KR20130063290A - Digital broadcasting system and method thereof - Google Patents

Abstract

The present invention discloses a relay apparatus and method for a digital broadcasting system. According to the present invention, a digital broadcasting signal of 8VSB transmission method of ATSC standard having poor radio transmission characteristics transmitted from a broadcasting station is converted into a digital broadcasting signal of COFDM transmission method of DVB-T standard with improved transmission characteristics and transmitted to a receiving apparatus. In addition, it is possible to eliminate the blind spot shadow area for digital broadcast signals caused by environmental and human factors, and to pay the fee free of charge for viewing the existing digital broadcast signal to eliminate the shadow area for digital broadcast signals. As a result, the cost of watching digital broadcasting can be reduced to a minimum, and the sharing of various media such as cable broadcasting, terrestrial wave, and public hearing antenna can be improved. As a result, various mobile terminals can be applied.

Description

Digital broadcasting system and its control method {DIGITAL BROADCASTING SYSTEM AND METHOD THEREOF}

The present invention relates to a digital broadcasting system and a control method thereof, and more particularly, to a digital broadcasting system, a control method thereof, a relay apparatus, and a receiving apparatus capable of improving the compatibility of a plurality of transmission digital broadcasting systems. .

The transmission method of terrestrial digital broadcasting in Korea adopts the ATSC (Advanced Television System Committee) standard, which is a US technical standard, and since such ATSC transmits a lot of video data in one carrier, large capacity information transmission and high quality are possible.

The key element of this standard is the compression and transmission of video and audio. It uses VSB (Vestigial Side Band) technology as the transmission technology that compresses the video signal to MPEG2 and the audio and audio signal to AC-3 and carries these signals. In addition, 18 signal formats are available, allowing multiple channels to broadcast simultaneously, and video and data broadcasts.

Therefore, the transmission speed of video and audio data is high, it is compatible with personal computer (PC), and the domestic analog broadcasting channel and frequency band (6MHZ) are the same.

However, the most disadvantageous disadvantage of the ATSC scheme, which is the US technical standard, is that the radio wave transmission characteristics are poor.

Therefore, viewers equipped with a digital broadcast receiver are unable to watch digital broadcasts in an astigmatism area where radio wave reception is extremely poor even if a dedicated reception antenna is installed outdoors. In particular, Korea has to be invisible as a natural environmental factor in the mountainous region, and as the high-rise buildings in large cities are rapidly increasing, the invisible region continues to increase due to artificial environmental factors.

In order to solve this blind spot, a repeater with medium and small outputs was installed, but due to the ATSC type radio transmission characteristics, the blind spot could not be completely eliminated.

Since most viewers who have difficulty in viewing digital broadcasting signals are watching terrestrial broadcasting through pay broadcasting, each family has to pay a separate pay broadcasting fee.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to provide a digital broadcast signal of 8VSB transmission method of ATSC standard, which is poor in radio wave transmission characteristics transmitted from a broadcasting station. Provides a relay device and a relay method of a digital broadcast system that can convert the digital broadcast signal of the COFDM transmission method and transmit it to the receiving device, which can eliminate the shadow area for the digital broadcast signal according to the transmission method and fundamentally improve the image quality. To be.

According to a first aspect of the present invention,

A transmission device for transmitting the digital broadcast signal produced by the broadcasting station in a first transmission method;

A relay device for modulating and transmitting the digital broadcast signal transmitted from the transmission device by using a second transmission method which is one of a plurality of preset transmission methods;

And a receiving device for receiving the digital broadcast signal transmitted by the second transmission method from the relay device and displaying the same on the screen.

Preferably, the first transmission method is 8VSB (8Vestigial Side Band) transmission method of the Advanced Television System Committee (ATSC) standard, and the second transmission method is the DVB-T (Digital Video Broadcasting-Terrestrial) standard. Code Orthogonal Frequency Division Multiplexing (COFDM) is characterized in that the transmission scheme.

