JP2019054428A - Catv head end device - Google Patents

Abstract

To allow for appropriate changeover of a television broadcast signal transmitted to the terminal side according to the signal quality of input signal, in a head end device capable of transmitting the television broadcast signal, diversity received base on multiple input signals, to the terminal side.SOLUTION: A CATV head end device includes a signal selection part for selecting one of input signals, inputted to multiple input terminals, as a transmission signal to the terminal side and outputting, a diversity reception part for receiving the television broadcast signal of a specific broadcast channel from multiple input signals, a signal generation part for generating the television broadcast signal of a specific broadcast channel from the broadcast data restored in the diversity reception part, and outputting as the transmission signal to the terminal side, and a control section for changing over the signal selection part so as to select an input signal containing a television broadcast signal capable of restoring the broadcast data normally on the terminal side, according to the evaluation results of signal quality from the diversity reception part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a CATV head-end device that takes in a received signal from a receiving antenna that receives a broadcast wave of terrestrial digital television broadcasting (so-called terrestrial digital broadcasting) and outputs a television broadcast signal included in the received signal to a transmission path of a CATV system. About.

  This type of headend device receives a received signal from a receiving antenna that receives broadcast radio waves. If the installation point of the receiving antenna is far away from the broadcasting station (for example, on a remote island), it is received by so-called fading. An electric field may be reduced or interference may occur, resulting in poor reception.

  Also, as a receiving device that can improve such reception failure, diversity reception that takes in received signals from a plurality of receiving antennas, extracts and synthesizes a TV broadcast signal of a specific broadcast channel from each received signal, and demodulates the broadcast data An apparatus is known (for example, Patent Documents 1 to 3).

JP 2013-191992 A JP 2009-278504 A JP 2008-42855 A

  According to the diversity receiver, each OFDM signal is weighted and synthesized according to the signal quality of the television broadcast signal (specifically, OFDM signal) obtained from each receiving antenna, thereby improving the signal quality of the television broadcast signal. Thus, the broadcast data can be demodulated well.

  For this reason, if a diversity receiving device is provided in the CATV headend device and a television broadcast signal to be transmitted to the terminal side is generated from the broadcast data demodulated by the diversity receiving device, the terminal side has a desired quality. Broadcast TV broadcast signals.

  By the way, when the television broadcast signal is generated from the broadcast data demodulated by the diversity receiver, the generated television broadcast signal includes program information included in the television broadcast signal received by the receiving antenna. It is difficult to add additional information.

  This is because, in order to be able to add additional information such as program information to a television broadcast signal generated by the receiving device, the circuit configuration becomes extremely complicated for data processing, resulting in an increase in cost. It is.

  For this reason, if a diversity receiver is provided in the headend device to generate a television broadcast signal for transmission from the demodulated broadcast data, even if there is no reception failure at the receiving antenna, the terminal side Thus, additional information such as program information cannot be received.

  One aspect of the present disclosure is that in a head-end device capable of transmitting to a terminal side a television broadcast signal that is diversity-received based on a plurality of reception signals, the television broadcast signal to be transmitted to the terminal side according to the signal quality of the reception signal is appropriately The purpose is to enable switching.

  As described in claim 1, a CATV headend device according to one aspect of the present disclosure includes a plurality of input terminals for receiving received signals from a plurality of receiving antennas that receive broadcast waves of digital terrestrial television broadcasting. ing. Then, one of the plurality of reception signals input to the plurality of input terminals is selected and output as a transmission signal to the terminal side by the signal selection unit.

In addition, the CATV headend device of the present disclosure includes a diversity reception unit, a signal generation unit, and a control unit.
Here, the diversity receiving unit extracts a television broadcast signal (in other words, an OFDM signal) of a specific broadcast channel from a plurality of received signals input to a plurality of input terminals, and signals of the extracted plurality of television broadcast signals. Evaluate each quality. Then, according to the evaluation result, the plurality of extracted television broadcast signals are combined to restore the broadcast data.

  Note that the above-described conventional diversity receiver can be used for the diversity receiver. In addition, a CN ratio (carrier-to-noise ratio), BER (Bit Error Rate), MER (Modulation Error Rate), and the like can be used for signal quality evaluation in the diversity receiver.

