KR100655941B1 - Network identification method for digital multimedia broadcasting - Google Patents

Abstract

A network identification method for a digital multimedia broadcasting is provided to easily obtain the cost for installing a relay network with a gap filler system. In the transmission data transmission process(S10), the main broadcasting network identification data and the first relay network identification data are loaded at a null area of digital multimedia broadcasting transmission data from a main broadcasting network and then transmitted. The null area and a phase reference symbol area of the broadcasting data are converted by the FFT(Fast Fourier Transform)(S20). In the digital data coding process(S30), the main broadcasting network fourier data and the first main broadcasting phase reference symbol transformation data are compared and then the main broadcasting digital data are outputted.

Description

Network identification method for digital multimedia broadcasting

1 is a system configuration diagram for implementing a general digital multimedia broadcasting service;

2 is a process flowchart showing a digital multimedia broadcasting network identification method of the present invention;

3 is a transmission frame structure diagram of transmission data for digital multimedia broadcasting;

4A and 4B are subcarrier layout diagrams of a null area and a phase reference symbol area of transmission data transmitted in a main network according to the present invention;

4C and 4D are subcarrier layout diagrams of a null region and a phase reference symbol region of transmission data transmitted from a relay network according to the present invention;

5A to 5C are schematic diagrams for explaining a digital data coding step for fast Fourier transform of a null region and a phase reference symbol region received at a receiver;

 FIG. 6 is a diagram illustrating an example of coded digital data of a main broadcasting digital data, a first relay network digital data, and a second relay network digital data; FIG.

7 is a schematic diagram for decrypting an encryption block of a receiver;

8A to 8C are schematic diagrams for explaining the present invention.

The present invention relates to a network identification method for digital multimedia broadcasting, and in particular, a free receiver and a paid receiver for a signal transmitted from the main broadcasting network by dividing a free receiver and a paid viewer pay receiver for a terrestrial digital multimedia broadcasting service. The present invention relates to a digital multimedia broadcasting network identification method that distinguishes the main broadcasting network from the relay network so that only the paying receiver can view the signals transmitted from the relay network installed for the shadow area.

1 is a system configuration diagram for implementing a general digital multimedia broadcasting service.

As shown in FIG. 1, a system for implementing a terrestrial digital multimedia broadcasting (DMB) service includes a main broadcasting network 10 for compressing image, voice, and data signals and then transmitting modulated terrestrial multimedia broadcasting data; In order to receive terrestrial multimedia broadcasting data in shaded areas such as mountains and buildings, a relay network 20 having a gap filler system installed in a transliteration region, a main broadcasting network 10 and a relay network 20 It consists of a user receiver 30 for receiving the terrestrial multimedia broadcast data transmitted from the.

The terrestrial digital multimedia broadcasting can receive a terrestrial digital multimedia broadcasting for free by purchasing a receiver for terrestrial digital multimedia broadcasting.

However, in order to receive terrestrial multimedia broadcasting data in the shaded areas such as mountains or buildings, a relay network equipped with a gap filler system must be installed, and terrestrial broadcasting service providers incur huge expenses to install such a relay network. It is difficult to raise costs for this.

An object of the present invention is to provide the main broadcasting network identification data and the relay network identification data so that the free receiver and the paying receiver for pay-viewing can watch digital multimedia broadcasting in the null area of the digital multimedia broadcasting transmission data transmitted from the main broadcasting network. Subcarrier identification data is transmitted to subcarriers of a specific location so that only the paid receiver for viewing can watch digital multimedia broadcasting in a null area of digital multimedia broadcasting transmission data areas transmitted from the relay network. The terrestrial broadcasting service provider provides a digital multimedia broadcasting network identification method that can easily pay for the installation of the relay network by receiving a certain amount of reception fee from the paying receiver user. There is.

