JPH05260465A - Scramble signal compatible receiver - Google Patents

Abstract

PURPOSE:To supply a scramble television signal and a non-scramble television signal to a modulator through one transmission line. CONSTITUTION:A low pass filter clamp circuit 14 applies processing of non- scramble television signal to an output signal of a reception demodulation section 12, and a scramble release circuit 16 applies scramble release processing to an output signal from the reception demodulation section 12. A changeover switch 28 selects one of outputs from the circuits 14, 16 and the reception demodulation section 12 and the selected output is fed to an output terminal 30. The changeover switch 28 gives an output of the reception demodulation section 12 to the output terminal 30 when an output of the reception demodulation section 12 is a scramble television signal and the scramble is not released, and the changeover switch 28 gives an output of the circuit 14 to the output terminal 30 when an output of the reception demodulation section 12 is a scramble television signal and the scramble is released, and the changeover switch 28 gives an output of the circuit 14 to the output terminal 30 when an output of the reception demodulation section 12 is a non-scramble television signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scramble signal compatible receiver capable of receiving a scrambled scramble signal which may be transmitted from, for example, a broadcasting satellite or a communication satellite.

[0002]

2. Description of the Related Art Generally, satellite broadcasting or satellite communication is received and may be transmitted in a frequency different from the reception frequency in the area of a joint hearing facility. By the way, satellite broadcasting and satellite communication may be scrambled and transmitted for the purpose of paying. When this is transmitted within the area of the joint hearing facility, it is transmitted after descrambling at the head end of the joint hearing facility, or it is transmitted without descrambling and each terminal side of the joint hearing facility There are cases where the scramble is canceled with. Therefore, a receiver for satellite broadcasting or satellite communication used in such a headend is configured to be able to output a signal that is descrambled and a signal that is not descrambled.

Conventionally, as a receiver capable of outputting both the scrambled signal and the non-scrambled signal as described above, there is a receiver as shown in FIG. Input terminal 1 of this receiver
0 is supplied with an intermediate frequency signal obtained by converting a satellite broadcast signal or satellite communication signal received by a parabolic antenna or a plane antenna (not shown) by a converter attached to the parabolic antenna or the plane antenna. This is the reception demodulator 12
The signal is received and demodulated by and converted into a baseband signal. This baseband signal may be a scrambled signal that is scrambled or a non-scrambled signal that is not scrambled, depending on the time zone, for example.

The output of the receiving / demodulating section 12 is supplied to a low-pass filter / clamp circuit 14. The low-pass filter / clamp circuit 14 is for coping with the case where the output of the reception demodulation unit 12 is a non-scrambled signal. In many cases, the dispersal signal is superimposed on the non-scrambled signal. Since the subcarrier signal for voice is superimposed, it is desirable to remove the high frequency component with a low pass filter for NTSC (cutoff frequency is 4.5 MHz). Therefore, in order to deal with the case where the output of the reception demodulator 12 is a non-scrambled signal, the low-pass filter clamp circuit 14
Is provided.

The output of the reception demodulator 12 is also supplied to the descrambling circuit 16. The descrambler 16 is for canceling the output of the reception demodulator 12 when the output is a scrambled signal to obtain a non-scrambled signal, and when an instruction to cancel the scramble is given from the outside. , Descramble is performed.

One of the original non-scrambled signal from the low-pass filter / clamp circuit 14 and the non-scrambled signal obtained by descrambling the scrambled signal in the descrambler 16 is selected by the change-over switch 18.
It is supplied to the non-scrambled signal output terminal 20. The changeover control of the changeover switch 18 is performed by the scramble canceling circuit 1
6 is generated based on the first control signal indicating whether or not descramble is being performed. When descramble is not performed, the output of the low-pass filter / clamp circuit 14 is output to the non-scrambled signal output terminal 20. When supplied and descrambled, the output of the descrambling circuit 16 is supplied to the non-scrambled signal output terminal 20.

The output of the reception demodulator 12 is supplied to the scramble signal output terminal 22. This is when the output of the reception demodulator 12 is a scrambled signal,
This is for outputting without scrambling.

The descrambling circuit 16 is also configured to generate a second control signal indicating whether the signal supplied from the reception demodulation unit 12 is a scrambled signal or a non-scrambled signal. The second control signal is supplied to the control signal output terminal 24.
At the same time, the first control signal is also supplied to the control signal output terminal 26.