Preferably the relay device,

An ATSC receiver for tuning an RF broadcast digital broadcast signal transmitted in a frequency band of a channel selected by a user;

Converts the 8VSB transmission digital tuned signal transmitted through the ATSC receiver into an ASI (Asynchronous Serial Interface) signal and extracts PSIP (Program and System Information Protocol) data having information necessary for broadcast program and broadcast data and reproduction. Grandfather,

The ASI signal extracted by the demodulator is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into the SI data of the DVB-T standard, and the SI data is converted into the ASI signal converted to the DVB-T standard frequency band. A signal processor for synthesizing the ASI signal to a DVB-T standard;

A COFDM modulator for synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processor and modulating the COFDM transmission scheme to generate an IF signal;

A COFDM transmitter for converting the IF signal of the COFDM modulator into an RF frequency signal and amplifying the COFDM modulator to a predetermined amplification degree and transmitting the amplified signal to the receiver;

And a controller for controlling the overall digital broadcasting system.

Preferably the signal processing unit,

A transcoder for converting the ASI signal into a frequency band of the DVB-T standard;

A PSIP conversion and SI generator for converting the PSIP data into SI (Service Information) of the DVB-T standard to generate SI data;

Synthesize the ASI signal of the DVB-T standard by synthesizing the ASI signal of the transcoder and the SI data of the PSIP conversion and the SI generator, and scrambling the generated ASI signal of the DVB-T standard according to an encryption code supplied from the outside. And a scrambler for coding the ASI signal of the DVB-T standard into a corresponding channel and transmitting the same to the COFDM modulator.

Preferably the signal processing unit,

And a memory for storing an encryption code in advance to encrypt the ASI signal of the DVB-T standard.

Preferably the signal processing unit,

And a communication module for receiving an encryption code for encrypting the ASI signal of the DVB-T standard from a preset CAS (conditional access system) or digital rights management (DRM).

Preferably the receiving device,

Characterized in that it is provided to receive at least one or more digital broadcast signals of satellite digital broadcast signal, digital cable broadcast signal, terrestrial digital broadcast signal.

Preferably the receiving device,

An RF frequency signal receiver for receiving an RF frequency signal supplied from the relay device;

And a display processor configured to descramble the RF frequency signal based on an encryption code supplied from the outside, demultiplex, decode, and display the video and audio.

According to a second aspect of the present invention,

An ATSC receiver for tuning a digital broadcast signal of an RF broadcasting station transmitted in a frequency band of a channel selected by a user;

Converts the 8VSB transmission digital tuned signal transmitted through the ATSC receiver into an ASI (Asynchronous Serial Interface) signal and extracts PSIP (Program and System Information Protocol) data having information necessary for broadcast program and broadcast data and reproduction. Grandfather,

The ASI signal extracted by the demodulator is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into the SI data of the DVB-T standard, and the SI data is converted into the ASI signal converted to the DVB-T standard frequency band. A signal processor for synthesizing the ASI signal to a DVB-T standard;

A COFDM modulator for synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processor and modulating the COFDM transmission scheme to generate an IF signal;

A COFDM transmitter for converting the IF signal of the COFDM modulator into an RF frequency signal and then amplifying the COFDM modulator with a predetermined amplification signal and transmitting the signal to a receiver;

And a control unit for controlling the overall digital broadcasting system.

Preferably the signal processing unit,

A transcoder for converting the ASI signal into a frequency band of the DVB-T standard;

A PSIP conversion and SI generator for converting the PSIP data into SI (Service Information) of the DVB-T standard to generate SI data;

Synthesize ASI signal of the transcoder and SI data of the PSIP conversion and SI generator to generate ASI of DVB-T standard and scramble the generated ASI signal of DVB-T standard according to an encryption code supplied from the outside; And a scrambler for coding the scrambled DVB-T standard ASI signal into a corresponding channel and transmitting the scrambler to the COFDM modulator.

Preferably the signal processing unit,

And a memory for storing an encryption code in advance to encrypt the ASI signal of the DVB-T standard.

Preferably the signal processing unit,

And a communication module for receiving an encryption code for encrypting the ASI signal of the DVB-T standard from a preset CAS (conditional access system) or digital rights management (DRM).

Technical problem according to another aspect of the present invention for achieving the above object,

A first step of transmitting, by the transmitting apparatus, the broadcast signal produced by the broadcasting station to the relay apparatus in a first transmission method;

A second step of modulating, by the relay device, the digital broadcast signal transmitted from the transmission device to a second transmission method, which is one of a plurality of preset transmission methods, and transmitting the same to a receiving device;

And a third process of receiving and processing a digital broadcast signal transmitted by the second transmission method of the relay device to be displayed on the screen by the receiving device.

