JP2000209072A - Receiver for digital ground wave broadcasting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver for digital ground wave broadcasting capable of solving problems generated accompanying transition from the analog system of ground wave broadcasting to a digital system and surely receiving the digital broadcasting of a desired channel. SOLUTION: In this receiver 100 for the digital ground wave broadcasting, the three kinds of frequencies that are a normal frequency, the frequency of an upper side offset and the frequency of a lower side offset allocated for digital broadcasting to each channel are stored in a channel initial data storage part 17 beforehand. When a user specifies the desired channel, a front end part 13 is operated based on the three kinds of the frequencies allocated to it and the frequency by which the digital broadcasting is performed in the three kinds of the frequencies is obtained based on OFDM synchronizing signals outputted from an OFDM demodulation part 39 inside the front end part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital terrestrial broadcasting receiver.

[0002]

2. Description of the Related Art In conventional analog terrestrial broadcasting, one regular frequency is assigned to one channel. Therefore, the receiver for analog terrestrial broadcasting is 1
A method is used in which one frequency is assigned to one selected channel. When one desired channel is selected, one assigned frequency is selected. We were able to. In addition, when a frequency shift occurs, there is some time, but the tuning frequency is automatically shifted to select a correct channel.

However, in digital terrestrial broadcasting,
One frequency is assigned to one of three types of frequencies, a regular frequency, an upper offset frequency, and a lower offset frequency. Which frequency is assigned differs depending on a region.
Not determined. Therefore, each broadcasting station that performs digital broadcasting determines which of the three types of frequencies to use for the channel assigned to that broadcasting station.

At the time when terrestrial broadcasting shifts from an analog system to a digital system, analog broadcasting may be performed on a channel adjacent to a digital broadcasting channel in some areas. In this case, since the radio wave of the digital broadcasting and the radio wave of the analog broadcasting of the adjacent channel may interfere with each other, a broadcasting station performing digital broadcasting is prepared for the channel assigned to the digital broadcasting. Which of the three types of frequencies is to be used is determined in consideration of the presence of analog broadcasting in the adjacent channel.

[0005] Now, a broadcasting station that performs digital broadcasting has 21c.
Assuming that h is assigned (here, the channel of channel number N is referred to as “Nch”; the same applies hereinafter), in the area where the broadcasting station is located, for example, as shown in FIG. Adjacent channel 2
If analog broadcasting is not being performed on any of the channels 0 and 22, the normal frequency of channel 21 is used as the frequency of digital broadcasting by the broadcasting station.
On the other hand, in the area where the broadcasting station is located, for example, as shown in FIG.
When analog broadcasting is performed on channel ch, 21 ch
Digital broadcasting is performed at the regular frequency (that is, the frequency band indicated by the dotted line in FIG. 20 is used for digital broadcasting),
The 2ch analog broadcast radio waves interfere with each other. Therefore, in this case, the lower offset frequency of 21 ch is used as the frequency of digital broadcasting by the broadcasting station. In addition, as shown in FIG. 21, when analog broadcasting is performed on the lower adjacent channel 20ch, digital broadcasting is performed on the regular frequency of 21ch (that is, indicated by a dotted line in FIG. 21). If the frequency band is used for digital broadcasting), the radio wave of the digital broadcasting and the radio wave of the analog broadcasting of 20 ch interfere with each other, so that the upper offset frequency of 21 ch is used as the frequency of the digital broadcasting by the broadcasting station. Is done.

[0006]

However, at the present time,
The existence of analog broadcasting in a channel adjacent to the terrestrial digital broadcasting channel has not led to a situation in which radio waves of the digital broadcasting and radio waves of the analog broadcasting interfere with each other.

For this reason, the conventional digital terrestrial broadcasting receiver uses one channel when selecting one desired channel.
It is configured to select only one regular frequency. For this reason, there has been a problem that there may be channels that cannot be selected by a conventional digital terrestrial broadcasting receiver.

A terrestrial broadcast receiver usually has a function (preset function) of searching for broadcast frequencies of all receivable broadcast channels and storing the search results. If the digital terrestrial broadcasting receiver has such a preset function, at the time when the terrestrial broadcasting shifts from the analog system to the digital system, after presetting, digital broadcasting is started on a new channel, A situation in which a broadcast of a certain channel is changed from an analog broadcast to a digital broadcast, or a frequency of a digital broadcast of a certain channel is changed (for example, from a regular frequency to a lower offset frequency). Can also occur. When such a situation occurs, it becomes impossible to receive digital broadcasts of the new channel or the channel targeted for such a change.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problem caused by the transition from the analog system to the digital system of terrestrial broadcasting, and to provide a digital terrestrial broadcasting system capable of reliably receiving digital broadcasting of a desired channel. It is to provide a receiver for wave broadcasting. That is, an object of the present invention is to provide a digital terrestrial broadcasting reception system that can reliably receive a desired channel digital broadcast in consideration of the fact that three types are assigned to one channel as frequencies used for digital broadcasting. Is to provide a machine. Further, another object of the present invention is to provide a case where digital broadcasting is started on a new channel after presetting of each channel, a case where broadcasting of a certain channel is changed from analog broadcasting to digital broadcasting, or a case where a certain channel is broadcasted. It is an object of the present invention to provide a digital terrestrial broadcast receiver capable of receiving digital broadcasts of these channels even when the frequency of the digital broadcast is changed.

[0010]

According to a first aspect of the present invention, a digitally modulated digital terrestrial signal is received by an antenna, and a digital terrestrial signal corresponding to a digital broadcast on a channel designated by a user is received. A digital terrestrial broadcasting receiver that extracts and demodulates from a digital terrestrial signal received by the antenna, wherein a desired channel desired by a user is specified by a predetermined operation of the user. Channel selecting means for outputting channel designation information indicating a desired channel; and three kinds of frequencies: a regular frequency, an upper offset frequency, and a lower offset frequency assigned to each of a plurality of predetermined channels for digital broadcasting. Channel initial data storage means for storing frequencies in advance, and three types assigned to desired channels Receiving a control signal instructing a channel selection operation at any one of the frequencies, performing selection and demodulation operations on the digital terrestrial signal received by the antenna based on the control signal, and performing the channel selection operation. And a front-end unit that generates synchronization confirmation information that is information indicating whether or not the processing has been completed normally, and generates a control signal based on the channel designation information, and supplies the generated control signal to the front-end unit. Control means for controlling the end portion, wherein the control means generates a control signal based on the frequencies stored in the channel initial data storage means as three types of frequencies assigned to one channel, and generates the control signal. Three types assigned to the one channel based on synchronization confirmation information obtained by supplying a signal to the front end unit It includes single channel selection search means for searching the broadcast frequency used in the digital broadcast out of the frequency, obtaining the broadcast frequency of the desired channel by a single channel selection search means.

According to the first aspect, the channel selection operation is performed in consideration of the fact that three types of frequencies are prepared for one channel as the frequency for digital broadcasting, that is, the desired channel is selected. Since the frequency used for digital broadcasting is searched from among the three types of frequencies allocated, digital broadcasting of a desired channel can be reliably received.

A second invention according to the first invention further comprises a rewritable nonvolatile storage means for storing a frequency used for digital broadcasting of each of a plurality of channels in association with each channel. The control means further includes storage determination means for determining whether or not the broadcast frequency used for digital broadcasting of the desired channel is stored in the nonvolatile storage means, and the broadcast frequency of the desired channel is stored in the nonvolatile storage means. If the save determination means determines that the broadcast frequency has been set, the control signal instructing the channel selection operation at the stored broadcast frequency is supplied to the front end unit, and the broadcast frequency of the desired channel is stored in the nonvolatile storage means. If the save determination means determines that it has not been done,
A single-channel tuning search means is made to search for a broadcast frequency of a desired channel, a control signal for instructing a tuning operation at the broadcast frequency of the desired channel is supplied to the front end unit, and a broadcast frequency obtained by the search is supplied. Is stored in the nonvolatile storage means in association with the desired channel,
It is characterized by the following.

According to the second aspect of the present invention, when a search for a broadcast frequency of a desired channel is performed, of the three types of frequencies assigned to the channel, the frequency actually used for digital broadcasting, that is, the frequency of that channel is used. The broadcast frequency is stored in the non-volatile storage means. Therefore, after that, when the user again designates the channel as the desired channel, the front end unit can immediately start the channel selection operation at the frequency stored as the broadcast frequency of the desired channel. Therefore, the time required from the designation of the desired channel to the completion of the channel selection operation can be shortened. Digital broadcast can be reliably received.

In a third aspect based on the second aspect, the control means generates a control signal for instructing a channel selection operation at a frequency stored in the non-volatile storage means as a broadcast frequency of a desired channel, and generates a control signal. As a result of supplying to the end part,
If the tuning operation is not completed normally, the single-channel tuning search means is made to search for the broadcast frequency of the desired channel. The broadcast frequency supplied and stored in the nonvolatile storage means in association with the desired channel is updated to the broadcast frequency obtained by the search.

According to the third aspect of the present invention, when the channel selection operation is performed at the frequency stored as the broadcast frequency of the desired channel and the channel selection operation of the front end section is not completed normally, the single channel The broadcast frequency of the desired channel is searched by the tuning search means, a tuning operation is performed at the broadcast frequency of the desired channel, and the frequency stored as the broadcast frequency of the desired channel is determined by the search. Updated to frequency. Therefore, even when the frequency of a digital broadcast of a certain channel is changed, the digital broadcast of that channel can be received.

According to a fourth aspect of the present invention, there is provided a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user, wherein the digital terrestrial signal is received by the antenna. A digital terrestrial broadcasting receiver for extracting and demodulating from among the above, and when a desired channel desired by a user is specified by a predetermined operation of the user, outputs channel designation information indicating the desired channel. Channel selection means,
An all-channel scanning unit for receiving a predetermined preset instruction and sequentially outputting channel designation information for designating each of the plurality of predetermined channels one by one in response to the preset instruction; Channel initial data storage means for storing in advance three types of frequencies, a regular frequency, an upper offset frequency, and a lower offset frequency, which are allocated for digital broadcasting; and a digital broadcasting for each of a plurality of channels. A rewritable nonvolatile storage unit for storing a frequency to be used in association with each channel, and instructing a channel selection operation at any one of three types of frequencies assigned to one channel. Receives control signal and receives digital terrestrial signal received by antenna Based on the control signal make a selection and demodulation operations, and front-end unit for generating a synchronization confirmation information indicating whether 該選 station operation is completed successfully,
Control means for generating a control signal based on channel designation information output from the channel selection means or all-channel scanning means, and controlling the front-end unit by supplying the generated control signal to the front-end unit, When the all-channel scanning unit receives the preset instruction, the control unit initializes the channel as three types of frequencies assigned to the designated channels, which are channels designated by the channel designation information sequentially output from the all-channel scanning unit. A control signal is generated based on the frequency stored in the data storage unit, and three types of frequencies assigned to the designated channel are determined based on synchronization confirmation information obtained by supplying the generated control signal to the front end unit. Search the broadcast frequency used for digital broadcasting from inside All channel selection search means for storing the broadcast frequency obtained by the search in a nonvolatile storage means in association with a designated channel, and when the channel designation information is output from the selection means, it is associated with a desired channel. The broadcast frequency stored in the sex storage means is read, and a control signal for instructing a tuning operation at the read frequency is generated and supplied to the front end unit.

