MXPA06012670A

MXPA06012670A - Digital broadcast transmitting and receiving system having an improved receiving performance and signal processing method thereof.

Info

Publication number: MXPA06012670A
Application number: MXPA06012670A
Authority: MX
Inventors: Yong-Deok Chang; Hae-Joo Jeong; Sung-Woo Park; Eui Jun Park
Original assignee: Samsung Electronics Co Ltd
Priority date: 2004-05-06
Filing date: 2005-05-04
Publication date: 2007-01-16
Also published as: CA2565740C; WO2005109878A1; CA2565740A1

Abstract

A digital broadcast transmitting and receiving system and a signal processing method thereof that improves the receiving performance of the system. A digital broadcast transmitter can include a randomizer to receive and randomize a data stream into a specified position of which stuff bytes are inserted, a stuff -byte exchange unit to generate known data having a predefined pattern and insert the known data into the specified position of the data stream into which the stuff bytes are inserted, an encoder to encode the data stream output from the stuff-byte exchange unit for an error correction, and a modulator and RF converter to modulate the encoded data stream, RF-convert the modulated data stream and transmit the RF-converted data. The digital broadcast receiving performance can be improved even in an inferior multi-path channel by detecting the known data from the received transmission and using the known data for synchronization and equalization in a digital broadcast receiver.

Description

includes a scrambler 110 for scrambling a transport stream of MPEG-2 (Movie Expert Group) (TS), an RS (Reed-Solomon) coder 120 to add RS parity bytes to the transport stream in order to correcting the bit errors that occur due to the channel characteristic in a transport process, an interleaver 130 for interleaving the RS-encoded data according to a specified pattern and a Trellis encoder 140 for mapping the interleaved data onto symbols of 8 levels when performing a Trellis coding of the interleaved data at the speed of 2/3. The digital broadcast transmitter performs an error correction coding of the MPEG-2 transport stream. The digital broadcast transmitter further includes a multiplexer 150 for inserting a segment synchronization signal and a field signal signal to the data encoded by error correction and a modulator and an RF converter 160 for inserting a pilot tone to the symbols of data at which the segment synchronization signal and the field synchronization signal are inserted by inserting a specific DC value into the data symbols, effecting a VSB modulation of the data symbols by pulse formation of the symbols data and upconversion of the modulated data symbols to an RF channel band signal to transmit the RF channel band signal. Thus, the digital broadcast transmitter randomizes the transport stream MPEG-2, encodes the data externally scrambled by RS encoder 120 that is an outer coder, and distributes the coded data through the interleaver 130. Also, the transmitter digital broadcast internally encodes the interleaved data in the unit of 12 symbols through the trellis coder 140, performs mapping of the encoded data internally on the symbols of 8 level, inserts the sync signal and field sync signal segment to the encoded data, it performs the VSB modulation of the data and then up-converts the modulated data to the RF signal to emit the RF signal. The digital broadcast receiver of Figure 1 includes a tuner 210 for the downconversion of an RF signal received by means of a channel to a baseband signal, a demodulator 220 for effecting a synchronization detection and demodulation of the converted baseband equalizer 230 to compensate for a channel distortion of the demodulated signal occurring due to multipath, a decoder trellis 240 for correcting errors of the equalized signal and decoding the equalized signal to symbol data, a deinterleaver 250 for rearranging the data distributed by the interleaver 130 of the transmitter digital broadcast decoder RS 260 to correct errors and a descrambler 270 for descrambling the corrected data by decoder RS 260 and outputting a transport stream of MPEG-2. Thus, the digital broadcast receiver of FIG. 1 descends the RF signal to the baseband signal, demodulates and equalizes the converted signal and decodes the demodulated signal per channel to restore it to the original signal. Figure 2 illustrates a VSB data frame for use in the American-type digital broadcast system (8-VSB), at which a segment synchronization signal and a field synchronization signal are inserted. As shown in Figure 2, a table consists of two fields. A field is composed of a field synchronization segment that is the first segment and 312 data segments. The other segment in the VSB data box corresponds to the MPEG-2 packet and is composed of a segment synchronization signal of four symbols and 828 data symbols. In Figure 2, the segment synchronization signal and the field synchronization signal are used for synchronization and equalization in the digital broadcast receiver. This is, the field synchronization signal and the segment synchronization signal refer to known data between the digital broadcast transmitter and receiver, which is used as a reference signal when the equalization is effected on the receiver side. As shown in Figure 1, the VSB system of the American-type digital terrestrial broadcast system is a single-carrier system and thus has a deficiency in that it is weak in a multipath fading channel environment that has the effect of Doppler. Thus, the performance of the receiver is greatly influenced by the performance of the equalizer to remove the multiple trajectory. However, according to the existing transport chart as shown in Figure 2, since the field synchronization signal which is the equalizer reference signal appears every time for every 313 segments, its frequency is quite low with respect to to a frame signal and causes the equalization performance to deteriorate. Specifically, it is not easy for the existing equalizer to estimate the channel using a small amount of data as before and equalize the received signal by eliminating the multiple path. Thus, the conventional digital broadcast receiver has disadvantages that its reception performance deteriorates in a lower channel environment and especially in a Doppler front channel environment.

