JPH04156195A - Four-pattern scramble system - Google Patents

Abstract

PURPOSE:To release scramble for each program and to release the entire screen by allowing a scramble encoder at a sender side to synthesize a video signal and an audio data into four kinds of different signals for transmission and releasing scramble individually from the signals at a receiver side and separating one pattern and outputting it. CONSTITUTION:Scramble encoders 1-4 at a sender equipment use scramble keys K1-K4 to scramble a frame data and a relevant video signal. A receiver side equipment down-converts the received radio wave and inputs the result to a tuner 9. An FM detection signal from the tuner 9 is inputted to scramble decoders 10-13, in which scramble is released. Each of the scramble decoders 10-13 corresponds respectively to each encoder and only one pattern whose key is matched is subjected to scramble release. Thus, the scramble release for each program and release of entire screens are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to video and audio scramble communication using a satellite, and particularly to a four-screen scramble system that transmits four programs simultaneously.

[Conventional technology]

Conventionally, the scrambling method using BS system signals has been adopted under the Radio Law, ``Television Broadcasting Standard Transmission Method No. 17''.
The concept of scrambling multiple screens is not included.

However, the video signal to be scrambled only needs to be an NTSC signal, so if image 1 synthesis is performed before scrambling,
Scraming is possible as in the case of one screen, and the receiving side performs screen separation after descrambling. This makes it possible to transmit multiple screens.

Furthermore, since it is possible to transmit audio in four channels in A mode, when transmitting four programs, it is possible to simultaneously transmit audio by making each channel correspond to one audio.

[Problem B to be solved by the invention] In this conventional method, video scrambling is performed after image υ synthesis, so it is not possible to perform bus scrambling using a different key for each screen, making it difficult to control scrambling in the program building. Met.

Therefore, there is a problem in that the entire screen is descrambled in a decoder 7 that is capable of descrambling, whereas in a decoder that is not capable of scrambling, it is not possible to descramble the plan J.

An object of the present invention is to provide a system that makes it possible to cancel the scramble for each program, and therefore to cancel the entire screen.

lz (Means for solving the problem) 4 of the present invention
The screen scrambling system is
A PCM encoder that inputs the analog audio of the channel and configures a BS format audio transmission frame and modulates the data into 4-phase PSK, and four scramble encoders that scramble the video signal and the audio data. , a multiplexer that multiplexes the four types of audio data scrambled by these scramble encoders, and a four-screen synthesizer that synthesizes the four types of video signals scrambled by the scramble encoder described above.

In addition, on the receiving side, a 4-part scramble decoder for descrambling and a 4-part scramble decoder are installed corresponding to these scramble decoders, and one screen is separated from the 4-screen synthesized video signal from each scramble light decoder and output. It is equipped with a 4-screen separation device.

) In this case, the four scramble encoders on the transmitting side scramble each video signal and audio data using different scramble keys, and the four scramble encoders on the receiving side scramble each video signal and audio data using different scramble keys.
Each of the scramble decoders uses a corresponding scramble key to descramble the corresponding video signal and audio data.

[Effect]

According to the present invention, on the transmitting side, the video signal and audio data are converted into four different types of signals using a scramble encoder, and these are combined and transmitted, and on the receiving side, these four types of signals are individually descrambled. , and it becomes possible to separate and output one screen.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

1 and 2 are diagrams showing one embodiment of the present invention, with FIG. 1 being a system diagram of a transmitting side device, and FIG. 2 being a system diagram of a receiving side device.

In the transmitting side device shown in FIG. 1, 1 to 4 are four scramble encoders, each of which is connected to the audio data multiplexing device 5 so as to be input/outputable, and further connected to the PCM encoder 6. Further, the outputs of each of the scramble encoders 1 to 4 are outputted to a four-screen synthesis device 7 and then outputted through a modulator 8.