According to the fourth aspect, when a preset is designated, all channels are selected in consideration of the fact that three types of frequencies are prepared in advance for one channel as frequencies for digital broadcasting. Since the search means searches for the broadcast frequencies of a plurality of predetermined channels, it is possible to reliably search for the broadcast frequencies of all of the plurality of predetermined channels. After the preset, as long as digital broadcasting is performed on a plurality of predetermined channels, the broadcasting frequencies of the plurality of channels are stored in the nonvolatile storage means. Therefore, assuming that the plurality of channels are all channels that can receive digital broadcasting, after presetting, the broadcast frequency of the desired channel is read from the non-volatile storage means, and the front end unit immediately starts the channel selection operation,
A digital broadcast of a desired channel can be received.

In a fifth aspect based on the fourth aspect, the control means generates a control signal based on the frequencies stored in the channel initial data storage means as three types of frequencies assigned to one channel, Based on the synchronization confirmation information obtained by supplying the generated control signal to the front end unit, a search for a broadcasting frequency used for digital broadcasting is performed from among three types of frequencies assigned to the one channel. A channel selection search means; and a storage determination means for determining whether or not a broadcast frequency used for digital broadcast of the desired channel is stored in the nonvolatile storage means, wherein the broadcast frequency of the desired channel is stored in the nonvolatile storage means. If the save determination means determines that the broadcast frequency is stored in the means, the tuning operation is performed at the stored broadcast frequency. The control signal to be instructed is supplied to the front end unit, and when the storage determining unit determines that the broadcast frequency of the desired channel is not stored in the nonvolatile storage unit, the broadcast frequency of the desired channel is transmitted to the single channel tuning search unit. To provide a front end unit with a control signal instructing a channel selection operation at a broadcast frequency of a desired channel, and associate the broadcast frequency obtained by the search with the desired channel in the nonvolatile storage means. Saving.

According to the fifth invention, when the broadcast frequency of the desired channel is not stored, the broadcast frequency of the desired channel is searched by the single-channel tuning search means. Even when a new digital broadcast is started on a channel that has not been performed, the newly started digital broadcast can be received. Since the broadcast frequency obtained by the search is stored in the non-volatile storage means, when the channel is subsequently designated again as the desired channel, the broadcast frequency is read out from the non-volatile storage means and the channel selection operation is immediately performed. Can be started.

In a sixth aspect based on the fourth aspect, the control means generates a control signal based on the frequencies stored in the channel initial data storage means as three types of frequencies assigned to one channel, Based on the synchronization confirmation information obtained by supplying the generated control signal to the front end unit, a search for a broadcasting frequency used for digital broadcasting is performed from among three types of frequencies assigned to the one channel. Further comprising a channel selection search means for generating a control signal for instructing a channel selection operation at a frequency stored in the non-volatile storage means as a broadcast frequency of a desired channel and supplying the control signal to the front-end unit; If the operation is not completed normally, have the single channel tuning search means search for the broadcast frequency of the desired channel. A control signal for instructing a channel selection operation at the broadcast frequency of the desired channel is supplied to the front end unit, and the broadcast frequency obtained by the search is stored in the nonvolatile storage means in association with the desired channel. Updating to a frequency.

According to the sixth aspect, when the channel selection operation is performed at the frequency stored as the broadcast frequency of the desired channel and the channel selection operation of the front end unit is not completed normally, the single channel Since the broadcast frequency of the desired channel is searched by the channel selection search means, even if the frequency of digital broadcast of a certain channel is changed after presetting, digital broadcast of that channel can be received. Also, since the broadcast frequency of the channel stored in the nonvolatile storage means is updated to the broadcast frequency obtained by the search, when the channel is subsequently designated again as the desired channel, the broadcast frequency is changed to the nonvolatile channel. The tuning operation can be started immediately after reading from the sex storage means.

According to a seventh aspect based on the fourth aspect, the apparatus further comprises an all-channel search instruction means for giving a preset instruction to the all-channel scanning means when operated by a user.

According to the seventh invention, when digital broadcasting is started on a new channel that has not existed before, or when the channel arrangement of digital broadcasting is changed, the all-channel search instruction means is operated. Then, a preset instruction is given to the all-channel scanning unit, and the all-channel selection search unit associates the digital broadcasting frequency on the new channel and the digital broadcasting frequency after the channel arrangement is changed with each channel in a nonvolatile storage. Stored in the means. As a result, even when digital broadcasting is started on a new channel or when the channel arrangement of digital broadcasting is changed, those digital broadcasting can be received.

According to an eighth aspect based on the fourth aspect, the apparatus further comprises a timer means for outputting a signal for giving a preset instruction to the all-channel scanning means at predetermined intervals.

According to the eighth aspect, since the signal for giving the preset instruction to the all-channel scanning means is output by the timer means at every predetermined period, the digital broadcasting is started on the new channel. And even if the channel arrangement of digital broadcasting is changed,
After a predetermined period has elapsed at the latest, those digital broadcasts can be received.

According to a ninth aspect, in the fourth aspect, information transmitted by a predetermined communication path is received, and the received information includes addition of a new channel for digital broadcasting or change in channel arrangement. And receiving means for giving a preset instruction to the all-channel scanning means when this indicates.

According to the ninth aspect, when information indicating that a new channel for digital broadcasting has been added or the channel arrangement has been changed is received by the receiving means, a preset instruction is given to all the channel scanning means. Therefore, even when digital broadcasting is started on a new channel or when the channel arrangement of digital broadcasting is changed, the digital broadcasting can be received.

According to a tenth aspect, in the fourth aspect, when information transmitted through a predetermined communication path is received, and the received information includes identification information of a channel on which digital broadcasting is currently performed. Receiving means for outputting the identification information, and the control means generates a control signal based on the frequencies stored in the channel initial data storage means as three types of frequencies assigned to one channel, and A single channel selection for searching a broadcasting frequency used for digital broadcasting from among three types of frequencies assigned to the one channel, based on synchronization confirmation information obtained by supplying the control signal to the front end unit. A station search means for outputting a broadcast of the channel identified by the identification information when the identification information is output from the reception means; Determined by single-channel selection search means wavenumber, in association with the channel identified by the identification information the broadcast frequency obtained is stored in non-volatile memory means.

According to the tenth aspect, when the information received by the receiving means includes identification information of a channel on which digital broadcasting is being performed, the broadcast frequency of the channel is searched by the single channel tuning search means. And the frequency of the search result is stored. Therefore, even if digital broadcasting is started on a new channel that did not exist before, or even if the channel arrangement of digital broadcasting is changed, after receiving the information including the identification information of those channels, Can receive digital broadcasting of those channels.

In an eleventh aspect based on the fourth aspect, information transmitted through a predetermined communication path is received, and the received information is identification information of a channel on which digital broadcasting is currently performed and a broadcast frequency. Further comprising receiving means for outputting the identification information and the broadcast frequency when including
The control means, when the identification information and the broadcast frequency are output from the reception means, stores the broadcast frequency output from the reception means in the nonvolatile storage means in association with the channel identified by the identification information. I do.

According to the eleventh aspect, when the information received by the receiving means includes identification information of a channel on which digital broadcasting is being performed and a broadcast frequency, the broadcast frequency is stored in association with the channel. Is done. Therefore, even when digital broadcasting is started on a new channel that did not exist before or when the channel arrangement of digital broadcasting is changed, the above information including the identification information and the broadcasting frequency of those channels is retained. After receiving, it becomes possible to receive digital broadcasts of those channels.

In a twelfth aspect based on the first or fourth aspect, the digital terrestrial signal is an OFDM modulated signal, and the front end section includes an OFDM demodulating means for demodulating the digital terrestrial signal. When the means correctly demodulates the digital terrestrial signal, an OFDM synchronization signal is generated as synchronization confirmation information.

In a thirteenth aspect based on the first or fourth aspect, the digital terrestrial signal is an OFDM modulated signal, and the front-end section includes an OFDM demodulator for demodulating the digital terrestrial signal, and an OFDM demodulator. And a voltage-controlled oscillating means for generating the system clock of the above, wherein the synchronization confirmation information is a signal indicating a control voltage supplied to the voltage-controlled oscillating means.

[0034] In a fourteenth aspect based on the first or fourth aspect, the digital terrestrial signal is an OFDM modulated signal, and the front-end section includes an OFDM demodulator for demodulating the digital terrestrial signal, and an OFDM demodulator. And error correction means for correcting an error contained in a signal obtained by demodulating a digital terrestrial signal, wherein the synchronization confirmation information is BER measurement information generated by the error correction means. .

A fifteenth invention is characterized in that, in the first invention, the single-channel tuning search means performs a search by giving priority to a regular frequency among three kinds of frequencies.

A sixteenth invention is characterized in that, in the fourth invention, the all-channel selection search means performs a search by giving priority to a regular frequency among three kinds of frequencies.

In a seventeenth aspect based on the fifth or sixth aspect, the all-channel tuning search means preferentially searches for a regular frequency among the three types of frequencies, and the single-channel tuning search means has A feature is that a search is performed with priority given to regular frequencies among the three types of frequencies.

According to the fifteenth, sixteenth, or seventeenth aspect, at the time of the search by the single-channel tuning means and the search by the all-channel tuning means, of the three frequencies assigned to one channel, The regular frequency is searched with priority. That is, the front end section first performs a channel selection operation at a regular frequency that is more likely to be used as a broadcast frequency than the upper and lower offset frequencies. Therefore, according to the fifteenth, sixteenth, or seventeenth aspect, the time required from the designation of the desired channel to the completion of the channel selection operation and the time required for presetting are reduced on average.

In an eighteenth aspect based on the first, fifth or sixth aspect, the single-channel tuning search means is one of three types of frequencies assigned to one channel. It is determined whether or not the tuning operation at the first frequency has been normally completed based on synchronization confirmation information obtained by supplying a control signal instructing the tuning operation at the first frequency to the front end unit. A first synchronization confirming means that performs a second synchronization with a second frequency other than the first frequency among the three types of frequencies allocated to one channel when it is determined that the channel selection operation at the first frequency is not normally completed. It is determined whether or not the channel selection operation at the second frequency has been completed normally based on the synchronization confirmation information obtained by supplying a control signal instructing the channel selection operation at the second frequency to the front end unit. Second And a period confirmation unit, if the channel selection operation with the first frequency is determined to have completed successfully the first
Is regarded as the broadcast frequency of the one channel, and when it is determined that the channel selection operation at the second frequency has been completed normally, the second frequency is regarded as the broadcast frequency of the one channel, and the first frequency is determined. If it is determined that the tuning operation at any one of the two frequencies and the second frequency is not completed normally, the third frequency other than the first and second frequencies among the three types of frequencies assigned to the one channel is determined. 3 is regarded as the broadcast frequency of the one channel.