BRIEF DESCRIPTION OF THE INVENTION Technical Problem The present general inventive concept provides a digital broadcast transmission and reception system and a signal processing method thereof, which can improve the reception performance of the system when generating and transmitting a transport signal with known data added to it on one side of the transmitter and when detecting the transport signal on a receiver side. Additional aspects and advantages of the present inventive general concept will be summarized in part in the description that follows and in part will be obvious from the description or can be learned by the practice of the general inventive concept.

Technical Solution The foregoing and other aspects of the present general inventive concept are substantially accomplished by providing a digital broadcast transmitter comprising a scrambler to receive a stream of data from which filler bytes are inserted to a specified position and randomize the data stream received, a padding byte exchange unit for generating known data having a predefined pattern and inserting the known data at the specified position of the data stream to which the padding bytes are inserted, an encoder for encoding the current of data emitted from the packet byte exchange unit by an error correction and an RF modulator and converter to modulate the encoded data stream, convert the modulated data stream by RF and transmit the converted data to RF. The data stream may include information about the specific position at which the padding bytes are inserted. The information may be inserted into a position of the data stream preceding the position at which the padding bytes are inserted and may include information about the length of the padding bytes. The digital broadcast transmitter may further include a control signal generation unit for generating a control signal for controlling the padding byte exchange unit to insert the known data to the position according to the information. The encoder can comprise a first RS encoder (Reed-Solomon) to add a specified parity of bytes to the data in order to correct errors that occur due to channels, an interleaver to interleave the data to which the parity is aggregated in a specific pattern and a Trellis encoder to perform the Trellis encoding of the interleaved data. The Trellis encoder may have a memory device for a Trellis coding operation and may perform Trellis coding when initializing the memory device from the position at which the known data is inserted. The encoder may further include a buffer or packet buffer to receive and temporarily store the data stream from the first RS encoder. The temporary memory or packet buffer can receive from the Trellis encoder and temporarily store the known encoded data according to the initialization of the memory device. The encoder may further include a second RS coder to generate and issue a changed parity by performing an RS encoding of the known encoded data entered from the temporary memory or packet buffer to the Trellis encoder, to replace the parity added by the first RS coder for the parity changed. The interleaver can output the known data inserted to the same position of a plurality of different data streams emitted from the first RS encoder as a successive data stream. The modulator and RF converter can modulate the data by a vestigial sideband modulation (VSB) method. The above and other aspects of the present inventive general concept are also substantially realized by providing a signal processing method of a digital broadcast transmission, which comprises receiving a stream of data from which filler bytes are inserted to a specific position and randomizing the received data stream, generating a data stream having specific known data and inserting the known data into the current position of the data stream. randomized data to which the padding bytes are inserted, coding by error correction of the data stream issued from a padding byte exchange unit and modulation of the data stream encoded by error correction, RF conversion of the modulated data stream and transmission of the RF-converted data stream. Preferably, the coding operation can include a first RS (Reed-Solomon) coding operation of adding a parity of specified bytes to the data in order to correct errors that occur due to channels, an interleaving operation of interleaving the data to which the parity is aggregated in a specific pattern and a Trellis coding operation to effect the Trellis encoding of the interleaved data. The Trellis coding operation can perform Trellis coding by initializing a specific memory device used for a Trellis coding operation at the position at which the known data is inserted. The coding operation may further include the operation of receiving and temporarily storing the data stream generated in the first RS coding operation and receiving and updating the known data encoded according to the initialization of the memory device. The coding operation may further include a second RS coding operation of generating a changed parity upon re-encoding of the known encoded data, replacing the parity added in the first RS coding operation with the changed parity, and effect the Trellis coding of the data conditions. The modulation and RF conversion operation can modulate the data by a vestigial sideband modulation (VSB) method. The above and other aspects of the present inventive general concept are also substantially realized by providing a digital broadcast receiver comprising a tuner for receiving a signal from a digital broadcast transmitter and for converting the signal to a baseband signal, the signal that is encoded by inserting known data at a specific position, with respect to a data stream to which fill bytes are inserted at the specified position, a demodulator for demodulating the baseband signal, a known data detector for detecting data known from the demodulated signal and an equalizer to equalize the demodulated signal using the known data detected. The known data may comprise a sequence having a predefined pattern. The known data detector may comprise a symbol number detector for detecting information about the specified position at which the known data is inserted from the received signal, a segment generator for generating a data frame including at least one segment for indicating the position of an identification signal, an error correction encoder for effecting an error correction coding of the data frame and a known symbol output unit for inserting known data at the position of the coded data frame indicated by the identification sign. The known data detector can output the known data detected to the demodulator and the demodulator can perform the demodulation using the known data. The above and other aspects of the present inventive general concept are also substantially realized by providing a signal processing method of a digital broadcast reception comprising receiving a signal from a digital broadcast transmitter and converting the signal to a baseband signal, the signal is encoded by inserting known data at a specified position with respect to a data stream to which filler bytes are inserted at the specified position, demodulating the baseband signal, detecting the known data of the demodulated signal and equalizing the signal demodulated using the known data detected.