  Next, the signal generator generates a television broadcast signal of a predetermined broadcast channel from the broadcast data restored by the diversity receiver, and outputs the generated television broadcast signal as a transmission signal to the terminal side.

  In addition, the control unit selects a reception signal including a television broadcast signal that can normally restore the broadcast data on the terminal side from the plurality of reception signals according to the signal quality evaluation result in the diversity reception unit. , Switch the signal selector.

  From the CATV headend device configured as described above, a television broadcast signal of a predetermined broadcast channel generated by the signal generation unit and a reception signal from the reception antenna selected by the signal selection unit are output.

  Therefore, if there is no problem in the signal quality of the television broadcast signal of the specific broadcast channel included in the reception signal selected by the signal selection unit, the user of the receiving device on the terminal side selects the television broadcast signal. By demodulating, it is possible to enjoy all broadcast services implemented on the specific broadcast channel.

  On the other hand, when reception failure occurs due to quality degradation in all receiving antennas, the receiving device on the terminal side can normally demodulate the TV broadcast signal of the specific broadcast channel from the received signal selected by the signal selection unit. become unable.

  However, since the TV broadcast signal generated by the signal generation unit is output from the CATV headend device of the present disclosure, the user of the receiving device on the terminal side selects and demodulates the TV broadcast signal. As a result, it becomes possible to view a television broadcast (audio and video) of a specific broadcast channel.

  By the way, in terrestrial digital broadcasting, one channel broadcast frequency band is divided into 13 segments, one segment is used for one segment broadcasting (one segment broadcasting), and the remaining segments are used for full segment broadcasting (full segment broadcasting). ).

  Then, as described in claim 2, the diversity receiving unit can restore both full-segment broadcast data and one-segment broadcast data from a television broadcast signal obtained by combining a plurality of received signals. In this case, the signal generation unit may be provided with a modulation unit that generates a television broadcast signal for full-segment broadcasting using one of these two types of broadcast data having different systems.

In this way, for example, as shown in a) and b) below, it is possible to switch broadcast data used to generate a television broadcast signal in the modulation unit.
a) When the evaluation result of the signal quality at the diversity receiving unit is high and the broadcast data of the full segment broadcasting can be restored normally at the diversity receiving unit, the television broadcasting signal is generated using the broadcasting data of the full segment broadcasting. .

  b) When the evaluation result of the signal quality at the diversity receiver is low and the reliability of the broadcast data of the full segment broadcast restored by the diversity receiver is low, the full segment broadcast is performed using the broadcast data of the one segment broadcast. TV broadcast signal is generated.

By this switching, it is possible to prevent the terminal from being unable to view the television broadcast when the broadcast radio wave reception environment deteriorates.
In addition, as shown in the above b), when a television broadcast signal for full-segment broadcasting is generated using broadcast data of one-segment broadcasting, the image quality deteriorates, but it becomes possible to view the television broadcasting on the terminal side, It is possible to reduce the frequency (time rate) at which viewing is not possible on the side.

  Also, when generating a television broadcast signal for full-segment broadcasting as in a) and b) above, the video / audio signal (analog signal) is restored from the broadcast data of full-segment broadcasting and the broadcasting data of one-segment broadcasting, respectively. A television broadcast signal for full-segment broadcasting may be generated from the video / audio signal thus obtained.

  In this way, it becomes possible to switch the television broadcast signal output to the terminal side in a short time, and it is possible to reduce the possibility that the television broadcast cannot be normally received on the terminal side due to the switching. .

Further, the signal output from the modulation unit is re-modulated to reset the high frequency noise up to the diversity reception unit, so that it is possible to transmit a high-quality signal.
Next, as described in claim 3, the signal generation unit, as the modulation unit, serves as one-segment broadcasting data (or video / audio signals obtained from the broadcasting data) and full-segment broadcasting data (or this broadcasting). Video and audio signals obtained from the data), two modulation units that generate television broadcast signals using each of them, and one of the two types of television broadcast signals generated by these two modulation units And an output selection unit for outputting.

  In this way, the signal generation unit always uses the two modulation units to generate two types of television broadcast signals with different methods using the same program. By switching the output selection unit, the terminal side The TV broadcast signal to be output to can be switched.

