JPH04200083A - Subscription broadcast decoder - Google Patents

Abstract

PURPOSE:To facilitate the connection to a MUSE decoder and to prevent deterioration in sound quality due to the connection by deleting a bit from multiplexed scramble relating information, applying re-multiplex subsampling voice encode processing and multiplexing the result onto a multiplex subsampling coding signal resulting from descrambling a sound signal part again. CONSTITUTION:A scrambled sound data bit stream is descrambled by a pseudo random (PN) signal outputted from a descramble unit device 6. Then a scramble relation information bit delete device 43 deletes the bit relating to descrambling and multiplex subsampling coding (MUSE) sound encode processing such as 16-bit interleave, BCH (82, 74) error correction code addition, 25-frame interleave, time base compression, binary/ternary conversion, voice data rate conversion from 12.15MHz to 16.2MHz is implemented and the result is multiplexed again on the MUSE signal including descrambled video signal again during vertical blanking. Thus, the connection to a MUSE decoder is attained and the deterioration in the sound quality is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to surface quality television (MIJSE system-Mu
ltiple 5ub-Nyquist Sample
ng Encoding (Multiple Subsampling Encoding) System (Developed by NHK) This relates to a pay broadcast decoder that allows only contracted subscribers to unscramble and view programs in pay broadcasts.

BACKGROUND OF THE INVENTION In recent years, paid broadcasting has been put into practical use with the expansion of broadcasting satellites. Unlike conventional broadcasting formats that rely on advertising fees or license fees, paid broadcasting requires programs to be delivered only to contracted receivers, so programs are usually scrambled electrically.
and will be broadcast. For this reason, in order to view a pay broadcast program, a pay broadcast decoder is required to de-scramble and normally view the program.

Conventionally, multiple subsampling encoding (hereinafter M[ISE
As a pay-broadcast decoder for the signal (denoted as ), a method is being considered in which the pay-broadcast unit is built into the MUSE decoder. On the other hand, as for the existing MUSE decoder, an independent MUSE pay broadcast decoder is being considered which connects the unscrambled video signal and audio signal separately. This means that the video signal in the MUSE signal is unscrambled and then D/A converted.
Since the audio signal is connected to the E decoder, the audio signal in the audio signal area during vertical blanking is scrambled, but after the audio signal is descrambled, it is returned to an analog Heiss hand signal for each channel, and the analog signal state is It connects to an MIJSE decoder or VTR. Therefore, in the MUSE decoder or VTR,
When the independent MUSE pay-TV decoder is connected, by always selectively outputting the audio from this external input audio signal side, the descrambled audio is not played back during vertical blanking without playing back the scrambled audio. This is to obtain normal audio.

Below, with reference to the drawings, the above-mentioned conventional independent type M [I
An example of an SE pay broadcast decoder will be described.

FIG. 6 is a configuration diagram showing how a conventional MUSE pay broadcast decoder and a MUSE decoder are connected. In Figure 6, 2 is an independent MUSE pay broadcast decoder.
A scrambled MUSE signal is normally input to the signal input terminal. 3 is an A/D converter, analog Mtl
The SE signal is converted into a digital L/MUSE signal 19.

4 is a clock, and a synchronization playback unit receives the digital signal processing reference clock 16.2MHz (hereinafter referred to as VCK) from the digital L/MLISE signal 19 and the analog MUSE signal 2, and the video horizontal synchronization signal ( (hereinafter referred to as HD), an independent type that reproduces video frame synchronization signals (hereinafter referred to as νFRAM)? IUSE
Supplies to various parts within the pay broadcast decoder. Reference numeral 5 denotes an audio processing unit which reproduces an audio data bit stream 13 (hereinafter referred to as DBS) after 16-bit deinterleaving at a rate of 1.35 MIIz from the digital MUSE signal, and also reproduces audio data using an audio frame synchronization signal (hereinafter referred to as FSY). A reference clock of 1.35 MHz (hereinafter referred to as ACK) is supplied to each part.

