JPH11330997A - Receiver for broadcasting and receiver for digital broadcasting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent traffic information and weather information as a secondary program from being missed while tuning a car radio 10 for DAB to a desired program. SOLUTION: A receive signal regarding an ensemble indicated by a microcomputer 15 is demodulated by a demodulator 13, further decoded by a channel decoder 14 by selecting channels of two specific audio service components, and sent to MPEG decoders 20a and 20b respectively. The outputs of the MPEG decoders 20a and 20b are multiplied by specific coefficients through digital multipliers 21a and 21b respectively and then added by a digital adder 24, whose output is converted by a digital-to-analog converter 25 to an analog signal, so that it is reproduced by a speaker 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, DAB
(Digital Audio Broadcasti
More particularly, the present invention relates to a broadcast receiver and a digital broadcast receiver capable of simultaneously listening to a plurality of broadcast programs.

[0002]

2. Description of the Related Art DAB has attracted attention as a radio broadcast format capable of coping with deterioration of sound quality due to interference due to multi-localization of FM broadcasting and difficulty in receiving good quality on a mobile body. DA
B has been developed by EUREKA (European Advanced Technology Development Plan), and its specifications have already been defined. As a modulation method, π / 4 shift DQPSK-OFDM is used.
(Differential Quadrature
Phase Shift Keying-Orthog
onal Frequency DivisionMu
It employs an Itiplex (orthogonal frequency division multiplexing), and is characterized by being hardly affected by fading and multipath. A 1.5 MHz transmission band is used for audio encoding using a high-efficiency audio encoding MPEG layer II. It enables a wide range of stereo and data broadcasts.

[0003] In DAB, a plurality of services are included in one ensemble, and each service is composed of a primary audio service component and a secondary audio or data service component. It is allocated to different channels in a common transmission frame related to one ensemble, and is transmitted at a predetermined carrier frequency.

[0004]

The conventional radio cannot listen to the program on the other side, and cannot cope with missing. In particular, in DAB, in addition to programs such as music, programs dedicated to information such as traffic information and weather forecast are broadcast in parallel, so that users do not want to miss information while listening to the main program. However, the conventional DAB radio has not been able to respond to such a demand. In addition, conventional DA
In the radio for B, although only the entire transmission frame is demodulated, only one channel is MPEG-decoded.
The audio is not reproduced by decoding, and the tuner and the demodulator are not fully utilized.

An object of the present invention is to provide a broadcast receiver and a digital broadcast receiver which overcome the above-mentioned problems.

[0006]

SUMMARY OF THE INVENTION A broadcast receiver according to the present invention.
In (10), signals related to audios of a plurality of broadcast programs are mixed at a predetermined volume ratio, and the mixed audio signals are output from a common audio output unit (26).

The audio output unit 26 is not limited to a speaker, but includes any audio output unit such as an earphone for converting an electric signal into a sound wave so that a user can recognize it by hearing.

[0008] Broadcast programs include not only radio broadcast programs but also television broadcast programs. Television broadcast programs also include audio signals, and these audio signals can be mixed (mixed) and played back simultaneously. In other words, the plurality of broadcast programs that mix audio signals are not limited to only a plurality of radio broadcast programs, and may include a radio broadcast program and a television broadcast program. Furthermore, even when all broadcast programs that mix audio signals are radio broadcast programs, the present invention is not limited to the same type of radio broadcast format. For example, the present invention is not limited to only DAB radio broadcast programs or FM broadcast programs. And a plurality of types of radio broadcast formats. The number of broadcast programs for mixing audio signals is usually two, but audio signals for three or more broadcast programs may be mixed and output from an audio output unit (26) such as a speaker (26). . The predetermined value of the volume ratio between the plurality of audio signals at the time of mixing may be arbitrarily set by the user, or may be fixed. For example, normally, the playback sound of the front program should be output at a higher volume than the playback sound of the counterprogram,
When the user determines that it is necessary, the volume of the counterprogram can be temporarily increased by the user's operation.

In this way, the user can listen to a plurality of broadcast programs at the same time and avoid overlooking information.