In order to achieve the above object, a digital multimedia broadcasting network identification method of the present invention provides a null area having a transmission identification information signal, which is a fixed value, which informs a base station location of a broadcast service provider for free viewing by terrestrial digital multimedia broadcasting service. A digital multimedia broadcasting network identification method for distinguishing a main broadcasting network for transmitting terrestrial digital multimedia broadcasting data having a phase reference symbol region and reproduction data for matching and a relay network for transmitting terrestrial digital multimedia broadcasting data for pay-per-view, in the main broadcasting network The main broadcasting network identification data and the first relay network identification data are loaded on the subcarriers in the null area among the transmission data for digital multimedia broadcasting to be transmitted, and the second relay is transmitted to the null area among the transmission data for digital multimedia broadcasting transmitted from the relay network. Transmission data transmitting step for transmitting the identification data to the thread come subcarriers; A free receiver and / or a pay-per-view pay receiver, which receives terrestrial digital multimedia broadcasting data transmitted from the main broadcasting network, performs fast Fourier transformation by converting a null region and a phase reference symbol region among the terrestrial digital multimedia broadcasting data of the main broadcasting network. Subcarriers at the same position as the main broadcasting network identification data and the first relay network identification data in the phase reference symbol area are converted into the main broadcasting network Fourier data and the first relay network Fourier data, respectively. For the first main broadcasting network phase reference symbol conversion data and the second main broadcasting network phase reference symbol conversion data, respectively, the free receiver and / or the toll receiver receive terrestrial digital multimedia broadcasting data transmitted from the relay network, Null Young among Multimedia Broadcasting Data And converting the phase reference symbol region to fast Fourier transform to convert the second relay network identification data of the null region to the second relay network Fourier data, and relay network phase reference symbol for the subcarriers at the same position as the second relay network identification data among the phase reference symbol regions. A fast Fourier transform step of converting the transform data into transform data; The main broadcasting network Fourier data and the first main broadcasting network phase reference symbol conversion data are compared to output the main broadcasting digital data, and the first relay network Fourier data and the second main broadcasting network phase reference symbol conversion data are compared to compare the digital data for the first relay network. A digital data coding step of outputting the digital data for the second relay network by comparing the second relay network Fourier data and the relay network phase reference symbol conversion data; And if the receiver is a free receiver, the encryption block embedded in the free receiver receives the digital data for the main broadcast, releases the encryption block built in the free receiver, and the user of the free receiver transmits from the main broadcasting network by the playback data received from the main broadcasting network. You can watch the terrestrial broadcasts received, but the encryption block built into the free receiver is not released by the digital data for the second relay network, so the free receiver cannot play the terrestrial broadcasts received from the relay network, and the encryption built into the pay receiver. The block receives the digital data for the first relay network or the digital data for the second relay network and releases the encryption block built into the pay receiver so that the user of the pay receiver can watch both terrestrial broadcasts transmitted from the main broadcasting network and terrestrial broadcasts transmitted from the relay network. With encryption block decryption step And that is characterized.

The digital data coding step includes the main broadcasting network Fourier data and the first main broadcasting network phase reference symbol conversion data, the first relay network Fourier data and the first main broadcasting network phase reference symbol conversion data, and the second relay network Fourier data and the relay network phase reference symbol conversion data. When comparing data, it compares whether the data compared with each other are located on the same axis, and if the data compared with each other are located on the same axis, it outputs the activated digital data; do.

In the transmitting data transmitting step, the main broadcasting network identification data and the relay network identification data are positioned every 16 subcarrier intervals in the null area.

The subcarrier of the phase reference symbol region transmitted from the relay network located at the same position as the main broadcast network identification data transmitted from the main broadcast network is characterized by carrying a signal having zero power.

Hereinafter, a network identification method for digital multimedia broadcasting of the present invention will be described in detail with reference to the accompanying drawings.

2 is a process flowchart showing a digital multimedia broadcasting network identification method of the present invention.

As shown in FIG. 2, the network identification method for digital multimedia broadcasting according to the present invention includes a transmission data transmission step S10, a fast Fourier transform step S20, a digital data coding step S30, and an encryption block decryption step S40. do.

Transmission data transmission step (S10) is to serve the main broadcasting network identification data (MD) and the first relay network identification data (GDA) in the null area 100 of the digital multimedia broadcasting transmission data transmitted from the main broadcasting network 10 The second relay network identification data GDB is loaded on a subcarrier in a null area 10 of the digital multimedia broadcasting transmission data transmitted from the relay network 20.