Preferably, the first transmission scheme is an 8VSTI (8Vestigial Side Band) transmission scheme of the Advanced Television System Committee (ATSC).

Preferably, the second transmission method is a Code Orthogonal Frequency Division Multiplexing (COFDM) transmission method of the Digital Video Broadcasting-Terrestrial (DVB-T) standard.

Preferably the second process is,

ATSC receiving step of tuning the digital broadcast signal of the RF form transmitted in the frequency band of the channel selected by the user,

Converting the 8VSB transmission-type digital broadcast signal tuned through the ATSC receiving step into an ASI (Asynchronous Serial Interface) signal and extracting program and system information protocol (PSIP) data having information necessary for broadcast program and broadcast data and reproduction; Demodulation step,

The ASI signal extracted in the demodulation step is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into SI data of the DVB-T standard, and an SI is converted into the ASI signal converted to the DVB-T standard frequency band. A signal processing step of synthesizing the data to generate an ASI signal of the DVB-T standard;

A COFDM modulation step of synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processing step and modulating by the COFDM transmission method to generate an IF signal;

And converting the IF signal of the COFDM modulation step into an RF frequency signal, amplifying the signal to a predetermined amplification level, and transmitting the COFDM transmission signal to the receiving device.

Preferably the signal processing step,

Convert the ASI signal into a frequency band of the DVB-T standard,

The PSIP data is converted into SI (Service Information) of the DVB-T standard to generate SI data.

The ASI signal and the SI data are synthesized to generate an ASI of the DVB-T standard, and the ASI signal of the DVB-T standard is scrambled according to an encryption code supplied from the outside to generate the ASI signal of the scrambled DVB-T standard. And coding to the corresponding channel.

Preferably the third process,

An RF frequency signal receiving step of receiving an RF frequency signal supplied from the relay device;

And a display processing step of descrambling the RF frequency signal based on an encryption code supplied from the outside, demultiplexing, decoding the signal, and displaying the image in a video and audio.

As described above, according to the relay apparatus and method of the digital broadcasting system according to the present invention, the DVB-T standard having an improved transmission characteristic for the 8 VSB transmission method of the ATSC standard, which is inferior in the radio transmission characteristic transmitted from a broadcasting station, is improved. By converting the digital broadcast signal of the COFDM transmission method and transmitting it to the receiving device, the blind spot shadow area for digital broadcast signals generated by environmental and human factors can be eliminated, and the shadow area for digital broadcast signals is eliminated. By paying for the existing digital broadcasting signal for free, the digital broadcasting viewing cost can be reduced to a minimum, and the same channel can be improved by improving the sharing of various media such as cable broadcasting, terrestrial broadcasting, and public antenna. Channel can be used efficiently by sending other data It is possible to obtain the applicable effects of various mobile terminals.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further understand the technical idea of the invention. And should not be construed as limiting.
1 is a diagram showing the configuration of a digital broadcasting system according to the present invention.
2 is a view showing in detail the configuration of the relay device shown in FIG.
3A is a diagram illustrating in detail the configuration of the signal processor illustrated in FIG. 2.
3B is a diagram illustrating a configuration of another embodiment of the signal processor illustrated in FIG. 2.
4 is a diagram illustrating in detail the configuration of the receiving apparatus shown in FIG. 1.
5 is a flowchart illustrating a relay process of a digital broadcasting system according to another embodiment of the present invention.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

1 is a diagram illustrating a configuration of a digital broadcasting system according to an exemplary embodiment of the present invention, FIG. 2 is a diagram illustrating a configuration of a relay device shown in FIG. 1, and FIGS. 3A and 3B are signal processing units shown in FIG. 2. Figure shows the configuration. 4 is a diagram showing the configuration of the receiving device shown in FIG.

First, as shown in FIGS. 1 to 4, a digital broadcasting system according to an embodiment of the present invention includes a second transmission scheme in which a digital broadcasting signal of a first transmission scheme in which a radio wave transmission characteristic transmitted from a broadcasting station is inferior is improved. A digital broadcast signal is converted into a digital broadcast signal and transmitted to a reception device. The system includes a transmission device 100, a relay device 300, and a reception device 500.

