KR100667316B1 - Digital broadcasting transmission/reception devices capable of improving a receiving performance and signal processing method thereof - Google Patents

Abstract

Disclosed are a digital broadcast transmission / reception system and a signal processing method thereof for improving reception performance. The digital broadcasting transmitter according to the present invention includes a randomization unit for receiving and randomizing a dual TS stream having a predetermined format including a normal data packet having a stuff byte inserted at a predetermined position and a low data packet. A stuff byte exchanger for replacing the stuff byte with predetermined known data, a first RS encoder for performing RS encoding on data output from the stuff byte exchanger, and a low-loss packet among data output from the first RS encoder A packet format unit for interleaving and reconstructing the format, an interleaving unit for interleaving data output from the packet format unit, and a trellis encoding unit for trellis encoding for the data output from the interleaving unit Performs parity by performing RS encoding on the robust packet among trellis encoded data. Change the first portion and includes 2 RS encoding input to the trellis encoding. Therefore, it is possible to improve digital broadcast reception performance in a poor multipath channel while minimizing hardware complexity.

ATSC VSB, Stuff Byte, Known Data, Normal Data, Robust Data

Description

Digital broadcasting transmission / reception devices capable of improving a receiving performance and signal processing method

1 is a block diagram showing a transmitter of a typical US digital broadcasting (ATSC VSB) system,

2 is a diagram illustrating a format of ATSC VSB data;

3 is a frame structure diagram of a TS packet;

4 is a frame structure diagram of a TS packet including a stuff byte according to the present invention;

5 is a block diagram showing a digital broadcast transmitter according to the present invention;

6 is a diagram illustrating a format of data output from the randomization unit of FIG. 5;

7 is a diagram illustrating a format of data output from an interleaving unit of FIG. 5;

8 is a diagram illustrating a format of data output from the trellis encoding unit of FIG. 5;

9 is a diagram illustrating a format of data in which parity is reconstructed according to initialization of the trellis encoder of FIG. 5;

10 is a block diagram showing a digital broadcast receiver according to the present invention; and

FIG. 11 is a view provided to explain the known data output unit of FIG. 10.

Explanation of symbols on the main parts of the drawings

110: randomization unit 115: stuff byte exchange unit

120: first RS encoding unit 125: stuff byte control unit

130: packet format unit 135: packet buffer

140: interleaving unit 145: parity reconstruction unit

150: trellis encoding unit 160: control unit

170: second RS encoding unit

The present invention relates to a digital broadcast transceiver, and more particularly, a digital broadcast transmitter for transmitting a dual stream can improve the performance of a reception system by transmitting stuff bytes inserted in a data stream as predefined known data. The present invention relates to a digital broadcast transmitter and a signal processing method thereof, a digital broadcast receiver and a signal processing method corresponding thereto.

ATSC VSB, a terrestrial digital broadcasting system for the United States, is a single carrier system and field sync signals are used in units of 312 segments. This results in poor reception, especially on poor channels, especially the Doppler fading channel.

1 is a block diagram illustrating a transmitter of a general US terrestrial digital broadcasting system. The digital broadcast transmitter of FIG. 1 is an EVSB system proposed by Philips, and is configured to transmit and form a dual stream in which a robust data is added to normal data of an existing ATSC VSB system. to be.

As illustrated in FIG. 1, the digital broadcast transmitter includes a randomization unit 11 for randomizing data, a first RS encoding unit 12 for RS encoding the output of the randomization unit 11, and boost data among encoded data. At the output of the interleaving unit 14 and the interleaving unit 14 for interleaving data The trellis encoding unit 15 which performs enhanced 2/3 rate trellis encoding after performing enhanced coding on the low-boost data, and normal data and low-boost. The controller 16 outputs a signal for controlling data, and performs RS re-encoding on the enhanced coded robust data for compatibility with an existing receiver, and then replaces parity. 2 RS encoding section 17, A pilot is added to the output signal of the multiplexer section 18 and the multiplexer section 18 for inserting field sync and segment sync to the release coded data, and VSB modulation and RF upconverting. and a modulator 19 for performing upconverting.

Referring to FIG. 1, the normal data and the boost data are multiplexed (not shown) and input to the randomization unit 11 according to a dual stream method for transmitting the normal data and the low boost data through one channel. The input data is randomized by the randomization unit 11, inputted to the first RS encoding unit 12, and RS-encoded and corrected by the packet format unit 13 to correct an error caused by the channel. Robust processing is performed for interleaving and reconstructing packets at half rate and inserting PIDs for the boost data, and then multiplexed with the normal data to output the low data.

