JPH06165175A - Pay broadcast decoder for high quality television - Google Patents

Abstract

PURPOSE:To attain reproduction of high quality by descrambling a multi- sampling encoding signal and validating an iteration flag in the outputted multiple sampling encoding signal until the completion of waveform equalization. CONSTITUTION:When a power supply for a high quality television(TV) pay broadcast decoder is turned on, a waveform equalizing device 30 stars the sampling of a VITS signal for multi-sampling encoding (MUSE). Since a flag output 32 from the device 30 indicates the execution of VITS signal sampling, an output from a decoding device 150 is validated and a signal indicating the execution of waveform equalizing calculation is outputted. An iteration flag changing device 90 validates an iteration flag in a transmission control signal. The device 30 determines a filter coefficient, and at the time of completing waveform equalization, a flag output from the device 30 indicates the completion of waveform equalization, so that the output of the device 150 is invalidated and the device 90 does not change the iteration flag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a high-definition television (MUSE method = Multiple Sub-Nyqu).
The present invention relates to a high-definition television pay broadcast decoder that enables scrambling only by subscribed subscribers to view a program in pay broadcasting, which is developed by istampling encoding (multiple sampling coding) system.

[0002]

2. Description of the Related Art In recent years, pay broadcasting has been put into practical use with the expansion of broadcasting satellites. In the pay broadcasting, unlike the conventional broadcasting format by the advertisement fee and the receiving fee, it is necessary to deliver the program only to the contracted recipient, and therefore, the program is normally electrically disturbed (scrambled) to be broadcast. Therefore, in order to view a pay broadcast program, a pay broadcast decoder for descrambling and normally viewing the program is required.

Conventionally, as a pay broadcast decoder for high-definition television (multiple sampling coding system (hereinafter referred to as MUSE system)) signals, a system in which a descramble circuit block is built in the MUSE decoder as a pay broadcast unit has been considered. ing. On the other hand, for MUSE devices such as existing MUSE decoders, a stand-alone high-definition television pay broadcast decoder that can treat the MUSE signal after descrambling the pay broadcast as an ordinary non-scrambled MUSE signal is considered. ing.

An example of the above-mentioned conventional stand-alone high-definition television pay broadcast decoder will be described below with reference to the drawings.

FIG. 5 shows an example of the configuration of a conventional high-definition television pay broadcast decoder. In FIG. 5, reference numeral 10 denotes an analog MUSE signal input terminal to which a scrambled MUSE signal is normally input. 20 is A
A / D converter converts analog MUSE signal to digital MUS
Convert to E signal. A waveform equalizer 30 performs waveform equalization based on the VITS signal multiplexed in the MUSE signal. An audio processing unit 50 reproduces an audio data bit stream 51 (hereinafter referred to as DBS) after 16-bit deinterleaving at a rate of 1.35 MHz from a digital MUSE signal. A pay unit 40 takes out scramble-related information from the DBS 51, and based on this, descrambles the scrambled digital MUSE signal 31 and outputs a descramble MUSE signal 41, and at the same time, adds the scrambled audio data bit stream. A pseudo random signal 71 (hereinafter referred to as PN) for descrambling 51 is generated.
Reference numeral 70 denotes an exclusive OR element, which takes an exclusive OR of the DBS 51 and the PN signal 71 for descrambling. 80
Is a voice remultiplexing encoder, and the descrambling D
Re-encoded BS and unscrambled video signal 4
Remultiplex to 1. 110 is a D / A converter, which is a digital M
Convert the USE signal to an analog MUSE signal. The analog-converted MUSE signal is normally connected to a MUSE device such as a MUSE decoder. 120 and 130 are the latter M
An A / D converter and a waveform equalizer of a USE decoder.

