Digital multiplex transmission system

• US 5,506,903 A
• Filed: 04/05/1994
• Issued: 04/09/1996
• Est. Priority Date: 04/06/1993
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamashita, Masami
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/223,217
• Time in Patent Office: 735 Days
• Field of Search: 380/9, 380/10, 380/21, 380/20, 380/48, 380/49, 380/50, 370/79, 370/82, 370/84
• US Class Current: 380/216
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H04H 20/74 of satellite networks
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/52 Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal assembling of a multiplex stream by combining a video stream with other content or additional data, remultiplexing of multiplex streams, insertion of stuffing bits into the multiplex stream, assembling of a packetised elementary stream at server side H04N21/236; disassembling of a multiplex stream, remultiplexing of multiplex streams, extraction or processing of Service Information, disassembling of packetised elementary stream at client side H04N21/434
• CPC Class Codes: H04N 7/56 Synchronising systems therefor

Abstract

A digital multiplex transmission system wherein the rate of convolution codes can be changed over in accordance with an object of a user without changing the transmission rate. A frame for transmitting system data, first preliminary data, second preliminary data, scramble control data, audio data, video data and Reed-Solomon codes is constructed by allocation of them such that a boundary between each adjacent region may make a vertical straight line. Data of such a frame are coded by convolution coding and then transmitted. When the transmission line is in a deteriorated condition, the rate of the convolution codes is reduced to increase the correcting faculty for the convolution codes. In contrast, when the transmission line is in a good condition, the rate of the convolution codes is increased to transmit a large amount of data.

Claims

1. A digital multiplex transmission system, comprising:

first multiplexer means for multiplexing at least digital audio data and digital video data and scrambling resultant multiplexed data with a scrambling train;

second multiplexer means for multiplexing scrambled data from said first multiplexer means, scramble control data and system data, and allocating resultant scrambled multiplexed data on a two-dimensional frame;

means for coding the frame in units of a block in a horizontal direction by Reed-Solomon coding to add Reed-Solomon codes to the frame, the frame having respective regions for the video data, the audio data, the scramble control data, the system data and the Reed-Solomon codes, and each pair of adjacent regions having a boundary therebetween which is a vertical straight line; and

means for adding the system data including a frame synchronizing signal to the two-dimensional frame, coding resultant data by convolution coding to obtain digital multiplexed data and transmitting the digital multiplexed data.

2. A digital multiplex transmission system according to claim 1, further comprising means for changing over a redundancy of the convolution codes among 7/8, 5/6, 3/4, 2/3 and 1/2, and means operable upon changing over of the redundancy of the convolution codes for changing an allocation width of video data in the two-dimensional frame in response to a new redundancy value so that the digital multiplexed data may be transmitted at a fixed transmission rate.

3. A digital multiplexer transmission system according to claim 2, further comprising means for changing over the transmission rate in response to a transmission bandwidth.

4. A digital multiplex transmission system, comprising:

first multiplexer means for multiplexing at least digital audio data and digital video data and scrambling resultant multiplexed data with a scrambling train;

second multiplexer means for multiplexing scrambled data from said first multiplexer means, scramble control data and system data, and allocating resultant multiplexed scrambled data on a two-dimensional frame and coding the frame in units of a block in a horizontal direction by Reed-Solomon coding to add Reed-Solomon codes to the frame;

means for adding the system data including a frame synchronizing signal to the two-dimensional frame, coding resultant data by convolution coding to obtain digital multiplexed data and transmitting the digital multiplexed data; and

allocating means including means for forming packets of the digital audio data and the digital video data, for allocating the system data including the frame synchronizing signal, the scramble control data, packets including the digital audio data and the digital video data, and the Reed-Solomon codes on the two-dimensional frame, the frame having respective regions for the video data, the audio data, the scramble control data, the system data and the Reed-Solomon codes, and each pair of adjacent regions having a boundary therebetween which is a vertical straight line.