FIG. 2 shows the format of data output from the packet format unit 13 of FIG.

Referring to FIG. 2, normal data and low boost data are arranged at regular intervals, which is a data format for distributing normal signals and low boost signals at uniform intervals after trellis encoding.

Accordingly, the output data is interleaved through the interleaving unit 14 that distributes the data, and then subjected to enhanced coding of the low-boost data, and then the existing 2/3 rate trellis encoding. The trellis encoding unit 15 performs trellis encoding. The parity is trellis-encoded by the second RS encoding unit 17 which replaces parity after RS re-encoding for enhanced coded robust data for compatibility with an existing receiver. It is input to the part 15. The signal passed through the multiplexer section 18 that inserts field sync and segment sync into trellis encoded data adds a pilot to this signal, VSB modulates it, and then performs RF upconversion. It is transmitted via the modulator 19 to perform. Here, the normal data and the boost data are controlled by the controller 16 which outputs a signal for controlling the normal data and the low data.

 The terrestrial digital TV system of FIG. 1 is configured to form a dual stream by adding low boost data to normal data of an existing ATSC VSB system, and transmits the low boost data to the existing normal data.

However, the U.S. terrestrial digital TV system of FIG. 1 has little problem of improving the poor reception performance in the multipath channel according to the conventional normal data stream transmission despite the dual stream transmission due to the addition of the boost data. have. That is, there is a problem in that there is almost no improvement in reception performance due to the improvement of the normal stream. In addition, even in the low-boost stream, the reception performance improvement effect is not large in a multipath environment.

 Accordingly, an object of the present invention is to provide a digital broadcast transmitter and a signal processing method thereof capable of improving the performance of a reception system by replacing and transmitting stuff bytes inserted into a dual stream with known data to improve reception performance. There is provided a corresponding digital broadcast receiver and a signal processing method thereof.

The digital broadcast transmitter according to the present invention for achieving the above object is randomized by receiving a dual TS stream of a predetermined format consisting of a normal data packet and a boost data packet having a stuff byte inserted at a predetermined position. A randomization unit configured to replace the stuff byte with predetermined known data for the data output from the randomization unit, a first byte performing RS encoding on the data output from the stuff byte exchanger An RS encoding unit, a packet format unit for interleaving the low boost packet among data output from the first RS encoding unit, and reconstructing a format, an interleaving unit for interleaving the data output from the packet format unit, Trellis encoding for trellis encoding the data output from the interleaving unit A second RS encoding unit configured to perform RS encoding on the low boost packet among the trellis encoded data to change parity and input the trellis encoding unit, and to output data from the trellis encoding unit; And a modulator for performing modulation and performing RF upconversion.

Preferably, the trellis encoding unit includes a memory for performing trellis encoding, and performs the memory initialization on data input at a position where the stuff byte is inserted.

The stuff byte control unit may further include a stuff byte control unit configured to generate a control signal indicating information about the position of the stuff byte to control the memory initialization of the trellis encoding unit.

The apparatus may further include a packet buffer configured to output and temporarily store the data corresponding to the position of the stuff byte among the data output from the first RS encoder.

More preferably, the packet buffer receives data changed according to the memory initialization from the trellis encoder and updates the temporarily stored data.

In addition, the parity reconstruction unit receives the updated data from the packet buffer, performs RS encoding to generate a changed parity, outputs the trellis encoding unit, and replaces the parity added by the first RS encoding unit. It is preferable to further include.

More preferably, the stuff byte is inserted into an adaptation field of the normal data packet and the low data packet.

In addition, the normal data packet and the low data packet are preferably inserted with information about the position and length of the stuff byte inserted into a predetermined position.

The known data is preferably composed of a sequence having a predetermined predetermined pattern.

Meanwhile, a signal processing method for a digital broadcast transmitter includes a randomization step of receiving and randomizing a dual TS stream having a predetermined format including a normal data packet having a stuff byte inserted at a predetermined position and a low boost data packet. A stuff byte exchange step of replacing the stuff byte with predetermined known data for the data output in the randomization step, and a first RS encoding performing RS encoding on the data output in the stuff byte exchange step A packet reconstruction step of performing interleaving on the robust packet among the data output in the first RS encoding step and reconstructing a format, an interleaving step of interleaving the data output in the packet reconstruction step, the interleaving To perform trellis encoding on the data output in step A trellis encoding step, a second RS encoding unit configured to perform RS encoding on the low boost packet among the trellis encoded data to change parity and input the trellis encoding step; and the trellis And a modulation step of performing modulation on the data output in the encoding step and performing RF upconversion.