In a nineteenth aspect based on the first, fifth, or sixth aspect, the single-channel tuning search means is one of three types of frequencies assigned to one channel. It is determined whether or not the channel selection operation at the first frequency has been normally completed based on synchronization confirmation information obtained by supplying a control signal instructing the channel selection operation at the first frequency to the front end unit. A first synchronization confirming unit that performs the second synchronization except for the first frequency among the three types of frequencies allocated to one channel when it is determined that the channel selection operation at the first frequency is not normally completed. It is determined whether or not the channel selection operation at the second frequency has been completed normally based on the synchronization confirmation information obtained by supplying a control signal instructing the channel selection operation at the second frequency to the front end unit. Second Period checking means, and when it is determined that the channel selection operation at any one of the first and second frequencies is not completed normally, the first and second frequencies among the three types of frequencies assigned to one channel are determined. The tuning operation at the third frequency is normally completed based on the synchronization confirmation information obtained by supplying a control signal instructing the tuning operation at the third frequency other than the frequency 2 to the front end unit. A third synchronization confirmation means for determining whether or not the first
If it is determined that the channel selection operation at the frequency of has been completed normally, the first frequency is regarded as the broadcast frequency of the one channel, and it is determined that the channel selection operation at the second frequency has been completed normally. In this case, the second frequency is regarded as the broadcast frequency of the one channel, and if it is determined that the tuning operation at the third frequency has been completed normally, the third frequency is regarded as the broadcast frequency of the one channel. It is characterized by the following.

In a twentieth aspect based on the fourth, fifth or sixth aspect, the all-channel tuning search means comprises a first channel which is one of three types of frequencies assigned to the designated channel. It is determined whether or not the channel selection operation at the first frequency has been completed normally based on the synchronization confirmation information obtained by supplying a control signal instructing the channel selection operation at the first frequency to the front end unit. A first synchronization confirming unit, and a second frequency other than the first frequency among the three types of frequencies assigned to the designated channel when it is determined that the channel selection operation at the first frequency is not normally completed. Based on synchronization confirmation information obtained by supplying a control signal instructing a channel selection operation in the front end unit,
Second synchronization confirmation means for determining whether or not the channel selection operation at the second frequency has been normally completed; and if the channel selection operation at any of the first and second frequencies is not completed normally. When it is determined, by supplying a control signal for instructing a channel selection operation at a third frequency other than the first and second frequencies among the three types of frequencies allocated to the designated channel to the front end unit, A third synchronization confirmation unit for determining whether or not the channel selection operation at the third frequency is normally completed based on the obtained synchronization confirmation information, so that the channel selection operation at the first frequency is normally performed. If it is determined that the operation has been completed, the first frequency is stored in the non-volatile storage means as the broadcast frequency of the designated channel, and if it is determined that the channel selection operation at the second frequency has been completed normally, the second frequency Set the broadcast frequency of the specified channel Stored in the nonvolatile storage means as,
When it is determined that the channel selection operation at the third frequency has been completed normally, the third frequency is stored in the nonvolatile storage unit as the broadcast frequency of the designated channel.

According to a twenty-first aspect, a digital terrestrial signal which is digitally modulated is received by an antenna, and a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user is received by the antenna. A method for selecting a receiving channel for a digital terrestrial broadcasting receiver that extracts and demodulates a digital signal from a terrestrial broadcasting receiver, comprising: a normal frequency assigned to digital broadcasting for each of a plurality of predetermined channels; A channel initial data storing step of storing in advance three types of frequencies: a frequency and a lower offset frequency; Assign the desired channel to the desired channel and the channel A control signal generating step of generating a control signal instructing a tuning operation at any one of the three types of frequencies based on the frequencies previously stored in the channel initial data storing step as the three types of frequencies obtained; Based on the generated control signal, performs a selection and demodulation operation on the digital terrestrial signal received by the antenna, with information indicating whether the channel selection operation including the selection and demodulation operation has been completed normally. A synchronization confirmation information generating step of generating certain synchronization confirmation information, and a search step of searching a broadcast frequency used for digital broadcasting from among three types of frequencies assigned to a desired channel based on the synchronization confirmation information. Prepare.

According to a twenty-second aspect, a digital terrestrial signal which is digitally modulated is received by an antenna, and a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user is received by the antenna. A method for selecting a receiving channel for a digital terrestrial broadcasting receiver that extracts and demodulates a digital signal from a terrestrial broadcasting, comprising: a normal frequency assigned to digital broadcasting for each of a plurality of predetermined channels; A channel initial data storing step of storing in advance three kinds of frequencies of a frequency and a lower offset frequency; receiving a predetermined preset instruction; and specifying each of a plurality of predetermined channels in response to the preset instruction. All channel scanning steps to sequentially output channel designation information When receiving the instruction of the preset and the preset, the three kinds of frequencies are preliminarily stored as the three kinds of frequencies assigned to the designated channel which is the channel designated by each of the sequentially designated channel designation information. A control signal generating step of generating a control signal instructing a tuning operation at any one of the following frequencies: and a digital terrestrial signal received by an antenna based on the control signal generated in the first control signal generating step Performing a selection and demodulation operation on, a synchronization confirmation information generating step of generating synchronization confirmation information which is information indicating whether or not the channel selection operation including the selection and demodulation operation has been completed normally, A search function for searching for a broadcast frequency used for digital broadcasting from among three types of frequencies assigned to the designated channel based on the And a storage step of storing the broadcast frequency obtained in the search step in a predetermined nonvolatile storage means in association with the designated channel, and when a desired channel desired by the user is specified by a predetermined operation of the user, A channel designation step of outputting channel designation information indicating the desired channel; and a readout step of reading the broadcast frequency stored in the nonvolatile storage means in association with the desired channel when the channel designation information is output in the channel designation step. A second control signal generating step of generating a control signal for instructing a tuning operation at a frequency read from the non-volatile storage means, and an antenna based on the control signal generated in the second control signal generating step. Tuning operation for selecting and demodulating received digital terrestrial signals Operation step.

[0044]

Embodiments of the present invention will be described below with reference to the accompanying drawings. <1. First Embodiment><1.1 Configuration of First Embodiment> FIG. 1 is a digital terrestrial broadcasting receiver 100 according to a first embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. The digital terrestrial broadcasting receiver 100 includes a terrestrial broadcasting antenna 11, a front end unit 13, an MPEG decoding unit 14, a control microcomputer 15, a tuning unit 16, and a channel initial data storage unit 17. Have. The control microcomputer 15 controls each unit in the digital terrestrial broadcast receiver 100, and performs a later-described operation by executing a predetermined program stored in an internal memory thereof. The same applies to the embodiment). That is, the operation of the control microcomputer 15 which constitutes a main part such as a channel selection operation described later is realized by software.

The terrestrial broadcasting antenna 11 is an OFDM (Orthog) which is a digital terrestrial signal transmitted from a broadcasting station.
onal Freqency Division Multiplex) received. The received OFDM signal is input to the front end unit 13. On the other hand, the tuning unit 16 outputs a signal (hereinafter referred to as a “channel designation signal”) Sch that designates a channel desired by the user based on a user operation. This channel designation signal Sch is input to the control microcomputer 15. The channel initial data storage unit 17 includes a channel selection unit 1
6, for each of all the channels that can be specified by 6, data indicating three types of frequencies, a regular frequency, an upper offset frequency, and a lower offset frequency,
It is stored in advance as initial data. The control microcomputer 15 selects a channel desired by the user (also simply referred to as a “desired channel”) based on the channel designation signal Sch.
At least one of the data indicating the normal frequency, the upper offset frequency, and the lower offset frequency (hereinafter, referred to as “desired channel frequency data”) is read from the channel initial data storage unit 17. Then, the control microcomputer 15 controls the front end unit 13 based on the desired channel frequency data and a signal for confirmation of synchronization to be described later input from the front end unit 13. Under the control of the control microcomputer 15, the front end unit 13 digitally demodulates the OFDM modulated signal input from the terrestrial broadcast antenna 11 and corrects an error generated in the transmission path (hereinafter, this operation will be referred to as "front operation"). This operation is referred to as “tuning operation of the end unit 13. The details will be described later.) As a result, a transport stream signal of a channel desired by the user is obtained, and the transport stream signal is input to the MPEG decoding unit 14. This transport stream signal is MPEG
It is image data encoded by the method. The MPEG decoding unit 14 converts the transport stream signal into decoded image data (MPEG image data).
Is generated and output to the outside.

<1.2 Configuration of Front End Unit and Channel Selection Operation> FIG. 2 is a block diagram showing a first configuration example of the front end unit 13. The front end unit 13 of this configuration example includes an AGC circuit 31 and a tuning filter 32.
, Mixer 33, PLL synchronization circuit 34, IF + SA
W filter 36, AGC control unit 37, AD converter 38, oscillator 35, VCXO control unit 311
It includes an FDM demodulation unit 39 and an error correction unit 310.

The front end unit 13 having the above configuration receives control signals Sc1 and Sc2 based on desired channel frequency data from the control microcomputer 15. Control signal S
By c2, the PLL synchronization circuit 34 operates, and the channel selection operation starts. The OFDM modulated signal input from the terrestrial broadcasting antenna 11 to the front end unit 13 is first AGC
The power is controlled by the circuit 31 so as to be suitable for the subsequent digital demodulation system. That is, IF + SAW described later
The AGC control section 37 generates a control signal based on the output of the filter, and the AGC circuit 31 controls the gain based on the control signal, so that the OFDM modulated signal is controlled to a power amount suitable for the digital demodulation system at the subsequent stage. You. Thereafter, the OFDM signal is input to the channel selection filter 32.

The tuning filter 32 is provided for the control microcomputer 15.
Functions as a band-pass filter that passes only signals in the band corresponding to the desired channel frequency data based on the control signal Sc1 from. Therefore, a signal (hereinafter, referred to as "desired signal") of a frequency (hereinafter, referred to as "selected frequency") indicated by the desired channel frequency data from the OFDM modulated signal by the tuning filter 32.
Is extracted. The extracted desired signal is PLL
The IF signal (intermediate frequency signal) is mixed with the oscillation signal of the tuning frequency generated by the synchronization circuit 34.
Down-converted to The down-converted desired signal is shaped by passing through an IF + SAW filter 36, and is converted from an analog signal to a digital signal by an AD converter 38.
The signal is input to the DM demodulation unit 39.

