JPH07336656A - Television multiplex broadcasting system - Google Patents

Abstract

PURPOSE:To make multiplex broadcasting of two channels possible by utilizing the sub-carrier in which a center frequency is a specified value and making the frequency shift of a main carrier within a specified range. CONSTITUTION:A first sub-carrier of 4.5fH which is multiplexed on a sound signal is selected by a first band filter 14 and the sub-carrier is delivered to a first multiplex data demodulation part 18. Multiplex data is demodulated from the delivered first sub-carrier in the first multiplex data demodulation part 18. The demodulated multiplex data is displayed on a multiplex data display device 20. A second sub-carrier of 7.5fH which is multiplexed on the sound signal is selected by a second band filter 17 and the sub-carrier is delivered to a second multiplex data demodulation part 19. Multiplex data is demodulated from the delivered second sub-carrier in the second multiplex data demodulation part 19. The demodulated multiplex data is displayed on a multiplex data display device 21. The multiplex of data is performed by a multiplex digital modulation of a four-phase PSK, etc. The frequency shift of a main carrier wave is + or -2kHz.

Description

Detailed Description of the Invention

[0001]

[Industrial field of use] In television broadcasting, in addition to multiplex voice broadcasting and character multiplex broadcasting which have been previously multiplexed with television broadcasting, multiplex broadcasting system for broadcasting data such as character images and facsimile data Pertain to.

[0002]

2. Description of the Related Art In today's information age, attention has been paid to a data broadcast for broadcasting digital data as well as a conventionally broadcast voice or image or a facsimile broadcast for broadcasting image data.
Although it is considered that these broadcasts are performed by using a dedicated medium such as using a broadcasting satellite, multiple broadcasts that use the radio waves of existing audio broadcasts or television broadcasts are a radio resource. Technology development is being actively promoted from the viewpoint of effective utilization.

[0003] Multiplex broadcasting using broadcast waves includes stereo broadcasting, audio multiplex broadcasting, character multiplex broadcasting, facsimile broadcasting and data broadcasting. Among these multiplex broadcasts, stereo broadcasts using FM broadcast waves and television broadcast waves have been put to practical use in Japan, and voice multiplex broadcasts and character multiplex broadcasts have made use of television broadcast waves. ing. Further, as for facsimile broadcasting, one using FM broadcasting radio waves is about to be put into practical use in the United States, and one using television broadcasting radio waves is being considered in Japan. Data broadcasting using FM broadcasting waves is about to be carried out in Japan, and data broadcasting using television broadcasting waves is a subject for future study.

The multiplex broadcasting, particularly the multiplex broadcasting using the television broadcast radio wave will be described by taking the radio waves of the NTSC system color television broadcast adopted in Japan and the United States as an example. As shown in FIG. 1, the radio wave of the NTSC color television broadcast has an image carrier having a bandwidth of 5.5 MHz above the center frequency of the image carrier of 4.25 MHz and a total of 5.5 MHz above and above this carrier. ± 0.25 with center frequency at 4.5MHz
It is composed of a voice carrier having a bandwidth of 0.5 MHz in total, and the total bandwidth is 6 MHz.

Among the above-mentioned multiple broadcasts, the character multiplex broadcast using the radio wave of the television broadcast transmits the data multiplexed by utilizing the blanking period in the television video signal included in the video carrier. Other FM stereo broadcasts, FM data broadcasts, FM facsimile broadcasts, television stereo broadcasts, television audio multiplex broadcasts and television facsimile broadcasts broadcast programs by subcarriers in the audio band. The multiplex broadcasting using this subcarrier will be described with respect to the television sound multiplex broadcasting and the television facsimile broadcasting based on the report of the facsimile broadcasting committee of the Telecommunications Technology Council (February 16, 1991).