Advantageous Effects According to one embodiment of the present general inventive concept, the operating performance of the equalizer can be improved by means of appropriate adjustment of the quantity and pattern of the sequence of the known data inserted into the transport stream and thus the performance reception of the digital broadcast receiver can be improved. In addition, the performance of the equalizer and the performance of digital broadcast reception can be improved by adjusting the sequence of the known data by an appropriate amount for synchronization and receiver equalization.

BRIEF DESCRIPTION OF THE FIGURES These and / or other objects and advantages of the present general inventive concept will become evident and will be more easily appreciated from the following description of the modalities, taken in conjunction with the attached figures of which: Figure 1 is a block diagram of a transmission and reception system of a general American digital broadcast system (ATSC VSB); Figure 2 is a structure of an ATSC VSB data frame; Figure 3 is a block diagram of a digital broadcast transmission and reception system according to one embodiment of the present general inventive concept; Figure 4 is a structure of a general MPEG-2 transport stream packet; Figure 5 is a structure of an MPEG-2 transport stream packet that includes an adaptation field to which padding bytes are aggregated according to one embodiment of the present general inventive concept; Figure 6 is a data format of an MPEG-2 transport stream packet entered into a scrambler in accordance with one embodiment of the present general inventive concept; Figure 7 is the data format of a randomized packet according to one embodiment of the present general inventive concept; Figure 8 is the data format of an RS-encoded packet according to one embodiment of the present general inventive concept; Figure 9 is the data format of an interleaved packet according to one embodiment of the present general inventive concept; Figure 10 is the data format of a packet coded by Trellis according to one embodiment of the present general inventive concept; Figure 11 is the data format of the packet to which a parity issued from a second RS coder is aggregated according to an initialization of a Trellis coder; Figure 12 is the construction of a known data detector of a digital broadcast receiver according to an embodiment of the present general inventive concept; Figures 13 and 14 are flow diagrams illustrating the operation of a digital broadcast transmitter according to an embodiment of the present general inventive concept and Figures 15 and 16 are flow diagrams illustrating the operation of a digital broadcast receiver of according to one embodiment of the present general inventive concept.

BEST MODE Certain embodiments of the present inventive general concept will be described in more detail with reference to the accompanying figures. In the following description, the same reference numbers of the figures are used by the same elements even in different drawings. The matters defined in the description such as a detailed construction and elements are nevertheless provided to assist in the overall understanding of the general inventive concept. Thus, it is evident that the present general inventive concept can be carried out without those defined matters. Also, well-known functions or constructions are not described in detail since they would be obscured in general inventive concept in unnecessary detail. Figure 3 is a block diagram of the construction of a digital broadcast transmission and reception system according to one embodiment of the present general inventive concept. Referring to figure 3, the digital broadcast transmitter includes a scrambler 310, a stuffing byte exchange unit 315, a first RS 320 encoder, a temporary memory or packet buffer 325, an interleaver 330, a second RS 335 encoder, a Trellis encoder 340, a multiplexer 350, a modulator and RF converter 360 and a control signal generator 370. Scrambler 310 scrambles a PEG-2 transport data stream introduced in order to highlight the utility of a space of assigned channel. The data input to the scrambler 310 has the data format formed by inserting padding bytes, which has a specified length of bytes but does not include load data, to a specified position of the input transport data stream, which will be explained in detail. The padding byte exchange unit 315 generates a specified sequence (hereinafter referred to as "known data") having a specified pattern set between a transmitter side and a receiver side. The padding byte exchange unit 315 inserts the known data generated into a padding byte position of the randomized data in replacement of the padding bytes. Known data can easily be detected from the load data to be transmitted and thus are used for synchronization and equalization operations on the receiver side. The first RS 320 encoder adds a parity of specified bytes to the randomized data (also referred to as packet data) to which the known data is inserted by the padding byte exchange unit 315 in replacement of the padding bytes with In order to correct errors that occur due to channels. The interleaver 330 interleaves the packet data to which the parity emitted from the first RS 320 encoder is aggregated in a specified pattern. The Trellis encoder 340 converts the data emitted from the interleaver 330 to data symbols and effects the mapping of the symbols of the data symbols by means of a Trellis coding at the speed of 2/3. The Trellis 340 encoder initializes the temporarily stored value in its own memory device to a value specified at the starting point of the known data. For example, the value stored in the memory device can be initialized to "00". The temporary memory or packet buffer 325 extracts and temporarily stores the known data from packet data issued from the first RS 320 encoder of the known data starting point. If the known data is encoded by Trellis in the Trellis encoder 340 according to the initialization of the memory device, the temporary memory or packet buffer 325 receives the known data changed according to the initialization of the memory device of the encoder of Trellis 340 temporarily stores the changed known data in replacement of the previously known temporary stored data and then introduces the known data changed to the second RS 335 encoder for a parity regeneration. The second RS 335 encoder replaces the original parity with the newly generated parity by receiving the known data changed according to the initialization of the memory device and regenerates and introduces the newly generated parity according to the data changed to the Trellis 340 encoder. Thus, the data packet issued from the Trellis 340 encoder to the multiplexer 350 represents a data format having the known data changed in accordance with the initialization of the Trellis 340 encoder memory device and the parity added thereto in accordance with the coding of RS. The multiplexer 350 inserts a segment synchronization signal to the data that has been converted to symbols by the Trellis encoder 340 in the unit of a segment as shown in the data format of Figure 2 and inserts a synchronization signal of field to the data in the unit of a field. further, the second multiplexer 350 inserts a pilot signal to an edge portion of a low frequency band of a frequency spectrum by adding a specified DC value to the data signal of a specified level.