  Further, in this case, the control unit selects the television broadcast signal generated from the broadcast data of the full-segment broadcasting when the signal quality is high according to the evaluation result of the signal quality in the diversity receiving unit, and the signal quality is low. In this case, the output selection unit is switched so as to select a television broadcast signal generated from the broadcast data of the one-segment broadcasting.

  In this way, as a television broadcast signal output from the signal generation unit to the terminal side, a television broadcast signal that can be restored to the broadcast data by the receiving device on the terminal side so that the television broadcast can be viewed is transmitted by the control unit. You can select automatically.

  Also, when switching the TV broadcast signal output to the terminal side, two types of TV broadcast signals with different schemes are always generated in the same program, so that the TV broadcast signal output to the terminal side by the switching is generated. Is not temporarily blocked, and it is possible to suppress giving a sense of discomfort to the viewer on the terminal side.

It is a block diagram showing the structure of the CATV headend apparatus of embodiment. It is a flowchart showing operation | movement of the control part of embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
The headend device of this embodiment is used for capturing a terrestrial digital television broadcast reception signal and transmitting the television broadcast signal included in the reception signal to a transmission line on the terminal side in a CATV system or a television joint reception facility. Is.

  As shown in FIG. 1, the headend device 10 of the present embodiment captures received signals from a plurality (four in this embodiment) of receiving antennas 1, 2, 3, and 4 for receiving terrestrial digital television broadcasts. A plurality of input terminals T1, T2, T3, and T4.

  The reception signal input to the input terminals T1 to T4 may be an OFDM signal that is a terrestrial digital broadcast wave signal, and is generally a reception signal from a reception antenna, but is transmitted from another reception facility. It may be a signal that has been generated.

  The plurality of receiving antennas 1 to 4 may be installed at different positions. For example, one of the receiving antennas 1 to 4 is installed in the vicinity of the head end device 10 to transmit a received signal to a coaxial cable. It may be configured to input directly to the input terminal of the headend device 10 via

  In addition, one of the reception antennas 1 to 4 is installed at a location distant from the head end device 10, and a received signal is amplified by an amplifier to be transmitted to the head end device 10 through a coaxial cable and input. You may be comprised so that it may input into a terminal.

  In addition, one of the receiving antennas 1 to 4 is installed at a location distant from the head end device 10 and converts the received signal into an optical signal, which is transmitted to the head end device 10 through an optical cable. The optical signal may be converted into the original received signal (electric signal) and input to the input terminal.

  In the head end device 10, the received signals input to the input terminals T1 to T4 are divided into two by the distributors 11, 12, 13, and 14, respectively, and one of the distributed received signals is used as a signal selection unit. Input to the first RF switch 20.

  The first RF switch 20 is used to select one of the reception signals input from the distributors 11 to 14 as a transmission signal to the terminal side and output the signal from the output terminal To1 to the terminal side. The output from the first RF switch 20 is switched by the control unit 40. The operation of the control unit 40 will be described later.

Next, the other received signal distributed by distributors 11 to 14 is input to diversity receiver 30.
The diversity receiver 30 is the above-described diversity receiver, and a plurality of (this embodiment) each select a television broadcast signal (ODFM signal) of a specific broadcast channel from the received signals input from the distributors 11 to 14. Then, four) channel selection units (not shown) are provided.

  The channel selection unit, for example, converts the TV broadcast signal of a specific broadcast channel included in the received signal into a baseband TV broadcast signal, thereby converting the TV broadcast signal of a specific broadcast channel set in advance to receive diversity. Extract TV broadcast signals.

  Further, the diversity receiving unit 30 combines the signal quality of the television broadcast signal (specifically, the data carrier after OFDM demodulation) extracted (tuned) by each channel selection unit and each television broadcast signal. An evaluation unit 32 for evaluating the signal quality of the obtained data carrier is provided.

  The data carrier obtained by synthesizing the respective TV broadcast signals is broadcast data before error correction in the diversity receiving unit 30, and the evaluation unit 32 uses the data carrier after the synthesis. Evaluate the signal quality of broadcast data.

  In addition, in the evaluation of the signal quality in the evaluation unit 32, the CN ratio of the received signal, the BER obtained by demodulating the received signal, MER, etc. can be used. In this embodiment, the signal quality is evaluated from the CN ratio. It shall be.

