JP5412796B2 - Digital broadcast receiver - Google Patents

Description

  The present invention relates to a digital broadcast receiver capable of receiving a terrestrial digital television broadcast.

  Recently, the spread of terrestrial digital television broadcasting has been urgently promoted not only in Japan but also in the world. Digital broadcast receivers that can receive terrestrial digital television broadcasts have different broadcast stations that can be received in each region.

  When a digital broadcast receiver receives a terrestrial digital television broadcast in a state where the reception location does not change, the reception area can be easily identified and the receiver rarely moves. Once set, it is unlikely that it will cause inconvenience in subsequent tuning. On the other hand, for example, when receiving terrestrial digital television broadcasting while moving on a mobile terminal such as an in-vehicle device, it is conceivable that the receiver moves on a daily basis between a plurality of regions. It is necessary to search for broadcast stations that can be viewed in the area.

Conventionally, techniques that enable smooth automatic channel selection during movement have been proposed (see, for example, Patent Documents 1 and 2).
JP-A-2005-45592 Japanese Patent Laid-Open No. 2005-27221

  However, in the conventional automatic channel selection (auto seek preset) method in terrestrial digital television broadcasting, the received digital signal is demodulated into an analog signal and then a viewable broadcast station is determined. Prolonged.

In order to avoid this problem, when a broadcast station that can be viewed is determined based on the carrier-noise ratio of the digital signal (12 segments) before demodulation and the terminal voltage, the frequency band of 12 segments is determined. Then, accurate broadcasting station determination becomes difficult.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a digital broadcast receiver with high determination accuracy of a broadcast station that can be viewed in terrestrial digital television broadcasting. .

A first feature of the present invention is a digital broadcast receiver capable of receiving a terrestrial digital television broadcast, and the digital broadcast receiver receives a digital signal in a frequency band assigned to the terrestrial digital television broadcast. to the digital broadcast receiving unit, of the frequency band of the digital signal by the digital broadcast receiving unit receives a one optional band portion of the frequency band allocated to the broadcasting station in the digital terrestrial television broadcasting, Seg A band setting unit for setting a part of a frequency band different from the frequency band for broadcasting as a determination target band, and using the digital signal of the determination target band received by the digital broadcast reception unit without being demodulated, It is determined whether or not the broadcast in the viewing target band wider than the determination target band is viewable, and based on the determination result, The digital signal of the serial viewing target band is to comprise a broadcasting station determination unit for demodulating.

According to the first feature of the present invention, in a terrestrial digital television broadcast, a digital signal in a part of a frequency band assigned to one broadcasting station is used, and in a band wider than the part of the band. By determining whether or not the broadcast of the one broadcasting station can be viewed, it is possible to determine whether the same determination is performed using a digital signal in the entire frequency band assigned to the one broadcasting station. Accuracy is improved.

  As described above, according to the digital broadcast receiver of the present invention, the determination accuracy of a broadcast station that can be viewed in terrestrial digital television broadcasting is increased.

Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same parts are denoted by the same reference numerals.
(First embodiment)
With reference to FIG. 1, the configuration of a digital broadcast receiver according to the first embodiment of the present invention will be described. The digital broadcast receiver according to the first embodiment of the present invention is a digital broadcast receiver capable of receiving terrestrial digital television broadcasts, and receives radio waves in a band assigned to terrestrial digital television broadcasts. Among the digital signal received by the digital broadcast receiver 12a and the digital broadcast receiver 12a that receives the digital signal of the frequency band assigned to the terrestrial digital television broadcast from the radio wave received by the antenna 11, Using digital signals in a part of the frequency band allocated to one broadcasting station in terrestrial digital television broadcasting, the broadcasting of the one broadcasting station in a band wider than the part of the band can be viewed. A reception control unit 13a having a function as a broadcasting station determination unit for determining whether or not there is a digital A decoding unit 14 that demodulates a digital signal received by the transmission / reception unit 12a into an analog signal, a display unit 15 that displays video based on a video signal included in the analog signal demodulated by the decoding unit 14, and a demodulation by the decoding unit 14 A speaker 16 that outputs sound based on an audio signal included in the analog signal, a preset storage unit 17 that stores unique information of a broadcasting station that is determined to be viewable by the reception control unit 13, and a user And an operation unit 18 for receiving an operation.