That is, in the digital broadcasting system according to the embodiment of the present invention, an ATSC (Advanced Television) in which a carrier structure, which is a carrier for transmitting image data of a digital broadcasting signal transmitted from a broadcasting station, carries a plurality of image data in one carrier System Committee (Digital Video Broadcasting-Terrestrial) (DVB-T) standard of the second transmission method that carries the video data of the digital broadcast signal divided into several carriers in the first transmission method, which is the 8VSB (Vestigial Side Band) transmission method of the standard An example of converting to orthogonal frequency division multiplexing (COFDM) transmission and transmitting the same to the receiving apparatus 500 will be described.

The transmitting device 100 compresses the video data of the produced digital broadcasting signal into a predefined MPEG2, compresses the audio and audio data into a predefined AC-3, and compresses the compressed video data and the audio and audio data. It transmits by 8VSB (Vestigial Side Band) transmission method of the Advanced Television System Committee (ATSC) standard which is a single carrier transmission method.

In addition, a plurality of relay apparatuses 300 that receive a radio wave signal propagated as an RF signal by the transmitting apparatus 100 and receive a radio signal of 8VSB (Vestigial Side Band) transmission method of the Advanced Television System Committee (ATSC) standard It is provided to transmit to the receiving apparatus 500 modulated in one of the second transmission method of the transmission method of.

Here, the 8 VSB transmission scheme of the ATSC standard has a frequency bandwidth of 6 MHz and a transmission rate of 19.39 Mbps, and the RF signal for propagating the digital broadcast signal with the 8 VSB transmission scheme of the ATSC standard is a reed Solomon block. block) and PSIP (Program and System Information Protocol) data including various types of information necessary for receiving a broadcast program and data and a broadcast signal, including error correction data including a code and a trellis code. The PSIP includes a system time table (STT) for transmitting time information, a master guide table (MGT) for managing a transmission table, a virtual channel table (VCT) for providing virtual channel information, and a rating standard applicable to each country and region. It defines a RRT (Rating Region Table).

The RF signal propagated by the 8VSB (Vestigial Side Band) transmission scheme of the Advanced Television System Committee (ATSC) standard is provided to the relay device 300.

As illustrated in FIG. 2, the relay device 300 includes an ATSC receiver 310 for tuning a digital broadcast signal transmitted in a frequency band of a channel selected by a user, and an 8VSB tuned through the ATSC receiver 310. A demodulator 320 for converting a digital broadcast signal of a transmission method into an ASI (Asynchronous Serial Interface) signal and extracting program and system information protocol (PSIP) data having information necessary for broadcast program and broadcast data and reproduction; A signal processor 330 for generating the ASI signal of the DVB-T standard by converting the ASI signal and the PSIP data extracted from the grandfather 320 based on the COFDM transmission method of the DVB-T standard and then coding the signal; A COFDM modulator 340 for generating an IF signal by synthesizing the error correction data of the DVB-T standard after encoding the ASI signal of the DVB-T standard of 330 and the COFDM transmission method, and the COFDM A COFDM transmitter 350 converts the IF signal of the modulator 340 into an RF frequency signal, amplifies it to a predetermined amplification, and retransmits the signal to the receiver, and a controller 360 for controlling the overall digital broadcasting system. .

In addition, as shown in FIG. 3A, the signal processor 330 includes a transcoder 331 for converting the ASI signal into a frequency band of the DVB-T standard, and converts the PSIP data into the SI of the DVB-T standard. PSIP transform and SI generator 332 for converting to Serive Information to generate SI data, and the SI data of the PSIP transform and SI generator 332 to the ASI signal of the transcoder 331 to DVB-T standard. And a scrambler 334 for generating an ASI signal of the DVB-T standard and coding the generated ASI signal into a corresponding channel and transmitting the encoded ASI signal to the COFDM modulator 340.

In addition, as illustrated in FIG. 3A, the SI data of the DVB-T standard generated by the PSIP transform and the SI generator 332 is derived based on the PISP data generated by the demodulator 320 in the embodiment of the present invention. 3B, the SIB of the DVB-T standard is generated under the control of the controller 360 and then provided to the scrambler 334 to the DVB -T SI generator 332a. It may be provided.

The signal processor 330 may include a memory 335 for storing an encryption code in advance to encrypt an ASI signal of the DVB-T standard, or a preset code for encrypting an ASI signal of the DVB-T standard. The communication module 336 may be further provided from a conditional access system (CAS) or a digital right management (DRM).