The PCM encoder 6 frames analog audio for four programs into an audio transmission frame shown in FIG. After the frame data is divided into four parts, it is input to scramble encoders 1 to 4 for four channels. Each scramble encoder 1 to 4 uses frame data and the corresponding video signal as scramble keys 1 to 4, and the video signal uses the line permutation method (scanning line transfer method), and the frame data uses the audio data section. Scrambling is performed by adding the PN signal to the independent data. Further, information necessary for descrambling on the receiving side, such as a scramble key and contract conditions, is packetized and multiplexed into an independent data section. Furthermore, the timing required for descrambling (master frame timing, scramble timing) and the status of the scramble 0N10FF are also multiplexed into the frame data.

The frame data processed by each of the scramble encoders 1 to 4 is input to the audio data multiplexing device 5, and each data is selected from the corresponding encoder and combined into one frame data. At this time, since the control code and the like within the frame must be the same in each frame, when multiplexing is performed using the scramble encoder, each encoder is externally controlled so as to be synchronized.

The combined frame data is returned to the PCM encoder 6, and after processing such as BCH encoding and interleaving, is subjected to 4-phase PSK modulation onto 5.7 MH2 subcarriers.

On the other hand, the four scrambled video signals are input to the four-screen synthesis device 7. The 4-screen synthesis device 7 multiplexes the video signal of channel 1 to the left side of the odd field, channel 2 to the right side of the odd field, channel 3 to the left side of the even field, and channel 4 to the right side of the even field, using image compression or the like. Combine into one video signal.

The video signal from the four-screen synthesizer 7 and the PSK modulated wave from the PCM encoder 6 are input to the SHF modulator 8, FM-modulated into the SHF band, and transmitted to the satellite.

On the other hand, in FIG. 2, the receiving side device includes a tuner 9,
There are four scramble decoders 10 to 13 into which this tuner output is input, and four scramble decoders 10 to 13 connected to each decoder.
It has four screen separation devices 14 to 17.

The radio waves received from the satellite are downconverted and input to the tuner 9. F from tuner 9.

The M detection signal is input to four scramble decoders 10 to 13 and descrambled. Each scramble decoder 10 to 13 corresponds to an encoder,
The decoder 10 performs authorization from the encoder 1,
The first video signal and the first audio data are canceled. The same applies to decoders 11 to 13. Since the video signal is a composite of four different scrambled signals, only the one screen that has lost its key will be descrambled.

Furthermore, among the four 4-side screen separation devices 14 to 17, the 4-screen separation device 14 extracts only the left side of the odd field and outputs one regular image by performing interpolation. The four screen separators 15 to 17 are also on the right side of the odd field and on the left side of the even field.

Only the right side of the even field is extracted and one regular video signal is output.

〔Effect of the invention〕

As explained above, in the present invention, the transmitting side uses four different types of scrambling keys to generate video signals and audio data, and then combines and transmits these, and the receiving side uses the corresponding scrambling keys etc. Since the descrambling function is used to control whether or not to descramble for each program, it is possible to descramble for each program and to descramble the entire screen.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a transmitting device according to an embodiment of the present invention, and FIG.
The figure is a system diagram of a receiving side device according to an embodiment of the present invention, and FIG. 3 is a frame configuration diagram of a voice transmission frame. 1 to 4...Scramble encoder, 5...Audio data multiplexer, 6...PCM encoder, 7...4
Screen synthesis device, 8... SHF modulator, 9... Tuner, lO~13... Scramble decoder, 14~1
7...4 screen separation device.

Claims (1)

[Claims] 1. In satellite communication using BS system transmission signals, 4 channels of analog audio are input to the transmitting side and the BS
A PCM encoder that configures the audio transmission frame of the format and modulates the data into 4-phase PSK, four scramble encoders that scramble the video signal and the audio data, and four types of audio scrambled by these scramble encoders. comprising a multiplexing device for multiplexing data, and a four-screen synthesizing device for synthesizing four types of video signals scrambled by the scramble encoder,
On the receiving side, there are four scramble decoders that descramble the scramble decoders, and a four-screen separation system that is installed in correspondence with these scramble decoders and separates and outputs one screen from the four-screen synthesized video signal from each scramble decoder. A four-screen scrambling system characterized by comprising a device. The 2 and 4 scramble encoders scramble each video signal and audio data using different scramble keys, and the 4 scramble decoders scramble the corresponding video signals and audio data using the corresponding scramble keys. A four-screen scrambling system according to claim 1.