  The antenna 11 may be a Yagi / Uda antenna that can receive UHF radio waves. The digital broadcast receiver 12a has a function as a tuner for selecting a broadcast station that can be received from the radio wave received by the antenna 11. The frequency band assigned to each selectable broadcast station is divided into a plurality of (for example, 13) segments, of which 12 segments are assigned to high-definition broadcasting (HDTV) and 4 segments are assigned to standard-definition broadcasting. For example, mobile terminals such as in-vehicle devices, PDAs, and mobile phones have a small screen and perform low-resolution broadcasting by assigning one segment with a focus on portability and mobility by reducing performance. One segment is abbreviated as “One Seg”.

  The reception control unit 13a is composed of, for example, a microcomputer, and uses a digital signal in one segment of a frequency band (13 segments) allocated to one broadcast station selected by the digital broadcast reception unit 12a. It is determined whether or not the high-definition broadcast or the standard-definition broadcast of the one broadcasting station assigned to the 12 segment or the 4 segment, which is a wider band, can be viewed. Specifically, it will be described later with reference to FIG.

  The reception control unit 13a controls the demodulation operation of the decoding unit 14. Specifically, the digital signal of the frequency band (12 segments or 4 segments) allocated to the channel determined by the reception control unit 13 that the high-definition broadcast or the standard definition broadcast can be viewed is selectively demodulated.

  The analog signal selectively demodulated by the decoding unit 14 includes a signal indicating the specific information of the selected broadcast station, a video signal, and an audio signal. A signal indicating the unique information is transmitted to the reception control unit 13, and the reception control unit 13 stores the unique information of the broadcasting station and the preset information of the receivable broadcasting station in the preset storage unit 17. The video signal is transmitted to the display unit 15, and the display unit 15 displays a video based on the received video signal. Then, the audio signal is transmitted to the speaker 16, and the speaker 16 outputs audio based on the received audio signal.

  The operation unit 18 includes, for example, a preset button, and accepts a command operation for starting automatic channel selection (auto seek preset) from the user when the user presses the preset button.

A detailed configuration of the reception control unit 13a will be described with reference to FIG. The reception control unit 13a measures a carrier-noise ratio (hereinafter referred to as “CN ratio”) of a digital signal in a part of a frequency band assigned to one broadcasting station. 31 and a first comparison and determination unit 32 that determines whether or not the broadcast of the one broadcasting station is viewable by comparing the CN ratio measured by the CN ratio measurement unit 31 with a predetermined threshold value. Is provided.

  Specifically, as shown in FIG. 8, the CN ratio measuring unit 31 is a part of the frequency bands (12 segments) WD1 to WD3 allocated to the broadcasting stations 1 to 3 in the terrestrial digital television broadcasting. The CN ratio of the digital signal in the band (one segment) SD1 to SD3 is measured. For example, the bandwidth of one segment is 400 kHz, and the bandwidth of 12 segments is 5.5 MHz. The first comparison / determination unit 32 compares the CN ratio measured by the CN ratio measurement unit 31 with the 1-segment threshold, and if the CN ratio is equal to or greater than the 1-segment threshold, the frequency band WD1 to WD1 assigned to the broadcasting station. It is determined that the broadcast of WD3 can be received. The predetermined threshold value is not limited to the 1-segment threshold value in FIG. 8 and may be, for example, a 12-segment threshold value.

  An example of an automatic channel selection procedure by the digital broadcast receiver of FIG. 1 will be described with reference to FIG.

  (A) First, in step S01, the operation unit 18 receives a command operation for starting automatic channel selection (auto seek preset) when the preset button is pressed. Proceeding to step S03, the digital broadcast receiving unit 12a selectively receives a digital signal for one-segment broadcasting of one broadcasting station from the radio wave received by the antenna 11.