6 is a descrambling unit which extracts scramble related information from the DBS 13, descrambles the scrambled digital MtlSE signal 19 based on this, outputs a descrambled MUSE signal 12, and adds the scrambled audio data by A pseudorandom signal (hereinafter referred to as a PN signal) 11 for descrambling the bit stream 13 is generated.

7 is an exclusive OR element which outputs a descrambled DBS 15 by performing an exclusive OR of the DBS 13 and the PN signal 11 for descrambling.

8 is the audio processing unit, which is a descrambled DBS 15
MUSE audio decoding processing is performed on the MUSE, and 4 channels of analog baseband audio before audio selection are output. 10 is D/
The A converter converts the digital IL7MUSE signal 12 whose video signal portion is descrambled into analog.

Next, on the MIJSE decoder side, 20 is an A/D converter which converts the analog MLISE signal in which the video signal portion has been descrambled into a digital MUSE signal.

21 is an SE video signal processing unit that performs MIISE decoding processing and outputs a high-definition monitor input signal such as a GBR signal from a digital MLISE signal. 22 is MU
The SE audio processing unit extracts the audio signals multiplexed during the blanking period of the MUSE signal to obtain an analog baseband audio signal 32 before audio selection. 31 is audio selection information, which is output based on the mode of multiplexed audio. 23 is an analog switch that connects either the external audio input signal/internal audio signal 32 to the input signal to the audio selection block. Reference numeral 24 denotes an audio external/internal selection switching signal input terminal, which controls the analog switch 23 from the outside. 26 is a voice selection switch operated by the user;
For example, audio selection during bilingual broadcasting is performed. Reference numeral 25 denotes an audio selection prong which appropriately selects and supplies each audio channel to each speaker according to the audio selection switch 7,26 based on selection information 31 based on the audio mode. 27 is the audio selection R connected to each speaker via an amplifier or the like.

The C, Sf voice multiplication signal 30 is a video input signal to a high-definition monitor.

The operation of the independent MUSE pay broadcast decoder configured as described above will be described below.

For example, when a MUSE signal with both video and audio scrambled is input to an independent MUSE pay broadcast decoder, audio processing is performed for the video signal area of the MLISE signal input to an independent MUSE pay broadcast decoder. Based on the scramble-related information in the DBS 13 from the unit 5, the signal is descrambled by a descramble unit and a toro, and then connected to an M[ISE decoder as an analog MUSE signal via a D/A converter 10. Regarding the audio signal, first, the audio processing unit 5 extracts the audio signal from the audio signal area during vertical blanking of the MLISE signal 19, performs MUSE audio decoding processing halfway, and converts the audio signal into a scrambled 1.35 Mbit/sec signal. An audio data bitstream DBS 13 is obtained. Then, the descrambling unit 6 outputs a PN signal 11 for descrambling the DBS 13 based on the scrambling related information in the DBS 13, and the exclusive OR element 7 calculates the exclusive OR with the DBS 13. to descramble the audio data bitstream DBS 13. Furthermore, the audio processing unit 8 converts the descrambled DBS 15 into an analog baseband audio signal before audio selection, and in this state is connected to the MUSE decoder as shown in the figure.

Next, in the MIJSB decoder, only the input video signal region is descrambled, and the audio portion is scrambled. 41JSE decoding processing is performed on the descrambled video portion, and the video is played back on a high-definition monitor. On the other hand, as for the audio signal, in this case, the audio signal in the audio signal area during vertical blanking of the MUSE signal input to the inter-SR decoder is in a scrambled state, so the output 32 of the MUSE audio decoder 22 is in a scrambled state. be.

However, the audio mode focus area in the scrambled audio DBS is always in a non-scrambled state, so the audio selection information 31 is valid.

Therefore, normally, when the independent MUSE pay-TV decoder is connected, the signal applied to the audio external/internal switching control input terminal 24 is set to the external audio side by manual operation etc., and the audio selection section 25 selects Based on the information 31, descrambled audio is reproduced by appropriately selectively supplying the analog audio input from the independent MtlSE pay broadcast decoder to each speaker.

