JPH09205598A - Digitall television broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce occurrence of interference problems and to decrease number of program selection means by providing the program selection means selecting nearly simultaneously plural desired programs from a multiplex signal subject to error correction decoding and providing an output so as to reduce number of amplifier channel selection means. SOLUTION: A digital modulation signal is received from a reception input terminal 104, an amplifier channel selection means 10 selects a channel, a digital demodulation means 11 conducts digital demodulation, an error correction decoding means 12 decodes error correction, a program selection means 130 releases interleave multiplexing. Then the program selection means 130 uses a control microcomputer 20 to select plural desired programs and provides outputs 200-1, 200-2-200-N of plural sets of compression coding video information, compression coding audio information and additional information corresponding to each program. Through the constitution above, number of the program selection means is simplified into 20 sets and since number of amplifier channel selection means 10 is reduced, mutual interference is reduced and the circuit scale is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital television broadcasting such as satellite broadcasting, cable television broadcasting (CATV) and terrestrial television broadcasting in which a plurality of video information and audio information are compression-multiplexed and digitally modulated.
In particular, the present invention relates to a digital television broadcast receiver suitable for secondary use of multiple programs and multi-screen display for simultaneous display on the screen.

[0002]

2. Description of the Related Art In order to make effective use of a limited number of channels such as terrestrial broadcasting, satellite broadcasting and communication satellites, a highly efficient digital image compression technology and digital broadcasting are provided for one program service for one channel of conventional analog television broadcasting. By using the modulation technique, multi-channel digital television broadcasting is planned in which a plurality of program services are provided on one channel in the analog transmission band. The multi-channel digital television broadcasting system is described in "A multi-channel broadcasting assumed block diagram" in Figure 2-2-1 on page 21 of the "Study Group on Long-term Vision of Satellite Broadcasting Technology Interim Report" December 4, 1992. There is an example of disclosure. Further, digital image compression is described in FIG.
-2, there is a disclosure example of "Structure and elemental technology of a typical digital compression encoding system".

FIG. 7 shows a block diagram of a conventional example. In the figure,
1 is a transmitter, 2 is video coding means, 3 is audio coding means, 4 is data coding means, 5 is time division multiplexing means, 6
Is error code correction means, 7 is digital modulation means, 8 is frequency conversion / amplification means, 9 is a receiver, 10 is amplification / channel selection means, 11 is digital demodulation means, 12 is error correction decoding means, and 13 is a program. Selecting means, 14 is video decoding means, 1
5 is a data decoding means, 16 is an audio decoding means, 20 is a control microcomputer, 100 is a video signal input terminal, 101 is an audio input terminal, 102 is a data input terminal, 103 is a transmission output terminal, and 104 is a reception input terminal. is there. In transmitter 1,
Video information input terminals 100A to 100N
Input from the video rate coding means 2A to 2N, respectively, and digitally compressed into a plurality of compression coded video information.
101N, and speech coding means 3A to
Digitally compressed by 3N to become a plurality of compression-encoded voice information, other related information is input from the data input terminal 102, encoded by the data encoding means 4 and becomes additional data, and these information are obtained by the time division multiplexing means 5. For example, interleaved multiplexing is performed, error correction coding processing is performed by the error correction coding means 6, digital modulation is performed by the digital modulation means 7, frequency conversion is performed by the frequency conversion / amplification means 8, and digital modulation is performed from the transmission output terminal 103. Signals are transmitted by radio waves, coaxial cables, optical cables, etc.

In the receiver 9, the digital modulation signal is input from the reception input terminal 104, is tuned by the amplification / channel selection means 10, and is digitally demodulated by the digital demodulation means 11.
The error correction decoding means 12 performs error correction decoding, and the program selection means 13 releases interleaved multiplexing.
The control microcomputer 20 selects one of the compression-coded video information, the compression-coded audio information, and the bit stream of the additional data from among them, the video decoding means 14 decodes the compression-coded video information, and the data decoding means 15 Then, the additional data is decrypted, the compression-encoded audio information is decoded by the audio decoding means 16, and the image display and the audio output are obtained by the digital signal processing means (not shown).

