JPH04332284A - Radio video signal communication equipment - Google Patents

Abstract

PURPOSE:To transmit a video signal and an auxiliary frequency of an arrangement line signal or the like, and to constitute a system at a low cost without using plural channels. CONSTITUTION:As for a device which transmits by radio a TV video signal, and auxiliary signals to be transferred between radio stations, a transmission system is equipped with a synthesizing means 11 which synthesizes the auxiliary signals in a voice frequency band, modulating means 12 which frequency-modulates the output of the synthesizing means to the subcarrier of an empty frequency band by using the pertinent empty frequency area in the transmission band of the TV video signal, baseband synthesizing means 13 which baseband-synthesizes this modulated signal with the TV video signal, and transmitting means 16-19 which demodulates and transmits the baseband-synthesized signal. Then, a reception system is equipped with receiving means 26-29 which receive the transmitted signal and demodulate it to the original baseband signal, branching means 23 which divides the baseband signal into the TV video signal and the subcarrier frequency component, and outputs them, and demodulating means 22 which demodulates the subcarrier frequency component signal among the divided signals, returns it back to the original auxiliary signal and outputs it.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to television transmission wireless communications, and more particularly to a video signal wireless communication device with an improved transmission system for incidental signals such as meeting line signals.

0002

2. Description of the Related Art In a conventional television transmission radio system of this type, meeting signals, supervisory control signals and line switching signals are transmitted using independent radio channels as shown in FIG. That is, the conventional television transmission wireless system shown in FIG. 5 has the following details as shown in FIG. 6 (A station system) and FIG. 7 (B station system).
The antennas ANT of each station are arranged facing each other, and the transmission signal from the transmission system of the own station is sent to the antenna ANT of the own station via the duplexer DUP, and the signal received by the antenna ANT of the own station is sent to the duplexer DUP. It is sent to the receiving system of the local station via

The transmission system has a video signal input terminal and a meeting line signal input terminal, each of which is configured to be input to an FM modulator M via a baseband switch SW. There are three systems of FM modulators M, and a transmitter TX is provided corresponding to each of these FM modulators M. Therefore, there are also three transmitter TX systems, one with frequency f1, the other with frequency f2, and the rest with frequency f3.

Frequency f1 is the radio frequency of the protection line, frequency f2 is the radio frequency of the working line, and frequency f3 is the radio frequency of the meeting line. Therefore, the video signal is normally input to the FM modulator M for the working line via the baseband switch SW, where it is FM modulated and then frequency f
After being converted into a transmission output signal by the transmitter TX of No. 2, the signal is passed through the splitter filter BR of the transmission system, and then sent to the antenna ANT of the own station via the duplexer DUP, and then transmitted to the other station.

On the other hand, the radio waves from the other station are transmitted through the antenna ANT.
The signal is received by the transmitter/receiver duplexer DUP and sent to the receiving system's branching filter BR, where it is input to the receiver RX of the corresponding frequency according to the frequency band.

As mentioned above, the transmission system is divided into backup, working,
The reception system is configured so that three types of frequency bands can be used for the meeting line, and the receiving system is also used for backup (frequency f1'), for working (frequency f2'), and for the meeting line (frequency f3').
Three types of frequency bands are prepared, and the signal is input from the splitting filter BR to the receiver RX of the corresponding frequency according to the frequency band. Then, it is converted into an intermediate frequency signal by each receiver RX, and sent to an FM demodulator D corresponding to these receivers RX.
The video signal is demodulated via the baseband switch SW, and the video signal is output from each output terminal for the video signal, and the meeting line signal is output from each output terminal for the meeting line.

[0007] In this way, when sending a meeting line signal in addition to a video signal, the wireless channel for the meeting line signal is used in addition to the radio channel for the video signal. It requires a wireless channel and is not desirable from the standpoint of effective use of radio frequencies.

[0008]

SUMMARY OF THE INVENTION In order to solve this drawback, a configuration as shown in FIG. 8 was proposed. The details of this television transmission wireless system are shown in Fig. 9 (A station system) and Fig. 10 (B station system).The transmission system has a video signal input terminal and a meeting line signal input terminal. The line signal is input to the carrier terminal equipment MUX for the meeting line, and the video signal is input to the synthesis circuit SYN.
The output of YN is input to an FM modulator M via a baseband switch SW.