The RF modulator and converter 360 performs a VSB modulation of the signal to which the pilot signal has been inserted upon effecting a pulse formation of the signal and amplitude modulation of the signal with an intermediate frequency (IF) carrier, It converts by RF and amplifies the modulated signal and transmits the converted signal by means of an assigned channel. The control signal generator 370 receives the transport current at which the filling bytes are aggregated, detects information about the position at which the filling bytes are aggregated from the transport stream and generates and outputs the control signal to recognize the starting position and the final position of the known data to the filler byte exchange unit 315, the interleaver 320 and the Trellis 340 encoder. The digital broadcast receiver of FIG. 3 includes a tuner 410, a demodulator 420, an equalizer 430, a Trellis decoder 440, a deinterleaver 450, an RS 460 decoder, a descrambler 470 and a known data detector 480. The digital broadcast receiver operates in a reverse process with respect to the digital broadcast transmitter of Figure 3. The tuner 410 selects the received signal and converts the selected received signal to a baseband signal.

The demodulator 420 detects the synchronization signals of the baseband signal and demodulates the baseband signal according to a pilot signal and the synchronization signals inserted into the baseband signal. The equalizer 430 eliminates mutual interference between the received data symbols (ie, the Trellis 340 encoder (by compensating the channel distortion of the demodulated signal due to the multiple path of the channel.) The Trellis decoder 340 performs a correction of error of the data symbols, decodes the error-corrected data symbols and outputs decoded symbol data The deinterleaver 450 rearranges the decoded data, which was distributed by the interposer 330 of the digital broadcast transmitter. errors of the de-interleaved data and the descrambler 470 descrambles the corrected data by means of the RS 460 decoder, such that the data of the MPEG-2 transport stream is restored.The known data detector 480 detects the position of the data. known data from the demodulated data and outputs the known data generated by the gener ation and coding of a segment frame of the scrambler synchronization detection and equalizer compensation for channel distortion.