(B) Proceeding to step S05, the CN ratio measuring unit 31 measures the CN ratio of the digital signal in a part of the band (1 segment) among the digital signals in the frequency band (12 segments) allocated to the broadcasting station. . Proceeding to step S07, the first comparison / determination unit 32 compares the CN ratio measured by the CN ratio measuring unit 31 with the 1-segment threshold, and if the CN ratio is equal to or greater than the 1-segment threshold (S0).
In step S09, the first comparison / determination unit 32 determines that the high-definition broadcast or the standard-definition broadcast of the frequency bands WD1 to WD3 assigned to the broadcast station can be viewed, and the reception control unit 13a temporarily presets the broadcast station in the preset storage unit 17. Then, it progresses to S11 stage. In the example of FIG. 8, the first comparison / determination unit 32 determines that the high-definition broadcast (12 segments) in the frequency bands WD1 and WD3 is viewable, but the high-definition broadcast (12 segments) in the frequency band WD2 is not viewable. Judge that it is possible.

  (C) On the other hand, if the CN ratio is less than the 1-segment threshold (NO in S07), the process proceeds directly to step S11. In step S11, it is determined whether or not the determination is made based on the CN ratio for all broadcasting stations 1 to 3. If not completed for all broadcasting stations (NO in S11), proceed to step S13, select a broadcasting station that has not been determined, return to step S03, and repeat steps S03 to S13 for all broadcasting stations. To do.

  (D) After performing determination based on the CN ratio for all broadcasting stations (YES in S11), the process proceeds to step S15, and the reception control unit 13a stores information on the broadcasting stations provisionally preset in step S09 as the preset storage unit 17. Read from. Proceeding to step S17, the digital broadcast receiving unit 12a selectively receives the digital signal of the high-definition broadcast (12 segments) or the standard definition broadcast (4 segments) from the radio wave received by the antenna 11 for only the read broadcast station. To do.

  (E) Proceeding to step S19, the decoding unit 14 demodulates the digital signal received by the digital broadcast receiving unit 12a, and the reception control unit 13a presets the demodulated broadcast station in the preset storage unit 17, as shown in FIG. The flowchart ends.

  As described above, according to the first embodiment of the present invention, the following operational effects can be obtained.

  Using a digital signal in a part of the frequency band WD of the frequency band WD assigned to one broadcasting station in terrestrial digital television broadcasting, the broadcasting of the one broadcasting station can be viewed in a band wider than the part of the band. By determining whether or not it is possible, the accuracy of determination is improved as compared with the case where similar determination is performed using digital signals in the entire frequency band assigned to one broadcasting station.

  The decoding unit 14 selectively demodulates the digital signal in the frequency band (12 segments or 4 segments) assigned to the channel determined by the reception control unit 13 that the high-definition broadcast or the standard-definition broadcast can be viewed. Conventionally, since the broadcast station that can be viewed is determined after decoding the received digital signal, the processing time has been prolonged, but the digital signal is selectively demodulated after the broadcast station that can be viewed is determined. Therefore, the time required for automatic channel selection can be shortened.

  In addition, as shown in FIG. 8, when determining whether or not viewing is possible using the CN ratio of the 12-segment digital signal, since the digital signal band (12 segments) is wide, data loss occurs, and Cannot be judged. On the other hand, when determining whether or not viewing is possible using the CN ratio of the digital signal of one segment, since the band (one segment) of the digital signal is narrow, the determination accuracy becomes high. Therefore, the reception control unit 13a can view the broadcast of one broadcast station in 12 segments using the digital signal of one segment among the 13 segments of the frequency band assigned to one broadcast station. Therefore, the accuracy of automatic channel selection is improved.

By selecting a channel based on the CN ratio of the digital signal, the speed improvement range is reduced.
(First modification)
A first modification of the digital broadcast receiver according to the first embodiment in which the configuration of the reception control unit 13a shown in FIG. As shown in FIG. 2 (b), the reception control unit 13b in the first modified example is a terminal measurement unit that measures the terminal voltage of a digital signal in a part of the frequency band assigned to one broadcast station. 35 and a second comparison / determination unit 36 that determines whether or not the broadcast of the one broadcasting station is viewable by comparing the terminal voltage measured by the terminal voltage measurement unit 35 with a predetermined threshold value. Is provided.

  Specifically, the terminal electricity measuring unit 35 performs the frequency bands (12 segments) WD1 to WD3 allocated to the broadcasting stations 1 to 3 in the terrestrial digital television broadcasting in the same manner as the CN ratio shown in FIG. The terminal voltage of the digital signal in some of the bands (one segment) SD1 to SD3 is measured. The second comparison / determination unit 36 compares the terminal voltage measured by the terminal voltage measuring unit 35 with the 1-segment threshold, and if the terminal voltage is equal to or greater than the 1-segment threshold, the frequency band WD1 to WD1 assigned to the broadcasting station. It is determined that the WD3 high-definition broadcast or standard-definition broadcast can be received. Note that the predetermined threshold is not limited to the 1-segment threshold, and may be a 12-segment threshold, for example.