Here, the communication module 336 includes one of a wired Internet network using a LAN, a Zigbee, a Bluetooth and a WiBro using a local area network, and a wireless communication network having a Wi-Fi module.

In an embodiment of the present invention, a scrambler and a memory or a communication module are described as an example. However, in the case of a digital broadcasting system in which an encryption program for allowing conditional viewing of a digital broadcast signal cannot be executed, the scrambler and the memory or The communication module may be deleted.

Meanwhile, the reception apparatus 500 is provided to receive at least one or more digital broadcast signals among satellite digital broadcast signals, digital cable broadcast signals, and terrestrial digital broadcast signals.

That is, as shown in FIG. 4, the receiving device 500 includes an RF frequency signal receiving unit 510 for receiving an RF frequency signal supplied from the relay device and a cryptographic receiving unit for receiving an encryption code supplied from the outside ( 520 and a display processor 530 which demultiplexes the RF frequency signal, decodes the signal, and displays the decoded video and audio signals.

In the digital broadcasting system having such a configuration, first, the RF signal propagated from the transmitting device 100 is received through the ATSC receiving unit 310 of the relay device 300 operated under the control of the control unit 360, and received. The RF signal of the 8VSB transmission scheme of the ATSC standard is provided to the demodulator 320.

The demodulator 320 deletes the error correction code after converting the received RF signal into an ASI signal. In addition, the demodulator 320 separates the PSIP data included in the RF signal.

The ASI signal and the PSIP data of the demodulator 320 are supplied to the signal processor 330.

The signal processor 330 receives the ASI signal and the PSIP data and converts the ASI signal to an ASI signal of the DVB-T standard.

The process of converting the ASI signal and the PSIP data into the ASI signal of the DVB-T standard will be described in more detail with reference to FIG. 3.

That is, the ASI signal and the PSIP data are supplied to the transcoder 331 and the PSIP transform and SI generator 332 of the signal processor 330, respectively. Here, the transcoder 331 converts an ASI signal of the ATSC standard of the 6MHz frequency band into an ASI signal of the DVB-T standard.

At this time, the ASI signal of the DVB-T standard is converted to the same frequency band as the ASI signal of the ATSC standard. In practice, the ASI signal of the DVB-T standard has a frequency band of 6, 7, and 8 MHz, so that it can be switched to a bandwidth larger or smaller than that of the ASI signal of the ATSC standard.

It converts the data of the MPEG2 format of the 19.39Mbps transmission band of the receiving ATSC system into a larger bandwidth or a smaller bandwidth suitable for each mode of the DVB-T service. You can convert the current MPEG2 compression format to the same MPEG2 format or H.264 format of MPEG4. For example, data of a 19.39 Mbps transmission band of a receiving ATSC can be converted into a transmission band of the same 19.39 Mbps of the H.264 format of MPEG4 or smaller than about 13 Mbps.

Meanwhile, the PSIP conversion and SI generator 332 converts the received PSIP data into SI data of the DVB-T standard to generate SI data.

The ASI signal and SI data of the DVB-T standard supplied from the transcoder 331 and the PSIP conversion and SI generator 332 are supplied to the scrambler 334.

In addition, the SI 360 of the DVB-T standard may be generated under the control of the controller 360, and the SI data of the DVB-T standard and the ASI signal of the transcoder 331 may be provided to the scrambler 334. have.

The scrambler 334 synthesizes the ASI signal of the transcoder 331 and the SI data of the PSIP transform and the SI generator 332 to generate the ASI of the DVB-T standard, and generates the ASI signal of the DVB-T standard. Is scrambled based on an encryption code stored in a predetermined position of the memory 335 or an encryption code provided from a cas or a DRM through the communication module 336.

In addition, the scrambler 334 codes an ASI signal of the DVB-T standard into a corresponding channel and transmits the ASI signal to the COFDM modulator 340.

Meanwhile, the COFDM modulator 340 generates an IF signal by performing code orthogonal frequency division multiplexing (COFDM) modulation by applying an error correction code to the ASI signal of the DVB-T standard.

The error correction code has a reed Solomon block coder and a convolution code.

The IF signal is provided to the COFDM transmitter 350, and the COFDM transmitter 350 converts the IF signal into an RF signal and then amplifies the signal to a predetermined amplification and transmits it to the receiver 500.

The receiving device 500 receives the RF signal of the DVB-T standard supplied from the relay device 300 and processes the received RF signal.