Further, in the case of pay broadcasting service, encryption (or scramble) is performed by the encryption (or scramble) means before the time division multiplex means 5, and at the receiving side, encryption is performed by the output of the program selecting means 13. After the encryption (or scramble) is decrypted by the (or scramble) decryption means, the video, audio and data are decrypted.

[0006]

SUMMARY OF THE INVENTION In a secondary-use digital broadcasting receiver for receiving a multi-channel digital television broadcast and decoding each program again to the antenna or CATV, the digital television described in the above-mentioned conventional example is conventionally used. One John broadcasting receiver is prepared for decoding each program, and the outputs of the respective digital television broadcasting receivers are arranged in line by the number of programs. FIG. 8 shows a conventional example as a CATV head end. Reference numerals 9-1 to 9-N are digital broadcast receivers, 50-1 to 50-N are NTSC converters, and 60-1 to 60-N are remodulation means. In the digital television broadcast receivers 9-1 to 9-N, channels and programs are preselected so that each one decodes one program. Each of the decoded programs is converted into a conventional NTSC signal by the NTSC converters 50-1 to 50-N, remodulated by the remodulation means 60-1 to 60-N, and transmitted to the CATV cable. For example, if 5 programs are multiplexed on 1 channel and there are 20 channels, a total of 100 digital television broadcast receivers are required. If 100 digital receivers are arranged as they are, it will take up a lot of space, so only some of the internal units will be put together in one housing. At this time, the mutual interference of the amplifying / tuning means 10 for selecting a channel having an oscillator in the analog circuit becomes a problem.

An object of the present invention is to reduce the number of amplifying / tuning means 10 in a secondary use digital broadcast receiver which receives multi-channel digital television broadcasts, decodes each program and sends it back to the antenna or CATV. Therefore, it is to provide a digital television broadcast receiver in which the occurrence of problems due to mutual interference is reduced and the number of error correction decoding means 12 and program selection means 13 is reduced.

[0008]

Means for Solving the Problems The purpose of the above is to select an error correction / decoding means 1 when a channel is selected by an amplification / channel selection means 10.
After the error correction is performed in step 2, a control means for separating a plurality of programs from a transport stream packet in which a plurality of programs are multiplexed by the program selection means and a plurality of temporary storage means corresponding to each program are provided. This is achieved by selecting a plurality of desired programs from the multiplex signals at approximately the same time and separately outputting a plurality of programs and each information composed of the selected compression-encoded video information, compression-encoded audio information, and additional information.

The transport stream used in the digital broadcasting system is shown in FIG. 1 on page 489 of the April 1995 issue of the Institute of Television Engineers, "Image Information Engineering and Broadcasting Technology".
There are three examples. The program selection is performed by the program data in the transport stream packet, and conventionally, the program selecting means 13 desires 1 when solving the interleaved multiplexing.
Only the data string of the program was stored in the temporary storage means and output. As a means for separating a plurality of programs, a temporary storage means for each program is provided, and a data string of the interleaved programs is sequentially stored in the temporary storage means for each program by the program data and output, and a composite encryption code is provided. Alternatively, the compression-encoded video information, the compression-encoded audio information, and the additional information are combined for each of a plurality of outputs of the program selection means, and each program is retransmitted to the antenna or CATV. That is, a plurality of program information can be obtained substantially simultaneously by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means for one channel. Whereas a digital television broadcast receiver was required, the amplification / channel selection means 10, the error correction decoding means 12 and the program selection means were simplified to 20 sets, and the amplification / channel selection means 10 were reduced in number. Interference is reduced,
It is also effective in reducing the number of circuits.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, 130 is program selection means according to the present invention, and 200-1, 200-2 to 200-N are compression coded video information, compression coded audio information and additional information of a plurality of programs. Digitally modulated signal is received at input terminal 104
After being input from the input / amplifying / tuning means 10, the digital demodulation means 11 performs digital demodulation, the error correction / decoding means 12 performs error correction decoding, and the program selection means 13
Interleave multiplex is solved by. The conventional program selecting means 13 outputs only one desired program by the control microcomputer 20, and thus the obtained output is also a set of compression encoded video information, compression encoded audio information and additional information.
On the other hand, in the program selection means 130 of the present invention, a plurality of desired programs are selected by the control microcomputer 20, and at the same time, a plurality of sets of compression-coded video information, compression-coded audio information and additional information corresponding to each program are output. 200-1, 200-2 ~
Output 200-N.