Problems to be Solved by the Invention However, the independent MUSE pay broadcast decoder with the above configuration descrambles the audio by performing PN addition on the audio data bitstream, and then converts the descrambled audio signal to the analog baseband. This method involves converting the data into a MUSE decoder and connecting it to the MUSE decoder at the subsequent stage, which has the following problems.

(1) Since the audio data area during vertical blanking of the analog MIISE signal including the descrambled MUSE video signal output from the independent MUSE pay-TV decoder remains scrambled, the independent MUSE
The audio data during vertical blanking cannot be normally decoded by the MUSE decoder after the E pay broadcast decoder. This requires the MUSE VTR to have new functions, such as independent four-channel audio tracks for recording and playing back programs obtained by descrambling scrambled broadcasts.

(2) Scrambling related information remains in the independent data area of the audio data area during vertical blanking. This scramble-related information includes not only information for unscrambling but also information such as billing processing for paid broadcasting.
Normal operation is not guaranteed when the video is recorded using R or the like and later played back using a stand-alone MIISE pay broadcast decoder or a MIISE decoder with a built-in pay unit.

(3) Since the audio signal descrambled by the independent MUSE pay broadcast decoder is connected to the MUSE decoder on four channels independently from the video signal, a large number of signal lines are required for connection.

(4) The audio after descrambling is connected in an analog state to the MIISE decoder at the subsequent stage, resulting in deterioration of sound quality.

The present invention solves the above-mentioned problems by solving the problem after unscrambling paid broadcasting. IUSE signal is normal non-scrambled M
It provides an independent MUSE pay broadcasting decoder that can be handled in the same way as a USE signal, that is, it facilitates connection with a MIISE decoder, eliminates the need for new functions on the MtlSE VTR, and does not degrade sound quality due to connection. It is.

Means for Solving the Problems In order to achieve the above objects, the independent type M 11 S of the present invention
[The i pay broadcast decoder includes a scrambling-related information bit erasing section in the audio data bitstream, and an MU
SE audio encoding processing unit: 16-bit interleaving, BCH (82, 74) error correction code addition, 25 frame interleaving, time axis compression, binary/ternary conversion, 1
Adopts a transversal filter for audio data rate conversion from 2.15M) Iz to 16.2MIIz, a delay circuit for adjusting the timing of multiplexing video signals with audio data, and a multiplexing circuit for audio data in the vertical blanking period. It is a combination.

Operation According to the above-described configuration, the scrambled audio data bit stream is descrambled by the PN signal output from the descrambling unit, and after erasing bits related to scrambling, 16-bit interleaving and BCH (82, 74) error correction are performed. Code addition, 25 frame interleave, time axis compression, binary/ternary conversion, 12.
By performing MUSE audio encoding processing of audio data rate conversion from 15MHz to 16.2MHz and remultiplexing during vertical blanking of the MUSE signal containing the descrambled video signal, the The MUSE signal can be treated in the same way as a normal non-scrambled MUSE signal.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows MIISE in one embodiment of the present invention.
This shows the configuration of a pay broadcast decoder.

In FIG. 1, reference numeral 2 denotes an analog MUSE signal input terminal, into which normally a scrambled MUSE signal is input. 3 is an A/D converter that converts the analog MUSE signal into a digital MIISE signal. 4 is a Glock synchronization playback unit, which converts the digital signal processing standard clock 16.2MIIz (hereinafter referred to as VCK) from the digital I/MUsE signal and the video horizontal synchronization signal (hereinafter referred to as HD) necessary for each part of the independent MIISE pay broadcast decoder. , reproduces the video frame synchronization signal (hereinafter referred to as VFRAM) and
Supplied to various parts within the USE pay broadcast decoder.