FIG. 2 shows a modulation spectrum of the television multiplex broadcasting facsimile system in the NTSC system. In this figure, the horizontal axis is the horizontal scanning frequency fH = 525 lines × 59.94 Hz / 2 = 15.7342
It is a voice carrier in units of 5 KHz, and the vertical axis is KHz.
Is the amount of shift with respect to the main carrier. In this multiplex broadcast modulation spectrum, the center frequency of the main audio carrier is 0fH, and the center frequency of the audio subcarrier for stereo and dual audio sub-audio is 2fH. In addition,
In this case, the shift amount of stereo sound is 20 KHz and the shift amount of double sound is 15 KHz. Further, the center frequency of the sub-carrier for the control signal for controlling the sub-audio is set to 3.5 fH.

For this analog facsimile,
The center frequency of the sub-carrier for the digital facsimile is set at 4.5 fH from the viewpoint of interference with the audio multiplex broadcasting,
The frequency band used is 1 fH from 4 fH to 5 fH, the frequency deviation of the main carrier is ± 2 KHz, and the modulation method is 4-phase PSK (Phase Shift Keying).

FIG. 3 is a block diagram of a conventional television receiver which receives a multiplex facsimile data signal in addition to a stereo audio, a dual audio and a character multiplex data signal together with an image. This television receiver comprises a tuner section, an image processing section, and a voice / multiplex facsimile data processing section.

The tuner section is composed of a tuner 2 connected to an antenna 1. The image processing unit includes a video detection unit 3 connected to the tuner 2, a signal separation unit 4 connected to the video detection unit 3, a video amplification unit 5 and a character multiplex data demodulation unit 7 connected to the signal separation unit 4, and a video image. It is composed of an image display device 6 such as a cathode ray tube which is switchably connected to the amplifier 5 or the character multiplex data demodulator 7.

The audio processing section includes an audio detection section 8 connected to the tuner 2, an audio main / sub separation section 9 connected to the audio detection section 8, and an auxiliary audio demodulation section 10 connected to the audio main / sub separation section 9.
A stereo matrix circuit 11 connected to the audio main / sub separation unit 9 and the sub audio demodulation unit 10, a dual audio circuit 12 connected to the sub audio demodulation unit 10, a stereo matrix circuit 11 and a dual audio amplification unit 12. And a speaker 13. The voice detection unit 8 is further connected with a first bandpass filter 14 for passing a first subcarrier having a center frequency of 4.5 fH, and the first bandpass filter 14 is connected with a multiplex facsimile data demodulation unit 15 for transmitting multiplex facsimile data. A multiplex facsimile data printer 16 is connected to the demodulation unit 15.

With respect to the television signal received by the antenna 1, a tuner 2 tunes and selects a video signal and an audio signal. The selected video signal is detected by the video detection unit 3,
Further, the signal separation unit 4 separates the synchronization signal and the image signal,
The image signal is displayed on the image display device 6 through the image amplification section 5. The character multiplex data multiplexed with the sync signal is extracted from the separated sync signal, demodulated by the character multiplex data demodulator 7, further converted into a video signal, and displayed on the image display device 6.

On the other hand, the voice signal is detected by the voice detection unit 8, separated into a main voice signal and a sub voice signal by the voice main / sub separation unit 9, and when the sub voice is a stereo voice, the sub voice demodulation unit 10 is provided. If the stereo matrix circuit 11 extracts stereo sound from the demodulated sub-audio signal and the main audio signal, and if the demodulated sub-audio is dual audio, the sub-audio signal demodulated by the sub-audio demodulation unit 10 is 2 Heavy voice circuit 12
The audio signals are extracted through the speaker 13 and converted into audio by the speaker 13.

The voice detection section 8 has a first frequency of 4.5 fH.
A first band-pass filter 14 for passing subcarriers is connected, a multiplex facsimile data demodulator 15 is connected to the first bandpass filter 14, and a multiplex facsimile data printer 16 is connected to the multiplex facsimile data demodulator 15. First of 4.5 fH multiplexed with audio signal
The subcarrier is pass-selected by the first bandpass filter 14,
The first subcarrier that has been pass-selected by the band-pass filter 14 is sent to the multiplex facsimile data demodulation unit 15, and the multiplex facsimile data is demodulated from the first subcarrier sent by the multiplex facsimile data demodulation unit 15 and demodulated multiplex. Facsimile data is a multiplex facsimile printer 16
Printed with

