JP2754113B2 - Scrambled signal receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Generally, a satellite broadcast or satellite communication is received and transmitted at a frequency different from the reception frequency in an area of a joint viewing facility. By the way, in satellite broadcasting or satellite communication, scrambling may be performed in order to pay a fee. This is transmitted within the area of the joint hearing facility, when the scramble is descrambled at the joint hearing facility head end and then transmitted, or when the scramble is transmitted without descrambling, and the To release the scramble. Therefore, a receiver for satellite broadcasting or satellite communication used in such a head end is configured to output a descrambled signal and a signal not descrambled.

Conventionally, there has been a receiver as shown in FIG. 5 which can output both the scrambled signal and the non-scrambled signal as described above. Input terminal 1 of this receiver
To 0, an intermediate frequency signal obtained by converting a satellite broadcast signal or a satellite communication signal received by a parabolic antenna or a planar antenna (not shown) by a converter attached to the parabolic antenna or the planar antenna is supplied. This is because the reception demodulation unit 12
And demodulated to obtain a baseband signal. The baseband signal may be a scrambled scrambled signal or a non-scrambled non-scrambled signal depending on, for example, a time zone.

The output of the reception demodulation unit 12 is supplied to a low-pass filter / clamp circuit 14. This low-pass filter / clamp circuit 14 is for dealing with the case where the output of the reception demodulation unit 12 is a non-scrambled signal. In many cases, the non-scrambled signal is a signal in which a dispersal signal is superimposed. Since the audio subcarrier signal is superimposed, it is desirable to remove the high-frequency component with a low-pass filter for NTSC (cutoff frequency of 4.5 MHz). Therefore, in order to cope with the case where the output of the reception demodulation unit 12 is a non-scramble signal, the low-pass filter / clamp circuit 14
Is provided.

The output of the reception demodulation unit 12 is also supplied to a descrambling circuit 16. The descrambling circuit 16 is used to cancel the scrambled signal when the output of the reception demodulation unit 12 is a scrambled signal and to provide a non-scrambled signal. , And descrambling.

One of the original non-scrambled signal from the low-pass filter / clamp circuit 14 and the non-scrambled signal obtained by descrambling the descrambling signal by the descrambling circuit 16 is selected by the switch 18.
It is supplied to a non-scramble signal output terminal 20. The switching of the changeover switch 18 is controlled by the descrambling circuit 1
6 is performed based on a first control signal indicating whether or not descrambling is performed. If the descrambling is not performed, the output of the low-pass filter / clamp circuit 14 is output to the non-scramble signal output terminal 20. When the signal is supplied and descrambling is performed, the output of the descrambling circuit 16 is supplied to the non-scramble signal output terminal 20.

[0007] The output of the receiving and demodulating section 12 is supplied to a scramble signal output terminal 22. This is a case where the output of the reception demodulation unit 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 receiving / demodulating unit 12 is a scrambled signal or a non-scrambled signal. The second control signal is supplied to a 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, a scrambled scrambled signal and a non-scrambled non-scrambled signal are respectively converted into a scrambled signal output terminal 22 and a non-scrambled signal output terminal 20.
And these signals are provided to a modulator for transmission within the area of the joint hearing facility.
As described above, this modulation device can transmit a non-scrambled signal as it is, or a non-scrambled signal in which the original non-scrambled signal is descrambled, within the area so that the signal can be transmitted in the area as a scrambled signal as described above. The transmission of the scrambled signal or the transmission of 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, it is necessary to connect the input terminals of the modulation device to receive these signals, that is, two coaxial cables must be connected, and there is a problem that the connection work is troublesome.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a scrambled signal compatible receiver which can transmit a scrambled signal and a non-scrambled signal via a single transmission line, thereby facilitating connection work. .