The OFDM demodulator 39 operates based on the system clock Sck supplied from the oscillator 35. This oscillator 35 is a voltage controlled oscillator (VCXO) using a crystal oscillator.
), And the control voltage Vc is applied to the OFDM demodulation unit 39.
Is generated by the VCXO control unit 311 based on the signal from If the desired channel is selected correctly,
The VCXO control unit 311 and the oscillator 35 that generate the system clock Sck of the DM demodulation unit 38 operate normally, the digital demodulation is correctly performed by the OFDM demodulation unit 39, and the error generated in the transmission path is corrected by the error correction unit 310. Is done. The corrected signal is used as a transport stream signal of a desired channel by the MPEG decoding unit 14.
Sent to

When the front end unit 13 is operating normally as described above, the OFDM synchronization signal Ssync is
The signal is output from the M demodulation unit 39. This OFDM synchronization signal S
sync is the control microcomputer 1 as information for synchronization confirmation.
Sent to 5. When receiving the OFDM synchronization signal Ssync, the control microcomputer 15 determines that synchronization has been confirmed, that is, that the front end unit 13 has normally completed the channel selection operation. On the other hand, if the desired channel cannot be selected correctly, the OFDM synchronization signal Ssync is not sent to the control microcomputer 15, and the control microcomputer 15 does not confirm the synchronization. It is determined that it has not been completed.

FIG. 3 is a block diagram showing a second example of the configuration of the front end unit 13. As shown in FIG. The front end unit 13 of this configuration example uses a signal (hereinafter, referred to as “control voltage signal”) Svc indicating the control voltage Vc of the oscillator 35 that supplies the system clock Sck to the OFDM demodulation unit 39 as information for confirming synchronization. Send to microcomputer 15. The second in this regard
Is different from the first example in which the OFDM synchronization signal Ssync is transmitted to the control microcomputer 15 as information for confirming synchronization. The other parts are the same as those of the first configuration example, and thus the same components are denoted by the same reference characters and description thereof will be omitted.

The front end section 13 of the second configuration example
Control signals Sc1 and Sc2 supplied from the control microcomputer 15 (that is, information corresponding to a desired channel frequency)
If the desired channel is correctly selected based on
The VCXO controller 311 for generating the system clock Sck of the FDM demodulator 38 operates in an appropriate range, and the control voltage Vc of the oscillator 35 does not change. Therefore, in this configuration example, as described above, the control voltage signal Svc indicating the control voltage Vc is sent to the control microcomputer 15 as information for confirming synchronization. The control microcomputer 15 checks whether or not the control voltage Vc fluctuates based on the control voltage signal Svc (specifically, the control voltage Vc fluctuates for a predetermined period,
If the control voltage Vc does not fluctuate, it is determined that synchronization has been confirmed, that is, the front end unit 13 has normally completed the channel selection operation. On the other hand, when the control voltage Vc fluctuates, the control microcomputer 15 determines that synchronization has not been confirmed, that is, the front end unit 13 has not completed the channel selection operation.

FIG. 4 is a block diagram showing a third example of the configuration of the front end unit 13. As shown in FIG. The front end unit 13 of this configuration example is a BE
A signal indicating R (Bit Error Rate) measurement information DBER is sent to the control microcomputer 15 as information for synchronization confirmation. In this regard, the third configuration example is based on the first configuration in which the OFDM synchronization signal Ssync is transmitted to the control microcomputer 15 as information for confirming synchronization.
Is different from the above configuration example. The other parts are the same as those of the first configuration example, and thus the same components are denoted by the same reference characters and description thereof will be omitted.

The front end unit 13 of the third configuration example includes:
Control signals Sc1 and Sc2 supplied from the control microcomputer 15 (that is, information corresponding to a desired channel frequency)
If the desired channel is correctly selected based on the bit error rate (BE)
R: Bit Error Rate) becomes “0”. Therefore, in this configuration example, as described above, the signal indicating the BER measurement information DBER is used as information for synchronization confirmation by the control microcomputer 15.
Sent to When BER = 0, the control microcomputer 15 determines that synchronization has been confirmed, that is, that the front end unit 13 has normally completed the channel selection operation based on the BER measurement information DBER. In the case of ≠ 0, no synchronization is confirmed, that is, the front end unit 1
3 determines that the tuning operation has not been completed.

In the third configuration example, the BER value is stored in a predetermined register provided in the error correction section 310. As described above, the operation of the control microcomputer 15 constituting the channel selection operation is realized by software. Therefore, it can be said that the third configuration example is compatible with the channel selection operation in which the main part is realized by software in that synchronization can be confirmed by referring to a predetermined register.

<1.3 Channel Selection Operation in First Embodiment> Next, a channel selection operation of the digital terrestrial broadcast receiver according to the first embodiment will be described with reference to FIG. In addition,
As described above, the means of checking synchronization differs depending on the configuration of the front end unit 13, but the channel selection operation described below is basically the same regardless of which of the first to third configuration examples is adopted. (This point is the same for the channel selection operation in other embodiments).

When the user operates the tuning section 16 to select a desired channel (desired channel), a channel designation signal Sch is input from the tuning section 16 to the control microcomputer 15 as designation information of the desired channel (step S100). ). When the channel designation signal Sch is input, the control microcomputer 15 operates as follows. First, the normal frequency Fn of the desired channel indicated by the channel designation signal Sch is read from the channel initial data storage unit 17 (step S102). Next, control signals Sc1 and Sc2 based on the regular frequency Fn are generated, and these control signals Sc1 and Sc2 are transmitted to the front end unit 1.
3 to cause the front end unit 13 to perform a tuning operation at the regular frequency Fn (step S1).
04). Thereafter, information for synchronization confirmation (OFDM synchronization signal Ssync, control voltage signal Svc, or a signal indicating BER measurement information DBER) is received from the front end unit 13, and whether or not synchronization has been confirmed from this information is described above. The determination is made as described above (step S106). As a result of this determination, if synchronization is confirmed, the channel selection operation ends.

If it is determined in step S106 that synchronization has not been confirmed, the control microcomputer 15 operates as follows. First, the frequency Fu of the upper offset of the desired channel is stored in the channel initial data storage unit 1.
7 (step S108). Next, control signals Sc1 and Sc2 based on the upper offset frequency Fu are generated, and these control signals Sc1 and Sc2 are supplied to the front end unit 13, so that the upper offset frequency Fu is transmitted to the front end unit 13 at the upper offset frequency Fu. A tuning operation is performed (step S110). Thereafter, information for synchronization confirmation (OFDM synchronization signal Ssync, control voltage signal Svc, or signal indicating BER measurement information DBER) is received from the front end unit 13, and it is determined whether or not synchronization has been confirmed from this information ( Step S112). As a result of this judgment,
If the synchronization is confirmed, the channel selection operation ends.

If it is determined in step S112 that synchronization has not been confirmed, the control microcomputer 15 operates as follows. First, the frequency Fd of the lower offset of the desired channel is stored in the channel initial data storage unit 1.
7 (step S114). Next, by generating control signals Sc1 and Sc2 based on the lower offset frequency Fd and supplying these control signals Sc1 and Sc2 to the front end section 13, the front end section at the lower offset frequency Fd is generated. 13 is caused to perform a tuning operation (step S116). If digital broadcasting is being performed on the desired channel, the channel selection operation is normally completed here. As a result, the transport stream signal of the desired channel is transmitted to the front end unit 13.
And is decoded by the MPEG decoding unit 14.

The above steps S106 and S112
When the synchronization is confirmed in any one of the above, the transport stream signal of the desired channel is output from the front end unit 13 and the MPEG decoding unit 1
4 is decoded.

In the above-described channel selection operation shown in FIG. 5,
When a desired channel is selected, first, a tuning operation is performed at a regular frequency of the desired channel. As a result, when synchronization is not confirmed, a tuning operation is performed at a frequency of an upper offset of the desired channel, As a result, when the synchronization is not yet confirmed, the tuning operation is performed at the lower offset frequency of the desired channel. That is, in the above-described channel selection operation, the priority in the search of the broadcast frequency of the desired channel is in the order of the regular frequency → the frequency of the upper offset → the frequency of the lower offset. However, the present invention is not limited to this priority, and the priority may be in the order of normal frequency → lower offset frequency → upper offset frequency,
Further, the broadcast frequency may be searched in a priority other than these. However, when analog broadcasting is not performed on a channel adjacent to the desired channel, digital broadcasting is normally performed on the desired channel at a regular frequency. Is likely to be used. Therefore, it is preferable that the priority of the regular frequency be the highest among the three types of frequencies assigned to the desired channel. That is, when searching for a broadcast frequency of a desired channel, it is preferable to first perform a channel selection operation at a regular frequency. As a result, the time required for the tuning operation is shortened on average.

<1.4 Effects of First Embodiment> As described above, according to the first embodiment, three types of frequencies are prepared in advance for one channel as frequencies for digital broadcasting. Since the channel selection operation is performed in consideration of the above (see FIG. 5), digital broadcast of a desired channel can be reliably received. That is, even when the frequency of the desired channel is not the regular frequency of the desired channel but the upper offset frequency or the lower offset frequency, the digital broadcast must be reliably received. Can be.

<2. 2. Second Embodiment 2.1 Configuration of Second Embodiment FIG. 6 shows a digital terrestrial broadcasting receiver 200 according to a second embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. This digital terrestrial broadcasting receiver 200 includes a channel data nonvolatile storage unit 18, and is different from the digital terrestrial broadcasting receiver 100 according to the first embodiment shown in FIG. 1 in this point. The channel data non-volatile storage unit 18 is realized by a non-volatile memory, and is used to store a frequency obtained as a result of searching for a digital broadcast frequency of a desired channel. Since the configuration of this embodiment other than the channel data nonvolatile storage unit 18 is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

<2.2 Channel Selection Operation in Second Embodiment> The channel selection operation of the digital terrestrial broadcast receiver according to the second embodiment will be described below with reference to FIGS. 7 and 8. .

When the user operates the tuning unit 16 to select a desired channel (desired channel), a channel designation signal Sch is input from the tuning unit 16 to the control microcomputer 15 as designation information of the desired channel (step S200). ). When the channel designation signal Sch is input, the control microcomputer 15 operates as follows.

First, the frequency (broadcast frequency) of the digital broadcast of the desired channel indicated by the channel designation signal Sch
It is determined whether or not Fb is stored in the channel data nonvolatile storage unit 18 (step S202). As a result, when it is determined that the broadcast frequency of the desired channel is stored, the process proceeds to step S206. On the other hand, if it is determined that the broadcast frequency Fb of the desired channel is not stored, a single channel tuning search (details will be described later) whose procedure is shown in FIG. Find broadcast frequency (step S
204). Here, the single channel tuning search is executed, for example, when the digital terrestrial broadcasting receiver has not performed any single channel tuning search for the desired channel. As described later, after the single channel tuning search is executed, the broadcast frequency of the desired channel, that is, the search result is stored in the channel data nonvolatile storage unit 18 as long as the digital broadcasting is performed on the desired channel. I have.

