KR101358720B1 - Digital broadcast receiver and method for processing stream thereof - Google Patents

Abstract

A digital broadcast transmission system is disclosed. The present system includes a transport stream generating apparatus for coding a plurality of additional data streams at a variable coding rate, inserting them into a normal data stream to generate a transport stream, and a transmitting apparatus for encoding and transmitting the generated transport stream. Accordingly, it is possible to transmit a transport stream including streams having various coding rates.

Turbo unit, digital broadcast, transport stream, normal data stream, coding rate

Description

TECHNICAL FIELD [0001] The present invention relates to a digital broadcast receiver and a method for processing the same,

The present invention relates to a digital broadcast receiver and a stream processing method thereof, and more particularly, to a digital broadcast receiver and a stream processing method for receiving and processing a transport stream including streams having various coding rates.

ATSC VSB, a US terrestrial digital broadcasting system, uses a field sync signal in units of 312 segments. This results in poor reception on poor channels, especially Doppler fading channels.

1 is a block diagram showing a transceiver according to an ATSC DTV standard as a general US terrestrial digital broadcasting system. A dual transport stream in which turbo data is added to the normal data of the reference ATSC VSB system can be formed and transmitted.

1, a digital broadcasting transmitter includes a randomizer 11 for randomizing a dual transport stream, a convolutional encoder 11 for adding a parity byte to a transport stream to correct an error caused by channel characteristics in a transmission process, A Reed-Solomon encoder 12 in the form of a concatenated coder, an interleaver 13 for interleaving RS encoded data according to a predetermined pattern, and a 2/3 ratio trellis (2/3 rate trellis encoder) 14 that performs encoding and performs mapping to 8 level symbols, and performs error correction coding on the dual transport stream.

In addition, the digital broadcast transmitter includes a multiplexer 15 for inserting a field sync and a segment sync as well as the data format of FIG. 2 with respect to data subjected to error correction coding, a multiplexer 15 for multiplexing a segment sync signal and a field sync And a modulator 16 for adding a predetermined DC value to a data symbol into which a signal is inserted, inserting a pilot tone, performing pulse shaping, performing VSB modulation, up-converting the signal into an RF channel band signal, .

Accordingly, the digital broadcast transmitter multiplexes the normal data and the turbo data according to the dual transport stream method of transmitting the normal data and the turbo data on one channel, and inputs the multiplexed data to the randomizer 11 (not shown).

The input data is randomized by the randomizer 11 and the randomized data is externally coded by the Reed Solomon encoder 12 which is an outer coder and the data coded by the interleaver 13 Dispersed.

In addition, the interleaved data is internally encoded through the trellis encoding unit 14 in units of 12 symbols, and the interleaved data is mapped into 8-level symbols with respect to internally encoded data, and then a field sync signal and a segment sync signal are inserted. A pilot tone is inserted, VSB modulation is performed, and the signal is converted into an RF signal and transmitted.

1 includes a tuner (not shown) for converting an RF signal received through a channel into a base signal, a demodulator 21 for performing synchronization detection and demodulation on the converted base signal, A Viterbi decoder 23 for correcting an error of the equalized signal and decoding it into symbol data, an interleaver 13 of a digital broadcast transmitter, A deinterleaver 24 for rearranging the distributed data, an RS decoder 25 for correcting errors, and an RS decoder 25 for derandomizing the corrected data to output an MPEG-2 transport stream And a randomizing unit 26.

Accordingly, the digital broadcast receiver of FIG. 1 down-converts an RF signal to a baseband in a reverse process of a digital broadcast transmitter, demodulates and equalizes the converted signal, and then performs channel decoding to recover the original signal.

FIG. 2 shows a VSB data frame in which a segment sync signal and a field sync signal of a digital broadcast (8-VSB) system in the United States are inserted. As shown, one frame is composed of two fields, one field is composed of one field sync field segment (first sync segment) and 312 data segments. In addition, one segment in the VSB data frame corresponds to one MPEG-2 packet, and one segment is composed of a segment sync of 4 symbols and 828 data symbols.

In FIG. 2, a segment sync signal and a field sync signal, which are sync signals, are used for synchronization and equalization on the digital broadcast receiver side. That is, the field sync signal and the segment sync signal are already known data between the digital broadcast transmitter and the receiver and are used as a reference signal when performing equalization at the receiver side.