[0012]

To achieve the above object, the present invention provides a receiving demodulating means for receiving and demodulating a scrambled scrambled signal or an unscrambled non-scrambled signal, Non-scramble signal processing means for providing processing corresponding to the non-scramble signal, output of the reception demodulation means, descrambling means for descrambling the scramble signal, non-scramble signal processing means, scramble Selecting means for selecting one of the outputs of the canceling means and the receiving and demodulating means and supplying the selected output to one output terminal. The descrambling means includes a first control signal indicating whether the output of the reception demodulation means is the scrambled signal or the non-scrambled signal, and whether or not the descrambling means has performed descrambling. And a second control signal that represents
Supply to the selection means. The selecting means determines that the output of the receiving and demodulating means is the scrambled signal.
When the second control signal indicates that the descrambling means is performing descrambling, the output of the descrambling means is supplied to the output terminal, and the reception demodulation means When the first control signal indicates that the output is the scramble signal, and the second control signal indicates that the descrambling means has not performed descrambling, the output of the reception demodulation means Is supplied to the output terminal, and when the first control signal indicates that the output of the receiving and demodulating means is the non-scrambled signal, the output of the non-scrambled signal processing means is supplied to the output terminal.

[0013]

According to the present invention, a signal received demodulated by the receiving demodulation means includes a non-scrambled signal processing means, respectively, and scan <br/> Kuranbu Le releasing hand stage, is supplied to the selection means. The output of the non-scramble signal processing means and the scramble
Output Le releasing hand stage is also supplied to the selection means. Here, if the received and demodulated signal is an original non-scrambled signal, the selection means is controlled to supply the output of the non-scrambled signal processing means to the output terminal.

Further, as signals received demodulated is a scrambled signal, if released it in scrambling cancel unit, the non-scrambled signal which is the output of the descrambling means are supplied to the output terminal, select Means are controlled. Although the received demodulated signal is a scrambled signal, if not releasing the scrambling, the scramble signal is a signal of the reception demodulation means, to be supplied as it is output, that are controlled selection means .

[0015]

As shown in FIG. 1, this embodiment supplies a satellite broadcast or satellite communication television signal received by a parabolic antenna to a receiver 27. As in 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 descrambling circuit 16. The output of the low-pass filter / clamp circuit 14 is supplied to the contact 28 a of the switch 28.
Is supplied to The output of the descrambling circuit 16 is supplied to the contact 28b of the changeover switch 28. Further, the output of the reception demodulation unit 12 is supplied to the changeover switch 2
8 contact 28c. The contact 28d of the changeover switch 28 is supplied to only one output terminal 30. This output terminal 30
It is connected to a modulation device described later.

The contact 28d of the changeover switch 28 is switched based on the first and second control signals from the descrambling circuit 16. That is, 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 indicates, the contact 28d of the changeover switch 28
The changeover switch 28 is configured to be connected to the contact 28a. Therefore, at this time, the non-scrambled television signal from the low-pass filter / clamp circuit 14 is supplied to the output terminal 30.

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

Further, the first control signal indicates that the output of the reception demodulation unit 12 is a scrambled television signal, and the second control signal indicates that the descrambling is not performed by the descrambling circuit 16. Represents, the changeover switch 28 is configured such 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 supplied to the output terminal 30 as it is.

Then, similarly to the conventional one shown in FIG.
And the second control signal are supplied to control signal output terminals 24 and 26.

FIG. 2 shows a modulator 31 used with the receiver 27. The modulation device 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 a polarity inversion clamp processing circuit 36 or an AGC clamp processing circuit 38 via a changeover switch 34.

The polarity inversion clamp processing circuit 36 performs a process for AM modulation of the non-scrambled television signal as described later. In order to make the AM modulation of the non-scrambled television signal negative, the polarity is inverted. Then, AM modulation is performed. Furthermore, when 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. The AGC clamp processing circuit 38 converts the scrambled television signal to A
When the scrambled television signal is subjected to AM modulation, the upper peak of the color subcarrier on 100% white is set to 100% of the carrier and the lower peak of the color subcarrier on the black level. The peak needs to be 0% of the carrier. Therefore, AGC and clamp processing are performed on the scramble signal.