[0009] The carrier terminal equipment MUX transmits the negotiation line signal to 6MHz, which is an empty area of the baseband band.
It also demodulates the 6 MHz frequency band signal input from the receiving system to restore it to the original meeting line signal and outputs it to the meeting line signal output terminal.

There are two systems of FM modulator M, and these FM
A transmitter TX is provided corresponding to each modulator M. Therefore, there are two transmitter TX systems, one with frequency f1,
The other one has a frequency f2. Frequency f1 is the radio frequency of the protection line, and frequency f2 is the radio frequency of the working line.

Therefore, the video signal is normally sent to the synthesis circuit SYN.
It is combined with the negotiation line signal from the carrier terminal equipment MUX, inputted to the FM modulator M for the working line via the baseband switch SW, where it is FM modulated and then transmitted by the transmitter TX at frequency f2. After being made into an output signal, it passes through the transmission system's splitting filter BR, and then is sent to the local station's antenna ANT via the duplexer DUP, and then transmitted to the other station.

On the other hand, the radio waves from the other station are transmitted through the antenna ANT.
The signal is received by the transmitter/receiver duplexer DUP and sent to the receiving system's branching filter BR, where it is input to the receiver RX of the corresponding frequency according to the frequency band.

As mentioned above, the transmitting system is configured to be able to use two types of frequency bands, backup and working, and the receiving system also has backup (frequency f1') and working (frequency f2'). Two types of frequency bands are prepared, and the signal is inputted from the splitting filter BR to the receiver RX of the corresponding frequency according to the frequency band. Then, it is converted into an intermediate frequency signal by each receiver RX, and sent to the FM demodulator D corresponding to these receivers RX, and the FM
It is demodulated and sent to the branch circuit SP via the baseband switch SW.

[0014] The branch circuit SP separates and sends out a video signal and a meeting line signal using the 6MHz band, which is an empty area of the baseband band, so that the video signal is sent to the video signal output terminal. , and the meeting line signal is sent to the carrier terminal equipment MUX. Then, the carrier terminal equipment MUX receives the 6MHz
After demodulating the band meeting line signal and returning it to the original signal, it is output from the meeting line output terminal.

As described above, in the configuration shown in FIG. 8, by converting the meeting signal etc. into the 6 MHz band using the carrier end station equipment and combining it with the video signal etc. in the baseband band, the channel to be used can be changed. However, since a carrier end station device is required, this leads to an increase in cost, which is economically disadvantageous in a one-way television transmission wireless system.

As described above, although the above system requires only one transmission channel, there is a problem in that the scale of the system configuration becomes large because the system includes a carrier terminal device.

[0017] Therefore, the purpose of this invention is to
Video signals and ancillary signals such as meeting line signals can be transmitted with high quality without using multiple channels.
An object of the present invention is to provide a video signal wireless communication device that can minimize system costs.

[0018]

[Means for Solving the Problems] In order to achieve the above object, the present invention is constructed as follows. In other words, in a video signal wireless communication device that wirelessly transmits television video signals and also wirelessly transmits incidental signals such as meeting line signals exchanged between wireless stations, the transmission system synthesizes the incidental signals in the audio frequency band. a modulating means for frequency-modulating the output of the combining means onto subcarriers in the vacant frequency band using an empty frequency area in the transmission band of the television video signal; The receiver system receives the transmitted signal and demodulates it into the original baseband signal. a receiving means for dividing the baseband signal into a television video signal component and a frequency band component of the subcarrier, and a branching means for dividing the baseband signal into a television video signal component and a frequency band component of the subcarrier; and a demodulating means for receiving the signal, demodulating it, converting it into the original accompanying signal, and outputting the signal.

[0019]

[Operation] This system with such a configuration synthesizes incidental signals such as meeting line signals, supervisory control signals, line switching signals, etc. in the audio frequency band, and synthesizes incidental signals such as meeting line signals, supervisory control signals, line switching signals, etc. in the audio frequency band, and synthesizes the incidental signals such as meeting line signals, supervisory control signals, line switching signals, etc. in the audio frequency band. This area is used to perform frequency modulation on subcarriers in this vacant frequency band, baseband synthesis is performed with the TV video signal and TV audio signal, this is modulated and transmitted, and the receiving side uses this as the original signal. After demodulating into a baseband signal, the frequency band components of the TV video signal and the frequency band components of the subcarrier are demodulated, respectively, and the original TV video signal, meeting line signal, supervisory control signal, and line switching signal are demodulated. Try to return it to .