In step S206, the channel data nonvolatile storage unit 18 stores the broadcast frequency of the desired channel.
Control signals Sc1, S2 based on the frequency Fb stored in
c2, and supplies these control signals Sc1 and Sc2 to the front-end unit 13 so that the broadcast frequency Fb
Causes the front end unit 13 to perform a channel selection operation. Then, information for synchronization confirmation (OFDM synchronization signal Ssync,
The control voltage signal Svc or the signal indicating the BER measurement information DBER) is received from the front end unit 13 and it is determined from this information whether or not the synchronization has been confirmed (step S2).
08). As a result of this determination, if synchronization is confirmed, the channel selection operation ends normally.

If it is determined in step S208 that synchronization has not been confirmed, the process proceeds to step S210. Here, it is determined that the synchronization is not confirmed because the broadcast frequency of the desired channel is stored in the channel data nonvolatile storage unit 18 by the previously executed single channel tuning search.
After that, the broadcast frequency of the desired channel is changed, for example, the frequency is changed from the regular frequency to the upper offset frequency.

In step S210, the broadcast frequency of the desired channel is obtained by executing the single channel tuning search shown in FIG. 8 (step S210). Thereafter, control signals Sc1 and Sc2 based on the broadcast frequency Fb2 stored in the channel data nonvolatile storage unit 18 are generated as the search result frequency, and these control signals Sc1 and Sc2 are supplied to the front end unit 13. Thus, the front-end unit 13 performs a channel selection operation at the broadcast frequency Fb2 (step S212). Thereafter, the channel selection operation ends.

Next, the procedure of the single-channel tuning search executed in steps S204 and S212 will be described with reference to FIG. In the single channel tuning search, first, the normal frequency Fn of the desired channel is read from the channel initial data storage unit 17 (step S1).
2). Next, the control signal S based on this regular frequency Fn
By generating c1 and Sc2 and supplying these control signals Sc1 and Sc2 to the front end unit 13, the front end unit 13 performs a channel selection operation at the regular frequency Fn (step S14). Thereafter, information for synchronization confirmation (OFDM synchronization signal Ssync, control voltage signal Svc, or signal indicating BER measurement information DBER) is received from the front end unit 13, and it is determined whether or not synchronization has been confirmed from this information ( Step S16). If the synchronization is confirmed as a result of this determination, the frequency at which the synchronization is confirmed, that is, its normal frequency Fn is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the desired channel (step S30), and the single channel The channel selection search ends.

If it is determined in step S16 that the synchronization is not confirmed, the frequency Fu of the upper offset of the desired channel is read from the channel initial data storage unit 17 (step S18). Next, control signals Sc1 and Sc2 based on the frequency Fu of the upper offset are generated,
By supplying these control signals Sc1 and Sc2 to the front end unit 13, the frequency Fu of the upper offset is supplied.
Causes the front end unit 13 to perform a channel selection operation (step S20). After that, information for synchronization confirmation (OFDM
The synchronization signal Ssync, the control voltage signal Svc, or the signal indicating the BER measurement information DBER) is received from the front end unit 13 and it is determined whether or not the synchronization is confirmed based on the information (step S22). If the synchronization is confirmed as a result of this determination, the frequency at which the synchronization is confirmed, that is, the upper-side offset frequency Fu is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the desired channel (step S30), The channel selection search ends.

If it is determined in step S22 that synchronization has not been confirmed, the lower offset frequency Fd of the desired channel is read from the channel initial data storage unit 17 (step S24). Next, control signals Sc1 and Sc2 based on the lower offset frequency Fd are generated,
By supplying these control signals Sc1 and Sc2 to the front end unit 13, the lower offset frequency Fd
Causes the front end unit 13 to perform a channel selection operation (step S26). Thereafter, information for synchronization confirmation is received from the front end unit 13, and it is determined from the information whether synchronization has been confirmed (step S28). If the synchronization is confirmed as a result of the determination, the frequency at which the synchronization is confirmed, that is, the lower offset frequency Fd is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the desired channel (step S30). The single channel tuning search ends. On the other hand, if synchronization is not confirmed as a result of this determination, digital broadcasting is not being performed on the desired channel specified by the user. In this case, the single channel tuning search is terminated without storing the lower offset frequency in the channel data nonvolatile storage unit 18.

After the single channel tuning search is executed as described above, the broadcast frequency of the desired channel is stored in the channel data nonvolatile storage unit 18 as long as the digital broadcast is being performed on the desired channel. Will be.

<2.3 Effects of Second Embodiment> As described above, according to the second embodiment, when a search for a broadcast frequency of a desired channel (single channel tuning search) is performed, the channel is searched for. The frequency actually used for digital broadcasting, that is, the broadcasting frequency of the channel, out of the three types of frequencies assigned to is stored in the channel data nonvolatile storage unit 18 (step S in FIG. 8).
30). Therefore, after that, when the user designates the desired channel again as the desired channel, the front end unit 13 can immediately start the channel selection operation at the frequency stored as the broadcast frequency of the desired channel (FIG. 7). Step S202, S
206). For this reason, the time required from the designation of the desired channel to the completion of the channel selection operation can be made shorter than in the case of the first embodiment, and, similarly to the first embodiment, the time allocated to each channel can be reduced. The digital broadcast of the desired channel can be reliably received in consideration of the three types of frequencies.

Further, according to the second embodiment, if the synchronization is not confirmed as a result of the tuning operation being performed at the frequency stored as the broadcast frequency of the desired channel, the desired channel is searched by the single channel tuning search. The broadcast frequency of the channel is searched (step S210 in FIG. 7, FIG. 8),
A tuning operation is performed at the broadcast frequency determined by the search (step S212 in FIG. 7). For this reason, when the frequency of the digital broadcast of a certain channel is changed (for example, when the frequency is changed from the regular frequency to the upper offset frequency), the channel data nonvolatile storage unit 1 is changed.
Even if the broadcast frequency stored in 8 becomes different from the actual broadcast frequency, the stored broadcast frequency is updated and digital broadcast of the channel can be received.

<3. Third Embodiment><3.1 Configuration of Third Embodiment> FIG. 9 is a digital terrestrial broadcast receiver 300 according to a third embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. The digital terrestrial broadcast receiver 300 includes the all-channel search unit 21 and is different from the digital terrestrial broadcast receiver 200 according to the second embodiment shown in FIG. 6 in this point. Since the configuration of the third embodiment other than the all-channel search unit 21 is the same as that of the second embodiment, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

In the third embodiment, typically, when a digital terrestrial broadcast receiver is installed, the broadcast frequencies of all receivable digital broadcast channels are searched and the search results are stored. (Called "preset"). All channel search unit 21
Supplies the information of all the channels on which digital broadcasting can be performed to the tuning unit 16 in order one channel at a time when the preset is performed. Each time the tuning unit 15 receives information on one channel from the all-channel search unit 21, it outputs a channel designation signal Sch for designating that channel. This channel designation signal Sch is input to the control microcomputer 15. In this manner, at the time of presetting, the channel designation signals Sch for all channels on which digital broadcasting can be performed are sequentially input to the control microcomputer 15 one by one, and the control microcomputer 15 Preset is performed based on the procedure described below.

<3.2 Operation and Effect of Preset in Third Embodiment> Referring to FIG.
A preset in the digital terrestrial broadcasting receiver according to the embodiment will be described.

In the third embodiment, presetting is performed by executing a channel selection search whose procedure is shown in FIG. This all-channel selection search is executed by, for example, pressing a specific button (not shown). In the following, it is assumed that channels on which digital broadcasting can be performed are 1ch to 61ch.

In this channel selection search, first,
Based on the information supplied from the all-channel search unit, the tuning unit 16 outputs a channel designation signal Sch that designates a channel on which the tuning operation is not performed, that is, one unsearched channel among the 1ch to 61ch (step). S50). At the time immediately after the start of the all-channel selection search, all of channels 1 to 61 have not been searched. Therefore, assuming that the channels are searched in order from the channel with the smallest number, the channel designation for designating 1ch is first performed. The signal Sch is output. Hereinafter, step S50
The channel designated by the channel designation signal Sch output in is referred to as a “designated channel”.

The channel designation signal Sch output in step S50 is inputted to the control microcomputer 15, and the control microcomputer 15 operates as follows based on the channel designation signal Sch.

First, the normal frequency Fn of the designated channel
Is read from the channel initial data storage unit 17 (step S52). Next, control signals Sc1 and Sc2 based on the regular frequency Fn are generated, and these control signals Sc1 and Sc2 are generated.
By supplying c2 to the front end unit 13, the front end unit 13 performs a tuning operation at the regular frequency Fn (step S54). After that, information for synchronization confirmation (OFDM synchronization signal Ssync, control voltage signal Svc,
Or, a signal indicating the BER measurement information DBER) is received from the front end unit 13 and it is determined from this information whether synchronization has been confirmed (step S56). As a result of this determination, when synchronization is confirmed, the frequency at which the synchronization is confirmed, that is, the normal frequency Fn is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the designated channel (step S70), and step S72 is performed. Proceed to.

If it is determined in step S56 that synchronization has not been confirmed, the frequency Fu of the upper offset of the designated channel is read from the channel initial data storage unit 17 (step S58). Next, control signals Sc1 and Sc2 based on the frequency Fu of the upper offset are generated,
By supplying these control signals Sc1 and Sc2 to the front end unit 13, the frequency Fu of the upper offset is supplied.
Causes the front end unit 13 to perform a channel selection operation (step S60). Thereafter, information for synchronization confirmation is received from the front end unit 13, and it is determined from the information whether synchronization has been confirmed (step S62). When the synchronization is confirmed as a result of the determination, the frequency at which the synchronization is confirmed, that is, the upper-offset frequency Fu is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the designated channel (step S70). S7
Proceed to 2.

If it is determined in step S62 that the synchronization has not been confirmed, the lower frequency offset Fd of the designated channel is read from the channel initial data storage unit 17 (step S64). Next, control signals Sc1 and Sc2 based on the lower offset frequency Fd are generated,
By supplying these control signals Sc1 and Sc2 to the front end unit 13, the lower offset frequency Fd
Causes the front end unit 13 to perform a channel selection operation (step S66). Thereafter, information for synchronization confirmation is received from the front end unit 13, and it is determined from the information whether synchronization has been confirmed (step S68). As a result of this determination, when synchronization is confirmed, the frequency at which the synchronization is confirmed, that is, the lower offset frequency Fd is stored in the channel data nonvolatile storage unit 18 as the broadcast frequency of the designated channel (step S70). Step S7
Proceed to 2. On the other hand, if synchronization is not confirmed as a result of this determination, digital broadcasting is not being performed on the designated channel. In this case, the process proceeds to step S72 without storing the lower offset frequency in the channel data nonvolatile storage unit 18.

In step S72, it is determined whether or not all the channels 1ch to 61ch have been searched. Here, "the channel is searched" means that the frequency (broadcast frequency) of the digital broadcast being broadcast on the channel is searched by the above processing (steps S50 to S70). Step S72
As a result of the determination in step, if there is an unsearched channel, the process returns to step S50. Thereafter, 1ch to 61ch
Are repeatedly executed until all the channels are searched. When all the channels 1 to 61 are searched, the channel selection search for all channels ends.