  And the diversity receiver 30 sets a weighting coefficient according to the signal quality (CN ratio), for example, based on the evaluation result of the evaluation unit 32, and according to the weight of the television broadcast signal selected by each channel selection unit, Carrier synthesis.

  In addition, the diversity receiver 30 includes an OFDM demodulator that restores full-segment broadcast data from weighted and synthesized television broadcast signals (OFDM signals) and a one-segment demodulator that demodulates one-segment broadcasts.

The one-seg demodulation unit restores the broadcast data of the one-segment broadcast from the weighted and synthesized television broadcast signal, and demodulates the video signal and the audio signal from the restored broadcast data.
Then, the broadcast data restored by the OFDM demodulator of the diversity receiver 30 and the video / audio signal demodulated by the one-segment demodulator are output to the first modulator 42 and the second modulator 44, respectively.

  Note that, as described above, the diversity receiving apparatus that selects and broadcasts a television broadcast signal (OFDM signal) of a specific broadcast channel from a plurality of received signals as described in Patent Documents 1 to 3 and the like described above. The detailed description is omitted here.

  However, the diversity receiver is generally configured to demodulate full-seg broadcasting if the input signal is above a certain quality, otherwise demodulate one-seg broadcasting and output either one of the demodulated information. Is done.

  On the other hand, the diversity receiver 30 of the present embodiment demodulates the full-segment broadcast and the one-segment broadcast by the OFDM demodulator and the one-segment demodulator, respectively, and first modulates the broadcast data and the video / audio signal as the demodulation results. Output to the unit 42 and the second modulation unit 44.

  This is because if the demodulating operation is switched according to the quality of the input signal, both the broadcast data and the video / audio signal are not output from the diversity receiver 30 for the time required for the switching. That is, in the present embodiment, at least one of broadcast data and video / audio signals is necessarily output from the diversity receiver 30 to the first modulator 42 and the second modulator 44.

  Next, the first modulation unit 42 performs OFDM modulation on the broadcast data restored by the OFDM demodulation unit of the diversity reception unit 30 to generate a baseband television broadcast signal, which is converted into a television broadcast signal of a predetermined broadcast channel. The transmission signal to the terminal side is generated by frequency conversion to.

  Further, the second modulation unit 44 generates broadcast data for full segment broadcasting from the video / audio signal demodulated by the one-segment demodulation unit of the diversity receiving unit 30 and performs OFDM modulation, thereby converting the baseband television broadcast signal. Generate.

  Also in the second modulation unit 44, similarly to the first modulation unit 42, the generated television broadcast signal is frequency-converted into a television broadcast signal of a predetermined broadcast channel, thereby generating a transmission signal to the terminal side.

  The reason why the second modulation unit 44 generates a full-segment broadcast television broadcast signal from the one-segment broadcast video / audio signal is to allow the terminal-side receiving device to restore the broadcast data.

The television broadcast signal of the predetermined broadcast channel generated by the first modulation unit 42 and the second modulation unit 44 is input to the second RF switch 50 serving as an output selection unit.
The second RF switch 50 selects one of the television broadcast signals input from the first modulation unit 42 and the second modulation unit 44 as a transmission signal to the terminal side, and outputs it from the output terminal To2 to the terminal side. As with the first RF switch 20, the control unit 40 performs switching.

  For this reason, the broadcast channel of the television broadcast signal generated as a transmission signal to the terminal side by the first modulation unit 42 and the second modulation unit 44 is set to a broadcast channel different from the original specific broadcast channel.

  That is, in the present embodiment, the television broadcast signals output via the first RF switch 20 and the second RF switch 50 are respectively output from the output terminals To1 and To2 onto the transmission path on the terminal side. The frequency of the broadcast signal is not duplicated.

  Next, the control unit 40 is configured by a logical operation circuit composed of a microcomputer or the like, and based on the signal quality evaluation result by the evaluation unit 32 in the diversity receiving unit 30, the first RF switch 20 and the second RF switch 50. The transmission signal to the terminal side selected at is switched.