In the fast Fourier transform step (S20), the free receiving receiver 30a, which is a free viewing receiver, and / or the paying viewing pay receiver 30b, receives a terrestrial digital multimedia broadcasting data transmitted from the main broadcasting network 10 and receives the main broadcasting network. The primary broadcasting network identification data (MD) and the first relay network identification data of the null region 100 by fast Fourier transform (FFT) of the null region 100 and the phase reference symbol region 200 among the terrestrial digital multimedia broadcasting data. (GDA) is converted into main broadcasting network Fourier data (FMD) and first relay network Fourier data (FGDA), respectively, and main broadcasting network identification data (MD), first relay network identification data (GDA) and The subcarriers in the same position are converted into the first main broadcast network phase reference symbol conversion data (FMA) and the second main broadcast network phase reference symbol conversion data (FMB), respectively, and the free receiver 30a and / or the paid receiver 30b. ) Is transmitted from the relay network 20. Receives terrestrial digital multimedia broadcasting data and performs fast Fourier transform of the null region 100 and the phase reference symbol region 200 among the terrestrial digital multimedia broadcasting data to convert the second relay network identification data GDB of the null region 100 into a second signal. The RS is converted to the relay network Fourier data FGDB, and the subcarrier at the same position as the second relay network identification data GDB in the phase reference symbol region 200 is converted to the relay network phase reference symbol conversion data FGA.

The digital data coding step (S30) compares the main broadcasting network Fourier data (FMD) and the first main broadcasting network phase reference symbol conversion data (FMA) and outputs the main broadcasting digital data (MADA), and the first relay network Fourier data (FGDA) Compares the second main broadcasting network phase reference symbol conversion data (FMB) and outputs the digital data for the first relay network (GFDA), and compares the second relay network Fourier data (FGDB) and the relay network phase reference symbol conversion data (FGA). The digital data GFDB for the second relay network is output.

Encryption block decryption step (S40) is the receiver is a free receiver (30a), the encryption block 400a built in the free receiver (30a) receives the main broadcast digital data (MADA) to encrypt the built-in free receiver (30a) By releasing the block 400a, the user of the free receiver 30a can watch the terrestrial broadcast transmitted from the main broadcasting network 10 by the playback data DA received from the main broadcasting network 10, but the free receiver 30a. The encryption block 400a built in the encryption block 400a is not released by the digital data for the second relay network GFDB, so the free receiver 30a cannot reproduce the terrestrial broadcast transmitted from the relay network 20, The encryption block 400b embedded in the receiver 30b receives the first relay digital data GFDA or the second relay digital data GFDB to release the encryption block 400b embedded in the pay receiver 30b. The user of the pay receiver 30b is the main broadcasting network (1). Both terrestrial broadcasts transmitted from 0) and terrestrial broadcasts transmitted from the relay network 20 can be viewed.

The digital data coding step (S30) includes the main broadcasting network Fourier data (FMD) and the first main broadcasting network phase reference symbol conversion data (FMA), the first relay network Fourier data (FGDA) and the first main broadcasting network phase reference symbol conversion data (FMB). And digitally activated when data compared with each other is located on the same axis when comparing the second relay network Fourier data (FGDB) and the relay network phase reference symbol conversion data (FGA). Data, for example, a low logic value, is output. If it is not located on the same axis, inactivated digital data, for example, a high logic value, is output.

In the transmitting data transmission step S10, the main broadcasting network identification data MD and the relay network identification data GDA and GDB are located at intervals of 16 subcarriers in the null area 100.

The subcarrier of the phase reference symbol region 200 transmitted from the relay network 20 located at the same position as the main broadcasting network identification data MD transmitted from the main broadcasting network 10 carries a signal having zero power.

The operation of the present invention for identifying a digital multimedia broadcasting network according to the above configuration is as follows.