  With reference to FIG. 4, an example of the automatic channel selection procedure by the digital broadcast receiver according to the first modification will be described.

  (A) First, in step S21, the operation unit 18 receives a command operation for starting automatic channel selection (auto seek preset) when the preset button is pressed. Proceeding to step S23, the digital broadcast receiver 12a selectively receives a digital signal for one-segment broadcasting of one broadcasting station from the radio wave received by the antenna 11.

  (B) Proceeding to step S25, the terminal voltage measuring unit 35 measures the terminal voltage of the digital signal in a part of the band (1 segment) among the digital signals of the frequency band (12 segments) allocated to the broadcasting station. . Proceeding to step S27, the second comparison / determination unit 36 compares the terminal voltage measured by the terminal voltage measuring unit 35 with the 1-segment threshold and if the terminal voltage is equal to or greater than the 1-segment threshold (YES in S27), S29. Proceeding to the stage, the second comparison / determination unit 36 determines that the high-definition broadcast or the standard-definition broadcast of the frequency bands WD1 to WD3 assigned to the broadcast station can be viewed, and the reception control unit 13b 17 temporarily presets the broadcast station. Then, it progresses to S31 stage.

  (C) On the other hand, if the terminal voltage is less than the 1-segment threshold (NO in S27), the process proceeds directly to step S31. In step S31, it is determined whether or not determinations have been made based on terminal voltages for all broadcasting stations 1 to 3. If not completed for all broadcasting stations (NO in S31), proceed to step S33, select a broadcasting station that has not been determined, return to step S23, and repeat steps S23 to S33 for all broadcasting stations. To do.

  (D) After determining by terminal voltage for all broadcasting stations (YES in S31), the process proceeds to step S35, and the reception control unit 13b sets the information of the broadcasting stations temporarily preset in step S29 to the preset storage unit 17. Read from. Proceeding to step S37, the digital broadcast receiving unit 12a selectively receives a high-definition broadcast (12 segment) or standard definition broadcast (4 segment) digital signal from the radio wave received by the antenna 11 for only the read broadcast station. To do.

  (E) Proceeding to step S39, the decoding unit 14 demodulates the digital signal received by the digital broadcast receiving unit 12a, and the reception control unit 13b presets the demodulated broadcast station in the preset storage unit 17, as shown in FIG. The flowchart ends.

As described above, according to the first modification, by performing channel selection based on the terminal voltage of the digital signal, the time required for automatic channel selection can be shortened compared to the case of the CN ratio.
(Second modification)
In the first embodiment and the first modification, the case where a part of the band used for automatic tuning is one segment has been described. However, part of the band used by the reception control units 13a and 13b for automatic tuning. May be arbitrarily set by the user.

  In addition to the configuration shown in FIG. 1, the digital broadcast receiver according to the second modification further includes a band setting unit that arbitrarily sets a part of the frequency band allocated to one broadcast station. The reception control unit 13a uses the digital signal in the band set by the band setting unit to determine whether or not the broadcast of the one broadcasting station can be viewed in a band wider than the band (12 segments or 4 segments). Determine.

  FIG. 5 is a flowchart showing an example of an automatic channel selection procedure by the digital broadcast receiver according to the second modification, and shows a procedure for performing automatic channel selection using the terminal voltage of the digital signal. Compared with the flowchart of FIG. 4, there is a difference in that a process for arbitrarily setting a part of the band used for automatic channel selection (step S44) is added between steps S43 and S45. Are all the same. That is, in S41, S43, and S45 to S59, the same processing as S21 to S39 in FIG. 4 is performed.