[0020] In this way, incidental signals such as meeting line signals, supervisory control signals, line switching signals, etc. are transmitted and received as signals in this frequency band by using the vacant frequency area of the baseband frequency band of the television video signal. Since it is accommodated in the same baseband band as the TV video signal, and there is no need to use a separate radio channel, it is possible to make effective use of the radio channel, and the accompanying signal is accommodated in the audio frequency band. This can be realized using a simple method of combining the signals and storing them in the baseband band, which can reduce system costs.Also, since the meeting line signal is transmitted with double frequency modulation, it can be transmitted using Compared to transmission by equipment, it has lower noise and higher quality.

Therefore, according to the present invention, video signals and incidental signals such as meeting line signals can be transmitted with high quality without using multiple channels, and system costs can be kept to a minimum. A video signal wireless communication device can be provided.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The present invention allows incidental signals such as meeting line signals, supervisory control signals, line switching signals, etc. to be sent and received in the same baseband band as the television video signal in a simple manner. It is designed to transmit by using the vacant band between the TV audio signal band and the TV audio signal band. Specifically, it synthesizes incidental signals such as meeting line signals, supervisory control signals, and line switching signals in the audio frequency band, This combined signal is modulated using a frequency modulator in the 6 MHz band, which is an empty frequency band in the television signal transmission frequency band, and the modulated wave is combined with the video signal, television audio modulated wave, line pilot signal, etc. in the baseband band. On the other hand, at the receiving end, a frequency modulated wave is separated from the demodulated baseband signal using a 6MHz band bandpass filter, demodulated using an FM demodulation circuit, and a meeting signal and monitoring signal are processed using a branch filtering means. Separate into control signal and line switching signal.

According to the present invention, a meeting signal can be transmitted on the same radio channel as a video signal using a simple 6MHz band FM modulation means and FM demodulation means, so a one-way television signal transmission system can be realized with a simple configuration. This is possible, and the details will be explained below.

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 shows an enlarged view of the A station system, and FIG. 3 shows an enlarged view of the B station system. In these figures, 1 is a television audio signal input terminal, and 2 is a television video signal input terminal. Further, 3 is a meeting line signal input terminal, 4 is a supervisory control signal input terminal, and 5 is a line switching signal input terminal, which serve as transmission system terminals.

Further, 6 is a TV audio signal output terminal, 7 is a TV video signal output terminal, 8 is a meeting line signal output terminal, 9 is a supervisory control signal output terminal, and 10 is a line switching signal output terminal. It becomes the terminal of the system.

Reference numeral 11 denotes an audio frequency band synthesis circuit, which receives each of the meeting line signal, supervisory control signal, and line switching signal input from the meeting line signal input terminal 3, supervisory control signal input terminal 4, and line switching signal input terminal 5. It synthesizes and outputs signals in the audio frequency band. Further, 12 is an FM modulator, which performs frequency modulation (FM
modulation) and output.

13 is a baseband synthesizer, 14 is a TV audio FM modulator, 15 is a baseband switch, and 16 is an F
17 is a transmitter, 18 is an FM modulator, and 19 is a transmitter. The TV audio FM modulator 14 converts the TV audio signal input from the TV audio signal input terminal 1 into FM.
The baseband synthesizer 13 modulates and outputs the FM modulation output from the FM modulator 12, the TV video signal input from the TV video signal input terminal 2, the line pilot signal, and the TV audio FM modulator. It is combined with the frequency modulated wave from 14 to form and output a baseband signal as shown in FIG.

In order to switch the transmission frequency band, the baseband switch 15 separates the transmission path of the output of the baseband synthesizer 13 (the path consisting of the FM modulator 16 and the transmitter 17, and the path consisting of the FM modulator 18 and the transmitter 19). Therefore, the transmitters 17 and 19 have different transmission frequency bands, one for backup, one for backup, and one for backup.
The other one is currently in use.

