JP4703755B2 - Broadcast receiving apparatus and power consumption reduction method thereof - Google Patents

Description

The present invention relates to a technique for reducing the power consumption of a digital broadcast receiving device when the digital broadcast receiving device has a function other than the function of receiving a broadcast wave, for example, when a transmitting unit of a mobile terminal unit is operating.

In terrestrial broadcasting, service improvement by digitalization and SFN (Sing1e Frequ
enCy Network), MFN (Multi Frequency Network)
Digitization is performed in order to realize effective use of the band according to k). According to this, 6M
Using a region in Hz, it is possible to broadcast one program for HDTV and three programs for SDTV. At the same time, high-quality broadcasting services and data broadcasting services will be realized.

In general, video / audio information, which is content information in digital broadcasting, is compressed by the MPEG2 system, and data broadcasting is generated by a recarous cell transmission system using the BML language.

The compressed video, audio information, and data broadcast are multiplexed to generate a transport stream (TS). The generated TS signal is efficiently modulated and transmitted by a digital modulation method.

In the case of digital terrestrial broadcasting, BST-OFDM (Band Segmente is used in Japan.
d Transmission-Orthogonal Frequency Div
(Sion MuItplexing) method is employed, which is a multi-carrier transmission method using a plurality of carriers at the same time. Each carrier is orthogonal to each other and modulated by DQPSK, QPSK, 16QAM, and 64QAM. . The number of carriers used is about 1400 to 5600 in domestic terrestrial digital broadcasting, and OFDM modulation and OFDM demodulation are performed by inverse Fourier transform and Fourier transform, respectively.

In actual transmitters and receivers, I-DFT (lnvers) of 2K points to 8K points
e-Discule Fourier Transform) processing, DFT
(Discrete Fourier Transformation) processing is used.

Unlike terrestrial broadcasting, digital terrestrial broadcasting generates reflected waves due to obstacles such as buildings and mountains, which become ghosts and cause errors in digital modulation signals. For this reason, in the receiver, video and audio signals are broken, and reception quality is significantly deteriorated. In general, signal degradation due to noise can be corrected by error correction if the received signal satisfies the required C / N, and video / audio can be reproduced without error in the receiver.

In order to absorb the effects of ghost and multipath interference as described above, OFD
In the M method, a buffer area is provided so that information is not broken even if a delay wave exists. This buffer area is called a guard interval (GI). Since the code interference does not occur unless the delay time of the delay wave of the received signal exceeds the guard interval time, the error correction circuit can correct it. If the guard interval is exceeded, intersymbol interference occurs and causes an error. Guard interval length is 1 of the total transmission signal length
/ 4, 1/8, 1/16, 1/32, which corresponds to about 8 to 250 microseconds.

In general, in mobile reception and mobile reception in terrestrial broadcasting, a signal digitally modulated by multipath fading or the like deteriorates and an error occurs. OF adopted for digital broadcasting
In the DM system, a concatenated code is used in combination, and time interleaving is adopted to make the system robust to mobile reception and mobile reception.

The configuration of a conventional receiver is shown in FIG. A desired channel is selected by a tuner 12 which is a channel selection unit and output from a signal from an antenna 11 that receives a broadcast wave. IF selected and output
The signal is converted into a re-digital signal by the ADC 13 that performs analog-digital conversion. The IF signal converted into the digital signal is OFDM demodulated by the OFDM demodulator 14, and the decoder 1
5 is decoded and a TS signal is output.

The output TS signal is demultiplexed by the demax decoder 14, and each video / audio / data broadcast stream is output. Each of the separated signals is subjected to information decoding processing and converted into viewable information. Video is subjected to MPEG2 decoding and the like, and audio is mainly subjected to AAC decoding. Data broadcasting performs carousel processing, processes information embedded with MPEG4 and the like, and enables viewing of still images, simple moving images, and the like.

In digital terrestrial broadcasting, the high-quality mobile reception and mobile reception services are possible by this robust OFDM system, and a digital broadcast receiver (
A new system can be constructed using a composite terminal.

As described above, when services for mobile reception and mobile reception are performed in terrestrial digital broadcasting, the digital broadcast receiving device can view content such as normal video, audio, and data broadcasting, and communication means. New viewing modes and devices, such as interactive services, can be realized by interlocking with each other. Such a digital broadcast receiving apparatus (receiving terminal) is often operated with a battery, and it is desired to reduce its power consumption. For example, the power consumption during roaming of the transmitter of the communication means overlaps with the continuous operation of the broadcast wave receiver, resulting in an instantaneous increase in power consumption and an increase in the burden on the battery.