Hereinafter, the operation of the control unit 40 will be described with reference to the flowchart shown in FIG.
As shown in FIG. 2, in the control unit 40, the television of the specific broadcast channel input to each input terminal T <b> 1 to T <b> 4 from the evaluation unit 32 in the diversity receiving unit 30 in S <b> 110 (S represents a step). The CN ratio that is the evaluation result of the signal quality of the broadcast signal is read.

  In the next S120, it is determined whether or not the CN ratio of the television broadcast signal currently output to the terminal side via the first RF switch 20 among the read CN ratio is equal to or greater than a threshold value.

This threshold value is a determination value for determining whether or not the CN ratio of the television broadcast signal is low and adversely affects the received video on the terminal side.
If it is determined in S120 that the CN ratio is equal to or greater than the threshold value, there is no problem with the output from the first RF switch 20, so the process proceeds to S130, and the first RF switch 20 is held at the current switching position. The process proceeds to S150.

  On the other hand, if it is determined in S120 that the CN ratio is less than the threshold value, the process proceeds to S125, and after it is determined in S120 that the CN ratio is less than the threshold value, it is equal to or longer than a preset set time. Determine whether it has elapsed. If the set time has elapsed, the process proceeds to S140, and if not, the process proceeds to S150.

  In S140, the first RF switch 20 is switched so that the TV broadcast signal having the highest CN ratio (in other words, signal quality) is selected from the CN ratio read in S110, and the process proceeds to S150.

  That is, if it is determined in S120 that the CN ratio is less than the threshold value, the received signal currently output to the terminal side via the first RF switch 20 is the TV broadcast signal of the specific broadcast channel on the terminal side. The video may not be restored properly.

  Therefore, in S140, by switching the first RF switch 20, the television broadcast signal having the highest CN ratio is selected as the reception signal output to the terminal side via the first RF switch 20.

  Note that in S125, it is determined whether or not the set time has elapsed or not because the first RF switch 20 is frequently switched due to a change in the CN ratio, and accordingly, the terminal cannot receive the television broadcast normally. This is to alleviate.

Next, in S150, the CN ratio of the broadcast signal received by the diversity receiving unit 30 is read from the evaluation unit 32 in the diversity receiving unit 30.
In subsequent S160, it is determined whether or not the CN ratio read in S150 is equal to or greater than a threshold value.

  This threshold value is a determination value for determining whether or not the broadcast data generated by the diversity receiver 30 is of a quality that can normally restore a full-segment video image of a television broadcast. Originally, the determination is made by BER, but the evaluation of the generated broadcast data is made by replacing BER with the CN ratio.

  If it is determined in S160 that the signal quality (CN ratio) of the broadcast data generated by the diversity receiver 30 is equal to or higher than the threshold value, the process proceeds to S170 and the second RF switch 50 is switched to the first modulator. The output of 42 is switched to the selection side, and the process proceeds to S110.

  As a result, the second RF switch 50 outputs a television broadcast signal generated based on the broadcast data of the specific broadcast channel that is diversity-received by the diversity receiver 30.

On the other hand, if it is determined in S160 that the signal quality (CN ratio) of the broadcast data generated by the diversity receiver 30 is less than the threshold value, the process proceeds to S165.
In S165, since it is determined in S160 that the signal quality (CN ratio) is less than the threshold value, it is determined whether or not a preset set time has elapsed, and the set time or more has elapsed. If so, the process proceeds to S180, and if not, the process proceeds to S110.

  In S180, since it is determined that the signal quality (CN ratio) of the broadcast data generated by the diversity receiver 30 is poor by the determination process, the second RF switch 50 selects the output of the second modulator 44. And the process proceeds to S110.

As a result, the second RF switch 50 outputs a television broadcast signal generated based on the one-segment broadcast video / audio demodulated by the diversity receiver 30.
Note that in S165, it is determined whether or not the set time has elapsed or not because the second RF switch 20 is frequently switched due to a change in the signal quality of the broadcast data generated by the diversity receiver 30, and the terminal is associated with the switching. This is to reduce the possibility that the TV broadcast cannot be received normally on the side.

  As described above, in the CATV headend device 10 of the present embodiment, when the reception environment of the reception antennas 1 to 4 is not particularly deteriorated, the signal quality of the television broadcast signal of the specific broadcast channel included in each reception signal. (CN ratio) is all equal to or greater than the threshold value. Therefore, under this condition, the reception signal selected at that time is output from the first RF switch 20 to the terminal side from the output terminal To1.