According to the digital broadcast receiver (10) of the present invention, a plurality of audio broadcast programs broadcast simultaneously receive broadcast signals allocated to different channels in a common transmission frame and broadcast. . This digital broadcast receiver (10) has the following (a) to (d). (A) A channel decoding unit (14) that decodes a channel included in a transmission frame demodulated from a received signal and that corresponds to a plurality of selected audio broadcast programs. (B) Each output from the channel decoding unit (14). A compression signal decoding unit (20) for decoding a decoded signal for a channel into an audio signal before data compression; (c) an adding unit (24) for adding an audio signal for each broadcast program related to the output of the compressed signal decoding unit (20) , 32) (d) an audio output unit (26) for outputting audio relating to the output of the adding means (24, 32)

The data compression system of the signal decoded by the compressed signal decoding unit (20) includes at least MPEG, and the digital broadcast receiver (10) includes at least DAB radio,
In particular, it includes a DAB car radio (10). DA
The audio broadcast program in B is not limited to the primary audio service component of each service, but includes a secondary audio service component excluding the data service. The audio output unit (26) is, for example, a speaker (26), and an audio recording unit for recording audio is excluded from the concept of the audio output unit (26).

In this way, the user can listen to a plurality of audio broadcast programs at the same time and avoid overlooking information. In particular, in DAB, in addition to broadcast programs such as music, there is an audio broadcast program that broadcasts traffic information and weather forecasts. The user listens to the main audio broadcast program such as music while listening to traffic information and the like. You can listen to In the digital broadcast receiver (10), the transmission frame is demodulated as a whole irrespective of whether or not the channel is the audio broadcast program to be finally reproduced. Machine (10)
In order to audio-output the transmission frames, the entire transmission frame has already been demodulated. Therefore,
In this digital broadcast receiver (10), even if a function of mixing a plurality of selected audio broadcast programs and outputting the audio is added, the elements up to the demodulator (13) are the same as those of the conventional digital broadcast receiver. It is possible to use the device of the device without any change, to minimize the number of newly added elements, and to effectively use the elements up to the demodulator (13).

A digital broadcast receiver according to the present invention (10)
Has the following (e). (E) Input level setting means (21a, 21b, 31a, 31) for the adding means for setting the input level of the audio signal for each broadcast program from the compressed signal decoding section (20) to the adding means (24, 32).
b)

The adding means (24, 32) includes both digital and analog elements. Since the compressed signal decoding section (20) is a digital element, the output of the compressed signal decoding section (20) is digital. Therefore, when the adding means (32) is an analog element, the output of the compressed signal decoding unit (20) is converted from digital to analog and then input to the adding means (32), and the adding means (32) Then, an audio signal of each broadcast program is input as an analog signal, and they are added. In this case, the input level setting means (31a, 31b) for the adding means is realized by an analog amplifier having an amplification factor set or an analog amplitude adjuster (31a, 31b). When the adding means (24) is a digital element,
The adding means (24) is capable of inputting and adding an audio signal of each broadcast program in a digital state, and the input level setting means for the adding means (21a, 21b) is provided with a digital multiplier multiplier (21a, 21b). ).

The input level setting means (21a, 21b, 3
In 1a, 31b), by setting the input level of the audio signal for each broadcast program, the volume ratio between a plurality of audio broadcast programs can be set. By appropriately setting the volume ratio between a plurality of audio broadcasting programs, for example, the volume of an audio broadcasting program that the user wants to listen to preferentially is large, and the volume that is sufficient for preliminary listening is reduced, and the user can reduce the volume. Thus, it is possible to efficiently listen to a plurality of audio broadcast programs.

According to the digital broadcast receiver (10) of the present invention, the input level setting means (21a, 21b, 31a,
The set value of the input level in 1b) is freely adjustable.

Input level setting means for adding means (31a, 31b)
In the case of analog amplitude adjusters (31a, 31b) as
By adjusting the level, a digital multiplier (21) as input level setting means (31a, 31b) for addition means can be used.
In the case of (a, 21b), by adjusting the multiplication coefficient, the set value of the input level in the input level setting means (21a, 21b, 31a, 31b) for the adding means can be adjusted. Adjustment of the set value of the input level in the input level setting means (21a, 21b, 31a, 31b) for the addition means is performed when the user adjusts while simultaneously listening to a plurality of audio broadcast programs, and receives audio broadcast programs. Including adjustments based on previous user settings. Thus,
The volume ratio between a plurality of audio broadcast programs can be appropriately adjusted. If the user can adjust the volume ratio while listening to a plurality of audio broadcast programs at the same time, depending on the situation at that time, for example, a predetermined audio broadcast program becomes important content. At times, it is possible to temporarily increase the volume of the predetermined audio broadcast program relative to the others, and then reduce the volume again.

According to the digital broadcasting receiver (10) of the present invention, the digital-analog converter (25) for converting a digital signal into an analog signal is provided between the adding means (24) and the audio output section (26). Intervenes.

When audio signals related to a plurality of audio broadcast programs are added in an analog stage, a digital-analog converter for each audio signal is used.
(25) is required, but this digital broadcast receiver (10)
Then, in the digital stage, the signals are added to form a mixed signal and then converted from digital to analog, so that only one digital-analog converter (25) is required.