In addition, when the digital broadcast receiving apparatus is viewing content, in the case of data broadcasting, etc., when information is repeatedly transmitted in the carousel, the received content information can be viewed by performing decoder processing in that cycle. Is possible. For example, if the carousel has a period of 15 seconds and is updated after 3 minutes, it will be repeatedly transmitted 12 times. If one period of information can be completely acquired at this time, the processing of the broadcast wave receiving unit will continue to receive the same information. As a result, redundant operations are performed.

For this reason, when content information is repeatedly transmitted in the digital broadcast receiving apparatus, it is not necessary to set the reception operation to a normal reception operation, and the operation can be completely or partially stopped. .

In this way, even when there is a limit to battery or power, such as a small digital broadcast receiver, etc., power can be used efficiently and power consumption can be kept low, and the operation of the digital broadcast receiver can be reduced. The operating time can be extended stably.

In a digital broadcast receiver combined with a communication means such as a mobile phone, power is consumed due to the transmission state such as roaming processing of the communication means, and if the operation with the broadcast wave receiver occurs simultaneously, the load on the battery is large. Power consumption becomes significant.

In order to solve such problems, an object of the present invention is to provide a broadcast receiving apparatus that efficiently reduces power consumption by stopping the operation of the broadcast wave receiving unit by the operation of communication means including a portable terminal unit. There is to do. It is another object of the present invention to provide a broadcast receiving apparatus that stops the reception operation when receiving data broadcasts to reduce power consumption.

In order to solve the above problems, the present invention mainly adopts the following configuration.
In a digital broadcast receiver having an antenna for receiving a broadcast wave including data broadcast information by orthogonal frequency division multiplexing (OFDM), a tuner for selecting a desired frequency band from a signal received by the antenna, and the tuner An analog-digital conversion circuit that converts the selected signal into a digital signal, an OFDM demodulator that digitally demodulates the signal digitally converted by the analog-digital conversion circuit, and a demodulated signal demodulated by the OFDM demodulator A decoding unit that performs decoding, a demultiplexing unit that performs demultiplexing from the transport stream signal decoded by the decoding unit, a decoder unit that decodes information from the signal demultiplexed by the demaxing unit, mobile transmission / reception or Communication enabling mobile transmission / reception services And when the communication means is operated, all or part of the operations of the tuner, the analog-digital conversion circuit, the OFDM demodulator, and the decoder are temporarily performed by a control signal from the communication means. When the data broadcast information is acquired, the broadcast wave reception operation is temporarily stopped .

According to the present invention, when a communication means enabling mobile transmission / reception or mobile transmission / reception service operates, the operation of the broadcast wave reception unit is stopped, and when the data broadcast is received, the reception operation of the broadcast wave reception unit is stopped. Thus, power consumption can be reduced.

It is a figure which shows the whole structure of the digital broadcast receiver provided with the portable terminal part in addition to the broadcast wave receiver based on embodiment of this invention. It is a figure which shows the electric power control structure of the digital broadcast receiver provided with the broadcast wave receiver based on other embodiment of this invention. It is a figure which shows the operation | movement timing between the transmission part of a portable terminal part, and a broadcast wave receiving part. It is a figure which shows the operation | movement timing of a broadcast wave receiving part. It is a figure which shows the whole structure of the digital broadcast receiver in a prior art.

A digital broadcast receiver according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram illustrating an overall configuration of a digital broadcast receiving apparatus including a mobile terminal unit in addition to a broadcast wave receiving unit according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a power control configuration of a digital broadcast receiving apparatus including a broadcast wave receiving unit according to another embodiment of the present invention. FIG. 3 is a diagram illustrating operation timing between the transmission unit and the broadcast wave reception unit of the mobile terminal unit. FIG. 4 is a diagram showing the operation timing of the broadcast wave receiving unit.

In FIG. 1, first, the digital broadcast receiver 19 is mainly composed of a broadcast wave receiver 18 that receives broadcast waves, a portable terminal 32 (an example of communication means), and a controller 21 that controls the operation of both. Yes. Then, in the broadcast wave receiving unit 18 of the digital broadcast receiving apparatus 19 that receives the broadcast wave transmitted from the broadcast station by the receiving antenna 11, the signal received by the antenna 11 is sent to the tuner 12 that is a channel selecting unit for channel selection. Select the frequency you want to receive. The selected signal is converted into a digital signal by an analog-to-digital converter (ADC) 13,
An orthogonal frequency division multiplexing (OFDM) signal is demodulated by an OFDM demodulator 14 that digitally demodulates the signal. The demodulated signal is decoded by the decoding unit 15 and the transport stream signal (
(TS signal).