On the other hand, the turbo data may be included in the dual transport stream by applying a variable coding rate according to a broadcasting program. That is, a dual transport stream including turbo data and normal data having various coding rates can be generated.

However, in the conventional digital broadcasting system, there is not proposed a processing method capable of transmitting and receiving the dual transport stream including the turbo data having the various coding rates and the normal data as described above.

Accordingly, there is a need for a digital broadcasting system capable of transmitting and receiving a dual transport stream including turbo data and normal data having various coding rates.

The present invention has been proposed in order to meet the above-mentioned need, and an object of the present invention is to provide a digital broadcasting receiver and a stream processing method for receiving and processing a transport stream including streams having various coding rates .

A digital broadcast receiver according to an embodiment of the present invention includes a demodulator for receiving and demodulating a transport stream including an additional data stream and a normal data stream, and an equalizer for equalizing the demodulated transport stream. In this case, the transport stream may be generated by encoding the additional data stream in a digital broadcast transmitter, coding the data according to a variable coding rate, and then multiplexing the normal data stream.

The digital broadcast receiver may further include a decoding unit which performs decoding corresponding to the coding rate on the additional data stream of the equalized transport stream.

The decoding unit may include a trellis decoder for trellis decoding an additional data stream of the equalized transport stream, an outer deinterleaver for deinterleaving the trellis decoded additional data stream, and the deinterleaved additional data stream. And an outer interleaver for interleaving the decoded additional data stream and providing the decoded additional data stream to the trellis decoder.

In addition, the variable coding rate may be 1/2 rate or 1/4 rate.

Meanwhile, a stream processing method of a digital broadcast receiver according to an embodiment of the present invention includes receiving and demodulating a transport stream including an additional data stream and a normal data stream, and equalizing the demodulated transport stream. . Here, the transport stream may be generated by encoding an additional data stream in a digital broadcast transmitter, coding the data according to a variable coding rate, and then multiplexing the normal data stream.

The method may further comprise performing decoding corresponding to the coding rate on an additional data stream of the equalized transport stream.

The decoding may include trellis decoding an additional data stream of the equalized transport stream, a trellis decoder deinterleaving the trellis decoded additional data stream, and deinterleaving. Decoding the decoded additional data stream and interleaving the decoded additional data stream to provide the trellis decoder.

The variable coding rate may be a half rate or a quarter rate.

As described above, according to the present invention, it is possible to efficiently transmit and receive a transport stream including streams having various coding rates.

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

3 is a block diagram illustrating a configuration of a digital broadcasting system according to an embodiment of the present invention.

Referring to FIG. 3, the digital broadcasting system includes a transport stream generating apparatus 100, a transmitting apparatus 200, and a receiving apparatus 300.

The transport stream generating apparatus 100 is a device for generating and transmitting a multi-transport stream by receiving and multiplexing a turbo stream having a normal stream and a variable coding rate. 4 is a block diagram showing an example of the configuration of the transport stream generating apparatus 100. As shown in FIG.

According to FIG. 4, the apparatus for generating a multi transport stream includes a Reed Solomon encoder (hereinafter, referred to as an RS encoder) 110, a duplicater 120, and a mux 130.

The RS encoder 110 receives the turbo stream, adds parity, encodes it, and provides the encoded data to the duplicator 120.

The RS encoder 110 removes a sync signal from the turbo stream, and calculates parity for the turbo stream area, and adds parity of 20 bytes in size.

As a result, one packet of the final encoded turbo stream is composed of 207 bytes, three of which are assigned PID (Packet IDentity), 184 bytes are allocated to turbo data, and 20 bytes are allocated to parity.

Meanwhile, the duplicater 120 prepares a parity insertion region according to a variable coding rate in the encoded turbo stream.

That is, the duplicator 120 converts each byte constituting the turbo stream according to 1/2 rate, 1/4 rate, 3/4 rate, 5/6 rate, 7/8 rate and various other coding rates , And a parity insertion area is provided between the data bits in the turbo stream.

The method of providing the parity insertion area will be described in detail. Each byte, which is a constituent unit of the turbo stream, is divided into 1 to 7 bytes according to the coding rate. Each separated byte is filled with part of the bit value of the original byte and null data (for example, 0). The area filled with null data is the parity insertion area.