Figure 12 illustrates the construction of the known data detector 480 of the digital broadcast receiver according to one embodiment of the present general inventive concept. Referring to Figure 12, the known data detector 480 includes a symbol number detector 481, a segment generator 483, a 485 encoder and a known data output unit 487. The symbol number detector 481 extracts the information about the position of the known data from the control information bytes which includes information about the length of an adaptation field of a demodulated data header part. The information about the position of the known data includes the information about the length of the known data. Because the position of the known data is predetermined, the position and the number of known symbols according to the coding of the known data can be obtained from the length of the known data. The segment generator 483 generates at least one segment to indicate the corresponding position according to the position and the number of the known symbols by marking an identification sign corresponding to the symbol number and generating the MPEG-2 transport stream. which includes such segment. The encoder 485 encodes the transport frame generated by the segment generator 483 in the same way as that performed on the transmitter side. A) Yes, the known data output unit 487 inserts the predefined known data to the transport frame position encoded by the encoder 485 corresponding to the known symbols obtained according to the identification sign. Figure 4 illustrates the structure of a general MPEG-2 transport stream packet and Figure 5 illustrates the structure of an MPEG-2 transport stream packet that includes an adaptation field to which padding bytes are aggregated. according to one embodiment of the present general inventive concept. Referring to Fig. 4, the general MPEG-2 transport stream is composed of a 4-byte TS header part and an adaptation field or load data of 184 bytes. Referring to FIG. 5, according to the MPEG-2 transport stream of the present general inventive concept, an adaptation field of "n" bytes is located after the header part of 4 bytes and load data of "184". -n "bytes are located after the adaptation field. The fifth and sixth bytes, that is, the first two bytes, of the adaptation field constitute control information bits that include length information of the adaptation field and fill bytes according to an embodiment of the present general inventive concept are inserted into the seventh byte of the transport stream, that is, the third byte of the adaptation field. Thus, the transmission speed may be somewhat reduced due to the reduction of the load data as long as the adaptation field to which the padding bytes are inserted. However, the length of the adaptation field is changeable and thus it can be adjusted in order to improve the transmission performance. Figures 6 to 11 illustrate data formats that are changed in accordance with the data processing of an MPEG-2 transport stream packet in a digital broadcast transmitter according to one embodiment of the present general inventive concept. Fig. 13 is a flow chart illustrating the operation of the digital broadcast transmitter according to an embodiment of the present general inventive concept. Hereinafter, the operation of the digital broadcast transmitter according to one embodiment of the present general inventive concept will be explained with reference to the appended figures. Randomizer 310 scrambles an input MPEG-2 transport stream that includes padding bytes of a specified length of bytes (step S510). The data input to the scrambler 310 has the data format as shown in Figure 6. Referring to Figure 6, the MPEG-2 data packet includes a header part composed of the first byte representing a synchronization signal and a Three-byte PID (Packet Identifier), two-byte control information bits that include information about the position of the padding bytes and padding bytes composed of a specified length of bytes. Other bytes of the data refer to the load data to be transmitted. Specifically, the information about the position of the padding bytes is inserted into the first two bits of control information between the adaptation field after the three-byte PID of the header part and the padding bytes are inserted into the field of next adaptation. Because the starting position of the padding bytes is fixed, the information about the position of the bytes is expressed as the information about the length of the padding bytes. Next, the padding byte exchange unit 315 generates the known data and inserts the known data to the position of the padding bytes included in the randomized data by the scrambler 310 in replacement of the padding bytes (operation S5209. known are a specified sequence that It has a specified pattern known in advance between the transmitter side and the receiver side and can be easily detected in a distinctive way from the ++++ load data. The error correction coding of the data to which the known data output from the padding byte exchange unit 315 is inserted is performed in order to correct the error that occurs due to the channels (operation S530). Fig. 14 is a flow chart illustrating the process of coding by error correction. Referring to figure 14, for the error correction coding, the first RS 320 encoder performs a data RS encoding to add a specified byte parity to the data (operation S531), the interleaver 330 performs the data interleaving of the encoded data by RS in a specified pattern (operation S533) and the Trellis encoder 340 converts the interleaved data to data symbols and maps 8 level symbols of the converted data symbols by means of a Trellis coding at the speed of 2/3 (operation S535). Additionally, the second RS 335 encoder regenerates the parity upon re-coding of RS using the changed known data entered into the temporary memory or packet buffer 325 (operation S537) and adds the regenerated parity to the data in replacement of the previous parity Figures 7 to 11 illustrate the structure of the data packet that is changed according to the error correction coding process as described above. Figure 7 illustrates a data stream that is scrambled by scrambler 310 and to which known data is inserted by the pad byte exchange unit 315 in replacement of the padding bytes. In Figure 7, the length of the known data is not indicated, but can be adjusted according to the channel environment, the amount or importance of the data to be transmitted. Since these known data are inserted after randomization as the known data between the transmitter side and the receiver side, they can be easily detected in distinction from the randomized load data and are used for synchronization and equalization on the side of the receiver. receiver . Figure 8 is a view of the broadcast data format of the first RS 320 encoder. The first RS 320 encoder adds a parity of the specified bytes to the emitted data of the fill byte exchange unit 315 in order to correct the errors that occur due to the channels. Referring to Figure 8, the RS parity of 20 bytes is added to a final part of the data stream of the 188 bytes issued from the first RS 320 encoder. Figure 9 illustrates the data format emitted from the interleaver 330. interleaver 330 distributes the data on the time axis in such a way that the order of the data stream is distributed and the transport signal becomes strong against the interference. According to this data distribution effected by the interleaver 330, the data bytes arranged in the same positions of the different segments in a vertical direction as shown in FIG. 8, are re-accommodated