That is, the RF signal receiving unit 510 of the receiving device 500 receives the RF signal of the DVB-T standard supplied from the relay device 300, and the received RF signal of the DVB-T standard is displayed in the display processing unit ( 530.

Meanwhile, the encryption code supplied from the outside is received through the encryption receiving unit 520 and provided to the display processing unit 530.

The display processor 530 descrambles, demultiplexes, and decodes an RF signal received through the RF signal receiver 510 based on the encryption code received by the encryption receiver 520 to decode the video and audio signals. It outputs and displays the output video and audio on the screen.

In this case, in order to display the RF signal on the screen, a series of processes of descrambling, demultiplexing, and decoding sequentially according to an encryption code are well known techniques, and thus, detailed description thereof will be omitted.

According to an embodiment of the present invention, the relay device is described as converting a digital broadcast signal of the ATSC standard into a DVB-T standard and retransmitting it to the receiving device, but the mobility is lower than that of the DVB-T standard. It can be converted to a standard, or to the ISDB-T standard, which is a Japanese standard, for further compatibility with digital broadcasting systems.

Meanwhile, a process of converting a digital broadcast signal of an ATSC standard 8VSB transmission method having a low radio wave transmission characteristic transmitted from a broadcasting station into a digital broadcast signal of a COFDM transmission method of the DVB-T standard having improved transmission characteristics and transmitting the same to a receiving device is shown in FIG. 5. It demonstrates with reference to.

FIG. 5 is a flowchart illustrating a relay process of the digital broadcast system shown in FIG. 1. As illustrated therein, a relay process of a digital broadcast system according to another embodiment of the present invention will be described.

First, in step 701, the transmitting device 100 converts the digital broadcast signal into RF form using the 8VSB transmission method of the ASTC standard and transmits the digital broadcast signal to the relay device 300.

The relay device 300 receives the RF signal supplied from the transmitting device 100 through step 703, and then demodulates the received RF signal.

That is, in step 705 of the relay device 300, the RF signal supplied from the transmission device 100 is converted into an Asynchronous Serial Interface (ASI) signal and the error correction code of the ATSC standard included in the ASI signal is deleted. Subsequently, in step 707 of the relay device 300, program and system information protocol (PSIP) data having broadcast program and broadcast data and information necessary for reproduction are extracted. In step 709, the relay device 300 converts the ASI signal into an ASI signal of the DVB-T standard, and converts the PSIP data into SI data.

In addition, step 709 of the relay device 300 may convert the received ASI signal into an ASI signal of the DVB-T standard and generate SI data of the DVB-T standard by a command supplied from the outside.

Subsequently, the relay device 300 synthesizes SI data to the ASI signal of the DVB-T standard through step 711, and scrambling the ASI signal of the DVB-T standard to which the SI data is synthesized based on an encryption code supplied from the outside. COFDM modulation is then performed on the scrambled DVB-T standard ASI signal (step 715).

Through step 719 of the relay device 300, a COFDM modulated DVB-T standard ASI signal is converted into an IF signal, and the converted IF signal is amplified with a predetermined amplification and transmitted in RF form.

In addition, the receiving device 500 receives the RF signal supplied from the relay device 300 through step 721 and decodes the RF signal received through step 723 through an encryption code supplied from the outside. It scrambles, demultiplexes the descrambled digital broadcast signal, decodes it, and then processes it to be displayed on the screen.

According to an embodiment of the present invention, a digital broadcasting signal of 8VSB transmission method of ATSC standard having poor radio transmission characteristics transmitted from a broadcasting station is converted into a digital broadcasting signal of COFDM transmission method of DVB-T standard with improved transmission characteristics and received as a receiving device. Will be sent.

Therefore, it is possible to eliminate the blind spot shadow area for the digital broadcast signal caused by environmental and human factors, and to pay for the viewing of the existing digital broadcast signal free of charge to solve the shadow area for the digital broadcast signal. By switching, the cost of watching digital broadcasting can be reduced to a minimum.