As described above, in this receiver, the scrambled scrambled signal and the unscrambled non-scrambled signal are respectively scrambled signal output terminal 22 and non-scrambled signal output terminal 20.
And these signals are fed to a modulator for transmission into the area of the joint hearing facility.
As described above, the modulator can transmit the original non-scrambled signal as it is, or the descrambled non-scrambled signal can be transmitted in the area, while allowing the scrambled signal to be transmitted in the area as it is. Also, the transmission of the scrambled signal or the non-scrambled signal is performed according to the first and second control signals supplied from the control signal output terminals 24 and 26.

[0010]

However, in order to transmit a scrambled signal or a non-scrambled signal from such a receiver to the modulator, the non-scrambled signal output terminal 20 and the scrambled signal output terminal 22 are respectively connected via coaxial cables. Therefore, there is a problem that the connecting work is troublesome because the modulator must be connected to an input terminal for receiving these signals, that is, two coaxial cables must be connected.

It is an object of the present invention to provide a scrambled signal compatible receiver which enables easy connection work by enabling transmission of a scrambled signal and a non-scrambled signal through one transmission line. ..

[0012]

In order to achieve the above-mentioned object, according to the present invention, a reception demodulation means for receiving and demodulating a scrambled scrambled signal or an unscrambled non-scrambled signal, and this reception demodulation means. Is supplied to the non-scrambled signal processing means for performing the processing corresponding to the non-scrambled signal, and the output of the reception demodulation means is supplied to the descrambler for descramble the scrambled signal, the non-scrambled signal processing means, the scrambler Selecting means for selecting one of the outputs of the canceling means and the receiving / demodulating means and supplying it to one output terminal, wherein the selecting means is either a scrambled signal or a non-scrambled signal. Whether the signal is a signal or not, and the descrambling means performs descrambling. It is controlled according to the determining whether to state.

[0013]

According to the present invention, the signals received and demodulated by the reception demodulator are supplied to the non-scrambled signal processing means, the scrambled signal processing means and the selection means, respectively. The output of the non-scrambled signal processing means and the output of the scrambled signal processing means are also supplied to the selection means. Here, when the received and demodulated signal is the original non-scrambled signal, the selection means is controlled so as to supply the output of the non-scrambled signal processing means to the output terminal.

Further, the received and demodulated signal is a scrambled signal, and when the scrambled signal is canceled by the canceling means, the selecting means is provided so that the non-scrambled signal output from the scramble canceling means is supplied to the output terminal. Controlled. Further, when the received and demodulated signal is a scrambled signal, but the scrambled signal is not unscrambled, the selecting means is controlled so that the scrambled signal, which is the signal of the receiving and demodulating section, is directly supplied to the output terminal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, this embodiment supplies a television signal of satellite broadcasting or satellite communication received by a parabolic antenna to a receiver 27, like the conventional example shown in FIG. It has an input terminal 10, a reception demodulation unit 12, a low-pass filter clamp circuit 14, and a scramble descrambling circuit 16. The output of the low-pass filter / clamp circuit 14 is the contact 28a of the changeover switch 28.
Is being supplied to. The output of the scramble canceling circuit 16 is supplied to the contact 28b of the changeover switch 28. Further, the output of the reception demodulator 12 is the changeover switch 2
8 contact points 28c. The contact 28d of the changeover switch 28 is supplied to the output terminal 30 provided only one. This output terminal 30
It is connected to the modulator described later.

The contact 28d of the changeover switch 28 is changed over on the basis of the first and second control signals from the scramble canceling circuit 16. That is, that the output signal of the reception demodulation unit 12 is a non-scrambled television signal,
When the first control signal generated by the descrambling circuit 16 represents the contact 28d of the changeover switch 28,
The changeover switch 28 is configured so as to be connected to the contact 28a. Accordingly, at this time, the output terminal 30 is supplied with the non-scrambled television signal from the low-pass filter / clamp circuit 14.

The first control signal indicates that the output of the reception demodulator 12 is a scrambled television signal, and the second control indicates that the descrambler 16 is descrambled. The changeover switch 28 is configured so that the contact 28d of the changeover switch 28 is connected to the contact point 28b when the signal indicates. Therefore, at this time, the output terminal 30 is supplied with the non-scrambled television signal (the non-scrambled television signal obtained by descrambling the scrambled television signal) from the descrambler circuit 16.

Further, the first control signal indicates that the output of the reception demodulator 12 is a scrambled television signal, and the second control signal indicates that the descrambler 16 does not descramble the signal. , The changeover switch 28 is configured so that the contact 28d of the changeover switch 28 is connected to the contact 28c. Therefore, at this time, the scrambled television signal from the reception demodulation unit 12 is directly supplied to the output terminal 30.

Then, as in the case of the conventional one shown in FIG.
The second control signal is supplied to the control signal output terminals 24 and 26.