The FM modulator 16 is the baseband switch 15
The output of the baseband synthesizer 13 given via F
The transmitter 17 modulates this FM and outputs it.
The modulated output is output as radio waves in a predetermined frequency band, and the FM modulator 18 is connected to the baseband switch 15.
The output of the baseband synthesizer 13 given via F
The transmitter 19 modulates this FM and outputs it.
The modulated output is output as radio waves in a predetermined frequency band.

20 is a transmitting duplexer, 30 is a receiving duplexer, 3
1 is a duplexer, and 32 is an antenna. Transmission splitter 2
0 sends the transmission output from the transmitter 17 or 19 to the duplexer 31, and the duplexer 31 sends the output from the transmission splitter 20 to the antenna 32, and the radio waves received by the antenna 32 are It is sent to the wave device 30. The reception branching filter 30 provides the radio waves received from the antenna 32 to the receivers 27 and 29.

The receivers 27 and 29 convert the signals corresponding to the frequency band that they can receive and process, out of the reception input received from the reception branching filter 30, into intermediate frequency band signals and output the converted signals. The FM demodulators 28 and 26 are circuits that FM demodulate the outputs of the corresponding receivers 29 and 27 and return them to the original baseband signals.

Reference numeral 25 denotes a baseband switch, which switches to output either the output of the FM demodulator 28 or 26. 21 is a branching filter, 22 is a demodulator, 23 is a baseband branching filter, and 24 is a television audio demodulator. The baseband branching filter 23 receives the baseband signal extracted via the baseband switch 25. It is divided into each frequency band.

As shown in FIG. 4, the baseband signals are in the range of 50 Hz to 4 MHz for the television video signal, the 6 MHz band for the meeting line signal, and the 7.5 MHz band for the television audio modulated wave signal. The pilot signal occupies the 8.5 MHz band and is a composite signal, so the baseband branching filter 23 extracts these components separately and sends the TV video signal to the TV video signal output terminal 7 for TV audio modulation. The wave signal is sent to the TV audio demodulation circuit 2.
4 and the rest can be sent to the demodulation circuit 22.

The television audio demodulation circuit 24 demodulates the television audio modulated wave signal received from the baseband branch filter 23 and returns it to an audio signal, and outputs it to the television audio output terminal 6. Branch filter 23
Demodulates the 6MHz band signal received from the demultiplexing filter 21
It is sent to The splitting filter 21 separates the demodulated signal into a meeting line signal, a supervisory control signal, and a line switching signal, and sends the meeting line signal to the meeting line signal output terminal 8, and sends the supervisory control signal to the supervisory control signal output terminal. 9, and the line switching signal is output to the line switching signal output terminal 10.

In such a configuration, each of the meeting line signal, supervisory control signal, and line switching signal input from the meeting line signal input terminal 3, supervisory control signal input terminal 4, and line switching signal input terminal 5 is an audio signal. The frequency band synthesis circuit 11 synthesizes the signals.

[0036] This composite signal is converted to 6MHz by the FM modulator 12.
The frequency modulated wave signal obtained by this frequency modulation is sent to the baseband synthesizer 1.
The baseband synthesizer 13 synthesizes the TV video signal input from the TV video signal input terminal 2, the line pilot signal, and the frequency modulated wave from the TV audio FM modulator 14, as shown in FIG. It becomes a baseband signal.

This baseband signal passes through the baseband switch 15 and is modulated by the FM modulator 16 (18).
The signal becomes an intermediate frequency signal, is converted to a high frequency band by the transmitter 17 (19), and is transmitted to the opposing station via the transmission duplexer 20, duplexer 31, and antenna 32.

At the opposite station, the antenna 32 receives this signal, and the received high frequency signal is converted into an intermediate frequency signal by the receiver 27 (29) via the duplexer 31 and the receiver duplexer 30. This intermediate frequency signal is transmitted to the FM demodulator 26 (
28) is demodulated into a baseband signal. This baseband signal passes through the baseband switch 25, enters the baseband branching filter 23, and is branched into a television video signal, a meeting line modulated wave, a television audio modulated wave, and a line pilot signal.

The branched meeting line modulated wave signal is demodulated by the demodulator 22 to become a signal in the audio frequency band,
The branching filter 21 branches the signal into a meeting signal, a supervisory control signal, and a line switching signal, which are output from a meeting signal output terminal 8, a supervisory control signal output terminal 9, and a line switching signal output terminal 10, respectively.