The digital broadcast receiver according to the present invention corresponding to the above digital broadcast transmitter is encoded by inserting predetermined known data into the position of a dual stream having a stuff byte inserted at a predetermined position. A demodulator for receiving and demodulating a signal from a digital broadcast transmitter; a known data output unit for detecting a position of the known data from the demodulated signal and outputting the known data; an equalizer for equalizing the demodulated signal; Using known data, a Viterbi decoder for correcting and decoding an error of the equalized signal, a deinterleaver for deinterleaving the output data of the Viterbi decoder, and inverse randomization for the output data of the deinterleaver It includes a reverse randomization unit for performing.

Preferably, the known data output unit includes a known symbol detection unit for detecting information on the predetermined position into which the known data is inserted from the received signal, and at least one segment indicating the position with a predetermined identification mark. A segment flag generator for generating a data frame, a trellis interleaver for performing an encoding operation performed by the digital broadcast transmitter on the data frame, and the base at the position where the identification mark is displayed among the interleaved data frames. It includes a known data extraction unit for inserting and outputting data.

More preferably, the known data output unit outputs the detected known data to the demodulator, and the demodulator performs the demodulation using the known data.

On the other hand, the signal processing method for a digital broadcast receiver, for a dual stream in which a stuff byte is inserted at a predetermined position, digitally broadcast a signal encoded by inserting predetermined known data at the position. A demodulation step of receiving and demodulating from a transmitter, a known data output step of detecting the position of the known data from the demodulated signal and outputting the known data, an equalizing step of equalizing the demodulated signal, and using the detected known data A decoding step of correcting and decoding an error of the equalized signal, a deinterleaving step of deinterleaving the output data of the decoding step, and an inverse randomization of the output data of the deinterleaving step. A randomization step.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

5 is a block diagram illustrating a digital broadcast transmitter according to the present invention. The digital broadcast transmitter of FIG. 5 is implemented using the EVSB system proposed by Philips of FIG. 1, and a stuff byte is added to a dual stream MPEG-2 packet so that the stuff byte is known from the transmitter. When transmitted in addition to the transmission signal, the receiver is implemented to detect the known data and use it to compensate for the distortion caused by the channel.

Referring to FIG. 5, the digital broadcast transmitter includes a randomization unit 110 that randomizes input data by multiplexing normal data and boost data, and stuff bytes of a normal data stream and a low data stream among randomized data. Reed-Solomon coding for correcting an error generated by a channel from the output of the stuff byte exchange unit 115 and the stuff byte exchange unit 115 replacing (stuff byte) with a specific sequence RS encoding unit 120, the packet format unit 130, packet format unit 130 for multiplexing the normal data after reconstructing the packet in the interleaving and rate 1/2 of the low data of the encoded data and inserting the PID The interleaving unit 140 for interleaving the output data of the data; and initializing a memory value of the stuff byte portion from the output data of the interleaving unit 140, Trellis encoding unit 150 that performs enhanced 2/3 rate Trellis encoding after enhanced coding for the control, and controls normal data and low data. A second RS encoding for parity replacement after RS re-encoding for enhanced compatibility with the existing receiver for enhanced coded robust data The unit 170 is included.

In addition, the digital transmitter buffers the output of the first RS encoding unit 120 for data initialization in the stuff byte control unit 125 and trellis encoding unit 150 generating a signal for controlling the position of the stuff byte. The packet buffer 135 receives and updates the data changed according to the initialization in the trellis encoder 150, generates parity by performing RS encoding on the data changed according to the initialization, and uses the trellis encoder ( A parity reconstruction unit 145 for inputting the parity to replace existing parity, a multiplexer unit 180 for inserting a field sink, segment sink into trellis encoded mapped data, and an output of the multiplexer unit 180. And a modulator 190 for adding a pilot to the signal and performing VSB modulation and RF upconverting.