By the way, as described above, the data broadcasting using the FM broadcasting radio wave is about to be carried out, and the one using the television broadcasting radio wave is a subject for future study. In the case of multiplex facsimile broadcasting using television waves, which is planned to be implemented, the center frequency of the subcarrier is 4.5 fH, and the frequency band used is 4
1 fH from fH to 5 fH, frequency deviation of main carrier is ± 2 KHz, modulation method is 4-phase PSK (Phase Shift Keyi)
ng = phase shift keying) is to be adopted. In addition to this, it has been considered to set the center frequency of the subcarrier to 7.5 fH. In this case, it was considered that the interference to the audio multiplex broadcasting was small, but the interference to the video signal occurred.

Therefore, in addition to the stereo broadcast and the audio multiplex broadcast which have been carried out up to now as the multiplex broadcast utilizing the sub-audio of the television, the maximum number of the multiple broadcast programs that can be multiplexed is one program and two channels are provided. It was not possible to multiplex the facsimile broadcast, the 2-channel data broadcast, or the 1-channel facsimile broadcast and the data broadcast.

As shown in FIG. 2, there is an analog facsimile system in which the center frequency of the subcarrier is set to 6fH and the frequency band is set to 4fH to 8fH. However, this analog system facsimile interferes with voice multiplex broadcasting. Therefore, the facsimile signal cannot be multiplexed during the audio multiplex broadcasting period. Therefore, from 4fH to 5
It has been considered to achieve both voice multiplexing and analog facsimile by deleting the frequency band up to fH, but it has not been realized so far.

[0017]

SUMMARY OF THE INVENTION The present inventor has conducted various experiments on multiplex broadcasting using sub-audio of a television, and as a result, even when a sub-carrier with a center frequency of 7.5 fH is used, this sub-carrier has a frequency deviation of the main carrier. Transfer was ± 2 to 3 KHz 4
It was confirmed that when multi-level digital modulation such as the phase PSK method was performed, no interference occurred in the video signal. In the present application, based on the knowledge obtained from this experiment, a facsimile or a data digital signal of 7.5 is used.
We propose a multi-broadcast system which is configured to perform multi-level digital modulation such as 4-phase PSK system on the fH subcarrier.

In this case, it is possible to perform two-channel multiplex broadcasting by simultaneously performing multiplex broadcasting using a subcarrier of 4.5 fH. In addition to the 2-channel data broadcast or 2-channel facsimile broadcast, each 1-channel broadcast of the 2-channel multiplex broadcast
Data broadcasting and facsimile broadcasting of channels can be performed.

[0019]

Embodiments of the present invention will be described with reference to the drawings. FIG. 4 shows a modulation spectrum in the broadcasting system of the embodiment of the present invention in which the multiplexed data of two channels is broadcast using the television broadcast radio wave. In this figure, the horizontal axis is the horizontal scanning frequency fH = 525 lines × 59.94
Hz / 2 = 15.773425 KHz is a voice carrier, and the vertical axis is the amount of deviation from the main carrier in KHz. In this multiplex broadcast modulation spectrum, the center frequency of the main audio carrier is 0fH, and the center frequency of the audio subcarrier for stereo and dual audio sub-audio is 2fH. In this case, the shift amount of stereo sound is set to 20 KHz and the shift amount of double sound is set to 15 KHz. Further, the center frequency of the sub-carrier for the control signal for controlling the sub-audio is set to 3.5 fH.

Modulation of the multiplexed data is performed by digital modulation, the center frequency of the first digitally modulated subcarrier is set to 4.5 fH, and the center frequency of the second digitally modulated subcarrier is 7. It is placed at .5fH. The frequency band used for each signal is 1fH from 4fH to 5fH and 1fH from 7fH to 8fH, data multiplexing is performed by multi-level digital modulation such as 4-phase PSK, and the frequency deviation of the main carrier is ± 2KHz. is there.