As described above, according to the second modification, the degree of freedom of automatic tuning is improved by arbitrarily setting a part of bands used for automatic tuning. When the band is set to be narrower than one segment, the time required for automatic channel selection can be shortened compared to the case of one segment.
(Second Embodiment)
With reference to FIG. 6, the configuration of a digital broadcast receiver according to the second embodiment of the present invention will be described. A digital broadcast receiver according to a second embodiment of the present invention is a digital broadcast receiver capable of receiving terrestrial digital television broadcasts, and receiving radio waves in a band assigned to terrestrial digital television broadcasts. And a television broadcast receiver 12 that receives from the radio waves received by the antenna 11 a digital signal in a frequency band assigned to terrestrial digital television broadcast and an analog signal in a frequency band assigned to terrestrial analog color television broadcast. Among the analog signals received by the television broadcast receiver 12, the terrestrial digital television corresponding to the one broadcasting station using the analog signal in the frequency band assigned to one broadcasting station in the terrestrial analog color television broadcasting. Whether or not the broadcast of one broadcasting station in John Broadcasting is viewable A reception control unit 13b having a function as a second broadcast station determination unit to be determined, a decoding unit 14 that demodulates a digital signal received by the television broadcast receiving unit 12 into an analog signal, and an analog signal demodulated by the decoding unit 14 The display unit 15 displays video based on the video signal included in the video signal, the speaker 16 outputs audio based on the audio signal included in the analog signal demodulated by the decoding unit 14, and the reception control unit when viewable. 13 includes a preset storage unit 17 that stores the unique information of the broadcasting station determined by 13 and an operation unit 18 that receives an operation from the user.

  The television broadcast receiver 12 receives a digital broadcast receiver 12a that receives a digital signal in a frequency band assigned to the terrestrial digital television broadcast from the radio waves received by the antenna 11, and the terrestrial analog color television from the radio waves received by the antenna 11. And an analog broadcast receiving unit 12b that receives an analog signal in a frequency band assigned to the broadcast.

  The reception control unit 13b measures the terminal voltage of the analog signal in the frequency band assigned to one broadcasting station, and compares the measured terminal voltage with a predetermined threshold value, thereby terrestrial corresponding to the one broadcasting station. It is determined whether or not the broadcasting of one broadcasting station in the wave digital television broadcasting can be viewed.

With reference to FIG. 7, an example of an automatic channel selection procedure by the digital broadcast receiver according to the second embodiment will be described.

  (A) First, in step S61, the operation unit 18 receives a command operation for starting automatic channel selection (auto seek preset) when the preset button is pressed. Proceeding to step S63, the analog broadcast receiving unit 12b selectively receives an analog signal in a frequency band assigned to the terrestrial analog color television broadcast of one broadcast station from the radio wave received by the antenna 11.

  (B) Proceeding to step S65, the terminal voltage measuring unit 35 measures the terminal voltage of the analog signal in the frequency band assigned to the broadcasting station. Proceeding to step S67, the second comparison / determination unit 36 compares the terminal voltage measured by the terminal voltage measuring unit 35 with a predetermined threshold, and if the terminal voltage is equal to or higher than the predetermined threshold (YES in S67), S69. The second comparison / determination unit 36 determines that the high-definition broadcast or the standard-definition broadcast by the broadcast station in the terrestrial digital television broadcast can be viewed, and the reception control unit 13b stores the preset storage unit 17 in the stage. Temporarily preset the broadcast station. Thereafter, the process proceeds to step S71.

  (C) On the other hand, if the terminal voltage is less than the predetermined threshold (NO in S67), the process proceeds directly to step S71. In step S71, it is determined whether or not determinations have been made based on terminal voltages for all broadcasting stations. If all the broadcasting stations are not completed (NO in S71), the process proceeds to step S73, selects a broadcasting station that has not been determined, returns to step S63, and repeats steps S63 to S73 for all broadcasting stations. To do.

  (D) After making a determination based on the terminal voltage for all the broadcasting stations (YES in S71), the process proceeds to step S75, and the reception control unit 13b stores the information on the broadcasting stations temporarily preset in step S69. Read from. Proceeding to step S77, the digital broadcast receiving unit 12a selectively receives a high-definition broadcast (12 segment) or standard definition broadcast (4 segment) digital signal from the radio wave received by the antenna 11 for only the read broadcast station. To do.

  (E) Proceeding to step S79, the decoding unit 14 demodulates the digital signal received by the digital broadcast receiving unit 12a, and the reception control unit 13b presets the demodulated broadcast station in the preset storage unit 17, as shown in FIG. The flowchart ends.