 In the present invention, the data packet input to the randomization unit 110 has a form in which stuff bytes are inserted. 3 is a frame structure diagram of a TS stream packet, and FIG. 4 is a frame structure diagram of an MPEG-2 TS stream packet including an adaptation field including a stuff byte according to the present invention. In this case, the 188 byte MPEG-2 packet includes a 4-byte information signal (MPEG-2 header) including an MPEG sync signal, adaptation field length information of 1 byte, other information of 1 byte, and n. Modified field data with one stuff byte, and " 188- (4 + 2 + n) " ES data.

The TS stream packet frame of FIG. 3 is composed of an MPEG-2 header and an adaptation field or ES data. As shown in FIG. 4, a stuff byte is inserted to form all TS streams including a modified field. These MPEG-2 TS packets are input as normal data and low boost data of FIG.

In FIG. 5, the robust data is processed by a robust data pre-processor (not shown), multiplexed with normal data, and input to the randomizer 110.

The randomization unit 110 randomizes data having a form as described above in which normal data and low boost data are multiplexed.

The randomized data through the randomization unit 110 is input to the stuff byte exchange unit 115 to generate a specific sequence generated by a specific sequence generation unit (not shown) for the stuff byte portion of the normal data and the low boost data. Is replaced by. The specific sequence is data having a predefined pattern known in advance between the transmitter and the receiver, hereinafter referred to as known data.

FIG. 6 shows a data format after replacing n stuff byte portions with specific sequence data for normal data and low data packets in the randomization unit 120 output. Referring to the figure, normal data and a low data packet appear at predetermined intervals, and known data is inserted in the modified fields of the normal data packet and the low data packet instead of the stuff byte.

In addition, as described above, the header of the MPEG-2 packet data output from the randomization unit 120 is composed of three bytes including a first byte as a synchronization signal and a packet identity (PID), and then a modified field composed of predetermined bytes. The first two bytes of the portion contain the adaptation field length information.

That is, the first two bytes of the transform field contain information about the stuff byte, i.e., the length of known data, inserted into the transform field. Since the start position of the known data in the packet is fixed, the receiver can know the position of the known data and its length, that is, the amount, according to the information inserted in the first two bytes of the modified field.

The output of the stuff byte exchanger 115 transmits to the packet format unit 130 for the boost data among the externally encoded and encoded data through the first RS encoder 120 to correct an error that may be generated by the channel. By performing interleaving and robust data processing for packet reconstruction and inserting PID at 1/2, the data is multiplexed with normal data, and the output data is interleaved through the interleaving unit 140.

7 illustrates a data format after data interleaving by the interleaving unit 140. The MPEG-2 packet of FIG. 6 is distributed in 52 units by the interleaving unit 140 as shown in FIG. 7. Here, the data of the same byte position of the MPEG-2 packet constitutes the same column as shown in FIG. 7 after data interleaving.

Subsequently, enhanced coding is performed on the low boost data in the output data of the interleaving unit 140, and the existing 2/3 rate trellis encoding is performed by the trellis encoder 150. 2/3 rate Trellis encoding).

 FIG. 8 is a data format for the output of the 12 symbol interleaved trellis encoder 150. Since one field includes six convolutional interleavers, six sequences including stuff bytes are shown. That is, when 10-bit stuff bytes are included in a TS stream, a sequence of "10 * 6 = 60" known symbols appears in one field.

Referring to the figure, it can be seen that data at the same byte position in MPEG-2 packets is included in one data segment after trellis encoding. Therefore, if a certain number of stuff bytes are continuously added to a certain portion of an MPEG-2 packet, randomized, replaced with a specific sequence, and trellis encoding, stuff bytes inserted at the same byte position are one data. A segment is formed, which is a known signal, which can be detected by a digital broadcast receiver and used to improve reception performance.

In addition, the RS is encoded by the second RS encoding unit 170 by RS re-encoding for enhanced compatibility with the existing receiver, and then replaces the parity with non-normal RS. Non-systematic RS encoding is performed.

The trellis encoding unit 150 has its own memory (not shown) for trellis encoding. The trellis encoding unit 150 performs a process for initializing the memory from the start point of the stuff byte or known data.

On the other hand, the packet buffer 135 receives the data corresponding to the memory initialization position of the trellis encoding unit 150 from the first RS encoding unit 120 and buffers the data, and then by the trellis encoding unit 150 Memory initialization is performed to receive the changed new data, update and buffer the previously buffered data, and input the updated data to the parity reconstruction unit 145. Accordingly, the parity reconstruction unit 145 generates parity by performing RS encoding on data changed according to memory initialization, and inputs the generated parity to the trellis encoding unit 150 to replace the previous parity.