FIG. 3 is a structure diagram of a transmission frame of digital multimedia broadcasting transmission data. As shown in FIG. 3, a transmission frame of transmission data transmitted by the main broadcasting network 10 and the relay network 20 is digital audio satellite broadcasting (DAB). According to the European standard, each station has zero power in subcarriers other than the transmission identification information, and has a fixed value for indicating the location of the base station and has weak power. A null region 100 for identifying a frame section, a phase reference symbol region 200 having fixed data promised to the transmitter and the receiver in order to synchronize the transmitter and the receiver; And playback data 300, which is video / audio data for playback by the receiver. The null region 100 and the phase reference symbol region 200 are composed of the same number of subcarriers. According to the European standard, the null region 100 and the phase reference symbol region 200 are composed of 1536 subcarriers. Consists of.

4A and 4B are layout views of subcarriers of a null region and a phase reference symbol region of transmission data transmitted from a main network according to the present invention, respectively. FIGS. 4C and 4D are transmissions transmitted from a relay network according to the present invention, respectively. A subcarrier arrangement diagram of a null region and a phase reference symbol region of data.

As shown in FIGS. 2 and 4A for transmitting a digital multimedia broadcasting network identification method according to the present invention, the transmission data transmission step S10 is a null area of digital multimedia broadcasting transmission data transmitted from the main broadcasting network 10. Based on the first subcarrier and the first subcarrier of (100), the main broadcasting network identification data (MD) is carried on the subcarrier for every 16 subcarrier intervals (assigned to position 1), and the main broadcasting network is also identical. Subcarriers of the first relay network identification data (GDA) for every 16 subcarrier intervals based on the second subcarrier and the second subcarrier of the null region 100 among the transmission data for digital multimedia broadcasting transmitted by (10). Send it on. As shown in FIG. 4C, second relay network identification data (GDB) for every 16 subcarrier intervals based on the second subcarrier and the second subcarrier of the null area 10 among the digital multimedia broadcasting transmission data transmitted from the relay network 20. ) Is transmitted on a subcarrier (assigned to position 2). In this way, the main broadcasting network identification data (MD) and the first relay network identification data (GDA) are loaded on specific subcarriers of the null area 100 of the transmission data transmitted from the main broadcasting network 10, and the relay network 20 A free receiver which does not pay a certain amount of service fee to a terrestrial broadcasting service provider by carrying the second relay network identification data (GDB) on specific subcarriers of the null area 100 of the transmitted data and transmitting it, as described below. The terrestrial broadcast transmitted by 10 may be viewed, but the terrestrial broadcast transmitted by the relay network 20 in which the gap filler system is installed for the shadow area cannot be viewed by a free receiver, and a certain amount of service fee is paid to the terrestrial broadcast service provider. The pay receiver can watch both terrestrial broadcasts transmitted from the main broadcast network 10 as well as terrestrial broadcasts transmitted from the relay network 20.

In the fast Fourier transform step (S20), the free receiver 30a and / or the paid receiver 30b receive terrestrial digital multimedia broadcasting data transmitted from the main broadcast network 10 and / or the relay network 20 to perform fast Fourier transform. It converts data on time axis into data on frequency. That is, the main broadcasting network as shown in FIGS. 5A and 5B by fast Fourier transforming the main broadcasting network identification data (MD) and the first relay network identification data (GDA) of the null area 100 among the main broadcasting network terrestrial digital multimedia broadcasting data. Fourier data (FMD) and the first relay network Fourier data (FGDA) is converted into, as shown in FIG. 5C, the main broadcasting network identification data (MD) and the first relay network identification data (GDA) of the phase reference symbol region 200 and A fast Fourier transform is performed on the subcarriers MA and MB at the same position and converted into first main broadcast network phase reference symbol transform data FMA and second main broadcast network phase reference symbol transform data FMB, respectively.

By the same method as described above, the free receiver 30a and / or the paid receiver 30b receive terrestrial digital multimedia broadcasting data transmitted from the relay network 20 to refer to the null area 100 and phase of the terrestrial digital multimedia broadcasting data. Fast Fourier transform of the symbol region 200 to convert the second relay network identification data GDB of the null region 100 to the second relay network Fourier data FGDB, and the second relay network identification data of the phase reference symbol region 200. Subcarrier GB at the same position as GDB is converted into relay network phase reference symbol conversion data FGA.