  Next, when the reception environment of the reception antenna from which the first RF switch 20 selects the reception signal deteriorates and the signal quality of the television broadcast signal included in the reception signal becomes less than the threshold value, reception with the highest signal quality is performed. The first RF switch 20 is switched to select the signal.

  Therefore, on the terminal side, the television broadcast signal of the specific broadcast channel can be normally received by the selective switching of the first RF switch 20. Also, since the received signal transmitted to the terminal side by this switching is a received signal from a receiving antenna whose reception environment has not deteriorated, all data including additional information such as program information can be restored on the terminal side. .

  On the other hand, when the reception environment of all the reception antennas 1 to 4 is deteriorated, the reception signal selected by the first RF switch 20 and output to the terminal side cannot normally demodulate the television broadcast signal of the specific broadcast channel.

  However, the CATV headend device 10 of this embodiment is provided with the diversity receiver 30, the first modulator 42, the second modulator 44, and the second RF switch. Then, on the terminal side, a television broadcast signal generated based on the broadcast data of the specific broadcast channel diversity-received by the diversity receiver 30 is output from the output terminal To2.

Therefore, on the terminal side, by selecting and demodulating this television broadcast signal, it becomes possible to reproduce and view the television broadcast video and audio of the specific broadcast channel.
This is because the diversity receiver 30 can improve the limit value of the CN ratio of a television broadcast signal that can be normally received when receiving a full-segment broadcast of terrestrial digital broadcasting with a general receiver.

  Further, when the diversity receiving unit 30 receives the one-segment broadcasting, the limit value can be further improved by several (dB). In 1Seg broadcasting, the image quality of the received video is lower than in Full Seg Broadcasting. However, if a TV broadcast signal is generated using this received video and audio, even if the terminal does not have a 1Seg reception function, Digital video and audio can be played back.

  Therefore, in the present embodiment, the diversity receiving unit 30 demodulates the broadcast data and the one-segment broadcast video / audio signal from the diversity-received television broadcast signal.

  The demodulated broadcast data and video / audio signals are input to the first modulation unit 42 and the second modulation unit 44, respectively. The modulation units 42 and 44 are based on these signals and are used for full-segment broadcast television. Generate a broadcast signal.

  The two types of generated television broadcast signals are input to the second RF switch 50. In the second RF switch 50, under the control of the control unit 40, when the signal quality of the original television broadcast signal is high, the television broadcast signal generated from the broadcast data is selected, and the signal quality of the original television broadcast signal is low. Sometimes, a television broadcast signal generated from the video / audio signal is selected. Then, the television broadcast signal selected by the second RF switch 50 is output to the terminal side via the output terminal To2.

  Therefore, on the terminal side, when the reception environment is deteriorated, not only can the video / audio of the specific broadcast channel be reproduced using the TV broadcast signal output from the second RF switch 50, but also the specific broadcast channel is deteriorated due to the deterioration of the reception environment. Can be suppressed more effectively.

  In particular, in the present embodiment, the first modulation unit 42 and the second modulation unit 44 always generate a television broadcast signal from the broadcast data and the video / audio signal, and the first modulation unit 42 generates the television broadcast signal. This TV broadcast signal is output to the terminal side when the quality of the video signal exceeds the threshold value.

  Then, when the quality of the television broadcast signal generated by the first modulation unit 42 is deteriorated and the state has elapsed for a set time, the second RF switch 50 is switched and the television broadcast signal generated by the second modulation unit 44 is switched. Is output to the terminal side.

  For this reason, the TV broadcast signal capable of demodulating video and audio can be continuously transmitted to the terminal side, and the output of the TV broadcast signal is temporarily interrupted by the output switching at the second RF switch 50, It can suppress giving a sense of incongruity to the viewer on the terminal side.

Note that in the present embodiment, the first modulation unit 42, the second modulation unit 44, and the second RF switch 50 function as a signal generation unit of the present disclosure.
Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment, and can be implemented with various modifications.

  For example, in the above embodiment, it is assumed that the reception signal output from the first RF switch 20 and the television broadcast signal output from the second RF switch 50 are transmitted from the output terminals To1 and To2 onto the transmission line on the terminal side, respectively. explained.