5 is an audio processing unit, which converts 1.35 from the digital MUSE signal.
Important 2: In addition to reproducing the audio data bit stream (hereinafter referred to as DBS) after 16-bit deinterleaving at the rate, the audio frame synchronization signal (hereinafter referred to as FSY) and the audio data reference clock of 1.35 MHz (hereinafter referred to as A
CK) is supplied to the descramble unit.

6 is a descrambling unit which extracts scramble-related information from the DBS 13, descrambles the scrambled digital JL/MUSE signal 19 based on this, outputs a descrambled MIISE signal 12, and adds the scrambled signal to the scrambled signal 19. A pseudorandom signal (hereinafter referred to as PN) for descrambling the audio data bitstream 13 is generated. 7 is an exclusive OR element which outputs a descrambled DBS 15 by performing an exclusive OR of the DBS 13 and the PN signal 11 for descrambling. 43 is a scrambling related information bit erasing section which erases information bits related to scrambling multiplexed in the DBS 15.

41 is a bit interleave section, which is
Re-interleaves the 6-bit deinterleap. 42 is a BCH (82, 74) error correction code addition device that performs 8-bit error correction on 74 information bits in each row of the bit interleave matrix, excluding the descrambled synchronization signal and control code bits of DBS15. Add bits. 44 performs interleaving between 25 audio frames based on the vertical blanking period in the MUSE signal multiplexed in the 25 audio frame interleaving section.

Reference numeral 45 denotes a time axis compression unit which converts audio data at a rate of 1.35 MIIz into burst data for multiplexing within the vertical period of the MIJSE signal. 46 is a binary/ternary converter that converts continuous binary data into two consecutive three-value samples. Reference numeral 47 denotes a conversion filter that performs frequency conversion to match the 12.15 MBaud audio data, which has been subjected to time axis compression and binary/ternary conversion, to the video signal sample rate of 16.2 M rate. 48 is a video signal delay circuit;
Delay the video signal to match the timing with the audio signal. 49 is an audio multiplexing timing control section, and a video delay circuit 4
During the vertical retrace period of the output MtlSE signal from 8, a signal indicating the audio multiplexing area is output. Reference numeral 50 denotes a signal changeover switch, which connects the output from the video delay circuit 48 and the output from the audio data time axis compression section 47 to the audio multiplexing timing control section 49.
Switched by the output signal. 51 is a D/A converter;
Convert digital MUSE signal to analog MIISE signal. 52 is a MUSE signal output terminal, which is connected to the MUSE decoder and M[ISE VTR.

The operation of the MIISE pay broadcast decoder configured as described above will be explained below using FIG. 1. The explanation will be given by taking as an example a case where a MUSE signal in which both video and audio are scrambled is input. The input MUSE signal is digitally converted by the A/D converter 3 and supplied to the descrambling unit 6, the audio processing section 5, the clock, and the synchronous reproduction section 4. Descrambling processing is performed as follows. First, the descrambling unit 6 extracts and decodes the scramble related information in the DBS 13 from the audio processing section 5.

FIG. 4 shows the location of scramble-related information. FIG. 4 is an audio frame configuration diagram showing the focus allocation when multiplexing A-mode signals, the multiplexing position of scramble-related information, and bit allocation in the DBS 13 state. As shown by diagonal lines in FIG. 4, the scramble-related information bits are multiplexed into the control code, range bit, and independent data area.

In addition, these multiplexed scramble-related information bits can be divided into two types depending on the multiplex position: those that exist at a fixed position in the audio frame for each audio mode, and those that exist diagonally multiplexed in an independent data area whose area changes depending on the audio mode. being classified. Scramble-related information vias present in the control code area and range bits exist at fixed positions for each audio mode. The respective bits and positions are shown below. Video scramble flag bit...control code 12th focus,
Scramble timing bit: 13th control code pinto, audio scramble flag pinto: r#B bit position. On the other hand, FIG. 6 shows how scramble-related information is multiplexed diagonally in an independent data area whose area changes depending on the audio mode. FIG. 5 is a diagonal multiplexing method diagram showing how 288 bits of scrambling related information focus is multiplexed between 18 audio frames in A1 mode. As shown in FIG. 5, diagonal multiplexing of scramble-related information is performed for each line in the audio frame, one bit at a time.
One unit is 8 audio frames, or 288 bits (hereinafter, these 18 audio frames are defined as a super frame).