According to the digital broadcast receiver (10) of the present invention, a plurality of audio broadcast programs broadcast simultaneously receive broadcast signals allocated to different channels in a common transmission frame and broadcast. . This digital broadcast receiver (10) has the following (a) to (c). (A) A channel decoding unit (14) that decodes a channel included in a transmission frame demodulated from a received signal and that corresponds to a plurality of selected audio broadcast programs. (B) Each output from the channel decoding unit (14). A compressed signal decoding unit (20) for decoding a decoded signal for a channel into an audio signal before data compression (c) Dedicated audio for each broadcast program audio signal output from the compressed signal decoding unit (20) Audio output section for playback (26)

The dedicated audio output section (26) for each broadcast program is, for example, a left speaker and a right speaker of a stereo system when two audio broadcast programs are simultaneously reproduced. In this digital broadcast receiver (10), a plurality of audio broadcast programs are processed without mixing audio signals of the respective audio broadcast programs separated and extracted from the transmission frame demodulated collectively as including each audio broadcast program. Since the user can simultaneously listen to the program, the configuration of the digital broadcast receiver (10) can be simplified.

If one of the dedicated audio output units (26) for each broadcast program is used as a recorder, the user can record the broadcast program on the other side while listening to a predetermined broadcast program with a speaker or the like. .

According to the digital broadcast receiver (10) of the present invention, the volume of each audio output section (26) can be appropriately adjusted by the user.

This makes it possible to efficiently listen to the priority audio broadcast program, for example, by setting the audio broadcast program that the user prefers to listen to at a higher volume than the others.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5,
The communication protocol of various elements of the DAB such as a transmission frame is appropriately described. For details, see the European Telecommunication Standards Association (European Telec).
ommuinications Standards
European Telecommunications Standard (European Telecommui)
(Communications Standard).

FIG. 1 shows the structure of a DAB transmission frame. Transmission frame (Transmission fra
me) is the synchronization channel, FIC (Fast)
Information Channel) and M
It has SC (Main Service Channel). The FIC further includes a plurality of FIBs (Fast
Information Block), MS
C is a plurality of CIFs (Common Inter
left Frame). The specifications of DAB are determined from mode 1 to mode 4, and the transmission frame time (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 9
The number of FIBs and CIFs in one transmission frame of 6 ms is 12 and 4, respectively.

FIG. 2 is a view showing an example of the DAB service structure. The ensemble (Ensemble) whose ensemble label (ensemble name) is DAB ENSEMBLE ONE has a service label of Alpha 1 Radio (ALPHA1 RADIUS).
O), a plurality of services such as beta radio (BETA RADIO) and alpha 2 radio (ALPHA2 RADIO). The user will hear the selected service from the DAB car radio 10 (FIG. 6).

[0028] The alpha 1 radio is a primary (pri
service component (Service comp)
contents, one secondary and one secondary
It has two service components of y). The primary service component is audio, and the secondary service component is a traffic message channel: TMC (Traffic Message Cha).
nel) and service information: SI (Service In)
formation). The audio component and the SI are transmitted on separate sub-channels (SubCh) in the MSC, and the TMC is transmitted in the FIDC (Fast Info) in the FIC.
transmission (Ration Data Channel).

Beta radio has two service components.
A primary audio component and a secondary audio component, both of which are carried on the MSC subchannel.

The alpha 2 radio has the same TMC and SI as the alpha 1 radio, and the audio may be the same as the alpha 1 radio depending on the switch.

FIG. 3 is a structural diagram of the FIB. FIB
The entirety of the digital-analog converter is composed of 256 bits, and the first 30-byte FIB data area (FIB d
atafield) and the 16-bit CRC (Cy
click Redundancy Check wor
d). The FIB data area further includes a plurality of FIG (Fast Information) in order from the front.
Group), one end marker (End mar)
ker) and one padding (filling the remaining bits with zeros to fit the FIB data area to bytes). FIG is the useful data area (us
eful data field). Each FI
G is a FIG type, a Length (representing a bit length of a subsequent FIG data area) and a FIG data area (FIG data view) in this order from the front.
ld). Fig type and Length are fig
Configure the header.