A modulator 31 for use with the receiver 27 is shown in FIG. The modulator 31 has an input terminal 32 to which a scrambled television signal or a non-scrambled television signal is supplied from an output terminal 30 of the receiver 27. The signal supplied to the input terminal 32 is supplied to the polarity reversal clamp processing circuit 36 or the AGC clamp processing circuit 38 via the changeover switch 34.

The polarity reversal clamp processing circuit 36 performs processing for AM modulation of the non-scrambled television signal as described later, and inverts the polarity because the AM modulation of the non-scrambled television signal is negatively modulated. Then, AM modulation is performed. Further, when the AM modulation is performed, clamping is performed to keep the DC level constant so that the SYNC chip of the synchronization signal of the non-scrambled television signal becomes 100% of the carrier wave. Further, the AGC clamp processing circuit 38 converts the scrambled television signal into A
When the scrambled television signal is AM-modulated, the upper peak of the color subcarrier on 100% of the white is 100% of the carrier and the lower peak of the color subcarrier on the black level is M. The peak should be 0% of the carrier. Therefore, AGC and clamp processing are performed on the scrambled signal.

The change-over switch 34 outputs a first control signal supplied from the control signal output terminal 26 of the receiver 27 to the control terminal 40 and a second control signal supplied from the control signal output terminal 26 to the control terminal 42. The switching is controlled accordingly.

That is, when the first control signal indicates that the output of the reception demodulation unit 12 of the receiver 27 is a non-scrambled television signal, or the output of the reception demodulation unit 12 of the receiver is a scrambled television signal. When the first control signal indicates that the signal is a signal, but the second control signal indicates that descramble is being performed in the descramble circuit 16 (the output of the output terminal 30 is not scrambled). When it is a television signal), the changeover switch 34 changes its contactor 34a to a contact 34b connected to a polarity reversal clamp processing circuit 36.

Although the first control signal indicates that the output of the reception demodulation unit 12 of the receiver 27 is a scrambled television signal, it indicates that the descrambler 16 does not descramble. When the second control signal represents (when the output of the output terminal 30 is a scrambled television signal), the changeover switch 34 changes its contact 34a to the contact 34c connected to the AGC clamp processing circuit 38. Switch.

The output signals of the polarity reversal clamp processing circuit 36 and the AGC clamp processing circuit 38 are supplied to the contacts 48a and 48b of the changeover switch 48 via the variable resistors 44 and 46 for adjusting the modulation degree, respectively. The contact 48c of the changeover switch 48 is connected to the input side of the AM modulation circuit 50.

This changeover switch 48 also includes the control terminal 40,
It is controlled according to the first and second control signals supplied to 42. That is, when the first control signal generated by the descrambling circuit 16 indicates that the output signal of the reception demodulator 12 is a non-scrambled television signal (the output of the output terminal 30 is a non-scrambled television signal). The changeover switch 48 is configured so that the contact 48c of the changeover switch 48 is connected to the contact 48a.

As a result, the non-scrambled television signal input from the output terminal 30 to the input terminal 32 is
The polarity reversal clamp processing circuit 36 performs processing corresponding to the non-scrambled television signal, the modulation degree is adjusted by the variable resistor 44, and then the AM is set via the changeover switch 48.
It is supplied to the modulation circuit 50, where a carrier wave of an appropriate frequency is modulated, and this modulation signal is output from the output terminal 52.

Although the first control signal indicates that the output of the reception demodulation unit 12 of the receiver 27 is a scrambled television signal, it indicates that the descrambler 16 does not descramble the signal. The changeover switch 48 is configured such that the contact 48c of the changeover switch 48 is changed over to the contact 48b side when the second control signal represents (when the output of the output terminal 30 is a scrambled television signal). ing.

As a result, the scrambled television signal supplied from the output terminal 30 to the input terminal 32 is supplied to the AGC clamp processing circuit 38 via the changeover switch 34, where the processing corresponding to the scrambled television signal is performed. Then, after the modulation degree is adjusted by the variable resistor 46, it is supplied to the AM modulation circuit 50 through the changeover switch 48 to modulate a carrier wave of an appropriate frequency, and this modulation signal is output from the output terminal 52. ..

An example of using the receiver 27 and the modulator 31 as described above is shown in FIGS. FIG. 3 shows a case where the receiver side provided at the head end descrambles the scrambled signal and transmits it in the area of the joint viewing facility.

A plurality of satellite broadcasting signals and satellite communication signals received by the parabolic antenna 54 are transmitted to the parabolic antenna 54.
A receiver 27 which is converted to an intermediate frequency signal by a converter (not shown) attached to the receiver 27 and is provided via a distributor 56 so as to correspond to each satellite broadcast and satellite communication.
-1 to 27-n. These receivers 27-1
To 27-n have the same configuration as the receiver 27 shown in FIG. 1, are configured to receive and demodulate the corresponding satellite broadcasts or satellite communications, and are set to release the scrambled television signal. Has been done.

