CN2657315Y

CN2657315Y - Full digital TV broad easting plus disturbance eliminating circuit

Info

Publication number: CN2657315Y
Application number: CNU032336802U
Authority: CN
Inventors: 赖勇
Original assignee: SICHUAN HUIYUAN SCIENCE AND TECHNOLOGY DEVELOPMENT Co Ltd
Current assignee: SICHUAN HUIYUAN SCIENCE AND TECHNOLOGY DEVELOPMENT Co Ltd
Priority date: 2003-03-25
Filing date: 2003-03-25
Publication date: 2004-11-17
Anticipated expiration: 2013-03-25

Abstract

The utility model relates to a full digital television broadcasting scrambling and descrambling circuit. In a digital television transmission system, the utility model utilizes the available space of a prepared program allocating table to convey scrambling and descrambling information and addressable management information, adopts a stochastic cipher key method to scramble and descramble, and carries out graded manage for programs and addressing manage for users. The utility model is characterized in that a scrambling circuit is formed by bilaterally connecting a scrambling manage circuit, a scrambling control circuit and a scrambling machine circuit, and is positioned at the front of a QAM modulating circuit of a television transmitting system; a descrambling module is composed of an interference removing circuit, an addressing control code extracting circuit and an IC card, and is positioned between a QAM demodulation circuit and an MPEG2 demoding circuit.

Description

Full digital tv broadcasting adds descrambling circuit

Affiliated technical field

The utility model relates to the compress technique in a kind of digital signal communication, and particularly a kind of full digital tv broadcasting adds descrambling circuit.

Background technology

Present existing television broadcasting interference blanking system divides analog-and digital-two classes.According to " cable TV network adopts the temporary provisions of scrambling-descrambling technology ", the management system that China adopts scrambling-descrambling technology to carry out TV services is two level scrambling management systems.One level scrambling be used for central authorities, province, autonomous region and municipality directly under the Central Government via satellite, the scrambled television program of transmission such as microwave, optical fiber.Two level scramblings are used for through authorizing the central, and province level scrambled television program after receiving or being used for the scrambled television program that various places cable TV station manages by oneself.Central, and province level TV programme through authorize receiving adopts after can descrambling and is different from former scrambling mode and carries out scrambling, and also descrambling is not only changed managing control information, transmits to this cable TV network user.

Summary of the invention

The utility model purpose is to disclose a kind of in digital television transmission system, utilize the free space of reserved program allocation table to transmit to add, descrambling information and addressable management information, employing random key mode adds, descrambling, broadcasts to the management of program split pole with to the full digital tv of user's addressing management to add descrambling circuit.

The utility model is that the achieve the above object technical scheme that adopted is as follows:

Scrambling circuit is by scrambling management, control and the scrambling machine circuit is two-way connects and composes, and is arranged in the TS signal flow before the QAM modulation circuit of whole television transmission system; Descrambling module is by going to disturb and extract the addressing control sign indicating number and IC-card constitutes, and is arranged in the TS signal flow before MPEG 2 decoding circuits.As shown in Figure 1.

Described scrambling circuit is connected with the addressable data with scrambled data respectively with control circuit by management, and scrambled data is connected with TS stream through encryption TS stream back, inserts data and accepts to be connected with TS stream behind scrambled data, addressable data and the PID (transmission package).As shown in Figure 2.

In fact accompanying drawing 2 is disclosed is a kind of scrambled data and addressable data to be made circuit version connector, is inserted in reserved program (the insertion data square frame among Fig. 2) slot, and scrambled data is simultaneously to the TS stream encryption, thereby forms the circuit of enciphered data TS stream.In this circuit, reserved program allocation table (being the TS bag of PLD=0000H) is not encrypted.

Described descrambling module is: IC-card is connected with taking-up data, deciphering TS stream respectively by Subscriber Number, user gradation circuit respectively, takes out data and is connected with IC-card, PID, odd even secret key, TS stream again, and odd even secret key also process deciphering TS stream is connected with TS stream.As shown in Figure 3.

The disclosed descrambling module of Fig. 3 is to search reserved program allocation table (being the TS bag of PLD=0000H) from TS stream, and the in addition computing of number information of the obtained IC-card of taking-up information and user from table, after drawing the odd even secret key, the user gradation data in IC-card go to decipher the TS data flow again.

Embodiment

Description of drawings

Fig. 1 adds descrambling circuit position schematic diagram in the television broadcasting signal transmission course.

Fig. 2 is the scrambling circuit structural representation.

Fig. 3 is the descrambling circuit structural representation.