The operation of the conventional MUSE pay broadcast decoder configured as described above will be described below with reference to FIG. MU with scrambled video and audio
The case where the SE signal is input will be described as an example. The input MUSE signal is digitally converted by the A / D converter 20 and supplied to the waveform equalizer 30. Waveform equalizer 30
Then, the VITS signal multiplexed in the MUSE signal is sampled for a certain period, the filter coefficient for waveform equalization is determined based on this, and the MUSE signal after waveform equalization is output to the pay unit in the subsequent stage.

The pay unit 40 extracts and decodes the scramble-related information from the DBS 51, and based on this, descrambles the video signal and outputs the digital descramble video signal 41. For the audio signal, the PN signal 71 is generated so that it can be descrambled by the exclusive OR element 70 in the subsequent stage. The audio processing unit 50 extracts the audio data multiplexed during the blanking period from the digital MUSE signal and, for descrambling, the position scrambled by the broadcasting station, that is, up to the state where PN addition is performed on the audio signal. Returns the audio signal format. Since the audio signal is scrambled immediately before bit interleaving, the receiving side returns the audio signal format to the audio frame format in this state, and the same PN signal 71 as that added to the DBS 51 at the time of scrambling is subjected to exclusive logic. The addition is performed by the sum element 70 to descramble the audio signal.

Next, the descrambled DBS is re-encoded by the audio re-multiplex encoder 80 and then re-multiplexed during the vertical blanking period of the descrambled video signal 41. Furthermore, this MUSE signal is sent to the D / A converter 1
The analog conversion is performed by 10 and is input to a MUSE device such as a subsequent MUSE decoder. In the subsequent MUSE device, normal MUSE signal processing is performed via the A / D converter 120, the waveform equalizer 130, and the like.

[0009]

However, when the MUSE device is connected to the conventional high-definition television pay broadcast decoder having the above-mentioned structure, the MUSE connected to the latter stage is connected.
In the equipment, V for determining the waveform equalization filter coefficient
Since there is a possibility that the ITS signal sampling will compete for waveform equalization performed before the completion of waveform equalization by the high-definition television pay broadcast decoder in the preceding stage, after the waveform equalization by the high-definition television pay broadcast decoder is completed, However, the waveform equalization filter coefficient in the latter-stage MUSE device is not always optimum, and thus has a problem of causing image quality deterioration and the like.

In order to solve the above problems, the present invention prevents the contention of the waveform equalization operation of the high-definition television pay broadcast decoder and the MUSE device connected in the subsequent stage, and enables high-quality television pay broadcast. It realizes a decoder.

[0011]

In order to achieve the above object, a high-definition television pay broadcast decoder according to the present invention comprises:
A waveform equalizer that inputs a digital MUSE signal output from a D / D converter, forms a filter for waveform equalization based on the multiplexed VITS signal, and outputs a waveform equalization operation monitor flag , An iteration flag changing device for changing the iteration flag of the transmission control signal in the MUSE signal by the waveform equalizing operation monitor flag output from the waveform equalizing device.

[0012]

According to the present invention, with the above-described configuration, the waveform equalizer operation monitor flag output from the waveform equalizer in the high-definition television pay broadcast decoder is maintained until the equalization is completed while the filter coefficient is being calculated. According to the invention, the waveform equalizer in the MUSE device in the subsequent stage is made a high-definition television by enabling the iteration flag of the transmission control signal in the descrambled MUSE signal output from the high-definition television pay broadcast decoder. By preventing the waveform equalizer in the pay broadcast decoder from operating until the equalization is completed, it is possible to prevent the conflict between the waveform equalization operation between the high-definition television pay broadcast decoder and the MUSE device in the subsequent stage, and to reproduce high quality images. It is possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of a high-definition television pay broadcast decoder according to an embodiment of the present invention.

In FIG. 1, the same components as those of the conventional example will not be described here to avoid duplication. Three
2 is an operation monitor flag output from the waveform equalizer.
Indicates that the ITS signal is being sampled / the filter coefficient is being calculated / equalization is completed. An iteration flag changing device 90 changes the iteration flag of the transmission control signal in the digital MUSE signal. A decoding device 150 converts the operation monitor flag output from the waveform equalization device into a 1-bit signal indicating that the waveform equalization calculation is in progress / completion.