The changeover switch 34, the first control signal and a second control signal supply control signal output terminal 24 or al to the control terminal 42 supplied from the control signal output terminal 26 of the receiver 27 to the control terminal 40 The switching is controlled in accordance with.

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 when the output of the reception demodulation unit 12 of the receiver 27 is When the first control signal indicates that the signal is a version signal, the second control signal indicates that descrambling is being performed in the descrambling circuit 16 (the output terminal 30).
Is an unscrambled television signal), the changeover switch 34 changes its contact 34a to the contact 34b connected to the polarity inversion clamp processing circuit 36.
Switch to.

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 descrambling is not performed by the descrambling circuit 16. When the second control signal indicates (when the output of the output terminal 30 is a scrambled television signal), the changeover switch 34 connects the contact 34 a to the contact 34 c connected to the AGC clamp processing circuit 38. Switch.

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

The changeover switch 48 is also connected to the control terminal 40,
It is controlled in accordance with 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 demodulation unit 12 is a non-scrambled television signal (the output of the output terminal 30 is a non-scrambled television signal). The switch 48 is configured such that the contact 48c of the switch 48 is connected to the contact 48a.

Thus, the non-scrambled television signal input from the output terminal 30 to the input terminal 32 is
After a process corresponding to the non-scrambled television signal is performed by the polarity inversion clamp processing circuit 36, the modulation degree is adjusted by the variable resistor 44,
The modulated signal is supplied to a modulation circuit 50, which modulates a carrier having an appropriate frequency. The modulated signal is output from an 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 descrambling is not performed by the descrambling circuit 16. When the second control signal indicates (when the output of the output terminal 30 is a scrambled television signal), the changeover switch 48 is configured such that the contact 48c of the changeover switch 48 is switched to the contact 48b side. ing.

[0029] As a result, the output terminal 30 of the receiver 27
Scrambled television signal supplied to the input terminal 32 of the pressurized et modulator 31 via the switch 34 A
The signal is supplied to a GC clamp processing circuit 38, where the processing corresponding to the scrambled television signal is performed, the modulation degree is adjusted by a variable resistor 46, and then supplied to an AM modulation circuit 50 via a changeover switch 48. Modulates a carrier having an appropriate frequency, and the modulated signal is output from an output terminal 52.
Output from

FIGS. 3 and 4 show examples of the use of the receiver 27 and the modulator 31 as described above. FIG. 3 shows a case in which the scramble signal is descrambled on the receiver side provided at the head end and transmitted within the area of the joint viewing facility.

A plurality of satellite broadcast signals and satellite communication signals received by the parabolic antenna 54 are
Is converted into an intermediate frequency signal by a converter (not shown) attached to the receiver 27, and the receiver 27 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
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 broadcast or satellite communication, and are set to cancel the scrambled television signal. Have been.

Accordingly, the non-scrambled television signal obtained by descrambling the scrambled television signal or the original scrambled signal is supplied from each of the receivers 27-1 to 27-n to the modulation devices 31-1 to 31-n. The television signal is transmitted through coaxial cables 58-1 to 58-n.
Are supplied to the modulation devices 31-1 to 31-n.
The modulation devices 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 respective receivers 2.
7-1 to an output terminal of the 27-n, each modulation equipment 31- 1
It is connected between the input terminal of乃optimum 31- n.

Further, the respective receivers 27-1 to 27-n to the respective modulators 31-1 to 31-n via control cables 60-1 to 60-n and 62-1 to 62-n. First and second control signals are provided. Of course, the control cables 60-1 to 60-n are provided with control signal output terminals for the first control signals of the receivers 27-1 to 27-n,
Is connected between the first control terminal of the control signal of the modulation equipment 31- 1乃optimum 31- n, control cable 62-1 to 62-n, the receiver of 27-1 to 27-n a control signal output terminal for the second control signal, the modulation equipment 31- 1乃Itaru 3
1 to n control terminals for the second control signal.