The transport signal is defined by the MPEG2-systems standard, and video / audio / data broadcasting and SI / PSI signals are multiplexed. The transport signal output from the decoding unit 15 is subjected to demultiplexing processing by the demax / decoder unit 16, and the video / audio /
It is separated into content information such as data broadcasting and control signals (SI / PSI signals) (filtering process).

The separated signals are subjected to decryption processing of each content, and processed into information that can be viewed. The video signal is subjected to MPEG2 decoding, and the audio signal is mainly subjected to AAC decoding. Data broadcasting performs carousel processing and displays information using a BML browser. In addition, information embedded with MPEG4 or the like is processed to allow viewing of still images and simple moving images.

Then, voice and information are transmitted and received by the portable terminal unit 32 which is an example of a communication means. Information from the microphone 28 is amplified by the amplifier 27, subjected to modulation multiplexing processing by the modulation unit 26 and the time division multiplexing unit 25, amplified by the high frequency amplifier 24, and output from the antenna 23 (transmission of the portable terminal unit 32). Operation in the department). On the other hand, the signal received by the antenna 23 is amplified by the high-frequency amplifier 24, demodulated by the time division multiplexing 25 and the demodulator 29, amplified by the amplifier 30, and the sound is output by the speaker 31 (mobile phone). Operation in the receiving unit of the terminal unit 32).

The mobile terminal unit shown here shows a typical structure of a current mobile phone. However, the mobile terminal unit is not limited to this, and may be a next-generation mobile phone (IMT200) or the like that will appear in the future. . A similar effect can be expected with a PDA having a transmission function.

The mobile terminal unit 32 performs roaming at intervals of several hundred ms (see FIG. 3), and power for this transmission is consumed. In the present invention, the roaming state is detected, and the operations of the tuner unit 12, the ADC 13, the OFDM demodulator unit 14, and the decoding unit 15 in the broadcast wave receiving unit 18 are temporarily stopped to reduce power consumption. For example, the tuner 12, the ADC 13, the OFDM demodulator 14, and the decoder 15 are controlled by the power controller 20 of the broadcast wave receiver 18 through the controller 21 depending on the transmission state of the transmission controller 22 in the mobile terminal unit 32. The operation is temporarily stopped to reduce power consumption.

Further, only the ADC 13, the OFDM demodulator 14, and the decoder 15 may stop the operation. Further, only the operation of the OFDM demodulator 14 and the decoder 15 may be stopped. Further, the operation of only the decoding unit 15 may be stopped. When the broadcast wave receiver 18 is stopped,
The operation of the decoder unit after the broadcast wave receiving unit may also be stopped.

When the operations of the OFDM demodulator 14 and the decoder 15 are stopped, the synchronization operation of the broadcast wave receiver 18 can be made continuous so that the operation can be quickly recovered when the reception operation is recovered.

FIG. 3 is a timing chart showing typical operations in the broadcast wave receiving unit 18. Here, assuming that the mobile terminal unit 32 performs transmission at intervals of about 640 ms for roaming or the like,
The state is sent from the transmission control unit 22 to the power control unit 20 via the control unit 21, and the portable terminal unit 3
When 2 is in the transmission state, the reception operation of the broadcast wave receiver 18 is intermittently stopped. Power control unit 20
Based on the control signal, the operations of the tuner unit 12, the ADC 13, the OFDM demodulator unit 14, and the decoding unit 15 are temporarily or partially stopped to suppress power consumption.

The roaming timing of the portable terminal unit 32 is sent to the control unit 21 based on the information from the transmission control unit 22, and is synchronized with the power control unit 20 to control the transmission timing for roaming. Wave receiver operation is performed exclusively, and power consumption can be suppressed. Also, at the time of transmission for reply to the communication carrier, the operation of the broadcast wave receiving unit may be temporarily or partially stopped in the same manner as described above.

Next, FIG. 2 shows a representative block diagram of another embodiment of the present invention. The signal from the antenna 11 that receives the broadcast wave is obtained by extracting one wave of the desired frequency by the tuner 2 for tuning.
F signal is output. The output IF signal is converted to a digital signal by an analog-to-digital converter (ADC) 13 and digitally demodulated an orthogonal frequency division multiplexing (OFDM) signal.
Demodulated by the FDM demodulator 14. The demodulated signal is decoded by the decoding unit 15 and output as a transport stream signal (TS signal). Transport signal is MPE
Defined in the G2-systems standard, video / audio / data broadcasting and SI / PSI
The signals are multiplexed.