Embodiment

As shown in Figure 1, scrambling circuit is by scrambling management, control and the scrambling machine circuit is two-way connects and composes, and is arranged in the TS signal flow before the QAM demodulation circuit system of whole television transmission system; Descrambling module is by going to disturb and extract the addressing control sign indicating number and IC-card constitutes, and is arranged in the TS signal flow before MPEG 2 decoding circuits.The scrambling machine is accepted the TS stream signal without the ASI interface (or SPI interface) of the DVB standard of scrambling, under the control of management control system, the TS stream signal of the ASI interface (or SPI interface) after the output scrambling, the scrambling machine is connected by Ethernet interface with control system place computer with management.In the descrambling part, by digital TV set-top box, descrambling module and IC-card read write line constitute.Management and control system software and scrambling communication realize adding, separating control, program grade control, and user's IC-card is supplemented with money and subscriber management function.

As shown in Figure 2, described scrambling circuit, be connected with the addressable data with scrambled data respectively with control circuit by management, scrambled data is connected with TS stream through encryption TS stream back, inserts data and accepts to be connected with TS stream behind scrambled data, addressable data and the PID (transmission package).In the scrambling part, management and control system are realized by computer software, comprise that mainly communication module (being used for carrying out communication with the MCU of scrambling machine inside), user data are (being used to preserve user data), IC-card module for reading and writing (being used for the IC-card read-write) and addressing control module (being used for user's control and management) etc.The scrambling machine comprises scrambling module (be used for carry out code stream scrambling, scrambling and Datagram insertion etc.), communication module (being used for the communication with computer), random code generator (being used to produce random key) and interface module, comprises DVB standard interface compositions such as (ASI, SPI input, output interfaces).Select the respective encrypted password according to strange, even key and program level of confidentiality, the payload portions of TS stream is carried out cryptographic calculation, reach and upset normal program data, realize to the grading control of program and to the purpose of the Conditional Access of charge program.

In fact accompanying drawing 2 be disclosed be a kind of with scrambled data and addressable data circuit version connector, be inserted in the reserved program (the insertion data square frame among Fig. 2), scrambled data is simultaneously to the TS stream encryption, thereby forms the circuit of encrypting TS stream.In this circuit, reserved program allocation table (being the TS bag of PLD=0000H) is not encrypted.

As shown in Figure 3.Described descrambling module is: IC-card is connected with taking-up data, deciphering TS stream respectively by Subscriber Number, user gradation circuit respectively, takes out data and is connected with IC-card, PID, odd even secret key, TS stream again, and odd even secret key also process deciphering TS stream is connected with TS stream.The digital TV set-top box of descrambling module and IC-card read write line is according to the user profile on the IC-card, and the control descrambling module is realized the descrambling function, and can retrieve the control signal that network transmits, and IC-card is carried out long-range operation such as supplement with money.The IC-card read-write equipment adopts the MCU software control, realizes the read-write operation to IC-card.Descrambling module is finished by programmable logic device, it realizes taking out the descrambling control information from code stream on the one hand, on the other hand it with IC-card read Subscriber Number contrast with the control information that receives, if it is identical, just carry out corresponding operation, as IC-card is supplemented with money, change user class etc.Simultaneously, will compare, if user class greater than program level, is just carried out descrambling operation from user class and program level that IC-card is obtained.

Claims

1, a kind of in digital television transmission system, utilize the free space of reserved program allocation table to transmit to add, descrambling information and addressable management information, employing random key mode adds, descrambling, add descrambling circuit to the management of program split pole with to the full digital tv broadcasting that user's addressing is managed, it is characterized in that: scrambling circuit is by scrambling management, control and the scrambling machine circuit is two-way connects and composes, be positioned at the QAM demodulation circuit system of television transmission system before; Descrambling module is by going to disturb and extract the addressing control decoding circuit and IC-card constitutes, between QAM demodulator circuit and MPEG 2 decoding circuits.

2, full digital tv broadcasting according to claim 1 adds descrambling circuit, it is characterized in that: described scrambling circuit, be connected with the addressable data with scrambled data respectively with control circuit by management, scrambled data is connected with TS stream through encrypting TS stream back, inserts data and accepts to be connected with TS stream behind scrambled data, addressable data and the PID.

3, full digital tv broadcasting according to claim 1 adds descrambling circuit, it is characterized in that: described descrambling module is to be connected with taking-up data, deciphering TS stream respectively by Subscriber Number, user gradation circuit respectively by IC-card, take out data and be connected with IC-card, PID, odd even secret key, TS stream again, the odd even secret key also connects and composes with TS stream through deciphering TS stream.