The modulators 27-1 to 27-n modulate carrier waves having different frequencies with the non-scrambled television signal to obtain respective modulated signals. These modulated signals are mixed by the mixer 64, Sent within the area of the hearing facility. Are supplied to the television receivers 68, 68,... From the splitters 66, 66,. Therefore, each television receiver does not require a descrambling device for descrambling.

FIG. 4 shows a structure for transmitting data in each area without releasing the scramble by the receiver on the head end side. The structure is almost the same as that of FIG. Are different from FIG. 3 in that the ramblers 70, 70... Are provided.

When the satellite broadcast and satellite communication received by the parabolic antenna 54 are scrambled television signals ,
In the receiver 27-1 through 27-n, signals that are received Shinfuku tone is supplied to the modulator 31-1 to 31-n through the coaxial cable 58-1 to 58-n, 3 of these Is supplied to each terminal as in the case of
Are descrambled by 0, 70,... And supplied to the television receivers 68, 68,. Also,
When satellite broadcasting and satellite communication received by the parabolic antenna 54 are changed to non-scrambled television signals depending on the time zone , the receivers 27-1 to 27-n receive and demodulate the non- scrambled television signals. The signals are supplied to the modulators 31-1 to 31-n via the coaxial cables 58-1 to 58-n, and are supplied to the respective terminals in the same manner as in FIG.・
Are supplied to the television receivers 68, 68,.

[0037]

As described above, according to the scramble-capable receiver according to the present invention, the non-scrambled television signal which is originally a non-scrambled television signal and the non-scrambled television signal obtained by descrambling the scrambled television signal by the selecting means are provided. Since one of the television signal and the scrambled television signal is selected and supplied to one output terminal, the scrambled television signal and the non-scrambled television signal are transmitted from such a receiver to the modulation device. 1 transmission line for transmitting the John signal
Only books are required, and the connection work can be simplified.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a modulation device used with the receiver of FIG.

FIG. 3 is a block diagram illustrating an example of the use of the receiver of FIG. 1 and the modulator of FIG. 2;

FIG. 4 is a block diagram showing another example of the use of the receiver of FIG. 1 and the modulation device of FIG. 2;

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

[Explanation of symbols]

12 reception demodulation unit (reception demodulation means) 14 low-pass filter / clamp circuit (non-scramble signal processing means) 16 descramble circuit (scramble signal processing means) 28 changeover switch (selection means) 30 output terminal

Claims (1)

(57) [Claims] 1. A receiving and demodulating means for receiving and demodulating a scrambled scrambled signal or a non-scrambled non-scrambled signal, and a non-scrambler to which an output of the receiving and demodulating means is supplied to perform processing corresponding to the non-scrambled signal. A signal processing means, an output of the reception demodulation means, a descrambling means for descrambling the scrambled signal, and one of the outputs of the non-scramble signal processing means, the descrambling means, and the reception demodulation means. Selecting means for selecting and supplying the selected signal to one output terminal, wherein the descrambling means controls the first control indicating whether the output of the receiving and demodulating means is the scrambled signal or the non-scrambled signal. Signal and the descrambling means release descrambling. And a second control signal indicating whether or not the output is received by the first control signal, wherein the first control signal indicates that the output of the receiving and demodulating means is the scramble signal, and When the second control signal indicates that the descrambling means is descrambling, the output of the descrambling means is supplied to the output terminal, and the output of the receiving and demodulating means is the scramble signal. When the first control signal indicates that there is a signal, and the second control signal indicates that the descrambling means has not performed descrambling, the output of the receiving and demodulating means is supplied to the output terminal. ,
A scramble signal compatible receiver for supplying the output of the non-scramble signal processing means to the output terminal when the first control signal indicates that the output of the reception demodulation means is the non-scramble signal.