FIG. 5 shows that in addition to the stereo sound, the double sound and the character multiplex data together with the image, the first sub-carrier having the center frequency of 4.5 fH and the center frequency of 7.5 fH shown in FIG. It is a block configuration diagram of a television receiver used in a method of broadcasting multiplexed data of two channels using a second subcarrier. In this broadcasting system, the data to be multiplexed is such that the center frequency of the subcarrier in the multiplex broadcasting spectrum of the present invention shown in FIG. 4 is 4.5 fH and the used frequency band is 1 fH from 4 fH to 5 fH. The center frequency of the channel and subcarrier is 7.
The second channel, which is located at 5 fH and whose use frequency band is 1 fH from 7 fH to 8 fH, is multiplexed by the 4-phase PSK modulation method in which the frequency deviation of the main carrier is ± 2 KHz.

This television receiver includes a tuner section,
It is composed of an image processing unit and a voice / multiplex signal processing unit. Among these components, the configuration and operation of the tuner unit and the image processing unit, and the configuration and operation for processing stereo audio and dual audio are the configuration and operation of the conventional television receiver shown in FIG. Since it is the same as, the description thereof will be omitted here.

The voice detector 8 further includes first band-pass filters 14 and 7.5f for passing a first subcarrier of 4.5fH.
A second bandpass filter 17 that passes the second subcarrier of H is connected, a first multiplex data demodulation unit 18 is connected to the first bandpass filter 14, and a second multiplex data demodulation unit 19 is connected to the second bandpass filter 17. , A multiplex data display unit 20 is connected to the first multiplex data demodulation unit 18, and a multiplex data display unit 21 is connected to the second multiplex data demodulation unit 19. In addition, the two multiple data display devices 20 and 2
1 multiplex data display device is used instead of 1, and this one multiplex data display device is switched and connected to the first multiplex data demodulation unit 20 and the second multiplex data demodulation unit 21 for switching display. Alternatively, they can be connected simultaneously and displayed at the same time. Also, instead of the multiple data display device 20 or 21, or together with the multiple data display device 20 or 21, a printer that prints multiple data may be used.

The first sub-carrier of 4.5 fH multiplexed in the voice signal is pass-selected by the first band filter 14, and the first sub-carrier pass-selected by the first band filter 14 is the first multiplex data demodulator. The multiplex data is demodulated from the first subcarrier sent to the first multiplex data demodulator 18 and is displayed on the multiplex data display device 20. Further, the second subcarrier of 7.5 fH multiplexed in the audio signal is pass-selected by the second bandpass filter 17, and the second subcarrier passed by the second bandpass filter 17 is selected by the second multiplexed data demodulation unit 19. Sent to the second
The multiplex data is demodulated from the second subcarrier transmitted in the multiplex data demodulator 19, and the demodulated multiplex data is displayed on the multiplex data display device 21.

FIG. 6 shows a case where a first subcarrier of 4.5 fH and a second subcarrier of 7.5 fH shown in FIG. 4 are used in addition to stereo sound, double sound and character multiplexed data together with an image. FIG. 3 is a block diagram of a television receiver for receiving two-channel multiplexed facsimile data. In this broadcasting system, the facsimile data to be multiplexed is such that the center frequency of the subcarrier in the multiplex broadcasting spectrum of the present invention shown in FIG. 4 is 4.5 fH and the used frequency band is 1 fH from 4 fH to 5 fH. The frequency deviation of the main carrier is ± 2 using the second channel in which the center frequency of one channel and the subcarrier is 7.5fH and the used frequency band is 1fH from 7fH to 8fH.
It is multiplexed by a 4-phase PSK modulation method of KHz.

This television receiver replaces the function of demodulating and displaying two-channel multiplexed data using the first subcarrier of 4.5fH and the second subcarrier of 7.5fH shown in FIG. A function of demodulating / displaying 2-channel multiplexed facsimile data by using a first subcarrier of 4.5 fH and a second subcarrier of 7.5 fH is added.

This television receiver has a tuner section,
It is composed of an image processing unit and a voice / multiplex signal processing unit. Among these components, the configuration and operation of the tuner unit and the image processing unit, and the configuration and operation for processing stereo audio and dual audio are the configuration and operation of the conventional television receiver shown in FIG. Since it is the same as, the description thereof will be omitted here.