The operation of the high-definition television pay broadcast decoder of the present invention configured as described above will be described below with reference to FIG. The descrambling operation of the input MUSE signal is the same as that of the conventional example, and therefore its explanation is omitted here.

First, when the power of the high-definition television pay broadcast decoder is turned on, the waveform equalizer 30 starts VITS signal sampling for waveform equalization of the MUSE signal. At this time, since the flag output 32 from the waveform equalizer 30 indicates that the VITS signal is being sampled, the output of the decoder 150 becomes valid and outputs the waveform equalization calculation signal, and the iteration flag in the transmission control signal is output. The change device 90 enables the iteration flag.

Here, the transmission control signal and the iteration flag will be described with reference to FIGS. 3 and 4.
Is a list showing the contents of the transmission control signal in the MUSE signal. As shown in the figure, the iteration flag is assigned to bit number b13 and is set to 1 (valid) during the iteration operation on the transmitting side. On the other hand, in the waveform equalizer on the receiving side, normally, when the iteration flag is 1, the equalizing operation is stopped to prevent the competing operation.

FIG. 4 shows the transmission order of each block of the transmission control signal. The transmission control signal in the MUSE signal consists of 32 bits shown in FIG. 3, and is divided into 8 groups in units of 4 bits from the smallest number, and each group is composed of (8, 4) expanded Hamming code for one block 8
Bits are configured, the left 4 bits are information bits, the right 4 bits are check bits, and the data is transmitted from the left. 1 to
Each block of 8 is transmitted three times at the timing shown in FIG.

Further, the iteration flag changing device will be described with reference to FIG. FIG. 2 shows the internal configuration of the iteration changing device 90. In FIG. 2, 31
A timing generator 0 outputs the block position timing including the iteration flag in each field. A control signal extracting unit 320 extracts a corresponding block including an iteration flag of the transmission control signal in the MUSE signal. A (8, 4) extended Hamming code check device 330 corrects an error in a block. An iteration flag validator 340 sets the iteration flag bit to 1. Reference numeral 350 denotes an (8,4) extended Hamming code generator, which adds (8,4) extended Hamming code to 4 bits of information bits including an iteration flag. A signal switching device 370 switches the output signal at an appropriate timing to replace the block including the iteration flag in the transmission control signal with the block in which the iteration flag is changed. Three
A logical product device 60 controls the operation of the signal switching device 370.

The operation of the iteration flag changing device configured as described above will be described below. Since the iteration flag b13 is included in the fourth block of the transmission control signal, the control signal extracting device 320 extracts the control signal of the fourth block for 8 bits including the error correction code. (8, 4) The expanded Hamming code check device 330 outputs the error-corrected 4-bit information bits. The iteration flag operating device 340 sets the iteration flag bit b13 to 1
And Further, (8, 4) expanded Hamming code generator 3
At 50, code generation is performed on the 4-bit information bit including the changed iteration flag bit, and the fourth block having the 8-bit configuration is generated again. The generated fourth block is inserted into the corresponding block position in the MUSE signal by the signal switch 370. In the logical product device 360, the insertion operation of the fourth block is performed only when the output of the decoding device 150 is valid, and is controlled so that the fourth block is not inserted after the waveform equalization is completed, that is, when the output of the decoding device 150 is not valid. There is.

The operation of FIG. 1 will be described below. Next, when the VITS signal sampling is completed by the waveform equalizer 30 and the filter coefficient calculation is started, the flag output 32 from the waveform equalizer 30 indicates that the filter coefficient is being calculated, but the output of the decoding device 150 is the waveform etc. Since the conversion is not completed, it does not change in the valid state, and the iteration flag changing device 90 validates the iteration flag.

When the filter coefficient is determined in the waveform equalizer 30 and the waveform equalization is completed, the flag output from the waveform equalizer 30 indicates the completion of the waveform equalization, so the output of the decoding device 150 becomes ineffective. The iteration flag changing device 90 does not change the iteration flag.