As described above, according to the second embodiment, an analog signal for terrestrial analog color television broadcasting is received, and the terrestrial digital television corresponding to the one broadcasting station is received using the terminal voltage of the analog signal. Since it is determined whether or not the John broadcast can be viewed, the time required for automatic channel selection can be shortened as compared with the first modification using the terminal voltage of a one-segment digital signal.
(Other embodiments)
As described above, the present invention has been described in terms of two embodiments and modifications thereof. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the case where the automatic channel selection is started by the pressing operation of the preset button by the user has been described. However, when a predetermined time elapses or the CN ratio or terminal voltage of the preset broadcasting station is below a predetermined threshold value In such a case, a means for detecting this may be provided so as to be automatically started.

  In the second embodiment, the case where the terminal voltage of the analog signal is used has been described, but the CN ratio of the analog signal may be used. That is, the reception control unit 13a shown in FIG. 2A may be used instead of the reception control unit 13b shown in FIG.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters according to the scope of claims reasonable from this disclosure.

It is a block diagram which shows the structure of the digital broadcast receiver concerning the 1st Embodiment of this invention. 2A is a block diagram showing a detailed configuration of the reception control unit 13a, and FIG. 2B is a block diagram showing a detailed configuration of the reception control unit 13b. 3 is a flowchart showing an example of an automatic channel selection procedure by the digital broadcast receiver of FIG. 1. It is a flowchart which shows an example of the automatic channel selection procedure by the digital broadcast receiver concerning a 1st modification. It is a flowchart which shows an example of the automatic channel selection procedure by the digital broadcast receiver concerning a 2nd modification. It is a block diagram which shows the structure of the digital broadcast receiver concerning the 2nd Embodiment of this invention. It is a flowchart which shows an example of the automatic channel selection procedure by the digital broadcast receiver concerning 2nd Embodiment. It is a graph which shows the difference in the bandwidth of 1 segment (narrow band) and 12 segments (wide band).

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Antenna 12 ... Television broadcast receiving part 12a ... Digital broadcast receiving part 12b ... Analog broadcast receiving part 13a, 13b ... Reception control part 14 ... Decoding part 15 ... Display part 16 ... Speaker 17 ... Preset memory | storage part 18 ... Operation part 31 ... CN ratio measuring unit 32 ... first comparison / determination unit 35 ... terminal voltage measuring unit 36 ... second comparison / determination unit

Claims (4)

In a digital broadcast receiver capable of receiving terrestrial digital television broadcasts,
A digital broadcast receiver for receiving digital signals in a frequency band assigned to terrestrial digital television broadcasting;
Among the frequency bands of the digital signal received by the digital broadcast receiving unit, any one of the frequency bands allocated to one broadcasting station in the terrestrial digital television broadcasting, the frequency band for one-segment broadcasting, Is a band setting unit for setting a part of different frequency bands as a determination target band;
Using the digital signal in the determination target band received by the digital broadcast receiving unit without being demodulated, it is determined whether or not a broadcast in a viewing target band wider than the determination target band is viewable, A digital broadcast receiver comprising: a broadcast station determination unit that demodulates a digital signal in the viewing target band based on a determination result. The band setting unit sets, as the determination target band, one segment out of 13 segments divided from a frequency band assigned to one broadcasting station,
The broadcast station determination unit, by using the digital signal of the determination target band, broadcast of the broadcast station in two or more segments according to claim 1, characterized in that determining whether a viewable Digital broadcast receiver. The broadcasting station determination unit
A CN ratio measuring unit for measuring a carrier / noise ratio of a digital signal in the determination target band;
A first comparison / determination unit that determines whether the broadcast of the broadcast station is viewable by comparing the carrier / noise ratio measured by the CN ratio measurement unit with a predetermined threshold value. The digital broadcast receiver according to claim 1 or 2 . The broadcasting station determination unit
A terminal measurement unit that measures a terminal voltage of the digital signal in the determination target band;
A second comparison / determination unit that determines whether the broadcast of the broadcast station is viewable by comparing the terminal voltage measured by the terminal voltage measurement unit with a predetermined threshold value. The digital broadcast receiver according to claim 1 , wherein the digital broadcast receiver is a digital broadcast receiver.

Images