5. A digital multiplex transmission system according to claim 4, wherein the packets include the scramble control data as well as the audio data and the video data, and said allocating means allocates the system data including the frame synchronizing signal, the packets including the scramble control data as well as the audio data and the video data, and the Reed-Solomon codes on the two-dimensional frame.

6. A digital multiplex transmission system according to claim 5, further comprising means for changing over a redundancy of the convolution code among 7/8, 5/6, 3/4, 2/3 and 1/2, and means operable upon changing over of the redundancy of the convolution codes for changing an allocation width of the packets in response to a new redundancy value so that the digital multiplexed data may be transmitted at a fixed transmission rate.

7. An encoder for a digital multiplex transmission system, comprising:

a first multiplexer for multiplexing at least digital audio data and digital video data;

a second multiplexer for scrambling the data multiplexed by said first multiplexer with a scrambling train, multiplexing the scrambled data and scramble control data, and allocating the scrambled data and the scramble control data on a two-dimensional frame;

a Reed-Solomon coder for coding the frame multiplexed by said second multiplexer in units of a block in a horizontal direction by Reed-Solomon coding to add Reed-Solomon codes to the frame;

a third multiplexer for adding system data to the frame to which the Reed-Solomon codes have been added, the frame having respective regions for the video data, the audio data, the scramble control data, the system data and the Reed-Solomon codes, and each pair of adjacent regions having a boundary therebetween which is a vertical straight line;

a convolution coder for coding the data of the frame outputted from said third multiplexer by convolution coding; and

a phase shift keying modulator for modulating the data convolution coded by said convolution coder by phase shift keying modulation and transmitting the modulated data.

8. An encoder according to claim 7, wherein said second multiplexer allocates the scramble control data, the audio data, the video data the Reed-Solomon codes and the system data to the two-dimensional frame.

9. An encoder according to claim 7, wherein the system data includes a frame synchronizing signal, said second multiplexer includes means for forming packets of the scramble control data, the audio data and the video data, and said second multiplexer, said Reed-Solomon coder and said third multiplexer allocate the packets including the scramble control data as well as the audio data and the video data, the Reed-Solomon codes, and the system data including the frame, synchronizing signal, respectively, on the two-dimensional frame.

10. A digital multiplex transmission system, comprising:

means for multiplexing at least digital audio data and digital video data and scrambling the multiplexed data with a scrambling train;

means for multiplexing the scrambled data with scramble control data, allocating video data, audio data and the scramble control data on a two-dimensional frame and coding the frame in units of a block in a horizontal direction by Reed-Solomon codes to the frame;

means for adding system data to the two-dimensional frame, processing the resultant data by convolution coding and phase shift keying modulation to obtain encoded data and transmitting the encoded data, the frame having respective regions for the video data, the audio data, the scramble control data, the system data and the Reed-Solomon codes, and each pair of adjacent regions having a boundary therebetween which is a vertical straight line;

means for demodulating the transmitted digital data multiplexed in a two-dimensional frame by phase shift keying demodulation, decoding the demodulated data by bitervi decoding to correct an error of the convolution coded digital multiplexed data, and correcting an error of the frame in units of a block in a horizontal direction using one of the Reed-Solomon codes added to the frame;

means for separating the scramble control data from the multiplexed data after the error correction and descrambling the multiplexed data with the separated scramble control data; and

means for demultiplexing the descrambled multiplexed data into video data, audio data and preliminary data.

11. A decoder for a digital multiplex transmission system, comprising:

a bitervi decoder for decoding convolution codes by bitervi decoding;

a Reed-Solomon decoder for correcting an error of the thus bitervi decoded multiplexed data in units of a block in a horizontal direction using Reed-Solomon codes added to the multiplexed data;

a descrambler for separating scramble control data from the multiplexed data after the error correction and descrambling the multiplexed data with the thus separated scramble control data; and

a demultiplexer for demultiplexing the descrambled multiplexed data at least into video data and audio data.