In addition, the control unit (Normal / Robust Control unit) 160 outputs a signal for controlling normal data and low-boost data, and the stuff byte control unit 125 generates a signal for controlling the position of the stuff byte. .

The encoded data is mapped to 8 level symbols and then inserted into the field sink and the segment sink as shown in the data formats of FIGS. 2 and 8. In addition, the modulation unit 190 gives a DC offset for pilot generation, performs VSB modulation, and converts the RF into RF.

On the other hand, the stuff byte control unit 125 detects the adaptation field length of FIG. 4 and accordingly, the stuff bytes or known symbol sequence data of FIGS. 6, 7 and 8 are known. Generate and output a flag signal indicating the position of.

In addition, in FIG. 5, the trellis encoding unit 150 performs initialization of 12 trellis encoders at a known data start point, in order to initialize a value in a memory device of the encoder. The data changed by the initialization replaces the previous value stored in the packet buffer 135, and is input to the trellis encoding unit 150 using the new parity generated by the parity reconstruction unit 145 according to the changed data. Replaces the parity position of.

9 illustrates a data format after RS encoding and parity reconstruction are performed by the parity reconstruction unit 145 of FIG. 5. When the trellis encoding unit 150 is initialized at the start of the symbol sequence of the known data, the output parity of the first RS encoding unit 120 is changed by changing the data value according to the initialization. Accordingly, the parity reconstruction unit 145 updates the previous parity with the changed parity so that trellis encoding is performed, so that there is no problem in decoding the RS decoder of the digital broadcast receiver described later.

That is, the memory initialization of the trellis encoding unit 150 is performed to allow the trellis encoded data to form a predetermined specific sequence during the symbol sequence period of the known data, and in response to the changed data of the memory initialization position. In order to change the parity, RS encoding is performed on the changed data to generate a new parity, which replaces the original parity. 9 illustrates a process of replacing a corresponding parity according to a data value change according to memory initialization.

FIG. 10 is a block diagram of a digital broadcast receiver according to the present invention corresponding to the digital broadcast transmitter of FIG. 5, and if a received signal includes normal, robust and stuff bytes, it is decoded. Includes components for

The digital broadcast receiver of FIG. 10 lowers the received RF signal to the baseband and demodulates the demodulator 310, the equalizer 320 to remove inter-symbol interference, and a beater for error correction and decoding from the equalized signal. De-muxing the outputs of the Viterbi decoder 330, the deinterleaver 340, and the deinterleaver 340, among them, Packet Re-Formatting and Deinterleaving RS correction for the output of the packet format unit 350 for performing de-interleaving, the control signal generator 360 for generating a control signal for controlling the dual stream, and the packet format unit 350 RS decoder 370, de-randomizer 380, and known symbol output detector / Known symbol location detector / known data output for processing the known data. , 400).

The demodulator 310 converts an RF signal received through a channel into a baseband signal through a tuner / IF (not shown), and performs synchronization detection and demodulation on the converted baseband signal. The equalizer 320 compensates for channel distortion caused by the multipath of the channel from the demodulated signal.

Meanwhile, the known symbol location detector / Known data output 400 detects the amount of stuff bytes inserted into the reserved part of the field sync data segment section and detects the known information. Acquire position information of a symbol and output known data from the acquired position information.

11 shows a known data output unit 400 for detecting known data in a digital broadcast receiver.

The known data output unit 400 includes a known symbol number detector 410, a segment flag generation unit 420, a trellis interleaver 430, and a known data extractor. (Known data sequence) 440.

If the digital broadcast transmitter inserts the amount (number) of stuff bytes into the reserved part of the field sync data segment, the known symbol of the known data output unit 400 of the digital broadcast receiver. The detection unit 410 detects the amount information of the known data, finds the position information of the known symbol by the segment flag generator 420 and the trellis interleaver 430 according to the detected amount information, and obtains the obtained position information. Known data is output from the known data extractor 440 to be used for improving the reception performance of the digital broadcast receiver. Knowing the amount of stuff byte, the location of the stuff byte is always fixed, so the segment flag generator 420 and trellis interleaver 430 may be implemented using a counter and control logic.