In addition, by improving the commonality of various media such as cable broadcasting, terrestrial wave, and public hearing antenna, it is possible to transmit different data through the same channel to efficiently utilize the channel and to receive mobile, so that various mobile terminals can be applied. .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Environmental factors and the conversion of the digital broadcasting signal of the ATSC standard 8VSB transmission method is less than the radio transmission characteristics transmitted from the broadcasting station to the COFDM transmission system digital transmission signal of the DVB-T standard with improved transmission characteristics and transmitted to the receiving device, Digital broadcast viewing is possible by eliminating the blind spot shadow area for digital broadcast signals caused by human factors, and by paying free for viewing of existing digital broadcast signals to eliminate shadow areas for digital broadcast signals. As the cost can be reduced to a minimum, and the sharing of various media such as cable broadcasting, terrestrial wave, and public hearing antenna is improved, different data can be transmitted through the same channel so that the channel can be efficiently used and mobile reception can be performed. Apparatus and room of digital broadcasting system of the applicable effect of the terminal It is possible to make great progress in terms of accuracy and reliability of operation, and furthermore, in terms of performance efficiency, and because it is not only commercially viable or commercially applicable, but also practically evident. This is an invention.

Claims (19)

A transmission device for transmitting the digital broadcast signal produced by the broadcasting station in a first transmission method;
A relay device for modulating and transmitting the digital broadcast signal transmitted from the transmission device by using a second transmission method which is one of a plurality of preset transmission methods;
And a receiving device for receiving the digital broadcast signal transmitted by the second transmission method from the relay device and displaying the same on the screen. The digital broadcasting system as claimed in claim 1, wherein the first transmission scheme is an 8VSTI (8Vestigial Side Band) transmission scheme of the Advanced Television System Committee (ATSC). The digital broadcasting system as claimed in claim 2, wherein the second transmission scheme is a coded orthogonal frequency division multiplexing (COFDM) transmission scheme of a digital video broadcasting-terrestrial (DVB-T) standard. According to claim 3, The relay device,
An ATSC receiver for tuning an RF broadcast digital broadcast signal transmitted in a frequency band of a channel selected by a user;
Converts the 8VSB transmission digital tuned signal transmitted through the ATSC receiver into an ASI (Asynchronous Serial Interface) signal and extracts PSIP (Program and System Information Protocol) data having information necessary for broadcast program and broadcast data and reproduction. Grandfather,
The ASI signal extracted by the demodulator is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into the SI data of the DVB-T standard, and the SI data is converted into the ASI signal converted to the DVB-T standard frequency band. A signal processor for synthesizing the signal to generate an ASDI signal of the DVB-T standard;
A COFDM modulator for synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processor and modulating the COFDM transmission scheme to generate an IF signal;
A COFDM transmitter for converting the IF signal of the COFDM modulator into an RF frequency signal and amplifying the COFDM modulator to a predetermined amplification degree and transmitting the amplified signal to the receiver;
Digital broadcasting system comprising a control unit for controlling the overall digital broadcasting system. The method of claim 4, wherein the signal processing unit,
A transcoder for converting the ASI signal into a frequency band of the DVB-T standard;
A PSIP conversion and SI generator for converting the PSIP data into SI (Service Information) of the DVB-T standard to generate SI data;
The ASI signal of the transcoder and the SI data of the PSIP conversion and SI generator are synthesized to generate the ASI of the DVB-T standard, and the scrambling is performed by scrambling the generated ASI signal of the DVB-T standard according to an encryption code supplied from the outside. And coding the ASI signal of the DVB-T standard into a corresponding channel and transmitting the same to the COFDM modulator. The method of claim 5, wherein the signal processing unit,
And a memory for storing an encryption code in advance to encrypt the ASI signal of the DVB-T standard. The method of claim 6, wherein the signal processing unit,
And a communication module receiving an encryption code for encrypting the ASI signal of the DVB-T standard from a preset CAS or Conditional Access System (DRM). The method of claim 1, wherein the receiving device,
And at least one digital broadcast signal among satellite digital broadcast signals, digital cable broadcast signals, and terrestrial digital broadcast signals. The method of claim 1, wherein the receiving device,
An RF frequency signal receiver for receiving an RF frequency signal supplied from the relay device;
And a display processor configured to descramble the RF frequency signal based on an encryption code supplied from the outside, demultiplex it, decode it, and display the video and audio signal. An ATSC receiver for tuning a digital broadcast signal of an RF broadcasting station transmitted in a frequency band of a channel selected by a user;