In the digital data coding step (S30), the main broadcasting network Fourier data (FMD) and the first main broadcasting network phase reference symbol conversion data (FMA) are compared with each other, and the data compared with each other are shown on the same axis as shown in FIGS. 5A and 5C. If the data is located at, i.e., if there is no phase difference, it is coded as digital data having a low logic value which is an activated signal, and if the data to be compared are not located on the same axis as shown in FIGS. 5B and 5C, For example, if there is a 180 degree phase difference, the data is coded into digital data having a high logic value which is an inactivated signal and outputs main broadcasting digital data (MADA). In the same way, the first relay network Fourier data (FGDA) and the second main broadcast network phase reference symbol conversion data (FMB) are compared, and the first relay network digital data (GFDA) is output, and the second relay network Fourier data (FGDB) The relay network phase reference symbol conversion data (FGA) is compared and the second relay network digital data (GFDB) is output. FIG. 6 shows an example of the values of the main broadcasting digital data MADA, the first relay network digital data GFDA, and the second relay network digital data GFDB output in the digital data coding step S30.

In the digital data coding step S30, the terrestrial broadcast service provider is fixed data that the subcarriers of the phase reference symbol region are known in advance, and therefore, the main broadcasting digital data (MADA) and the digital data for the first relay network (GFDA). ) And the second relay network digital data GFDB are to transmit the information having the low logical value, the subcarriers of the same phase as the subcarriers of the same position (MA, MB, GB) of the phase reference symbol region. In order to transmit information loaded with a null logic in the null area 100 and to transmit information having a high logic value, subcarriers having 180 degrees out of phase are loaded on the null area 100 of the transmission data and transmitted.

As shown in FIGS. 5A to 5C, the main broadcasting network Fourier data (FMD), the first kitchen network phase reference symbol conversion data (FMA), the first relay network Fourier data (FGDA) and the second main broadcasting network phase reference symbol conversion data ( FMB) and second network Fourier data (FGDB) and relay network phase reference symbol conversion data (FGA) all have a value of 1 or -1 depending on differential binary phase shift keying (DBPSK) coding. The present invention is not limited thereto, and a differential quarter phase shift keying (DQPSK) method may be used.

As shown in FIG. 7 in the encryption block decryption step (S40), the encryption block 400a embedded in the free receiver 30a uses the main broadcasting digital data (MADA) as an encryption key to encrypt the built in free receiver 30a. By releasing the block 400a, the reproduction control unit 500 receives the reproduction data DA received from the main broadcasting network 10 and outputs the reproduction data DA to the display unit 600 to output the reproduction data DA to the user of the free receiver 30a. Can watch the terrestrial broadcast received from the main broadcasting network 10, but the encryption block 400a built in the free receiver 30a is not released by the digital data for the second relay network (GFDB). The free receiver 30a cannot reproduce the terrestrial broadcast received from the relay network 20. The encryption block 400b embedded in the pay receiver 30b receives the digital data for the first relay network GFDA or the digital data for the second relay network GFDB to receive the encryption block 400b embedded in the pay receiver 30b. The user of the pay receiver 30b may release the terrestrial broadcast received from the main broadcasting network 10 and the terrestrial broadcast received from the relay network 20.

That is, as shown in FIG. 8A, when both the free receiver 30a and the pay receiver 30b are in a state capable of receiving transmission data sent to the main broadcasting network 10, the free receiver 30a is connected to the main broadcasting network 10. A fast Fourier transformed by fast Fourier transform on the subcarriers MA of the phase reference symbol region located at the same position as the main broadcasting network identification data MD and the main broadcasting network identification data MD received from the An encryption block 400a embedded in the free receiver 30a by main broadcasting digital data (MADA) according to phase comparison by comparing phases of the broadcasting network Fourier data (FMD) and the first main broadcasting network phase reference symbol conversion data (FMA). The free receiver 30a can watch the terrestrial broadcasting transmitted from the main broadcasting network 10, and the toll receiver 30b also identifies the first relay network of the null area 100 received from the main broadcasting network 10. Receive paid by data (GDA) The terrestrial broadcast transmitted by the main broadcasting network 10 can be viewed by releasing the encryption block 400b of the device 30a.