The descrambling unit 6 extracts and decodes these scramble-related information bits from the DBSL 3, and as for the video signal, descrambles the scrambled digital MIISE signal 19 and generates the digital descrambled video signal 1.
Outputs 2. As for the audio signal, a PN signal 11 is generated so that it can be descrambled by the exclusive OR element 7 at the subsequent stage. Is the audio processing unit 5 digital? The audio data of the blanking period is extracted from the IUSE signal, and for descrambling, the audio signal format is returned to the scrambled position on the broadcasting station side, that is, the state where PN addition has been performed to the audio DBS 13. Since the audio signal is scrambled just before bit interleaving, the receiving side returns the audio signal format to the audio frame format in this state, and adds the same PN signal 11 that was added during scrambling to the DBS 13 as an exclusive logic The audio signal is descrambled by addition by the summation element 7.

Next, the descrambled DBS 15 is input to the scramble related information bit erasing section 43. The related information focus erasing unit 43 erases all the scramble related information in the data bitstream after descrambling.

This is because if the scramble-related information remains in the descrambled MUSE signal, the subsequent MUSE decoder will scramble it even though the M[ISE signal has been descrambled? This is because the program cannot be viewed normally because it is recognized as an IUSE signal.

FIG. 2 shows an example of the circuit configuration of the scramble-related information erasing section. In FIG. 2, 15 is an audio DBS, and the output j of the exclusive OR element 7 is input thereto.

62 is an audio frame synchronization signal (FSY), and 63 is an audio reference clock of 1.35 MHz (8 CK). 60 is an audio bit counter which is reset for each audio frame and counts from 0 to 1349 in response to ACK 63. A bit gate 69 indicates the timing of related information bits that exist at fixed positions in the audio frame depending on the audio mode, such as the control code bit and the R#8 bit, among the scramble-related information bits. 64 is a data flip-flop, and the first bit of the control code indicates the A/B mode of the audio (hereinafter, the first bit to the 22nd bit of the control code are referred to as bits, respectively).
~b#22) is detected.

Reference numeral 68 denotes a diagonal multiplexing timing generation circuit which detects the audio mode for determining the diagonal multiplexing position in the audio frame of scramble-related information and outputs a pulse indicating the start timing of each row of the audio frame. 90 is a pulse for IJI detection of DBS15, and 91 is a bill indicating audio mode.
Timing pulse for detecting lJ6, 92 indicates the audio mask frame timing transmitted every 2 superframes, that is, 36 audio frames b#1
A timing pulse 93 is used to detect 4, and a pulse signal 93 indicates the beginning of each line in the audio frame.

70 is a data flip-flop, and b indicates the audio mode.
The timing pulses 91 of 11 to b16 are delayed by 1/2 clock. 71 is an AND device, which outputs the audio reference clock A.
By gating CK with the output of data flip-flop 70, a burst timing clock is generated for detecting bll-bl16 indicating the audio mode of data bit stream 15. 72 is a data flip-flop block that detects IJI to bl16 of the data bit stream using the burst clock from 71. 73 is a shift register, 74 is a data flip-flop, and the data flip-flop 72 is
The outputs of b#1 to b#6 are output in parallel. Reference numeral 75 denotes a data flip-flop, which detects the bll14 in the DBS 15 by a b old 4 detection timing Hals 92 for each audio frame in order to detect the audio mask frame timing. 76 is a data flip-flop, 78 is an AND element, and by this combination, the b#14 detection signal output from the data flip-flop 75 is differentiated into one clock width.