The voice detection section 8 has a first frequency of 4.5 fH.
First bandpass filters 14 and 7.5 that pass subcarriers
Second bandpass filter 17 for passing the second subcarrier of fH
, A first multiplex facsimile data demodulation unit 22 is connected to the first bandpass filter 14, a second multiplex facsimile data demodulation unit 23 is connected to the second bandpass filter 17, and a first multiplex facsimile data demodulation unit 23 is connected. Is connected to a multiplex facsimile data printer 24, and the second multiplex data demodulator 23 is connected to a multiplex data display device 25. It should be noted that one multiplex facsimile data printer is used instead of the two multiplex facsimile data printers 24 and 25, and this one multiplex facsimile data printer is used as the first multiplex facsimile data demodulation unit 24 and the second multiplex facsimile data. It can also be switched and connected to the demodulation unit 25. In addition, the multiplex facsimile printer 24
Alternatively, instead of 25 or with a multiplex facsimile printer 24 or 25, a display device for displaying multiplex facsimile data may be used.

The first subcarrier of 4.5 fH multiplexed with the voice signal is pass-selected by the first bandpass filter 14, and the first subcarrier passed by the first bandpass filter 14 is demodulated by the first multiplex facsimile data. The first multiplex facsimile data demodulation unit 22
The multiplex facsimile data is demodulated from the subcarrier, and the demodulated multiplex facsimile data is printed by the multiplex facsimile data printer 24. The second subcarrier of 7.5 fH multiplexed in the voice signal is pass-selected by the second band filter 17, and the second sub-carrier pass-selected by the second band filter 17 is the second multiplex facsimile data demodulator. 25, and the second multiplex facsimile data demodulation unit 2
5, the multiplex facsimile data is demodulated from the second subcarrier, and the demodulated multiplex facsimile data is printed by the multiplex facsimile data printer 25.

FIG. 7 shows that stereophonic audio, dual audio and character multiplex data are used together with an image and a first subcarrier of 4.5 fH and a second subcarrier of 7.5 fH shown in FIG. 7 are used. FIG. 3 is a block diagram of a television receiver for receiving 1-channel multiplexed facsimile data and 1-channel multiplexed data. In this broadcasting system, the data to be multiplexed is such that the center frequency of the subcarrier in the multiple broadcasting spectrum of the present invention shown in FIG. 4 is 4.5 fH and the used frequency band is 1 fH from 4 fH to 5 fH.
The frequency deviation of the main carrier wave is multiplexed by the 4-phase PSK modulation method in which the frequency deviation of the main carrier is ± 2 KHz. Further, the center frequency of the subcarrier of the multiplexed facsimile data is 7.5fH and the used frequency band is 7f.
The second channel, which is set to 1 fH from H to 8 fH, is multiplexed by the 4-phase PSK modulation method in which the frequency deviation of the main carrier is ± 2 KHz.

This television receiver replaces the function of demodulating and displaying the multiplexed data of two channels by using the first subcarrier of 4.5fH and the second subcarrier of 7.5fH shown in FIG. Demodulate and print 1-channel multiplex facsimile data using the first subcarrier of 4.5 fH, and 7.
A function of demodulating / displaying the multiplexed data of one channel by using the second subcarrier of 5fH is added.

This television receiver comprises a TV tuner section, a TV image processing section, and a TV sound / multiplex signal processing section. Among these components, the configuration and operation of the TV tuner unit and the TV image processing unit, and the configuration and operation for processing TV stereo sound and TV double sound are the same as those of the conventional television receiver shown in FIG. Since the configuration and operation are the same, repetitive description will be omitted here.

The voice detection section 8 has a first frequency of 4.5 fH.
First bandpass filters 14 and 7.5 that pass subcarriers
Second bandpass filter 17 for passing the second subcarrier of fH
, A multiplex facsimile data demodulator 26 is connected to the first bandpass filter 14, and a second bandpass filter 17 is connected.
Is connected to a multiplex data demodulator 27, the multiplex facsimile data demodulator 27 is connected to a multiplex facsimile data printer 28, and the multiplex data demodulator 27 is connected to a multiplex data display device 29. Instead of or in addition to the multiplex facsimile data printer 28, a display device for displaying multiplex facsimile data may be used. Further, instead of or in addition to the multiplex data display device 29, a printer that prints multiplex data may be used.