FIG. 2 is a block diagram showing an embodiment of the configuration of the program selection means 130 of the present invention. 170 is a demultiplexer according to the present invention, and 18 is a temporary storage means.

The means for separating a plurality of programs is provided with temporary storage means 18-1 to 18-N corresponding to each program, and the data string of the interleaved program is sequentially de-multiplexed by the demultiplexer 170 according to the control microcomputer, and temporarily according to each program. The data is stored in the storage means 18-1 to 18-N and output. That is, a plurality of sets of program information can be obtained at substantially the same time by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means for one channel.

FIG. 3 is a block diagram showing an embodiment of the present invention. In FIG. 3, 14 is a video decoding means, and 15
Is a data decoding means, and 16 is a voice decoding means. In the embodiment shown in FIG. 3, a plurality of pieces of program information 2 of the program selecting means 130 is used.
Video decoding means 14-1 to 14-1 to each output of 00-1 to -N
N, data decoding means 15-1 to N, voice decoding means 1
6-1 to N are provided respectively. According to this embodiment, a plurality of pieces of program information can be obtained substantially simultaneously by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means 130 for one channel.

FIG. 4 is a block diagram showing another embodiment of the present invention. Reference numerals 19-1 to 19-N are encryption decryption units. In FIG. 4, encryption / decryption 19-1 to 19-N are provided at the output of the program selection means 130 in comparison with the above embodiment. In the case of pay broadcasting service, encryption (or scrambling) is performed by the encrypting (or scrambling) means before the time division multiplexing means 5, and at the receiving side, the encryption (or scrambling) is performed by the output of the program selecting means 130. After decryption means decrypts the cipher (or scramble), video decoding means 14-1 to N, data decoding means 15-1 to N, and audio decoding means 16-1 to N decode video, audio, and data. I do. According to the present embodiment, it is possible to obtain a plurality of pieces of program information that have been decrypted at substantially the same time by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means 130 for one channel.

FIG. 5 is a block diagram showing another embodiment of the present invention. In FIG. 5, 50-1 to 50-N are N
The TSC converters 60-1 to 60-N are remodulation means. FIG. 5 shows an embodiment of a secondary-use digital broadcast receiver that receives a multi-channel digital television broadcast, decodes each program, and sends it back to the antenna or CATV. The encrypted composite video, audio, and additional information obtained in FIG. 3 are converted into conventional NTSC signals by the NTSC converters 50-1 to 50-N, and the remodulation means 6 is used.
Each of them is re-modulated by 0-1 to 60-N and sent again to the antenna or CATV. That is, a plurality of program information can be obtained substantially simultaneously by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means for one channel. While the digital television broadcast receiver was required, the number of programs selected by the program selection means 130 is made to match the number of programs included in one channel, so that the amplification / channel selection means 10, the error correction decoding means 12 and the programs The selecting means is simplified to 20 sets, and the number of amplifying / tuning means 10 is reduced, so that mutual interference is reduced, and it is effective in reducing circuits. Although the present invention has been described by taking the adaptation to the conventional NTSC signal as an example, the NTSC converter can be applied to other video signal formats,
For example, it is obvious that a converter for PAL, SECAM, high definition, etc. does not depart from the gist of the present invention.