[0040] In this way, this system synthesizes incidental signals such as meeting line signals, supervisory control signals, and line switching signals in the audio frequency band, and synthesizes them in the vacant frequency area between the frequency bands of the television video signal and the television audio signal. A certain 6MHz band is used to frequency modulate the subcarrier of this 6MHz band, and this is combined with the TV video signal and the TV audio signal in baseband, and then FM modulated and transmitted, and the receiving side also uses this. After demodulating to the baseband signal of the TV video signal and TV audio signal, the frequency band components and 6M
Hz band frequency band components and demodulated to return them to the original TV video signal, TV audio signal, meeting line signal, supervisory control signal, and line switching signal. Ancillary signals such as supervisory control signals and line switching signals are sent and received as signals in the 6MHz band by using the 6MHz band, which is an empty frequency area between the frequency bands of TV video signals and TV audio signals. Therefore, it is accommodated in the same baseband band as the TV video signal and the TV audio signal, and there is no need to use a separate wireless channel, making it possible to effectively use the wireless channel. Since it can be realized by a simple method of combining in the frequency band and accommodating it in the baseband band, the system cost can also be suppressed. Further, since the meeting line signal is transmitted with double frequency modulation, the signal has lower noise and higher quality than transmission by conventional carrier terminal equipment. It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope without changing the gist thereof.

[0041]

[Effects of the Invention] As detailed above, according to the present invention,
Video signals and ancillary signals such as meeting line signals can be transmitted with high quality without using multiple channels.
It is possible to provide a video signal wireless communication device that can minimize system costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a block configuration diagram showing details of the A station system in FIG. 1 in an enlarged manner.

FIG. 3 is a block configuration diagram showing details of the B station system in FIG. 1 in an enlarged manner.

FIG. 4 is a diagram showing an example of a baseband signal in the system of the present invention.

FIG. 5 is a block diagram showing the overall configuration of a conventional example.

FIG. 6 is a block configuration diagram showing details of the A station system in FIG. 5 in an enlarged manner.

FIG. 7 is a block configuration diagram showing details of the B station system in FIG. 5 in an enlarged manner.

FIG. 8 is a block diagram showing the overall configuration of the conventional improvement system shown in FIG. 5;

FIG. 9 is a block configuration diagram showing details of the A station system in FIG. 8 in an enlarged manner.

FIG. 10 is a block configuration diagram showing details of the B station system shown in FIG. 8 in an enlarged manner.

[Explanation of symbols]

1... TV audio signal input terminal, 2... TV video signal input terminal, 3... Meeting signal input terminal, 4... Supervisory control signal input terminal, 5... Line switching signal input terminal, 6... TV audio signal output terminal, 7... Television Video signal output terminal, 8... Meeting signal output terminal, 9... Monitoring control signal output terminal, 10
...Line switching signal output terminal, 11...Audio frequency band synthesis circuit, 12...FM modulator, 13...Baseband synthesizer, 14
...TV audio FM modulator, 15...baseband switch,
16...FM modulator, 17...transmitter, 18...FM modulator,
19... Transmitter, 20... Transmission demultiplexer, 21... Branch filter,
222... Demodulator, 23... Baseband branching filter, 24
...TV audio demodulator, 25...Baseband switch, 26
...FM demodulator, 27...Receiver, 28...FM demodulator, 29
...Receiver, 30...Reception branching filter, 31...Transmission/reception duplexer, 32
...It's an antenna.

Claims (1)

[Claims] 1. A video signal wireless communication device configured to wirelessly transmit a television video signal and also wirelessly transmit ancillary signals such as a meeting line signal exchanged between wireless stations, wherein a transmission system transmits the ancillary signal at an audio frequency. a modulating means for frequency modulating the output of the combining means onto subcarriers of the vacant frequency band by using an empty frequency area in the transmission band of the television video signal; It consists of a baseband synthesis means for synthesizing the baseband with a television video signal, and a transmission means for modulating and transmitting the baseband synthesized signal, and a receiving system receives the transmitted signal and returns it to the original baseband. a receiving means for demodulating the signal; a branching means for dividing and outputting the baseband signal into a television video signal component and a frequency band component of the subcarrier; What is claimed is: 1. A video signal wireless communication device comprising demodulating means for receiving a frequency band component signal, demodulating the signal, converting it into an original accompanying signal, and outputting the signal.