The operation of the duplicator 120 will be described in more detail as follows.

In other words, if the input rate is doubled by applying the coding rate at 1/2 rate, bits in one byte are represented by MSB through a, b, c, d, e, f, g, h Assuming the inputs are in order, the output of the duplexer 120 is a, a, b, b, c, c, d, d, e, e, f, f, g, g, h, h Can be expressed.

In this case, a 1-byte 2-byte output consisting of a 1-byte composed of a, a, b, b, c, c, d and d and e, e, f, f, g, g, h and h is sequentially It can be seen that it is outputted.

A, a, a, b, b, b, b, c, c, and c are used when the coding rate is applied at 1/4 rate to make the input four times larger. , c, d, d, d, d, e, e, e, f, f, f, g, g, g, g, h, h, h and h. Thus, four bytes are output.

On the other hand, the duplicator 120 may not necessarily copy the input bits, but may insert any other value, i.e., null data, at locations other than the designated location.

A, b, b, c, c, ... instead of the outputs a, x, b, ... if the duplexer 120 doubles the input according to the 1/2 coding rate, x, c, x ..., the first part of the two consecutive bits may hold the original input and the second part may contain any value.

The size of the input can also be transformed for other coding rates in the manner described above.

Meanwhile, a data interleaver (not shown) may be inserted between the RS encoder 110 and the duplicator 120.

On the other hand, the MUX 130 prepares an adaptation field for each packet of the multi-transport stream. Here, the adaptive field means an area provided for inserting a turbo stream or other data.

Specifically, the adaptive field includes an adaptive field header, and an insertion area. The insertion area means an area where arbitrary data can be inserted.

Such a private data flag or the like can be used as the insertion area. The adaptive field header indicates the two-byte portion following the PID as the portion indicating the adaptive field length and the flag in the adaptive field.

Accordingly, the MUX 130 may provide an area for inserting the turbo stream into the stuffing area included in the adaptive field of the multi-transport stream. Alternatively, the turbo stream may be inserted into the private data flag included in the adaptive field.

On the other hand, the adaptive field may be used as an option field in which various packet information is recorded. Packet information refers to a program clock reference (PCR) used for synchronization of a demodulator of a receiver, an original program clock reference (OPCR) used for recording, scheduling, and reproducing a program in a receiver, The number of macroblocks (splice countdown), the number of macroblocks (consecutive number of macroblocks) of one Cr and Cb blocks, the transport private data length which is the length of the character data of the character broadcast, and the adaptive field extension length adaptation field extension length).

In this case, it is preferable that the area where the turbo stream is recorded and the option field are arranged such that their positions do not overlap each other.

Meanwhile, the MUX 130 may generate a multi-transport stream having a different coding rate in units of a turbo, in order to transmit a turbo stream having various coding rates and various data rates. Here, the turbo unit is preferably a multiple of 52 packet units.

FIG. 5 shows the structure of a multi-transport stream output via the MUX 140 of FIG. Referring to FIG. 5, a VSB data frame is composed of 312 packets. At this time, 52 packets can be composed of six turbo units consecutively in one turbo unit.

In detail, the multi transport stream 1 packet in which the turbo stream and the normal stream are mixed and the multi transport stream 3 packet in which only the normal stream is inserted constitute one frame, and these 13 frames mean one turbo unit.

In other words, it can be seen that 52 packets are turbo units and turbo stream is inserted alternately every 4 packets. At this time, the amount of the inserted turbo stream affects the data rate of the normal stream and the turbo stream.

On the other hand, a turbo stream having various coding rates can be inserted into each of the six turbo units.

For example, the turbo 1 is a data packet of the program 1, which means a packet including a turbo stream to which a half rate is applied. The turbo 2 means a packet including a turbo stream to which a 1/4 rate is applied as a data packet of the program 2.

Similarly, turbo 3 and turbo 6 refer to a packet including a turbo stream having a 1/2 rate applied to data packets of program 3, and turbo 5 and turbo 6 refer to a turbo stream having a 1/4 rate applied to data packets of program 4 This means packets included.