At this time, in the latter MUSE device,
Since the iteration flag is valid until then, the stopped waveform equalizer starts the equalization operation. As a result, in the MUSE device in the latter stage, VITS signal sampling is performed on the MUSE signal for which waveform equalization is completed by the high-definition television pay broadcast decoder in the former stage to perform waveform equalization, and there is a conflict in waveform equalization. Absent.

As described above, according to this embodiment, the iteration flag in the MUSE signal output from the pay broadcast decoder is valid until the waveform equalization in the high quality television pay broadcast decoder is completed. There is no competition for waveform equalization with the waveform equalizer in the MUSE device, and the high-definition high-definition signal can be reproduced in the MUSE device in the subsequent stage.

[0025]

As described above, according to the present invention, a filter for waveform equalization based on the VITS signals multiplexed with the digital multiple sampling coded signal output from the A / D converter as an input. And a waveform equalizer for outputting a flag indicating that the filter coefficient is being calculated / finished, and a transmission control signal in the descrambled MUSE signal output from the high-definition television pay broadcast decoder of the present invention. By providing an iteration flag changing device that effectively changes the iteration flag b13 until the waveform equalization in the pay broadcast decoder is completed, the waveform equalization is completed in the high-definition television pay broadcast decoder in the former stage in the latter MUSE device. Waveform equalization is performed on the generated MUSE signal, and there is no competition for waveform equalization. You can play vision signal, and makes it possible provide a high definition television pay television decoder by the simple structure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a high-definition television pay broadcast decoder according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a main part of the present invention.

FIG. 3 is a transmission control signal list diagram showing the contents of a MUSE signal transmission control signal.

FIG. 4 is a block transmission sequence diagram showing a transmission sequence of each block of a transmission control signal.

FIG. 5 is a block diagram showing a configuration of a main part of a conventional high-definition television pay broadcast decoder.

[Explanation of symbols]

 20 A / D converter 30 Waveform equalizer 40 Pay unit 50 Speech processing device 70 Exclusive OR device 80 Speech remultiplexing encoder 90 Iteration flag changing device 110 D / A converter 150 Decoding device

Claims (1)

[Claims] 1. An A / D converter that receives a multiplex sampling coded signal in an analog state and outputs a digital multiplex sampling coded signal, and a digital multiplex sampling coded signal output from the A / D converter. A waveform equalizer that forms a filter for waveform equalization based on the multiplexed VITS signal as an input and outputs a waveform equalization operation monitor flag, and a digital multiple sampling coded signal as an input,
Voice frame deinterleave, BCH (82,74)
An audio processing unit that outputs an audio data bit stream after error correction, a digital multiple sampling coded signal output from the waveform equalizer and an audio data bit stream output from the audio processing unit as inputs, and a video signal. A pay unit device that outputs a pseudo-random signal for descrambling the digital multiple sampling coded signal and the audio data bitstream that have been subjected to the descrambling process of a part, and a pseudo-random signal output from the descrambling unit device. An exclusive OR device that adds the scrambled audio data bitstreams and descrambles the audio data bitstreams, and a descrambled audio data bitstream output from the exclusive OR device as input, Day After the re-encoding process, the audio re-multiplex encoding device for re-multiplexing to the video signal, and the iteration flag in the transmission control signal of the multiple sampling encoded signal output from the audio re-multiplex encoding device, the waveform An iteration flag changing device for changing the waveform equalization operation monitor flag outputted from the equalizing device, and a D / A for analog-converting and outputting the multiple sampling coded signal outputted from the iteration flag changing device.
A converter, which descrambles the scrambled multi-sampling coded signal, and completes the waveform equalization in this device until the data in the multi-sampling coded signal output from this device A high-definition television pay broadcast decoder characterized by preventing the contention of waveform equalization operation with subsequent high-definition related equipment by enabling the activation flag.