The transport signal decoded by the decoding unit 15 is subjected to demultiplexing processing by the demax / decoder unit 16, and the content information (video / audio / data broadcasting) and the control signal (SI ·
(Filtering process). Demultiplexed signal is decoder 1
6, the content information is decoded and a video signal, an audio signal, and a data broadcast are output.

Among digital broadcasting, data broadcasting uses a carousel data transmission system, and the same information is sent periodically. In the digital broadcast receiving apparatus of the present invention, once the data broadcast information is acquired, it is not necessary to receive the data until the information is updated, so the reception operation is temporarily stopped. The broadcast control unit 3 displays the carousel acquisition state of the demax decoder unit 16.
5, and a control signal is sent to the power control unit 20, and the power control unit 20
The operation of the ADC 13, the OFDM demodulator 14, and the decoder 15 is temporarily or partially stopped,
Reduce power consumption.

FIG. 4 is a timing chart showing the power control operation in data broadcasting. In the present invention, the digital broadcast receiving operation is stopped for a predetermined period (interval) to suppress the power consumption accompanying the reception of the broadcast wave. At this time, the interval is variable, and when the acquisition of the carousel data of the data broadcast in the broadcast wave is completed, further power saving can be achieved by stopping the receiver operation.

As described above, the operation of the embodiment of the present invention will be described. When the mobile terminal unit roams, the operation of the broadcast wave receiving unit is stopped in synchronization with the transmission unit of the mobile terminal unit, and the communication business The operation of the broadcast wave receiving unit is stopped at the time of transmission for reply to the user, and the operation of the broadcast wave receiving unit is stopped and the operation is started after an interval after acquiring the carousel at the time of data broadcast reception. In addition, as a specific configuration example in the embodiment of the present invention, a communication unit that transmits and receives audio, a decoding unit that processes a signal obtained from a broadcast wave into viewable information, and an operation of the communication unit And control means for controlling the operation of the broadcast wave receiving means including the decoding means, and the control means is configured to stop the operation of the decoding means when the communication means is operating.

11 Broadcast wave receiving antenna 12 Tuner 13 ADC
DESCRIPTION OF SYMBOLS 14 OFDM demodulation part 15 Decoding part 16 Demax decoder 17 Output terminal 18 Broadcast wave receiving part 19 Digital broadcast receiver 20 Power control part 21 Control part 22 Transmission control part 23 Transmission / reception antenna 24 High frequency amplifier 25 Time division multiplexing 26 Modulation part 27 Amplifier 28 Microphone 29 Demodulator 30 Amplifier 31 Speaker 32 Mobile Terminal 40 Control Unit

Claims (2)

In a digital broadcast receiving apparatus having an antenna for receiving broadcast waves including data broadcast information by orthogonal frequency division multiplexing (OFDM),
A tuner for selecting a desired frequency band from a signal received by the antenna;
An analog-to-digital conversion circuit that converts a signal selected by the tuner into a digital signal;
An OFDM demodulator that digitally demodulates the signal digitally converted by the analog-to-digital converter;
A decoding unit for decoding from the demodulated signal demodulated by the OFDM demodulation unit;
A demultiplexing unit that performs demultiplexing from the transport stream signal decoded by the decoding unit;
A decoder unit for decoding information from the signal demultiplexed by the demax unit;
Communication means enabling mobile transmission / reception or portable transmission / reception service,
When the communication means is operated, the tuner , the analog-digital conversion circuit, the OFDM demodulator, the operation of all or part of the decoder is temporarily stopped by a control signal from the communication means,
A digital broadcast receiving apparatus characterized in that, when the data broadcast information is acquired, a broadcast wave receiving operation is temporarily stopped . A tuner for selecting a desired frequency band from a signal received by an antenna;
An analog-to-digital conversion circuit that converts a signal selected by the tuner into a digital signal;
An OFDM demodulator that digitally demodulates the signal digitally converted by the analog-to-digital converter;
A decoding unit for decoding from the demodulated signal demodulated by the OFDM demodulation unit;
A demultiplexing unit that performs demultiplexing from the transport stream signal decoded by the decoding unit;
A decoder unit for decoding information from the signal demultiplexed by the demax unit;
A communication means that enables mobile transmission / reception or portable transmission / reception services, and a method for reducing power consumption of a digital broadcast receiver that receives broadcast waves including data broadcast information by orthogonal frequency division multiplexing (OFDM).
When the communication means is operated, the tuner, the analog-digital conversion circuit, the OFDM demodulator, the operation of all or part of the decoder is temporarily stopped by a control signal from the communication means,
When the data broadcast information is acquired, the broadcast wave reception operation is temporarily stopped.
A method for reducing power consumption of a digital broadcast receiver.

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