Therefore, from the receivers 27-1 to 27-n to the modulators 31-1 to 31-n, a non-scrambled television signal obtained by descrambling the scrambled television signal or the original scrambled signal is obtained. Television signals are coaxial cables 58-1 to 58-n
Are supplied to the modulators 31-1 to 31-n via the.
The modulators 31-1 to 31-n have the same configuration as that shown in FIG. Although not shown in FIG. 3, the coaxial cables 58-1 to 58-n are connected to the receivers 2 respectively.
7-1 to 27-n output terminals and each modulator 10-1
Through 10-n input terminals.

Also, from the receivers 27-1 to 27-n to the modulators 31-1 to 31-n, control cables 60-1 to 60-n and 62-1 to 62-n are used. First and second control signals are provided. Of course, the control cables 60-1 to 60-n include control signal output terminals for the first control signals of the receivers 27-1 to 27-n,
The control cables 62-1 to 62-n are connected between the modulators 10-1 to 10-n and the control terminals for the first control signals, and the control cables 62-1 to 62-n are the second cables of the receivers 27-1 to 27-n. Control signal output terminal for the control signal of the
It is connected between the control terminals for 0-n second control signals.

In the modulators 27-1 to 27-n, carrier waves having different frequencies are modulated with non-scrambled television signals to obtain the respective modulated signals. These modulated signals are mixed by the mixer 64 and are jointly operated. Sent within the area of the hearing facility. Then, the signals are supplied to the television receivers 68, 68 ... From the branching devices 66, 66. Therefore, each television receiver side does not need a descrambling device for descrambling.

FIG. 4 is for transmitting in each area without descrambling by the receiver on the headend side, and although the configuration is almost the same as that of FIG. 3, a disk is provided for each terminal side. The difference from FIG. 3 is that the ramblers 70, 70 ... Are provided.

When the satellite broadcast and satellite communication received by the parabolic antenna 54 are scrambled television signals,
The received and demodulated signals are coaxial cables 58-1 to 5-5.
8-n to the modulators 31-1 to 31-n, and from these are supplied to each terminal as in the case of FIG.
Descrambling is descrambled by the descramblers 70, 70, ... And supplied to the television receivers 68, 68. Also, depending on the time of day, parabolic antenna 5
When the satellite broadcasting or satellite communication received in 4 is changed to a non-scrambled television signal, the signal received and demodulated from the non-scrambled television signal is the coaxial cable 5
Modulators 31-1 to 31 through 8-1 to 58-n
Is supplied to each terminal in the same manner as in the case of FIG. 3, passes through the descrambler 70, 70 ... And is supplied to the television receivers 68, 68.

[0037]

As described above, according to the scramble-compatible receiver of the present invention, the non-scrambled television signal originally obtained by the selecting means and the non-scrambled television signal obtained by descrambling the scrambled television signal are obtained. Since either one of the television signal and the scrambled television signal is selected and supplied to one output terminal, the scrambled television signal or the non-scrambled television signal is supplied from such a receiver to the modulator. 1 transmission line for transmitting the John signal
Only a book is needed, and connection work can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of a scramble-capable receiver according to the present invention.

2 is a block diagram of a modulator for use with the receiver of FIG.

3 is a block diagram illustrating an example of use of the receiver of FIG. 1 and the modulator of FIG.

4 is a block diagram illustrating another example of use of the receiver of FIG. 1 and the modulator of FIG.

FIG. 5 is a block diagram of a conventional scramble-compatible receiver.

[Explanation of symbols]

12 reception demodulator 14 low-pass filter / clamp circuit (non-scrambled signal processing means) 16 descrambler circuit (scrambled signal processing means) 28 changeover switch (selection means) 30 output terminal

Claims (1)

[Claims] 1. A reception demodulation means for receiving and demodulating a scrambled scrambled signal or a non-scrambled non-scrambled signal, and a non-scrambled signal supplied with the output of the reception demodulation means for performing processing corresponding to the non-scrambled signal. One of the outputs of the signal processing means, the descrambling means for descrambled the scrambled signal supplied with the output of the reception demodulation means, the non-scrambled signal processing means, the descramble means and the reception demodulation means. Selecting means for selecting and supplying to one output terminal, the selecting means being in a state of whether the output of the receiving and demodulating means is the scrambled signal or the non-scrambled signal, and the descrambling means. Depending on the state of whether or not the scramble is descrambled Controlled scramble signal compatible receiver.