As shown in FIG. 8B, when both the free receiver 30a and the pay receiver 30b are in a state capable of receiving the transmission data sent to the relay network 20, the free receiver 30a receives a null received from the relay network 20. Fast Fourier-transformed second relay network Fourier data (FGDB) and relay network phase reference symbol conversion data (FGA) by fast Fourier transforming the second relay network identification data (GDB) of the region 100 and the subcarriers (GB) of the phase reference symbol region. By comparing the phases of the encryption block 400a embedded in the free receiver 30a by the second relay digital data (GFDB) according to the phase comparison, the free receiver 30a transmits from the relay network 20. The terrestrial broadcast cannot be viewed, but the pay receiver 30b releases the encryption block 400b of the pay receiver 30a by the second relay network identification data GDB of the null area 100 received from the relay network 20. Is transmitted from the relay network (20) You can watch the broadcast waves.

As shown in FIG. 8C, when both the free receiver 30a and the paid receiver 30b are in a state capable of receiving the transmission data sent to the main broadcasting network 10 and / or the relay network 20, the method as described above may be used. By this, the free receiver 30a can watch the terrestrial wave of the main broadcasting network 10 by the transmission data received from the main broadcasting network 10, and the toll receiver 30b from the main broadcasting network 10 or the relay network 20. The terrestrial wave can be viewed by the transmitted data.

In the transmitting data transmission step S10, as shown in FIG. 4A, the main broadcasting network identification data MD is allocated to position # 1, and as shown in FIG. 4C, the first and second relay network identification data GDA and GDB are allocated. When the main broadcasting network identification data (MD) and the first and second relay network identification data (GDA, GDB) are located at every 16 subcarrier intervals in the null area 100 by allocating to position 2, the base station is located in the null area 100. According to the terms of use of weakly transmitted transmission identification information (TII), which has a fixed value to indicate the position, only three combos out of 24 combos and 70 positions cannot use three combo values of 1, 9, and 17. Since the network identification method of the present invention can be used simultaneously with the transmission identification information (TII) by digital audio satellite broadcasting (DAB).

The subcarriers of the phase reference symbol region 200 are for synchronization and have a fixed value promised by the transmitter and the receiver. The subcarriers of the phase reference symbol region 200 transmitted by the main broadcasting network 10 of FIG. And the subcarriers of the phase reference symbol region 200 transmitted from the relay network 20 of FIG. 4D should have the same value, but the receiver and the terrestrial transmission data transmitted from the main broadcasting network 10 as shown in FIG. When the terrestrial transmission data transmitted from the relay network 20 overlaps, the subcarrier in front of the second relay network identification data GDB transmitted from the relay network 20 has zero power, so that the main broadcasting network 10 and the relay network 20 Since the phase of the main broadcasting network Fourier data (FMD) may be shaken during the fast Fourier transform on the transmission data, the same position as that of the main broadcasting network identification data (MD) transmitted by the main broadcasting network 10 is prevented. Subcarrier (GA) of the phase reference symbol region 200 to be transmitted from the relay network 20 transmits, in placing the signals having zero power.

In the digital multimedia broadcasting network identification method of the present invention, the main broadcasting network identification data (MD) and the first and second relay network identification data (GDA, GDB) both have 96 bits, but the data of 20 bits or less for data protection and synchronization. You can also use only.

The digital multimedia broadcasting network identification method of the present invention includes the main broadcasting network identification data and the relay network identification data at a specific position so that the free receiver and the paid receiver can watch the digital multimedia broadcasting in the null area of the digital multimedia broadcasting transmission data transmitted from the main broadcasting network. Subcarriers are loaded on the subcarriers, and the relay network identification data is loaded on the subcarriers of a specific position so that only the paying receiver can watch the digital multimedia broadcasting in the null area of the digital multimedia broadcasting transmission data areas transmitted from the relay network. By dividing the main broadcasting network and the relay network, terrestrial broadcasting service provider can receive a certain amount of subscription fee from the paid receiver user and can easily raise the cost for the installation of the relay network, which must install the gap filler system for the shadow area. By activating the installation of the relay network, users can easily watch terrestrial broadcasting anywhere.