FIG. 6 is a block diagram showing another embodiment of the present invention. In FIG. 6, 21 is a composition / video processing means, and 22 is an image display means. The present invention synthesizes a plurality of encrypted composite decrypted video signals obtained in the embodiment of FIG.
By synthesizing by the image processing means 21 and displaying them on the image display means 22 at the same time, a multi-screen display by moving images can be performed.

[0018]

According to the present invention, the temporary storage means corresponding to each program is provided, and the data sequence of the interleaved program is sequentially stored in the temporary storage means corresponding to each program by the program data and output. That is, a plurality of sets of program information can be obtained at substantially the same time by one set of amplification / channel selection means 10, error correction decoding means 12 and program selection means for one channel. In the secondary use digital broadcast receiver that receives multi-channel digital television broadcasts and decodes each program and retransmits them to the antenna or CATV, 100 digital television broadcast receivers for 20 channels were conventionally required. On the other hand, the amplification / channel selection means 10, the error correction decoding means 12, and the program selection means 20
Since the number of amplifying / tuning means 10 is reduced, the mutual interference is reduced and the circuit is effectively reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of program selection means of the present invention.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a conventional example.

FIG. 8 is a block diagram showing a conventional example.

[Explanation of symbols]

 14 ... Video decoding means, 15 ... Data decoding means, 16 ... Audio decoding means, 18 ... Temporary storage means, 19 ... Encryption / decryption means, 20 ... Control microcomputer, 21 ... Screen synthesis / video processing means, 50 ... NTSC Converter, 60 ... Remodulation means, 130 ... Program selection means, 200 ... Program information output.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Adachi, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Hitachi, Ltd. multimedia system development headquarters

Claims (7)

[Claims] 1. A selection for selecting at least a desired channel for receiving a digitally modulated signal in which a plurality of programs including compression-encoded video information, compression-encoded audio information, and additional information are multiplexed and error-correction encoded. Station means, digital demodulation means, error correction decoding means, program selection means for selecting and outputting a desired program from the error-correction-decoded multiplexed signal,
In a digital television broadcast receiver having means for decoding compression-encoded video information, compression-encoded audio information, or additional information of a selected desired program, a plurality of desired programs are approximately simultaneously produced from the error-correction-decoded multiplexed signal. A digital television broadcast receiver having a program selecting means for selecting and outputting each. 2. The program selecting means for selecting a plurality of desired programs from a multiplex signal in one channel substantially at the same time according to claim 1, and means for separating and controlling a plurality of programs from the multiplex signal and each program. A digital television broadcast receiver, which is a plurality of temporary storage means, and which individually outputs a plurality of programs consisting of the selected compression-encoded video information, the compression-encoded audio information, and the additional information, and each information. 3. A means for decoding the compression coded video information, the compression coded audio information, or additional information corresponding to each of a plurality of selected outputs of the program selection means. Digital television broadcast receiver. 4. The digitally modulated signal to be received according to claim 1, wherein the digitally modulated signal is a multiplexed signal in which a program including the compression coded video information, the compression coded audio information, and the additional information is encrypted. Therefore, the digital television broadcast reception is provided with an encryption / decryption means and means for decoding the compression-coded video information, the compression-coded audio information, and the additional information corresponding to the plurality of selected outputs of the program selection means. Machine. 5. The program according to claim 3 or 4, which is composed of video information, audio information and additional information corresponding to a plurality of selected outputs of the program selecting means, or each information is retransmitted to a cable or an antenna. A digital television broadcast receiver provided with means for transmitting. 6. The method of claim 1, 2, 3, 4, or 5,
A digital television broadcast receiver in which the plurality of outputs selected and output by the program selection means at substantially the same time coincide with the number of multiplexed programs of one channel. 7. A digital television broadcast reception according to claim 1, 2, 3, 4, 5 or 6, further comprising means for displaying image information of all or a plurality of selected video information at the same time. Machine.