According to the preset operation as described above, the channel selection search is performed in consideration of the fact that three types of frequencies are prepared in advance for one channel as frequencies for digital broadcasting. , 1ch to 6
The broadcasting frequency can be reliably searched for all the channels of 1ch. After the preset, as long as the digital broadcast is being performed on the channel specified in the all-channel tuning search, the broadcast frequency of the specified channel is stored in the channel data nonvolatile storage unit 18.
It will be stored in.

<3.3 Channel Selection Operation and Effect in Third Embodiment> Next, a channel selection operation of a desired channel specified by the user will be described. It is assumed that before the channel selection operation is performed, presetting by the above-described channel selection search is performed.

FIG. 10 is a flowchart showing an example of a channel selection operation (hereinafter, referred to as a "first operation example") in the third embodiment. In the first operation example, first, when the user selects a desired channel (desired channel) by operating the tuning unit 16, a channel designation signal Sch is transmitted from the tuning unit 16 to the control microcomputer 15 as designation information of the desired channel. Entered (Step S30
0). The control microcomputer 15 receives the channel designation signal Sch
Is input, the digital broadcast frequency (broadcast frequency) F of the desired channel indicated by the channel designation signal Sch
b is read from the channel data nonvolatile storage unit 18 (step S302). Next, the control microcomputer 15
The control signal Sc based on the read broadcast frequency Fb
1 and Sc2 are generated, and the control signals Sc1 and Sc2 are supplied to the front end unit 13 to cause the front end unit 13 to perform a channel selection operation at the broadcast frequency Fb (step S304). If digital broadcasting is being performed on the desired channel specified by the user, this channel selection operation outputs a transport stream signal of the desired channel from the front end unit 13, and the transport stream signal is output by the MPEG decoding unit 14. The decoded image data is output from the digital terrestrial broadcast receiver to the outside.

In the first operation example, when a new digital broadcast is started on a channel on which digital broadcast was not performed at the time of presetting, or when a frequency of a digital broadcast of a certain channel is changed ( For example, when the frequency is changed from the regular frequency to the lower offset frequency), the digital broadcast of those channels cannot be received correctly. In this case, a channel selection operation similar to the channel selection operation in the second embodiment, that is, a channel selection operation according to the procedure shown in FIG. 7 (hereinafter, referred to as a “second operation example”) may be performed. According to the second operation example, when the broadcast frequency of the desired channel is not stored, the broadcast frequency of the desired channel is searched by the single-channel tuning search (step S in FIG. 7).
202, FIG. 8), even when a new digital broadcast is started on a channel where digital broadcast was not performed at the time of presetting, the newly started digital broadcast can be received. Further, according to the second operation example, if the channel selection operation is performed at the frequency stored as the broadcast frequency of the desired channel and the synchronization is not confirmed, the broadcast frequency of the desired channel is determined by a single channel selection search. Is searched (step S210 of FIG. 7, FIG. 8), even if the frequency of the digital broadcast of a certain channel is changed after the preset, the digital broadcast of that channel can be received.

<4. Fourth Embodiment><4.1 Configuration of Fourth Embodiment> FIG. 12 shows a digital terrestrial broadcasting receiver 40 according to a fourth embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a 0. The digital terrestrial broadcasting receiver 400 includes a communication control unit 52 such as a modem for connecting the digital terrestrial broadcasting receiver to a communication line such as a telephone line or a wide area network (WAN) as a channel arrangement information receiving unit. This is different from the digital terrestrial broadcast receiver 300 according to the third embodiment shown in FIG.
Further, the digital terrestrial broadcasting receiver 400 includes an all-channel search button 54 for starting a preset operation according to a user's instruction, and a circuit associated therewith. Since the configuration of the fourth embodiment other than these is the same as that of the third embodiment, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

<4.2 Operation and Effect of Fourth Embodiment> In the digital terrestrial broadcasting receiver 400 according to the fourth embodiment, as shown in FIG. When pressed (ON) (step S400), a signal indicating the start of the preset operation is sent from the all-channel search unit 21 to the control microcomputer 15.
, And an all-channel tuning search is performed according to the procedure shown in FIG. 11 (step S402).

Therefore, according to the fourth embodiment, when digital broadcasting is started on a new channel that has not existed before, or when the channel arrangement of digital broadcasting is changed, the all channel search button is pressed. Is pressed (ON), the frequency of the digital broadcast on the new channel and the frequency of the digital broadcast after the channel arrangement is changed are stored in the channel data nonvolatile storage unit 18 in association with each channel. As a result, even when digital broadcasting is started on a new channel or when the channel arrangement of digital broadcasting is changed, those digital broadcasting can be received. In the above description, “change of channel arrangement” means that a broadcast of a certain channel is changed from an analog broadcast to a digital broadcast, or that the frequency of a digital broadcast of a certain channel is changed (for example, a regular frequency). To the frequency of the upper offset).

Further, in the fourth embodiment, when digital broadcasting is started on a new channel or when the channel arrangement of digital broadcasting is changed, the channel assignment from the broadcasting station via a telephone line or WAN is performed. It has a configuration on the premise that information is transmitted to each digital terrestrial broadcast receiver. That is, when the channel arrangement information is transmitted from the broadcasting station via the communication line 51, the digital terrestrial broadcasting receiver 400 receives the information by the communication control unit 52. And digital terrestrial broadcasting receiver 400
Performs one of the following processes according to the content of the received channel arrangement information.

(1) When the channel arrangement information is to notify only that a new channel for digital broadcasting has been added or a channel arrangement has been changed, the communication control unit 5
2 receives the channel arrangement information (step S4).
10), and sends the channel arrangement information to the all channel search unit 21. When receiving the channel arrangement information, the all-channel search unit 21 sends an instruction to start the preset operation to the control microcomputer 15. As a result, FIG.
(Step S412).

(2) When the Channel Arrangement Information Includes the Number of Digital Broadcasting Channels Newly Added or Relocated The communication control unit 52 includes the number N of newly added or relocated digital broadcasting channels. When the channel arrangement information is received, the digital broadcast channel number N
At the same time, an instruction for single channel tuning search is sent to the control microcomputer 15. As a result, a single-channel tuning search is executed according to the procedure shown in FIG. 8 (step S42).
4). Then, by this single channel tuning search, the broadcast frequency for the channel of the number N is obtained,
The channel data is stored in the nonvolatile storage unit 18.

(3) In the case where the channel arrangement information includes information indicating the broadcast frequency of the newly added or changed digital broadcasting channel, the communication control unit 52 determines whether the newly added or changed digital broadcasting channel has been changed. When the channel arrangement information including the information indicating the broadcast frequency Fb is received, an instruction for a single-channel tuning search is sent to the control microcomputer 15 together with the information indicating the broadcast frequency Fb. Upon receiving these, the control microcomputer 15 stores the broadcast frequency Fb in the channel data nonvolatile storage unit 18 as the frequency of the digital broadcast channel (step S434).

In the fourth embodiment, the above (1) to (5)
By the operation in each case of (3), among the broadcast frequencies of the respective channels stored in the non-volatile channel data storage unit 18, the broadcast frequency of the newly added or rearranged digital broadcast channel is newly stored or Because it is updated, even if digital broadcasting starts on a new channel that did not exist before, or even if the channel arrangement of digital broadcasting is changed, it is possible to receive those digital broadcasting Become.

In the digital terrestrial broadcasting receiver according to the fourth embodiment, the channel selection operation performed when the user selects a desired channel is the same as that in the third embodiment, and will not be described. Omitted (FIGS. 7, 8, and 10)
reference).

<4.3 Modification of Fourth Embodiment> In the fourth embodiment described above, only when a new channel for digital broadcasting is added or the channel arrangement is changed, the channel from the broadcasting station is changed. The arrangement information is transmitted. However, even when the channel arrangement information is transmitted periodically, the same operation is performed (FIGS. 14 to 14).
The same effect can be obtained. Further, the channel arrangement information may include identification information of a channel which is not a channel related to addition or change but is being digitally broadcast at the time of transmission, and may include, together with the identification information, a broadcast frequency of the channel. May be included. In this case, similarly to the fourth embodiment, the broadcast frequency of the digital broadcast channel may be newly stored or updated in the channel data nonvolatile storage unit 18 based on the channel arrangement information.

Further, in the fourth embodiment, a communication line such as a telephone line is used for transmitting channel arrangement information from a broadcasting station to a digital terrestrial broadcasting receiver. May be used to transmit the channel arrangement information.

<5. Fifth Embodiment><5.1 Configuration of Fifth Embodiment> FIG. 17 shows a digital terrestrial broadcasting receiver 50 according to a fifth embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a 0. This digital terrestrial broadcasting receiver 500 includes a timer 62 that outputs a signal for starting a channel selection search (preset operation) at predetermined time intervals. In this respect, the third timer shown in FIG. Digital terrestrial broadcasting receiver 3 according to the embodiment
Different from 00. Further, the digital terrestrial broadcasting receiver 500 includes an all-channel search button 54 for starting a preset operation and a circuit associated therewith. Since the configuration of the fifth embodiment other than these is the same as that of the third embodiment, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

<5.2 Operation and Effect of Fifth Embodiment> In the digital terrestrial broadcasting receiver 500 according to the fifth embodiment, the digital terrestrial broadcasting according to the fourth embodiment shown in FIG. As in the case of the broadcast receiver 400, as shown in FIG. 13, when the all channel search button 54 is pressed (ON) by a user or the like (step S400).
A signal indicating the start of the preset operation is input from the all-channel search unit 21 to the control microcomputer 15, and an all-channel tuning search is performed according to the procedure shown in FIG. 11 (step S402).

Therefore, according to the fifth embodiment, similarly to the fourth embodiment, the case where digital broadcasting is started on a new channel that did not exist before, or the channel arrangement of digital broadcasting has been changed. Even in this case, by pressing (ON) the search button for all channels,
These digital broadcasts can be received.

In the fifth embodiment, the timer 62 is provided in order to cope with a case where digital broadcasting is started on a new channel which has not existed before or a case where the channel arrangement of digital broadcasting is changed. ing. The timer 62 outputs the all-channel search start signal Ss every predetermined period (for example, every day or every week).
Is output (step S500). The all channel search start signal Ss is input to the all channel search unit 21. When the all-channel search start signal Ss is input, the all-channel search section 21 sends an instruction to start the preset operation to the control microcomputer 15. As a result, an all-channel tuning search is executed according to the procedure shown in FIG. 11 (step S502). As a result, of the broadcast frequencies of the respective channels stored in the channel data nonvolatile storage unit 18, the broadcast frequency of the newly added or rearranged digital broadcast channel is newly stored or updated. As a result, even when digital broadcasting is started on a new channel that has not existed before, or when the channel arrangement of digital broadcasting is changed, it becomes possible to receive those digital broadcasting.

In the digital terrestrial broadcasting receiver according to the fifth embodiment, the channel selection operation performed when the user selects a desired channel is the same as that in the third embodiment. (FIGS. 7, 8, and 1)
0).