Reference numeral 79 is an audio frame row counter, which is a 288-decimal counter that is reset every mask frame, that is, every 36 audio frames.
287 is counted and output. Reference numeral 94 denotes a delay adjustment circuit which adjusts the timing so that the audio frame row counter 79, which uses the line pulse 93 as a counter clock, is appropriately reset based on the output of the AND element 78.

Reference numeral 80 denotes a bit position counter in the audio frame row, which is reset every line pulse 93 and outputs a count from 0 to 81. 81 is a ROM, and a data flip-flop 74
Each audio mode output value and audio frame in-line counter 79
The diagonally multiplexed bit position in each row of scramble related information bits is output from the output value.

82 is a comparator that connects the output of the bit position counter 80 and the ROM
A pulse is generated when the outputs of 81 are equal.

Reference numeral 65 denotes an AND element, which erases the scramble-related information bits at fixed positions in the audio data bit stream by forcing them to LOW based on the output of the dot logic 69. 95 is a delay adjustment circuit for timing adjustment between the output of the dot robot 9 and the data bit stream. 9
Reference numeral 6 denotes a delay adjustment circuit for the data bit stream, which adjusts the timing with respect to the output of the dot logic 69 and the output of the comparator 82.

Reference numeral 67 denotes an AND element, which erases the diagonally multiplexed bits of the scramble-related information bits in the audio data bit stream by forcibly turning them LOW based on the output of the comparator 82.

The operation of the scramble-related information bit erasing section will be explained below with reference to FIGS. 2 and 3.

FIG. 3 is a signal waveform diagram showing signal waveforms of each part of the scramble-related information erasing section shown in FIG. 2.

Numbers 1 to 135 shown in the waveform of DBS15 in Figure 3
0 indicates the sending order of each bit in the audio frame in oBs type B. aFSY62 is an audio frame synchronization signal indicating the timing of the first bit of the audio frame as shown in .

First, the video scramble flag bit, which is located at a fixed position for each audio mode, is the 12th bit of the control code, the scramble timing bit, the 13th bit of the control code, and the audio scramble flag bit..."#8 Scrambling at the focus position. The deletion operation of the related information pin [- will be explained. The bll 90 outputs a pulse at the timing of detecting the bll as shown in FIG. 3, and the detected DBS 15
The bill signal, that is, the audio A/B mode, is connected to the bit gate 69 as shown in FIG. As a result, the Bisito Gatero 9 has fixed positions for each audio mode, such as the video scramble flag bit, the control code 12th pinpoint, the scramble timing pin 1, and so on.
- 13th bit of control code, audio scramble flag focus...Outputs a pulse signal indicating the rt18 bit position. A delay-adjusted version of this pulse signal is the output of the delay adjustment circuit 95 shown in FIG. 3. By using this as a gate signal and forcing the corresponding bit of the delay DBS 64 to O- at the timing shown in FIG. The scramble-related information focus at a fixed position is erased for each audio mode.

Next, the operation of erasing the scramble-related information bits that are diagonally multiplexed in the independent data area that changes depending on the audio mode will be explained with reference to FIGS. 2 and 3. The scramble-related 1!1 bits that are diagonally multiplexed are configured with a superframe (18 audio frames) as one unit.

This 18 audio frame unit is a mask frame first frame identification bit bll1 sent every 36 audio frames.
It is detected on the receiving side based on 4. The output signal of the data flip-flop 75 shown in FIG.
It shows the results of detecting bll and l in the BS15 signal.

The example in FIG. 3 shows that bll4 of this audio frame is active, that is, it is the first audio frame of the master frame. This signal is as shown in Figure 2.
It is connected to a data flip-flop 76, an AND element 78, and a delay element 94, and is differentiated and delayed so that a line counter 79 is reset at the timing of a line pulse 93 (not shown in FIG. 3).

The output of the line counter 79 thus reset is used to count and amplify the line pulses 93 for one super frame (between 18 audio frames) from 0 to 287, as shown in FIG.

