type 0 field) in order from the front. When Extension is 1 to 4 and 7, when C / N = 0, it means that the current multiple structure is used, and when C / N = 1, it is the next multiple structure. means. Further, when C / N = 1, it means that the type 0 region is related to the next arrangement. When Extension is 6, 9, 11, 18, 21, 22, 23, 24, 25, 27, 30, C / N indicates the version number of the type 0 area. OE is used when Extension = 12, 16, 17, 21, 24, 30. OE = 0 means that the information of this type 0 area is related to this ensemble, and OE = 1 It means that it is related to the ensemble. P / D = 1 means that the SId of the type 0 area is a 16-bit SId used for the program service, and P / D = 0 means that the SId of the type 0 area is used for the data service. Means 32-bit SId. This P / D is used when Extension is 2, 9, 23, 24, and when it is not used, SId is in a 16-bit format.
[0029]
FIG. 6 is a structural diagram of FIG0 / 2. Each FIG is expressed as FIG 0/2 in FIG type and Extension. The type 0 area has a plurality of service (v... K... T) areas. In each service area, a service component description (Service comp. Description) is written together with a service ID (SId). In the service component description, when TMId = 00 (MSC stream audio), the SubChId of the MSC (FIG. 3) carrying the audio service is described, and the subchannel is decoded. The audio service can be output to a speaker or the like.
[0030]
FIG. 7 is a diagram showing the main part of the front panel portion of the DAB car radio 10. The front panel portion of the DAB car radio 10 is provided with a plurality of ensemble preset keys 40, one service switching up key 41 and one service switching down key 42. Each ensemble preset key 40 can be preset with one ensemble. By pressing a predetermined ensemble preset key 40, the ensemble preset to the ensemble preset key 40 is selected. It is like that. In the first mode, the service switching up key 41 and the service switching down key 42 are services that belong to the ensemble selected by the ensemble preset key 40 and are preset by the user every time the user performs a pressing operation. The service is cyclically up and down sequentially. Service presets include not only manual settings by the user, but also an automatic preset function. Even when presetting is performed by the automatic preset function, the services belonging to the same ensemble are preset to be switched and selected by the service switching up key 41 and the service switching down key 42. Up and down means moving to higher and lower services, respectively, and cyclic means when the top and bottom services are reached when the service is up and down, respectively. It means returning to the lowest level and the highest level. The upper and lower levels of the service may be assigned from the previously preset level to the higher level, or may be changed manually by the user once preset. In the second mode, the service switching up key 41 and the service switching down key 42 are not limited to the same ensemble, and are cyclically up and down between services of an arbitrary ensemble.
[0031]
FIG. 8 is a flowchart of processing for presetting a service designated by the user. In S46, it is determined whether or not there is a preset request from the user. If the determination is YES, the process proceeds to S47, and if the determination is NO, the routine is terminated. In S47, it is determined whether the preset requested by the user is an ensemble unit or a service unit. If the preset is an ensemble unit (corresponding to the first mode described above), the process proceeds to S48 and the service unit (the second unit described above) is processed. If this is the case, the process proceeds to S50. In S48, ensemble information about the ensemble to which the service to be preset by the user belongs is stored. The ensemble information includes an ensemble frequency, an ensemble ID, and an ensemble label (= name of the ensemble). In S49, the service information about the service to be preset by the user is stored. The service information includes a service ID, a service label (= service name), and a subchannel ID. In S50, the same service information as S43 is stored together with the ensemble frequency. In S51, the fact that the current preset is surely stored is displayed on the display 32. Thus, in the first mode, the user can switch and select services in the same ensemble by operating the ensemble preset key 40, the service switching up key 41, and the service switching down key 42. In the second mode, the service switching up key 41 and the service switching down key 42 can be operated to switch and select services between arbitrary ensembles.
[0032]
In the embodiment of the invention, the audio service component as the primary service component is output from the speaker by switching the service. In the first mode, service components in the same ensemble may be switched including the secondary audio service component.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a car radio for DAB.
FIG. 2 is a diagram illustrating a structure of a DAB transmission frame.
FIG. 3 is an exemplary diagram of a DAB service structure;
FIG. 4 is a structural diagram of FIB.
FIG. 5 is a structural diagram of a FIG data area in which the FIG type of FIG. 4 is 0;
FIG. 6 is a structural diagram of FIG0 / 2.
FIG. 7 is a diagram showing a main part of a front panel portion of a DAB car radio.
FIG. 8 is a flowchart of processing for presetting a service designated by a user.
[Explanation of symbols]
10 DAB Car Radio (Digital Broadcasting Receiver)
40 Preset keys for ensemble (ensemble selection operation section, preset key)
41 Up key for service switching (Sequential switching key for selecting upper direction service)
42 Down key for service switching (Sequential switching key for service selection in lower direction)

Claims (4)

A possible plurality of ensemble transmission, a plurality of services, are combined into a single ensemble, Oite a digital broadcasting receiver for receiving a digital broadcast transmitted by an orthogonal frequency division multiplexing modulation scheme,
Ensemble selection operation unit that is operated for selection of the ensemble, and the total ensemble-operation is to be operated in order sequentially switched service targeting only services belonging to Oite selected ensemble the ensemble selection operating part Has a common service selection operation section ,
The ensemble selection operation unit includes a plurality of preset keys, and one ensemble preset to each preset key can be selected by pressing a preset key associated with the preset. A receiver for digital broadcasting, characterized in that the operation unit is constituted by up / down keys. 2. The digital broadcast receiver according to claim 1, wherein the service selection operation unit is provided in common to all ensembles. 2. The receiver for digital broadcasting according to claim 1, further comprising an automatic service presetting means for storing data necessary for output of each service so that the service selection operation unit can be used. The ensemble selection operation unit, according to claim 1, characterized in that one of a preset key is operated when ensembles assigned selects its assigned ensembles Digital broadcast receiver.

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