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital terrestrial broadcasting receiver according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a first configuration example of a front end unit in the digital terrestrial broadcasting receiver according to the first embodiment.

FIG. 3 is a block diagram showing a second configuration example of the front end unit in the digital terrestrial broadcast receiver according to the first embodiment;

FIG. 4 is a block diagram showing a third configuration example of the front end unit in the digital terrestrial broadcast receiver according to the first embodiment;

FIG. 5 is a flowchart showing a channel selection operation of the digital terrestrial broadcast receiver according to the first embodiment;

FIG. 6 is a block diagram showing a configuration of a digital terrestrial broadcast receiver according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a channel selection operation of the digital terrestrial broadcasting receiver according to the second embodiment.

FIG. 8 is a flowchart showing a procedure of a single-channel tuning search in the digital terrestrial broadcasting receiver according to the second embodiment.

FIG. 9 is a block diagram showing a configuration of a digital terrestrial broadcasting receiver according to a third embodiment of the present invention.

FIG. 10 is a flowchart illustrating an example of a channel selection operation of the digital terrestrial broadcast receiver according to the third embodiment.

FIG. 11 is a flowchart showing a procedure of an all-channel tuning search in the digital terrestrial broadcasting receiver according to the third embodiment.

FIG. 12 is a block diagram showing a configuration of a digital terrestrial broadcasting receiver according to a fourth embodiment of the present invention.

FIG. 13 is a flowchart showing a process for presetting in the digital terrestrial broadcasting receiver according to the fourth embodiment.

FIG. 14 is a diagram illustrating a first process of a digital terrestrial broadcast receiver according to the fourth embodiment for coping with the addition of a new digital broadcast channel or a change in channel arrangement.
5 is a flowchart showing an example of the above.

FIG. 15 is a diagram illustrating a second process of the digital terrestrial broadcast receiver according to the fourth embodiment for coping with the addition of a new digital broadcast channel or a change in channel arrangement.
5 is a flowchart showing an example of the above.

FIG. 16 is a diagram illustrating a third process of the digital terrestrial broadcast receiver according to the fourth embodiment for coping with the addition of a new digital broadcast channel or a change in channel arrangement.
5 is a flowchart showing an example of the above.

FIG. 17 is a block diagram showing a configuration of a digital terrestrial broadcasting receiver according to a fifth embodiment of the present invention.

FIG. 18 is a flowchart illustrating an example of processing for coping with addition of a new digital broadcast channel or change in channel arrangement in the digital terrestrial broadcast receiver according to the fifth embodiment.

FIG. 19 is a diagram showing frequency assignment of digital broadcasting when analog broadcasting is not performed in an adjacent channel.

FIG. 20 is a diagram showing frequency allocation of digital broadcasting when analog broadcasting is performed in the upper adjacent channel.

FIG. 21 is a diagram showing frequency assignment of digital broadcasting when analog broadcasting is performed in a lower adjacent channel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Terrestrial broadcasting antenna 13 ... Front end part 14 ... MPEG decoding part 15 ... Control microcomputer 16 ... Tuning part 17 ... Channel initial data storage part 18 ... Channel data nonvolatile storage part 21 ... All channel search part 32 ... Selection Station filter 33 Mixer 34 PLL circuit 35 Oscillator 39 OFDM demodulation unit 310 Error correction unit 311 VCXO control unit 51 Communication line 52 Communication control unit 54 All channel search button 62 Timer 100, 200, 300 , 400, 500 ... Digital terrestrial broadcasting receiver Sch ... Channel designation signal Sc1, Sc2 ... Control signal Sck ... System clock Vc ... Control voltage Svc ... Control voltage signal Ssync ... OFDM synchronization signal DBER ... BER measurement information

Claims (22)