as the successive data stream in a horizontal direction in the 52-byte unit. The fourth and fifth bytes of the respective segments, which are composed of the control information bytes that include position information of the known data in Figure 8, are changed to the data stream (M56-M5 (B3) and M57). -M6 (B4)) successively in the horizontal direction as shown in Figure 9 after the collation is effected. Thus, the control information bytes are issued successively. The known data inserted into the fifth position of the respective segments are changed to the data stream (M58-M7 (B5), M59-M8 (B6), ..., (M60-M9 (B7)) successively in the address horizontal, as shown in figure 9, after the collation is made, so the same bytes of the known data inserted to the respective segments are emitted as the successive current in the unit of 52 bytes. data from the Trellis coder 340 of Figure 3. The Trellis coder 340 encodes each byte of the data emitted from the interleaver 330 to four 8 level symbols.In Figure 10, the known data appears for each 52 segments and appears as successive symbols for a specified length for example 208 symbols.Six known data sequences appear in a field., 10 * 6 = 60 known data sequences include 10 bytes of padding appear in a field of the transport stream. Thus, the known data sequences can easily be detected from the load data stream according to the length of the known data. Figure 11 illustrates the process of changing the parity according to the operation of the second RS 335 encoder. The temporary memory or packet buffer 325 extracts temporarily stores the known data from the packet issued from the first RS 320 encoder from the starting point of the known data. If the known data is encoded by Trellis in the Trellis 340 encoder according to the initialization, the temporary memory or packet buffer 325 receives the known data changed according to the initialization of the Trellis 340 encoder, temporarily stores the known data changed by updating the prior known data temporarily stored and introduces the known data changed to the second RS 335 encoder for parity regeneration. The second RS 335 encoder generates the new (changed) parity when performing the RS coding of the known changed data, transmits the newly generated parity to the Trellis 340 encoder to replace the previous parity with the changed parity and performs Trellis coding of the data symbols to emit the symbols coded by successive Trellis. Thus, the data packet issued from the Trellis 340 encoder to the multiplexer 350 is the data obtained by the Trellis coding of the known data changed in accordance with the initialization of the Trellis 340 encoder memory device and the data packet to the which parity is aggregated according to the RS decoding of 8 level symbols. Next, the multiplexer 350 inserts a segment synchronization signal to the symbol data in the unit of a segment of the symbol data, inserts a field synchronization signal to the symbol data in the unit of a field and then inserts a pilot signal to the frequency spectrum (step S540). The modulator and RF converter 360 performs a VSB modulation of the signal to which the pilot signal is inserted upon effecting a pulse formation of the signal and amplitude modulation of the signal with an intermediate frequency (IF) carrier, converts by RF and amplifies the modulated signal and transmits the converted signal through an assigned channel (operation S550). Figures 15 and 16 are flow charts illustrating the operation of the digital broadcast receiver according to one embodiment of the present general inventive concept. The tuner 410 selects the received signal and converts the selected signal to the baseband signal (operation S610). The demodulator 420 detects the synchronization signals of the baseband signal and effects the demodulation of the baseband signal according to the pilot signal and the synchronization signals inserted into the baseband signal (step S620). The known data detector 480 detects the position of the known data of the equalized data and outputs the known detected data (step S630). The symbol number detector 481 extracts the information about the position of the known data including the length of the known data of control information bits which include information about the length of an adaptation field of a header part of the data. demodulated data (operation S631). The symbol number detector 481 extracts the information about the position of the known data from the control information bits which include information about the length of an adoption field and a demodulated data header part. The information about the position of the known data includes the information about the length of the known data. Since the position of the known data is predetermined, the position and the number of known symbols, according to the coding of the known data can be obtained from the length of the known data. Segment generator 483 generates at least one segment to indicate the corresponding position according to the position and number of the known symbols by marking an identification signal corresponding to the number of symbols and generating the transport current of MPEG-2 which includes the segment (operation S633). The encoder 485 performs the error correction coding of the transport frame generated by the segment generator 483 in the same manner as that performed on the transmitter side (step S635). The known data output unit 487 inserts the predefined known data into the position of the transport frame of the encoder 485 having the identification signal to output the transport frame to which the known data is inserted into the equalizer 430 (step S637). The equalizer 430 performs equalization by compensating the channel distortion of the demodulated signal and eliminating mutual interference between the received data symbols (step S640). The equalizer 430 compensates for the channel distortion using the known data output from the known data detector 480. Also, the known detected data may be provided by the synchronization detection of the demodulator 420. The synchronized and equalized data are corrected by error and the symbols corrected by mistake are decoded. The decoded data is rearranged by means of the de-interleaving process and then converted by mistake by means of the RS decoding (operation S650). The incorrectly corrected data is descrambled and then emitted as the MPEG-2 transport stream data (step S660). As described above, according to one embodiment of the present general inventive concept, the reception performance of the digital broadcast receiver, such as synchronization and equalization can be improved even in a lower multipath channel by generating and inserting the bytes of filler to the MPEG-2 transport stream and transmit the transport stream to which the known data is inserted in replacement of the fill bytes in the digital broadcast transmitter and when detecting the known data of the received signal and using the known data for synchronization and equalization in the digital broadcast receiver. Mode for Invention Possibility of Industrial Application The present general inventive concept is concerned with a digital broadcast transmission and reception system and a signal processing method thereof. More particularly, the present general inventive concept is concerned with a digital broadcast transmission and reception system and a method of signal processing thereof, which can improve the reception performance of the system by inserting a known sequence into a data stream. of VSB (Vestigial Lateral Band) and transmit the data stream with the known sequence inserted.