Further, the in-line focus counter 80 is reset by the line pulse 93 as shown in FIG. 3, and counts and outputs the in-line focus positions 0 to 81 of each audio frame.

On the other hand, the output of the data flip-flop 74 is as shown in FIG.
It is output to the ROM 81 at every 1492 timings.

The ROM 81 determines the independent data area in the audio frame from the audio mode indicated by bill to b#6, and further calculates the bits of scramble-related information in the corresponding diagonal multiplexing in the independent data area based on the output of the line counter 79. The multiplex position is output for each row as shown in the output of ROW 81 in FIG. A comparator 82 compares the output of this ROM 81 and the output of the in-line counter 80, and when they match, generates a pulse signal as shown in the output of the comparator 82 in FIG.

Using the output signal of the comparator 82 as a gate signal, the AND element 67 forces the diagonally multiplexed bits of the 1-tahit stream to LOW, thereby erasing the diagonally multiplexed scramble related information bits. As mentioned above,
All information bits related to the ripples in the DBS are erased and input to the bit interleaving unit 41 in FIG.

The subsequent processing will be described below with reference to FIG.

Bit interleave unit 41, BCH (82, 74)
Processing unit 42.25 Frame interleaving unit 44
, 2/3 value conversion device 46.12.15- >16.2M
112 conversion filter unit 47 is an MU that re-encodes the MUSE audio processing decoded by the audio processing unit 5.
This is the SE audio encoding processing section, but this is a normal MU
Since it is the same as the corresponding part of the SE audio encoding processing section, the explanation will be omitted here. Next, changeover switch 5
0 switches the output signal from the output of the audio/video delay circuit 48 to the audio signal side during the audio multiplexing period according to the output signal of the audio timing control section 49.

As described above, according to this embodiment, the scrambled digital MtlSE signal and the audio data bitstream after 25-frame deinterleaving and BCI+ (82,74) error correction are input, and the audio data bitstream is descrambled. pseudorandom signal (
PN signal) and scrambled digital M [digitano L/ which descrambled the video signal part of the ISE signal
A desk simple unit device that outputs a MUSE signal, and a PM output from the descrambling unit device.
an exclusive OR device that adds the signal and the scrambled audio data bitstream and descrambles and outputs the audio data bitstream; and an exclusive OR device that receives the descrambled audio data bitstream as input and erases multiplexed scramble-related information bits. a scrambling-related information bit erasing device that erases the scramble-related information bits, and re-Ms the audio data bitstream from which the scramble-related information bits have been erased.
Bit interleaving device for USB audio encoding, BC) + (82,74) CF.

correction addition device, 25 frame interleaving device, time axis compression device, binary/ternary conversion device 12.15MHz/
a re-audio MUSE encoding device comprising a 16.2MHz resampling waveform shaping filter device; a delay device for delaying the digital MUSE signal output from the descrambling unit device in which the video signal portion has been descrambled; The descrambled and re-MIISE audio encoded MUS to the audio data signal position
By providing a signal switching device that multiplexes E audio signals and a timing control device that controls the signal switching device, after descrambling the audio signal portion of the scrambled MUSE signal, the multiplexed scramble related information bits are erased; After the re-MUSE audio encoding process, the video signal section is re-multiplexed with the descrambled MUSE signal, thereby making it possible to output a signal in the normal MUSE signal format in which the scrambled MUSE signal has been descrambled.