[Claims] 1. A digitally modulated digital terrestrial signal is received by an antenna, and a digital terrestrial signal corresponding to a digital broadcast of a channel designated by a user is extracted from the digital terrestrial signal received by the antenna. A digital terrestrial broadcasting receiver that demodulates and demodulates the data, wherein when a desired channel desired by the user is specified by a predetermined operation of the user, channel selecting means for outputting channel specification information indicating the desired channel; Channel initial data storage means for storing in advance three types of frequencies: a normal frequency, an upper offset frequency, and a lower offset frequency assigned to digital broadcasting for each of a plurality of predetermined channels; At any one of the three frequencies assigned to the desired channel Receiving a control signal instructing the channel selection operation, performs a selection and demodulation operation based on the control signal with respect to the digital terrestrial signal received by the antenna, to determine whether the channel selection operation has been completed normally A front-end unit that generates synchronization confirmation information that is information indicating the same, and generates the control signal based on the channel designation information, and supplies the generated control signal to the front-end unit. Control means for controlling, wherein the control means generates the control signal based on the frequencies stored in the channel initial data storage means as the three types of frequencies assigned to one channel, and generates the control signal. On the basis of the synchronization confirmation information obtained by supplying the control signal to the front end unit, A single-channel tuning search means for searching for a broadcasting frequency used for digital broadcasting from among the three types of frequencies assigned to the broadcast signal, and determining the broadcasting frequency of the desired channel by the single-channel tuning search means; Digital terrestrial broadcasting receiver. 2. The system according to claim 1, further comprising: a rewritable nonvolatile storage unit for storing a frequency used for digital broadcasting of each of the plurality of channels in association with each of the channels. A storage determination unit that determines whether a broadcast frequency used for digital broadcasting of a channel is stored in the nonvolatile storage unit; and the broadcast frequency of the desired channel is stored in the nonvolatile storage unit. If the storage determining means determines that the broadcast signal is present, the control signal instructing a tuning operation at the stored broadcast frequency is supplied to the front end unit, and the broadcast frequency of the desired channel is stored in the nonvolatile memory. If the storage determining means determines that the single channel selection search means is not stored in the sex storage means, A broadcast signal of a desired channel is searched, the control signal for instructing a tuning operation at the broadcast frequency of the desired channel is supplied to the front end unit, and the broadcast frequency obtained by the search is transmitted to the desired channel. 2. The digital terrestrial broadcast receiver according to claim 1, wherein the receiver stores the digital terrestrial broadcast in the non-volatile storage means in association with the non-volatile storage means. 3. The control unit generates the control signal for instructing a channel selection operation at a frequency stored in the nonvolatile storage unit as a broadcast frequency of the desired channel, and supplies the control signal to the front end unit. As a result, if the tuning operation is not completed normally, the control for instructing the single channel tuning search means to search for the broadcast frequency of the desired channel and instructing the tuning operation at the broadcast frequency of the desired channel is performed. Supplying a signal to the front end section;
3. The digital terrestrial broadcast receiver according to claim 2, wherein the broadcast frequency stored in the nonvolatile storage unit in association with the desired channel is updated to a broadcast frequency obtained by the search. 4. A digitally modulated digital terrestrial signal is received by an antenna, and a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user is extracted from the digital terrestrial signal received by the antenna. A digital terrestrial broadcasting receiver that demodulates and demodulates the data, wherein when a desired channel desired by the user is specified by a predetermined operation of the user, channel selecting means for outputting channel specification information indicating the desired channel; All channel scanning means for receiving a predetermined preset instruction and sequentially outputting channel designation information for designating each of a plurality of predetermined channels one by one in response to the preset instruction; The normal frequency assigned for digital broadcasting, and the frequency of the upper offset Channel initial data storage means for storing in advance three types of frequencies, i.e., the number and the frequency of the lower offset, and frequencies used for digital broadcasting of each of the plurality of channels in association with each of the channels. Rewritable non-volatile storage means for receiving a control signal instructing a channel selection operation at any one of the three types of frequencies assigned to one channel, and receiving the control signal at the antenna. A front-end unit that performs selection and demodulation operations on the digital terrestrial signal based on the control signal, and generates synchronization confirmation information that is information indicating whether or not the tuning operation has been completed normally; Means for generating said control signal based on said channel designation information output from said means or said all-channel scanning means, Control means for controlling the front end unit by supplying a control signal to the front end unit, wherein the control unit, when the all channel scanning unit receives the preset instruction, from the all channel scanning unit Generating the control signal based on the frequencies stored in the channel initial data storage means as the three types of frequencies assigned to the designated channel, which is a channel designated by each of the sequentially designated channel designation information; Searching for a broadcasting frequency used for digital broadcasting from among the three types of frequencies assigned to the designated channel, based on the synchronization confirmation information obtained by supplying the control signal to the front end unit. And designates the broadcast frequency obtained by the search as described above. An all-channel tuning search means for storing in the non-volatile storage means in association with a channel; and when the channel designation information is output from the tuning means, the non-volatile storage means is associated with the desired channel. A digital terrestrial broadcasting receiver for reading a stored broadcast frequency, generating the control signal for instructing a tuning operation at the read frequency, and supplying the control signal to the front end unit. 5. The control unit generates the control signal based on the frequency stored in the channel initial data storage unit as the three types of frequencies assigned to one channel, and the generated control signal On the basis of the synchronization confirmation information obtained by supplying the same to the front end unit, a single channel selection for searching a broadcasting frequency used for digital broadcasting from among the three types of frequencies assigned to the one channel. Station search means; and storage determination means for determining whether or not a broadcast frequency used for digital broadcast of the desired channel is stored in the nonvolatile storage means, wherein the broadcast frequency of the desired channel is the nonvolatile frequency. If the storage determination means determines that the data is stored in the sex storage means, Supplying the control signal instructing the channel selection operation at the broadcast frequency to the front end unit, and when the storage determination unit determines that the broadcast frequency of the desired channel is not stored in the nonvolatile storage unit, Controlling the single-channel tuning search means to search for the broadcast frequency of the desired channel, supplying the control signal instructing a tuning operation at the broadcast frequency of the desired channel to the front-end unit, and The digital terrestrial broadcasting receiver according to claim 4, wherein the broadcast frequency obtained by the search is stored in the nonvolatile storage unit in association with the desired channel. 6. The control unit generates the control signal based on the frequency stored in the channel initial data storage unit as the three types of frequencies assigned to one channel, and the generated control signal Based on the synchronization confirmation information obtained by supplying
A single-channel tuning search unit for searching a broadcast frequency used for digital broadcasting from the three types of frequencies assigned to the one channel; and the non-volatile storage unit as a broadcast frequency of the desired channel. When the control signal for instructing the tuning operation at the frequency stored in the memory is generated and supplied to the front end unit, if the tuning operation is not completed normally, the single-channel tuning search means is selected. To search the broadcast frequency of the desired channel, supply the control signal instructing the channel selection operation at the broadcast frequency of the desired channel to the front end unit, and the nonvolatile storage means and the desired channel The broadcast frequency stored in association with the broadcast frequency is updated to a broadcast frequency obtained by the search. Digital terrestrial broadcasting receiver. 7. An all-channel search instructing unit that is operated by a user to give the preset instruction to the all-channel scanning unit.
2. A digital terrestrial broadcasting receiver according to claim 1. 8. The digital terrestrial broadcasting receiver according to claim 4, further comprising timer means for outputting a signal for giving said preset instruction to said all-channel scanning means at predetermined time intervals. 9. Receiving information transmitted by a predetermined communication channel, and when the received information indicates that a new channel for digital broadcasting has been added or a channel arrangement has been changed, the all channels are transmitted. The digital terrestrial broadcasting receiver according to claim 4, further comprising a receiving unit that gives the preset instruction to a scanning unit. 10. Receiving means for receiving information transmitted by a predetermined communication path and outputting the identification information when the received information includes identification information of a channel on which digital broadcasting is currently performed. Further, the control means generates the control signal based on the frequencies stored in the channel initial data storage means as the three types of frequencies assigned to one channel, and the generated control signal A single-channel tuning search for searching a broadcasting frequency used for digital broadcasting from among the three types of frequencies assigned to the one channel, based on the synchronization confirmation information obtained by supplying the same to a front end unit. Means for receiving the identification information from the receiving means, and identifying the channel identified by the identification information. The digital broadcast according to claim 4, wherein a broadcast frequency of a channel is obtained by the single-channel tuning search means, and the obtained broadcast frequency is stored in the nonvolatile storage means in association with a channel identified by the identification information. Terrestrial broadcasting receiver. 11. When receiving information transmitted by a predetermined communication path, and when the received information includes identification information and a broadcast frequency of a channel on which digital broadcasting is currently performed, the identification information and the broadcast are transmitted. A receiving unit that outputs a frequency, wherein the control unit, when the identification information and the broadcast frequency are output from the receiving unit, identifies the broadcast frequency output from the receiving unit by the identification information The digital terrestrial broadcasting receiver according to claim 4, wherein the receiver is stored in the nonvolatile storage unit in association with a channel. 12. The digital terrestrial signal is an OFDM signal.
A modulated signal, wherein the front end unit includes an OFDM demodulator for demodulating the digital terrestrial signal, and an OFDM synchronization signal as the synchronization confirmation information when the OFDM demodulator correctly demodulates the digital terrestrial signal. The receiver for digital terrestrial broadcasting according to claim 1, wherein the receiver generates the signal. 13. The digital terrestrial wave signal is OFDM.
A modulated signal, wherein the front end unit includes: an OFDM demodulation unit that demodulates the digital terrestrial signal; and a voltage control oscillation unit that generates a system clock of the OFDM demodulation unit. The digital terrestrial broadcasting receiver according to claim 1, wherein the signal is a signal indicating a control voltage supplied to the voltage controlled oscillator. 14. The digital terrestrial signal is an OFDM signal.
A modulated signal, wherein the front end unit comprises: an OFDM demodulator for demodulating the digital terrestrial signal; and an error correcting an error included in a signal obtained by demodulating the digital terrestrial signal by the OFDM demodulator. The digital terrestrial broadcasting receiver according to claim 1, further comprising a correction unit, wherein the synchronization confirmation information is BER measurement information generated by the error correction unit. 15. The single-channel tuning search means,
The digital terrestrial broadcasting receiver according to claim 1, wherein a search is performed by giving priority to a regular frequency among the three types of frequencies. 16. The all-channel tuning search means,
The digital terrestrial broadcasting receiver according to claim 4, wherein a search is performed by giving priority to a regular frequency among the three types of frequencies. 17. The all-channel selection search means,
The single-channel tuning search means performs a search by giving priority to a regular frequency among the three kinds of frequencies, and the single-channel tuning search means performs a search by giving priority to a regular frequency among the three kinds of frequencies.
Or the digital terrestrial broadcast receiver according to 6. 18. A control signal for instructing a tuning operation at a first frequency which is one of the three types of frequencies allocated to the one channel, wherein the single-channel tuning search means includes: On the basis of the synchronization confirmation information obtained by supplying
First synchronization confirmation means for determining whether or not the channel selection operation at the first frequency is completed normally; and when it is determined that the channel selection operation at the first frequency is not completed normally, Synchronization confirmation obtained by supplying a control signal for instructing a channel selection operation at a second frequency other than the first frequency among the three types of frequencies allocated to the one channel to the front end unit. And a second synchronization confirmation unit for determining whether or not the channel selection operation at the second frequency is normally completed based on the information, wherein the channel selection operation at the first frequency is normally completed. If it is determined, the first frequency is regarded as the broadcast frequency of the one channel, and if it is determined that the channel selection operation at the second frequency is completed normally, the second frequency is set to the 1st frequency. Broadcast frequency of two channels However, if it is determined that the channel selection operation at any one of the first and second frequencies is not completed normally, the first and second frequencies among the three types of frequencies allocated to the one channel are The digital terrestrial broadcasting receiver according to claim 1, wherein a third frequency other than the second frequency is regarded as a broadcasting frequency of the one channel. 19. The control signal for instructing a tuning operation at a first frequency which is one of the three types of frequencies allocated to the one channel, On the basis of the synchronization confirmation information obtained by supplying
First synchronization confirmation means for determining whether or not the channel selection operation at the first frequency is completed normally; and when it is determined that the channel selection operation at the first frequency is not completed normally, Synchronization confirmation obtained by supplying a control signal for instructing a channel selection operation at a second frequency other than the first frequency among the three types of frequencies allocated to the one channel to the front end unit. A second synchronization confirmation unit for determining whether or not the channel selection operation at the second frequency is normally completed based on the information; and a channel selection operation at any one of the first and second frequencies. A control signal for instructing a channel selection operation at a third frequency other than the first and second frequencies among the three types of frequencies allocated to the one channel when it is determined that the selection is not completed normally; The front end Based on the synchronization confirmation information obtained by supplying the parts,
A third synchronization confirming means for determining whether or not the channel selection operation at the third frequency has been normally completed; and when it is determined that the channel selection operation at the first frequency has been completed normally. Considers the first frequency as the broadcast frequency of the one channel, and if it is determined that the channel selection operation at the second frequency has been completed normally, the second frequency is the broadcast of the one channel. 7. The frequency according to claim 1, 5 or 6, wherein the third frequency is regarded as the broadcast frequency of the one channel when it is determined that the tuning operation at the third frequency has been completed normally. 2. The digital terrestrial broadcasting receiver according to claim 1. 20. The all-channel tuning search means outputs a control signal for instructing a tuning operation at a first frequency which is one of the three types of frequencies allocated to the designated channel. First synchronization confirmation means for determining whether or not the channel selection operation at the first frequency is normally completed, based on synchronization confirmation information obtained by supplying the signal to the front end unit; When it is determined that the channel selection operation is not completed normally, a second frequency other than the first frequency among the three types of frequencies allocated to the designated channel is used.
It is determined whether or not the channel selection operation at the second frequency has been normally completed based on synchronization confirmation information obtained by supplying a control signal instructing the channel selection operation at the second frequency to the front end unit. A second synchronization confirming means for performing, when it is determined that the channel selection operation at any one of the first and second frequencies is not completed normally, the three types of frequencies assigned to the designated channel are Based on synchronization confirmation information obtained by supplying a control signal for instructing a channel selection operation at a third frequency other than the first and second frequencies to the front end unit, A third synchronization confirmation unit for determining whether or not the channel selection operation has been completed normally; and if it is determined that the channel selection operation at the first frequency has been completed normally, the first frequency is changed. The designated channel The non-volatile storage means is stored in the nonvolatile storage means as the broadcast frequency of the channel, and when it is determined that the channel selection operation at the second frequency is completed normally, the second frequency is used as the broadcast frequency of the designated channel. Stored in the sex storage means,
The third frequency is stored in the nonvolatile storage unit as the broadcast frequency of the designated channel when it is determined that the channel selection operation at the frequency of (i) has been completed normally.
7. The digital terrestrial broadcasting receiver according to any one of 5 and 6. 21. A digitally modulated digital terrestrial signal is received by an antenna, and a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user is extracted from the digital terrestrial signal received by the antenna. A method for selecting a receiving channel for a digital terrestrial broadcasting receiver that demodulates and demodulates the signal, comprising: a regular frequency, an upper offset frequency, and a lower frequency assigned to digital broadcasting for each of a plurality of predetermined channels. A channel initial data storing step of storing three kinds of frequencies of the side offset in advance; and when a desired channel desired by the user is designated by a predetermined operation of the user, channel designation information indicating the desired channel is output. Specifying a channel to be assigned, A control signal generating step of generating a control signal for instructing a tuning operation at any one of the three types of frequencies based on the frequencies previously stored in the channel initial data storing step as the three types of frequencies. Based on the generated control signal, performs a selection and demodulation operation on the digital terrestrial signal received by the antenna, whether or not the tuning operation including the selection and demodulation operation has been completed normally A synchronization confirmation information generating step of generating synchronization confirmation information that is information indicating: based on the synchronization confirmation information, a broadcast frequency used for digital broadcasting from among the three types of frequencies assigned to the desired channel. A receiving channel tuning method, comprising: a search step of performing a search. 22. A digitally modulated digital terrestrial signal is received by an antenna, and a digital terrestrial signal corresponding to digital broadcasting of a channel designated by a user is extracted from the digital terrestrial signal received by the antenna. A method for selecting a receiving channel for a digital terrestrial broadcasting receiver that demodulates and demodulates the signal, comprising: a regular frequency, an upper offset frequency, and a lower frequency assigned to digital broadcasting for each of a plurality of predetermined channels. A channel initial data storing step of storing three types of frequencies of the side offset in advance; and channel designation information for receiving a predetermined preset instruction and designating each of a plurality of predetermined channels in response to the preset instruction. Scanning all channels one by one sequentially, Upon receiving a preset instruction, based on the frequencies pre-stored as the three types of frequencies assigned to the designated channels, which are channels designated by the channel designation information sequentially output, the three types of frequencies are A first control signal generating step of generating a control signal instructing a tuning operation at any frequency; and a digital terrestrial signal received by the antenna based on the control signal generated in the first control signal generating step. A synchronization confirmation information generating step of performing selection and demodulation operations on the wave signal, and generating synchronization confirmation information that is information indicating whether or not the channel selection operation including the selection and demodulation operations has been normally completed; Based on the synchronization confirmation information, the three types of frequencies allocated to the designated channel are used for digital broadcasting. A search step for searching for a broadcast frequency that is present; a storage step of storing the broadcast frequency obtained in the search step in association with the designated channel in a predetermined non-volatile storage means; A channel designation step of outputting channel designation information indicating the desired channel when designated by the predetermined operation; and, when the channel designation information is output in the channel designation step, the non-volatile memory is associated with the desired channel. A reading step of reading a broadcast frequency stored in a storage unit; a second control signal generating step of generating a control signal instructing a channel selection operation at the frequency read from the nonvolatile storage unit; 2 Based on the control signal generated in the control signal generation step, Receiving channel selection method and a channel selection step of selecting and demodulation operations with respect to the digital terrestrial wave signals received by the antenna.