Claims (5)

For terrestrial digital multimedia broadcasting service, a terrestrial digital multimedia broadcasting data having a null area having a transmission identification information signal that is a fixed value indicating a base station location for free viewing, a phase reference symbol area for synchronization, and playback data A digital multimedia broadcasting network identification method for distinguishing a main broadcasting network for transmitting and a relay network for transmitting terrestrial digital multimedia broadcasting data for pay-per-view, Among the digital multimedia broadcasting transmission data transmitted from the main broadcasting network, the main broadcasting network identification data and the first relay network identification data are loaded on the subcarriers, and the null data of the digital multimedia broadcasting transmission data transmitted from the relay network is transmitted. A transmission data transmission step of carrying the second relay network identification data on a subcarrier in an area; A free receiver and / or a pay-per-view pay receiver, which is a free-viewing receiver, receives terrestrial digital multimedia broadcasting data transmitted from the main broadcasting network, and sets the null area and the phase reference symbol area of the main broadcasting network terrestrial digital multimedia broadcasting data at high speed Fourier. Converts the main broadcasting network identification data and the first relay network identification data of the null area into the main broadcasting network Fourier data and the first relay network Fourier data, respectively, and the same position as the main broadcasting network identification data and the first relay network identification data in the phase reference symbol region. Terrestrial digital multimedia broadcasting for converting subcarriers into first primary broadcast network phase reference symbol conversion data and second primary broadcast network phase reference symbol conversion data, respectively, wherein the free receiver and / or the toll receiver are transmitted from the relay network. The terrestrial terrestrial The second relay network identification data of the null region is converted to the second relay network Fourier data by fast Fourier transforming the null region and the phase reference symbol region among the multimedia broadcasting data, and the same as the second relay network identification data among the phase reference symbol regions. A fast Fourier transform step of converting the subcarrier of the position into relay network phase reference symbol transformed data; The main broadcasting network Fourier data and the first main broadcasting network phase reference symbol conversion data are compared to output the main broadcasting digital data, and the first relay network Fourier data and the second main broadcasting network phase reference symbol conversion data are compared to a first relay network. A digital data coding step of outputting the digital data for the second relay network by comparing the second relay network Fourier data and the relay network phase reference symbol conversion data; And When the receiver is a free receiver, the encryption block embedded in the free receiver receives the main broadcasting digital data, releases the encryption block embedded in the free receiver, and the user of the free receiver uses the playback data transmitted from the main broadcasting network. The terrestrial broadcast received from the main broadcasting network can be viewed, but the encryption block embedded in the free receiver is not released by the digital data for the second relay network so that the free receiver plays the terrestrial broadcast transmitted from the relay network. If not, the encryption block built in the pay receiver receives the digital data for the first relay network or the digital data for the second relay network and releases the encryption block embedded in the pay receiver so that the user of the pay receiver is connected to the main broadcasting network. On the terrestrial broadcast and relay network Digital multimedia broadcasting network identification method comprising the steps decrypting encrypted block to watch all received transmission terrestrial broadcast. The method of claim 1, wherein the digital data coding step Comparing the main broadcasting network Fourier data and the first main broadcasting network phase reference symbol conversion data, the first relay network Fourier data and the second main broadcasting network phase reference symbol conversion data and the second relay network Fourier data and the relay network phase reference symbol conversion data When the data to be compared with each other is located on the same axis, and compares the data compared to each other is located on the same axis outputs the activated digital data, and if not located on the same axis outputs the deactivated digital data Network identification method for digital multimedia broadcasting. 3. The method of claim 2, wherein the activated digital data has a low logic value and the deactivated data has a high logic value. The method of claim 1, wherein in the transmitting data transmitting step, the main broadcasting network identification data and the relay network identification data are located every 16 subcarrier intervals in a null area. The digital multimedia according to claim 1, wherein the subcarrier of the phase reference symbol region transmitted from the relay network located at the same position as the main broadcasting network identification data transmitted from the main broadcasting network carries a signal having zero power. Broadcast network identification method.

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