Claims

CLAIMS 1. A digital broadcast transmitter characterized in that it comprises: a scrambler to receive a stream of data of which filler bytes are inserted to a specified position and to randomize the received data stream; a padding byte exchange unit for generating known data having a predefined pattern and for inserting the known data at the specified position of the data stream to which the padding bytes are inserted; an encoder for encoding the stream of data emitted from the packet byte exchange unit by an error correction, and an RF modulator and converter for modulating the encoded data stream, converting the modulated data stream by RF and transmitting the data converted to RF.
2. The digital broadcast transmitter according to claim 1, characterized in that the data stream contains information about the specific positions at which the padding bytes are inserted.
3. The digital broadcast transmitter according to claim 2, characterized in that the information is inserted into a position of the data stream preceding the position at which the fill bytes are inserted and includes information about the length of the data. Fill bytes.
4. The digital broadcast transmitter according to claim 3, characterized in that it further comprises a control signal generator for generating a control signal for controlling the byte-swapping unit to insert the known data into the position of agreement. with the information.
The digital broadcast transmitter according to claim 1, characterized in that the encoder comprises: a first RS (Reed-Solomon) encoder for adding a specified parity of bytes to the data in order to correct errors that occur due to channels; an interleaver to collate the data to which the parity is added in a specified pattern; and a Trellis encoder to perform Trellis coding of the interleaved data.
6. The digital broadcast transmitter according to claim 5, characterized in that the Trellis encoder has a memory device for a Trellis coding operation and performs Trellis coding when initializing the memory device from the position to which the known data are inserted.
The digital broadcast transmitter according to claim 6, characterized in that it further comprises a temporary memory or packet buffer to receive and temporarily store the data stream of the first RS encoder.
The digital broadcast transmitter according to claim 7, characterized in that the temporary memory or packet buffer receives from the Trellis encoder and temporarily stores the known data encoded according to the initialization of the memory device.
The digital broadcast transmitter according to claim 8, characterized in that it further comprises a second RS coder for generating and outputting a changed parity when performing a RS coding of the known coded data entered from the temporary memory or buffer of package to the Trellis encoder to replace the parity added by the first RS encoder by the parity changed.
The digital broadcast transmitter according to claim 1, characterized in that the interleaver transmits the known data inserted to the same position of a plurality of different streams of data emitted from the first RS encoder as a successive data stream.
The digital broadcast transmitter according to claim 1, characterized in that the modulator and RF converter modulates the data by a vestigial sideband modulation (VSB) method.
12. A method of signal processing of a digital broadcast transmission, characterized in that it comprises: receiving a stream of data from which filler bytes are inserted to a specified position and randomizing the received data stream; generating a data stream having specified known data and inserting the known data to the position of the randomized data stream to which the padding bytes are inserted; encoding by error correction the stream of randomized data that includes the known data inserted; and modulating the data stream encoded by error correction, converting the modulated data stream by RF and transmitting the converted data stream by RF.
The method of signal processing according to claim 12, characterized in that the coding operation comprises: a first RS coding operation (Reed-Solomon) of adding a parity of specified bytes to the data in order to correct errors that occur due to channels; an interleaving operation of interleaving the data at which the parity is aggregated in a specified pattern; and perform a Trellis coding of the interleaved data.
The signal processing method according to claim 13, characterized in that the Trellis coding operation performs the Trellis coding by initializing a specified memory device for a Trellis coding operation in the position to which the known data with inserted.
15. The method of signal processing according to claim 14, characterized in that it further comprises receiving and temporarily storing the data stream generated in the first RS coding operation and receiving and updating the known data encoded according to the initialization of the memory device.
The method of signal processing according to claim 15, characterized in that it further comprises a second RS coding operation of generating a changed parity upon re-coding of the known encoded data, replacing the aggregated parity in the first RS coding operation for the changed parity and perform the Trellis coding of the known data.
17. The method of signal processing according to claim 12, characterized in that the modulation of an RF compression operation modulates the data by a vestigial sideband modulation (VSB) method.
18. A digital broadcast receiver characterized in that it comprises: a tuner for receiving a signal from a digital broadcast transmitter and converting the signal to a baseband signal, the signal that is encoded by inserting known data at a specified position with respect to a stream of data to which fill bytes are inserted in the specific position; a demodulator to demodulate the baseband signal; a known data detector for detecting the known data of the demodulated signal; and an equalizer to equalize the demodulated signal using the known data detected.
19. The digital broadcast receiver according to claim 18, characterized in that the known data comprises a sequence having a predefined pattern.
20. The digital broadcast receiver according to claim 18, characterized in that the known data detector comprises: a symbol number detector for detecting information about the specified position to which the known data is inserted from the received signal; a segment generator for generating a data frame that includes at least one segment to indicate the position by means of an identification sign; an error correction encoder for effecting an error correction coding of the data frame, and an output unit for known symbols for inserting the known data into the position of the encoded data frame indicated by the identification sign for issuing the frame of encoded data to which the known data is inserted.