 That is, the known symbol detection unit 410 extracts information about the position of the known data from the control information bit including information about the length of the deformation field of the demodulated data header portion. Here, the information on the location of the known data includes information on the length of the known data, and since the location of the known data is specified in advance, the length and the number of the known symbols according to the encoding of the known data can be determined by knowing the length of the known data. have.

The segment flag generating unit 420 generates at least one segment by a predetermined identification mark by a length corresponding to the number of symbols for a corresponding position according to the position and the number of the known symbols, and generates at least one segment. 2 Create a transmission frame.

The trellis interleaver 430 performs an encoding process such as an interleaving process performed by a transmitter on the transmission frame generated by the segment flag generator 420.

In addition, the base data extracting unit 440 performs encoding from the trellis interleaver 430 to insert predetermined base data at a position corresponding to a known symbol identified according to an identification mark among output frames. Output

On the other hand, the signal equalized by the equalizer 320 is corrected by the Viterbi decoder 330 and decoded into symbol data. The decoded data rearranges the data distributed by the interleaver 140 of the transmitter of FIG. 5 through a data deinterleaver 340. The deinterleaved data is de-muxed by the packet format unit 350 to be separated into low data and normal data, and packet re-formatting and deinterleaving are performed on the low data. Then, the error is corrected by being input to the RS decoding unit 370 together with the normal data. The control signal generator 360 generates a control signal for processing normal data and low boost data. The output of the RS decoder 370 is derandomized through a derandomizer 380.

As described above, stuff bytes are generated and inserted into MPEG-2 TS packets, and the inserted stuff bytes are transmitted from the digital broadcast transmitter as known data, and the digital broadcast receiver detects and uses known data to synchronize the digital broadcast receiver. Receive performance such as acquisition and equalization performance can be improved.

In addition, by inserting the stuff byte in the existing transmission frame structure and modifying only a part of the promise, it is compatible with the existing system, there is an advantage that the complexity of the additional hardware implementation is not large.

According to the present invention, a digital broadcast transmitter inserts a stuff byte into a dual data stream of an MPEG-2 TS packet, transmits the inserted stuff byte as known data, and detects and uses known data in a digital broadcast receiver. It is compatible with a full broadcast system, has low hardware complexity, and can improve digital broadcast reception performance in a poor multipath channel.

In addition, it is compatible with the ATSC VSB method, an American terrestrial DTV system proposed by ATSC, and the reception performance of the existing system is improved.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the present invention is not limited to the specific embodiments of the present invention without departing from the spirit of the present invention as claimed in the claims. Anyone skilled in the art can make various modifications, as well as such modifications are within the scope of the claims.

Claims (24)