Converts the 8VSB transmission digital tuned signal transmitted through the ATSC receiver into an ASI (Asynchronous Serial Interface) signal and extracts PSIP (Program and System Information Protocol) data having information necessary for broadcast program and broadcast data and reproduction. Grandfather,
The ASI signal extracted by the demodulator is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into SI data of the DVB-T standard, and the SI data is converted into an ASDI signal converted to the DVB-T standard frequency band. A signal processor for synthesizing the ASI signal to a DVB-T standard;
A COFDM modulator for synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processor and modulating the COFDM transmission scheme to generate an IF signal;
A COFDM transmitter for converting the IF signal of the COFDM modulator into an RF frequency signal and then amplifying the COFDM modulator with a predetermined amplification signal and transmitting the signal to a receiver;
And a control unit for controlling the overall digital broadcasting system. The method of claim 10, wherein the signal processing unit,
A transcoder for converting the ASI signal into a frequency band of the DVB-T standard;
A PSIP conversion and SI generator for converting the PSIP data into SI (Service Information) of the DVB-T standard to generate SI data;
Synthesize the ASI signal of the DVB-T standard by synthesizing the ASI signal of the transcoder and the SI data of the PSIP conversion and the SI generator, and scrambling the generated ASI signal of the DVB-T standard according to an encryption code supplied from the outside. And a scrambler for coding the ASI signal of the DVB-T standard into a corresponding channel and transmitting the same to the COFDM modulator. The method of claim 11, wherein the signal processing unit,
And a memory which pre-stores an encryption code for encrypting the ASI signal of the DVB-T standard. The method of claim 12, wherein the signal processing unit,
The relay device of the digital broadcasting system, characterized in that it comprises a communication module provided with a predetermined code (CAS: Conditional Access System) or DMR (Digital Right Management) for encrypting the ASI signal of the DVB-T standard . A first step of transmitting, by the transmitting apparatus, the broadcast signal produced by the broadcasting station to the relay apparatus in a first transmission method;
A second step of modulating, by the relay device, the digital broadcast signal transmitted from the transmission device to a second transmission method, which is one of a plurality of preset transmission methods, and transmitting the same to a receiving device;
And a third process of receiving, by the receiving device, the digital broadcast signal transmitted by the second transmission method of the relay device and processing the digital broadcast signal to be displayed on a screen. 15. The method of claim 14, wherein the first transmission method is an 8VSB (8Vestigial Side Band) transmission method of an ATSC (Advanced Television System Committee) standard. 15. The method of claim 14, wherein the second transmission scheme is a coded orthogonal frequency division multiplexing (COFDM) transmission scheme of a digital video broadcasting-terrestrial (DVB-T) standard. Way. The method of claim 14, wherein the second process,
ATSC receiving step of tuning the digital broadcast signal of the RF form transmitted in the frequency band of the channel selected by the user,
Converting the 8VSB transmission-type digital broadcast signal tuned through the ATSC receiving step into an ASI (Asynchronous Serial Interface) signal and extracting program and system information protocol (PSIP) data having information necessary for broadcast program and broadcast data and reproduction; Demodulation step,
The ASI signal extracted in the demodulation step is converted into a signal of the frequency band of the DVB-T standard, the PSIP data is converted into SI data of the DVB-T standard, and an SI is converted into the ASI signal converted to the DVB-T standard frequency band. A signal processing step of synthesizing the data to generate an ASDI signal of the DVB-T standard;
A COFDM modulation step of synthesizing error correction data to the ASI signal of the DVB-T standard of the signal processing step and modulating by the COFDM transmission method to generate an IF signal;
And converting the IF signal of the COFDM modulation step into an RF frequency signal, amplifying the signal to a predetermined amplification level, and transmitting the COFDM signal to the receiving device. The method of claim 17, wherein the signal processing step,
Convert the ASI signal into a frequency band of the DVB-T standard,
The PSIP data is converted into SI (Service Information) of the DVB-T standard to generate SI data.
The ASI signal and the SI data are synthesized to generate an ASI of the DVB-T standard, and the ASI signal of the DVB-T standard is scrambled according to an encryption code supplied from the outside, and the ASI signal of the scrambled DVB-T standard. The method of claim 1, further comprising the step of coding the channel. The method of claim 14, wherein the third process,
An RF frequency signal receiving step of receiving an RF frequency signal supplied from the relay device;
And a display processing step of descrambling the RF frequency signal based on an encryption code supplied from the outside, and then demultiplexing and decoding and displaying the RF frequency signal as an image and an audio signal.

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