21. The digital broadcast receiver according to claim 18, characterized in that the known data detector emits the known data detected to the demodulator and the demodulator demodulates using the known data.
22. A signal processing method of a digital broadcast reception, characterized in that it comprises: receiving a signal from a digital broadcast transmitter and converting the signal to a baseband signal, the signal which is encoded by inserting known data into a specified position with respect to a stream of data to which fill bytes are inserted at the specified position; demodulate the baseband signal; detect the known data of the demodulated signal; and equalize the demodulated signal using the known data detected.
23. The signal processing method according to claim 22, characterized in that the known data includes a sequence having a predefined pattern.
The digital broadcast receiver according to claim 22, characterized in that the known data detection operation comprises: detecting information about the position at which the known data is inserted from the received signal; generate a data box that includes at least one segment to indicate the position by means of an identification sign; perform an error correction coding of the data box; and inserting the known data into the position of the coded data frame indicated by the identification sign to emit the coded data frame to which the known data is inserted.
25. The method of signal processing according to claim 22, characterized in that the known data detection operation emits the known data detected to the demodulation operation and the demodulation operation effects the demodulation using the known data.
26. A digital broadcast transmitter characterized in that it comprises: an insertion unit for generating known data having a predefined pattern and inserting the known data at a specified position of a stream of randomized data to which the fill bytes are inserted; an encoder for encoding the emitted data stream of the insert unit for an error correction; and an RF modulator and converter for modulating the encoded data stream, converting the modulated data stream by RF and transmitting the converted data stream by RF.
27. The digital broadcast transmitter according to claim 26, characterized in that the encoder comprises: a first RS (Reed-Solomon) encoder for adding a specified parity of bytes to the data stream in order to correct errors that occur due to channels; an interleaver to interleave the data stream at which the parity is aggregated in a specified pattern; and a Trellis encoder for performing a Trellis coding of the interleaved data stream.
28. The digital broadcast transmitter according to claim 27, characterized in that the Trellis encoder has a memory device for a Trellis coding operation and performs a Trellis encoding upon initializing the memory device of the position to which the known data are inserted.
29. The digital broadcast transmitter according to claim 28, characterized in that it further comprises a temporary memory or packet buffer to receive and temporarily store the data stream of the first RS encoder.
30. The digital broadcast transmitter according to claim 29, characterized in that the temporary memory or packet buffer receives an output or result from the Trellis encoder and temporarily stores the known encoded data according to the initialization of the memory device.
31. The digital broadcast transmitter according to claim 30, characterized in that it further comprises a second RS coder for generating a changed parity when performing an RS coding of the known coded data received from the packet buffer and for issuing the parity changed to the Trellis encoder to replace the parity added by the first RS encoder with the parity changed.
32. A digital broadcasting system characterized in that it comprises: an insertion unit for generating known data having a predefined pattern and for inserting the known data at a specified position of a randomized data stream to which the filling bytes are inserted; an encoder for encoding the emitted data stream of the insert unit for an error correction; an RF modulator and converter for modulating the encoded data stream, converting the modulated data stream by RF and transmitting the converted data current by RF; a tuner for receiving the data stream converted by transmitted RF and for sharing the data stream converted by RF to a baseband signal; a demodulator to demodulate the baseband signal; a known data detector for detecting the known data of the demodulated signal; and an equalizer to equalize the demodulated signal using the known data detected.
33. A method of signal processing of a digital broadcast system, characterized in that it comprises: generating a data stream having known known data and inserting the known data at a specified position of a randomized data stream to which bytes of stuffing they are inserted; encoding by error correction the randomized data stream inserted; modulating the encoded data stream by error correction, converting the modulated data stream by RF and transmitting the converted data stream by RF; receiving the data stream converted by transmitted RF and converting the data stream to a baseband signal; demodulate the baseband signal; detect known data of the demodulated baseband signal; and equalize the demodulated signal using the known data detected.
34. The method of signal processing according to claim 33, characterized in that the coding operation comprises: a first RS coding operation (Reed-Solomon) of adding a parity of specified bytes to the data in order to correct errors that occur due to channels; an interleaving operation to interleave the data at which the parity is aggregated in a specified pattern; and perform a Trellis coding of the interleaved data.
35. The method of signal processing according to claim 33, characterized in that the known data detection operation comprises: detecting information about the specified positions to which known data are inserted from the RF converted data stream received.; generate a data box that includes at least one segment to indicate the position by means of an identification sign; perform an error correction coding of the data box; and inserting the known data into the position of the coded data frame indicated by the identification sign to output the coded data frame to which the known data is inserted.