FIG. 4 is a structural diagram of the FIG data area of FIG. 3 in which the FIG type is 0 (000 in 3-bit binary notation). The FIG data area further stores C / N
(Current / Next), OE (Other E)
nsemble), P / D (Programme / Da
ta), Extension, Type 0 area (Type
0 field). Extension is 1 to 4
And 7, when C / N = 0, it means the current multiplex structure, and when C / N = 1, it means the next multiplex structure. Also, C / N =
When it is 1, it means that the type 0 area is related to the following arrangement. Extension is 6, 9, 11, 1
In the case of 8, 21, 22, 23, 24, 25, 27, and 30, C / N indicates the version number of the type 0 area.
OE is Extension = 12, 16, 17, 21,
24, 30 are used, and OE = 0 indicates this type 0
The information of the area means that it is related to this ensemble, and OE = 1 means that it is related to another ensemble. P / D = 1 indicates SId of type 0 area
Is the 16-bit Sid used for program services
, And P / D = 0 indicates that S in the type 0 area
Id is the 32-bit Sid used for data service
Means that This P / D is Extension
Are 2, 9, 23 and 24, and when not used, SId is in 16-bit format.

FIG. 5 is a structural diagram of FIG. 0/2. Note that each FIG is represented by the FIG type and the Extension as FIG0 / 2. The type 0 area has a plurality of service (v... K... T) areas. The service ID (SI
d) together with the number of service components (Number ofc
components), service component description (Servi
ce description) is written. FIG. 0/2 includes the number of service component component descriptions by the number of service components. Then, in the service component description, when TMId = 00 (MSC stream audio) and P / S (Primary / Secondary: Primary / Secondary) = 0, the service component may be a secondary audio broadcast. I understand. Therefore, by examining FIG0 / 2 of the audio frame, it is possible to detect what kind of audio service component, that is, which subchannel of the MSC contains the audio radio program in the ensemble related to the audio frame.

FIG. 6 is a block diagram of the DAB car radio 10. The DAB radio wave being broadcast is received by an antenna 11 and input to a front end (tuner) 12. The microcomputer 15 sends a control signal to the front end 12 so as to tune to the reception frequency corresponding to the selected one ensemble, and the front end 12 changes the reception frequency specified by the microcomputer 15 to the intermediate frequency. The signal is converted, amplified, and sent to the demodulator 13. Demodulator 13
Receives a control signal relating to synchronization of a transmission frame from the microcomputer 15, demodulates an input signal from the front end 12, and extracts digital data relating to the transmission frame. The channel decoder 14 decodes only the channel specified by the microcomputer 15 in the transmission frame input from the demodulator 13, and outputs a decoded signal for each decoded channel to each MPEG decoder 20.
Send to a, 20b. The channel which the microcomputer 15 instructs the channel decoder 14 to decode relates to the data of the audio service component of the DAB which the user wants to listen to at the same time. The channel decoder 14 of FIG. 1 decodes the data of two audio components. ing. Each of the MPEG decoders 20a and 20b MPEG-decodes the digital signal of each channel from the channel decoder 14, and
Return to the digital audio signal before G encoding.
The digital multipliers 21a and 21b are connected to the MPEG decoders 20a and 20b.
The signal after the MPEG decoding input from 0b is multiplied by the coefficient specified by the microcomputer 15, and the product is output to the digital adder 24. Digital multipliers 21a, 21b
Are in the range of 0 to 1 and usually differ from each other, but may be equal to each other.

As examples of coefficients in the digital multipliers 21a and 21b, the following are planned. (A) The service component decoded by the MPEG decoder 20a is set to a service program that the user prefers to listen to over the service component decoded by the MPEG decoder 20b, and the coefficient of the digital multiplier 21a is digitally multiplied. Is set to a value larger than the coefficient of the detector 21b. In addition, the coefficients of the two MPEG decoders 20a and 20b may be set by the user in advance before listening to the audio broadcast program, or may be set to fixed values without setting by the user. (B) The volume ratio of each service component is determined by the content of the program (eg, when listening to a music program and a news program at the same time, when listening to a news program and traffic information, etc.) and the listening environment (eg, listening alone). The user can appropriately adjust the coefficients in the digital multipliers 21a and 21b so that the user can make adjustments according to whether the user is present or the companion wants to listen to another program.

The digital adder 24 is a digital multiplier 21
a and 21b are added, and the added digital value is converted to an analog value in a digital-analog converter 25, and is passed through an amplifier (not shown) to a speaker 26.
, And audio output from the speaker 26.