  On the other hand, the CATV headend device 10 selects one of the reception signal output from the first RF switch 20 and the television broadcast signal output from the second RF switch 50 and sends it out on the transmission line on the terminal side. A switching unit may be provided.

  In this case, the control unit 40 may switch the output switching unit according to the evaluation result of the evaluation unit 32. That is, when the signal quality of the TV broadcast signal of the specific broadcast channel from each of the receiving antennas 1 to 4 is low quality that cannot restore normal received video, the output from the second RF switch 50 is selected, and so on. Otherwise, the output from the first RF switch 20 is selected.

  Further, in this case, the first modulation unit 42 and the second modulation unit 44 generate a television broadcast signal of the same broadcast channel as the original specific broadcast channel based on the broadcast data and the video / audio signal from the diversity receiving unit 30. You may comprise.

  In this way, on the terminal side, the first RF switch 20, the first modulation unit 42, and the second modulation unit 44 are set in a state where the broadcast channel of the television broadcast signal to be selected by the receiving device is set to the specific broadcast channel. Video and audio of a specific broadcast channel can be reproduced using a television broadcast signal output from one.

  In the above embodiment, the CATV headend device 10 has been described as having four input terminals T1 to T4 in order to perform diversity reception. May be set arbitrarily according to the configuration of the built-in diversity receiver 30.

  In addition, a plurality of functions of one constituent element in the above embodiment may be realized by a plurality of constituent elements, or a single function of one constituent element may be realized by a plurality of constituent elements. Further, a plurality of functions possessed by a plurality of constituent elements may be realized by one constituent element, or one function realized by a plurality of constituent elements may be realized by one constituent element. Moreover, you may abbreviate | omit a part of structure of the said embodiment. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified only by the wording described in the claims are embodiments of the present disclosure.

  1, 2, 3, 4 ... receiving antenna, 10 ... head end device, 11, 12, 13, 14 ... distributor, 20 ... first RF switch, 30 ... diversity receiver, 32 ... evaluation unit, 40 ... control unit, 42 ... 1st modulation part, 44 ... 2nd modulation part, 50 ... 2nd RF switch, To1, To2 ... Output terminal.

Claims (3)

A plurality of input terminals for receiving received signals from a plurality of receiving antennas for receiving broadcast waves of digital terrestrial television broadcasting;
A signal selection unit that selects and outputs one of the plurality of reception signals input to the plurality of input terminals as a transmission signal to the terminal side;
A television broadcast signal of a specific broadcast channel is extracted from a plurality of received signals input to the plurality of input terminals, respectively, and the signal quality of the extracted plurality of television broadcast signals is evaluated. In response, a diversity receiving unit that combines the plurality of extracted television broadcast signals to restore broadcast data;
A signal generation unit that generates a television broadcast signal of a predetermined broadcast channel from the broadcast data restored by the diversity receiver, and outputs the generated television broadcast signal as a transmission signal to the terminal side;
The signal is selected so as to select a received signal including a television broadcast signal that can normally restore broadcast data on the terminal side from the plurality of received signals according to the evaluation result of the signal quality in the diversity receiving unit. A control unit for switching the selection unit;
CATV head-end device comprising: The diversity receiving unit is configured to be able to restore full segment broadcast data and one segment broadcast data from the combined television broadcast signal,
The signal generation unit includes a modulation unit that generates a full-segment broadcast television broadcast signal using either full-segment broadcast data or one-segment broadcast data restored by the diversity receiver. The CATV headend device according to claim 1, comprising: The signal generator is
Two modulation units for generating the full-segment broadcast television broadcast signal using the full-segment broadcast data and the one-segment broadcast data restored by the diversity receiver,
An output selection unit that selects and outputs one of the two types of television broadcast signals generated by the two modulation units;
The control unit selects a television broadcast signal generated from the broadcast data of the full segment broadcast when the signal quality is high according to the evaluation result of the signal quality in the diversity reception unit. 3. The CATV head according to claim 2, wherein when the signal quality is low, the output selection unit is switched to select a television broadcast signal generated from the broadcast data of the one segment broadcast. End equipment.

Images