Effects of the Invention As described above, according to the present invention, a scrambled digital MUSE signal and an audio data bitstream after 25 frame deinterleaving and BCH (82, 74) error correction are input, and the audio data bitstream is descrambled. Pseudo random signal (PN signal) for
Digitano L/MUSE which descrambled the video signal part of the scrambled Digitalano L/MUSE signal.
a desk simple unit device that outputs a signal; an exclusive OR device that adds a PN signal output from the descrambling unit device and a scrambled audio data bitstream and descrambles and outputs the audio data bitstream; a scramble-related information bit erasing device that receives a descrambled audio data bit stream as input and erases multiplexed scramble-related information; and a device for re-MUSE audio encoding the audio data bit stream from which the scramble-related information bits have been erased. Bit interleaving device, B
CII (82,74) Error correction addition device, time axis compression device, binary/ternary value conversion device, 12.15MHz/16
．． a re-audio MUSE encoding device comprising a 2MHz resampling waveform shaping filter device; a delay device for delaying the digital MUSE signal output from the descrambling unit device in which the video signal portion has been descrambled; and audio data output from the delay device. The signal position is descrambled and re-? ILISE audio encoded MU
By providing a signal switching device that multiplexes SE audio signals and a timing control device that controls the signal switching device, the scrambled MUSE signal can be descrambled and output in the regular MUSE signal format. Paid TV Tele-I'I&Danni? It is possible to connect with various types of MUSEa devices such as IUSEV TR, and in this case, the audio signal part is descrambled and then converted into the MtlSE signal in digital signal format, so there is no deterioration in sound quality. It has no effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a pay broadcast decoder in an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the main part of the present invention, and FIG. 3 is a block diagram showing the operation of FIG. 2. Fig. 4 is a frame configuration diagram of the MIJSE audio signal without showing the multiplexing position of scramble-related information.
□The figure is a scramble-related information multiplexing method diagram showing a method of diagonally multiplexing scramble-related signals into independent data areas, No. 6.
The figure is a block diagram showing the configuration of a conventional MIISE pay broadcast decoder. 6... Descrambling unit device, 7...
. . . Exclusive OR device, 41 . . . Bit interleaving device, 42 . . . BCH (82, 74
) Error correction code adding device, 43°... Scramble related information bit erasing device, 44...25
Frame interleave device, 45...Time axis compression device, 46...2(+!/3) Typesetting and word conversion device...12, 15/16.2MHz resampling waveform Shaping filter device, 48... Delay device, 49... Timing control device, 50...
...Signal switching device. Name of agent: Patent attorney Akira Kokaji and 2 other famous painters 4
figure

Claims (1)

[Claims] Scrambled digital multiplex subsampling encoded signal and 25 frame deinterleaving, BCH (
82, 74) A digital signal that takes an error-corrected audio data bitstream as input and performs descrambling processing on a pseudorandom signal for descrambling the audio data bitstream and a video signal portion of a scrambled digital multiplex subsampling encoded signal. a descrambling unit device that outputs a multiplex subsampling encoded signal;
an exclusive OR device that adds a pseudo-random signal outputted from the descrambling unit device and a scrambled audio data bitstream, and descrambles and outputs the audio data bitstream; , a scrambling related information bit erasing device for erasing multiplexed scramble related information bits, a bit interleaving device for re-multiplexing and subsampling audio encoding the audio data bit stream from which the scrambling related information bits have been erased, and a BCH (
82, 74) Re-audio multiplex subsampling code encoding consisting of error correction addition device, 25 frame interleave device, time axis compression device, binary/ternary conversion device, and 12.15MHz/16.2MHz resampling waveform shaping filter device a delay device for delaying the digital multiplex subsampling encoded signal output from the descrambling unit device with the video signal portion descrambled; and a delay device for delaying the digital multiplexed subsampling encoded signal output from the descrambling unit device with the video signal portion descrambled, and the descrambled and remultiplexed signal at the audio data signal position output from the delay device. A signal switching device for multiplexing multiple subsampling encoded audio signals subjected to subsampling audio encoding, and a timing control device for controlling the signal switching device: An audio signal portion of the scrambled multiplex subsampling encoded signal. After descrambling, the multiplexed scramble-related information bits are erased, and after re-multiplexing subsampling audio encoding processing, the video signal part is re-multiplexed into the descrambled multiplex subsampling encoded signal, thereby performing scramble multiplexing. A pay broadcast decoder characterized in that it descrambles a subsampling coded signal and outputs it in a regular multiplex subsampling coded signal format.