The first subcarrier of 4.5 fH multiplexed with the voice signal is pass-selected by the first bandpass filter 14, and the first subcarrier passed by the first bandpass filter 14 is selected by the multiplex facsimile data demodulator 26. Is transmitted to the multi-facsimile data demodulator 26, the multi-facsimile data is demodulated from the first subcarrier transmitted by the multi-facsimile data demodulation unit 26, and the demodulated multi-facsimile data is printed by the multi-facsimile data printer 22. Further, the second subcarrier of 7.5 fH multiplexed with the audio signal is pass-selected by the second band filter 17, and the second sub-carrier pass-selected by the second band filter 17 is sent to the multiplexed data demodulation unit 27. Then, the multiplexed data is demodulated from the second subcarrier transmitted from the multiplexed data demodulation unit 27, and the demodulated multiplexed data is displayed on the multiplexed data display device 29.

In the above-described embodiments, the method of broadcasting data and facsimile data as a combination of signals of two channels broadcast in multiplex broadcasting has been described, but the data to be broadcast is a signal that can be digitally modulated. If so, there is no particular limitation, and in addition to character data and facsimile data, binary data such as computer programs, image data other than facsimile data, or digital voice data can be handled.

The present invention can be applied to other television systems capable of performing multiplex broadcasting, for example, PAL system, etc. by modifying the numerical requirements of the present invention to ones adapted to the respective systems. It goes without saying that it is possible to do so.

[Brief description of drawings]

FIG. 1 is a radio wave standard diagram of NTSC color television broadcasting.

FIG. 2 is a modulation spectrum diagram of a television multiplex broadcasting facsimile system in the NTSC system.

FIG. 3 is a block configuration diagram of a conventional television receiver.

FIG. 4 is a modulation spectrum diagram in the NTSC broadcasting system according to the embodiment of the present invention.

FIG. 5 is a block configuration diagram of a television receiver that receives 2-channel multiplexed data.

FIG. 6 is a block configuration diagram of a television receiver for receiving 2-channel multiplex facsimile data.

FIG. 7 is a block configuration diagram of a television receiver that receives 1-channel multiplexed data and 1-channel multiplexed facsimile data.

[Explanation of symbols]

1 Antenna 2 Tuner 3 Video Detection Section 4 Signal Separation Section 5 Video Amplification Section 6 Image Display Device 7 Character Multiplexed Data Demodulation Section 8 Audio Detection Section 9 Audio Main / Sub Separation Section 10 Sub Audio Demodulation Section 11 Stereo Matrix Circuit 12 Dual Audio Circuit 13 Speakers 14 and 17 Bandpass Filters 15, 22, 23 and 26 Multiplexed Facsimile Data Demodulators 16, 24, 25 and 28 Multiplexed Facsimile Data Printers 16, 17 and 24 Multiplexed Data Demodulators 17 Multiplexed Data Demodulators 18, 19, 27 Multiple data display

Claims (4)

[Claims] 1. A television multiplex broadcasting system for multiplexing information other than main audio in a voice broadcasting band of a television broadcasting radio wave and broadcasting the first subcarrier having a center frequency of 4.5 fH in the voice broadcasting band. And center frequency 7.5 fH
Second sub-carrier of the first sub-carrier and the second sub-carrier with a frequency deviation amount of the main carrier of ± 2 to 3K.
A television multiplex broadcasting system that modulates with a multilevel digital system of Hz. 2. The television multiplex broadcasting system according to claim 1, wherein the two-channel multiplex broadcasting is two-channel data broadcasting. 3. The television multiplex broadcasting system according to claim 1, wherein the two-channel multiplex broadcasting is a two-channel facsimile data broadcasting. 4. The television multiplex broadcasting system according to claim 1, wherein the two-channel multiplex broadcasting is one-channel data broadcasting and one-channel facsimile data broadcasting.