A randomizer which receives and randomizes a dual TS stream having a predetermined format including a normal data packet having a stuff byte inserted at a predetermined position and a low data packet; A stuff byte exchange unit which replaces the stuff byte with predetermined known data for data output from the randomization unit; A first RS encoder for performing RS encoding on data output from the stuff byte exchanger; A packet format unit for interleaving the low-loss packet among data output from the first RS encoder and reconstructing a format; An interleaving unit performing interleaving on the data output from the packet format unit; A trellis encoding unit performing trellis encoding on the data output from the interleaving unit; A second RS encoding unit configured to change parity by performing RS encoding on the robust packet among the trellis encoded data and input the trellis encoding unit; And And a modulation unit for performing modulation on the data output from the trellis encoding unit and performing RF upconversion. The method of claim 1, And the trellis encoding unit includes a memory for performing trellis encoding, and performs the memory initialization on data input at a position where the stuff byte is inserted. The method of claim 2, And a stuff byte control unit configured to generate a control signal indicating information on the position of the stuff byte and control the memory initialization of the trellis encoding unit. The method of claim 2, And a packet buffer configured to output and temporarily store the data corresponding to the position of the stuff byte among the data output from the first RS encoder. The method of claim 4, wherein The packet buffer is a digital broadcast transmitter, characterized in that for receiving the data changed according to the memory initialization from the trellis encoder to update the temporarily stored data. The method of claim 5, A parity reconstruction unit configured to receive the updated data from the packet buffer to perform RS encoding to generate a changed parity, output the trellis encoding unit, and replace the parity added by the first RS encoding unit; Digital broadcast transmitter further comprises. The method of claim 1, The stuff byte is inserted into an adaptation field of the normal data packet and the low data packet. The method of claim 1, And the information on the position and length of the stuff byte inserted into the normal data packet and the low data packet is inserted at a predetermined position. The method of claim 1, And said known data is composed of a sequence having a predetermined predetermined pattern. A randomization step of receiving and randomizing a dual TS stream having a predetermined format including a normal data packet having a stuff byte inserted at a predetermined position and a low boost data packet; A stuff byte exchange step of replacing the stuff byte with predetermined known data for the data output in the randomization step; A first RS encoding step of performing RS encoding on the data output in the stuff byte exchange step; A packet reconstruction step of performing interleaving and reconstructing a format of the robust packet among data output in the first RS encoding step; An interleaving step of interleaving the data output in the packet reconstruction step; A trellis encoding step of performing trellis encoding on the data output in the interleaving step; A second RS encoder configured to change parity by performing RS encoding on the low boost packet among the trellis encoded data and to input the trellis encoding step; And And a modulation step of performing modulation on the data output in the trellis encoding step and performing RF upconversion. The method of claim 10, In the trellis encoding step, the memory initialization is performed on a memory provided for trellis encoding at a starting point of data input at a position where the stuff byte is inserted. Signal processing method. The method of claim 11, A stuff byte control step of controlling a memory initialization of the trellis encoding step by generating a control signal indicating information on the position of the stuff byte; . The method of claim 11, And outputting and temporarily storing the data corresponding to the position of the stuff byte among the data output in the first RS encoding step. The method of claim 13, The storing may include receiving data changed according to the memory initialization from the trellis encoding step and updating the temporarily stored data. The method of claim 14, A parity reconstruction step of receiving the updated data from the storing step, performing RS encoding to generate a changed parity, and outputting the trellis encoding step to replace the parity added in the first RS encoding step; Signal processing method for a digital broadcast transmitter, characterized in that it further comprises. The method of claim 10, The stuff byte is inserted into an adaptation field of the normal data packet and the low data packet. The method of claim 10, The normal data packet and the low data packet, the signal processing method for a digital broadcast transmitter, characterized in that the information on the position and length of the stuff byte is inserted at a predetermined position. The method of claim 10, And said known data is composed of a sequence having a predetermined predetermined pattern. For a dual TS stream of a predetermined format consisting of a normal data packet having a stuff byte inserted at a predetermined position and a low boost data packet, a predetermined signal is inserted by inserting predetermined known data at the position. A demodulator configured to receive and demodulate a digital broadcast transmitter; A known data output unit for detecting a position of the known data from the demodulated signal and outputting the known data; An equalizer for equalizing the demodulated signal; A Viterbi decoder that corrects and decodes an error of the equalized signal using the detected known data; A deinterleaver for deinterleaving the output data of the Viterbi decoder; And And a derandom randomizer for performing de randomization on the output data of the deinterleaver. The method of claim 19, The known data output unit, A known symbol detector detecting information about the predetermined position at which the known data is inserted from a received signal; A segment flag generator configured to generate a data frame including at least one segment indicating the position by a predetermined identification mark; A trellis interleaver for performing an encoding operation performed at the digital broadcast transmitter on the data frame; And And a known data extracting unit for inserting and outputting the known data at the position where the identification mark is displayed among the interleaved data frames. The method of claim 19, The known data output unit, Outputting the detected known data to the demodulator, And the demodulator performs the demodulation using the known data. For a dual TS stream of a predetermined format consisting of a normal data packet having a stuff byte inserted at a predetermined position and a low boost data packet, a predetermined signal is inserted by inserting predetermined known data at the position. A demodulation step received from a digital broadcast transmitter and demodulated; A known data output step of detecting a position of said known data from said demodulated signal and outputting said known data; An equalization step of equalizing the demodulated signal; A decoding step of correcting and decoding an error of the equalized signal using the detected known data; A deinterleaving step of performing deinterleaving on the output data of the decoding step; And And a derandom randomization step of performing inverse randomization on the output data of the deinterleaving step. The method of claim 22, The known data output step, Detecting information on the predetermined position where the known data is inserted from the received signal; Generating a data frame comprising at least one segment indicative of the location with a predetermined identification mark; Performing an encoding operation performed at the digital broadcast transmitter on the data frame; And And inserting and outputting the known data at the position where the identification mark is displayed among the interleaved data frames.  The method of claim 22, The known data output step, Outputting the detected known data to the demodulation step, And wherein said demodulating step performs said demodulation using said known data.

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