FIG. 7 is a block diagram of another DAB car radio 10 for simultaneously outputting two service components as audio. The part that overlaps with the DAB car radio 10 in FIG.
The description is omitted, and only the differences will be described. MPEG
Outputs of the decoders 20a and 20b are sent to digital-to-analog converters 30a and 30b, respectively, where they are converted from digital to analog. The amplitude adjusters 31a and 31b are digital
The amplitude of the analog signal from the analog converters 30a and 30b is
The amplitude is changed to the increase / decrease rate instructed by the microcomputer 15 and sent to the analog adder 32. The amplitude increase / decrease rate instructed from the microcomputer 15 to each of the amplitude adjusters 31a and 31b may be fixed, or may be appropriately adjusted by the user by operation. The analog adder 32 adds the analog values from the amplitude adjusters 31a and 31b, and outputs the added analog signal, that is, the audio signal obtained by mixing the audio of both audio service components, through an amplifier (not shown), The audio is output at 26.

In the illustrated DAB car radio 10, although two audio service components are to be mixed,
By increasing the number of EG decoders 20a, 20b, etc., three or more audio service components can be mixed and output as audio.

In the DAB car radio 10 shown in FIG. 7, the analog adder 32 is omitted, two speakers are provided corresponding to the amplitude adjusters 31a and 31b, and the outputs of the amplitude adjusters 31a and 31b are output. It can be sent directly to each speaker to output audio. In particular, when the DAB car radio 10 is equipped with left and right speakers, the outputs of the amplitude adjusters 31a and 31b are input to the left and right speakers, respectively, and sound of another audio service component is output from the left and right speakers. You can also.
It is also possible to send one of the outputs of the amplitude adjusters 31a and 31b to a speaker and output a sound from the speaker, and input the other to a recorder to record a counterprogram.

[Brief description of the drawings]

FIG. 1 shows the structure of a DAB transmission frame.

FIG. 2 is an exemplary diagram of a DAB service structure;

FIG. 3 is a structural diagram of an FIB.

FIG. 4 is a structural diagram of a FIG data area in which a FIG type in FIG. 3 is 0 (000 in 3-bit binary notation).

FIG. 5 is a structural diagram of FIG0 / 2.

FIG. 6 is a block diagram of a DAB car radio.

FIG. 7 is a block diagram of another DAB car radio that simultaneously outputs two service components as audio.

[Explanation of symbols]

10 DAB car radio (broadcast receiver, digital broadcast receiver) 14 channel decoder (channel decoding unit) 20a, 20b MPEG decoder (compressed signal decoding unit) 21a, 21b digital multiplier (input level setting means for addition means) 24) Digital adder (addition means) 26 Speaker (audio output section) 31a, 31b Amplitude adjuster (input level setting means for addition means) 32 Analog adder (addition means)

Claims (7)

[Claims] 1. A broadcast receiver, comprising: mixing audio signals of a plurality of broadcast programs at a predetermined volume ratio; and outputting the mixed audio signals from a common audio output unit (26). 2. A digital broadcast receiver (10) for receiving a broadcast signal in which a plurality of simultaneously broadcast audio broadcast programs are allocated to different channels in a common transmission frame and broadcast. A channel decoder (14) for decoding a channel included in a transmission frame demodulated from a received signal and corresponding to a plurality of selected audio broadcast programs, (b) the channel decoder
The compressed signal decoder (2) decodes the decoded signal for each channel output from (14) to an audio signal before data compression.
0), (c) adding means (24, 24) for adding the audio signal of each broadcast program related to the output of the compressed signal decoding section (20).
32) and (d) an audio output unit (26) for outputting audio relating to the output of the adding means (24, 32). 3. An input level setting means for an adding means (21a) for setting an input level of an audio signal for each broadcast program from the compressed signal decoding section (20) to the adding means (24, 32). , 21b, 31a, 31b). The digital broadcast receiver according to claim 2, comprising: 4. An input level setting means (21) for said adding means.
4. The digital broadcast receiver according to claim 3, wherein the set value of the input level in a, 21b, 31a, 31b) is adjustable. 5. A digital-to-analog converter (25) for converting a digital signal into an analog signal is provided by said adding means (2).
The digital broadcast receiver according to any one of claims 2 to 4, wherein the receiver is interposed between (4) and the audio output unit (26). 6. A digital broadcast receiver (10) for receiving a broadcast signal in which a plurality of simultaneously broadcast audio broadcast programs are allocated to different channels in a common transmission frame and broadcast. A channel decoder (14) for decoding a channel included in a transmission frame demodulated from a received signal and corresponding to a plurality of selected audio broadcast programs, (b) the channel decoder
The compressed signal decoder (2) decodes the decoded signal for each channel output from (14) to an audio signal before data compression.
0), and (c) an audio output unit (26) for exclusively reproducing audio relating to the audio signal of each broadcast program output from the compressed signal decoding unit (20). Digital broadcasting receiver. 7. The digital broadcast receiver according to claim 6, wherein the volume of each audio output section (26) can be appropriately adjusted by a user.