On the other hand, the coding information and program information having the above-described structure can be inserted repeatedly for every field, and they can be inserted differently for every field. That is, according to the design specification of the user, which coding information and which program information is inserted in which field can be arbitrarily configured. This information is used by the receiving apparatus.

In addition, the coding information for the coding rate applied to each turbo stream may be embedded in the synchronization signal of the multi-transport stream. Alternatively, coding information may be embedded in a part of the data area of each packet. Here, the method of inserting the coding information may be variously designed according to the design specification of the designer, but is not limited thereto.

Thereafter, it is possible to perform encoding in accordance with the coding rate in the transmitting apparatus 200 based on the coding information.

At this time, when a multi-transport stream of the same type is inserted for each VSB data frame, the data rate of each stream is determined according to the coding rate and the insertion amount of the turbo stream.

Meanwhile, the transmitting apparatus of FIG. 3 can be implemented as shown in FIG.

6, the transmitting apparatus 200 includes a randomizer 210, a turbo processor 220, an RS encoder 230, a data interleaver 240, a trellis encoder 250, a MUX 270, And a modulating unit 270. [

The randomization unit 210 randomizes the multi transmission stream received from the transport stream generating apparatus 100.

The turbo processing unit 220 detects only the turbo stream from the randomized multi-transport stream, and then robustly processes the detected turbo stream by encoding and interleaving.

Then, the robustly processed turbo stream is deinterleaved and inserted into the multi-transport stream to reconstruct the multi-transport stream. An example of the configuration of the turbo processor 220 is shown in Fig.

7, the present turbo processing unit 220 includes a turbo stream detecting unit 221, an outer encoder 223, an outer interleaver 225, a data deinterleaver 227, and a turbo stream stuffer 229 .

The turbo stream detection unit 221 detects only the turbo stream from the randomized multi-transport stream.

The outer encoder 223 performs encoding on the detected turbo stream.

Specifically, the turbo stream is convolutionally encoded, and the encoded value is inserted into a parity insertion region provided in the turbo stream. At this time, encoding can be performed based on the synchronizing signal or the coding information inserted in the data area.

The outer interleaver 225 performs outer interleaving of a turbo stream encoded in units of 52 packets.

The outer interleaver 225 performs interleaving according to a predetermined interleaving rule. For example, when the interleaving rules are {2, 1, 3, 0} and the ABCDs are sequentially input, they are interleaved and output in DBAC format. Here, the interleaving rule can be changed according to the design specification of the designer.

The outer interleaver 225 corresponds to the outer deinterleaver 420 in the turbo decoder 341 of the receiving apparatus 300. Outer interleaving refers to the interleaving required to perform turbo decoding on the turbo stream.

The data deinterleaver 227 serves to deinterleave the interleaved turbo stream. Here, the data deinterleaver 227 performs a reverse operation of the data interleaver 240 of FIG. 6 with respect to the turbo stream.

In addition, the data deinterleaver 227 can perform a position shift and a delay between the turbo streams.

In addition, the data deinterleaver 240 is performed in order to form a turbo stream among the interleaved multi-transport streams when the multi-transport stream is interleaved by the data interleaver 240 of FIG. That is, the turbo stream can be operated in units of turbo as shown in FIG.

Thus, by operating in units of the turbo, the operation time of the turbo decoder of the reception apparatus 300 can be reduced, and power consumption can be reduced.

For example, if the user only wants to watch the program 2, it is possible to operate only the turbo 2 without having to operate on all the data, thereby reducing power consumption.

The turbo stream stuffer 229 inserts the deinterleaved turbo stream into the multi-transport stream to reconstruct the multi-transport stream. Accordingly, it is possible to robustly process only the turbo stream without processing the entire multi-transport stream.

Although not shown in the present embodiment, a byte-symbol converter (not shown) and a symbol-byte converter (not shown) may be added before / after the turbo processor.

A byte-to-symbol conversion unit (not shown) and a symbol-to-byte conversion unit (not shown) convert a multi-transport stream into a byte unit, a symbol unit, and a symbol unit. Here, the conversion from byte unit to symbol unit and symbol unit to byte unit can be easily understood by referring to Table D5.2 of the US ATSC DTV standard (A / 53).

Referring again to the description of FIG. 6, the RS encoder 230 reed-solomon encodes the processed multi-transport stream.

The data interleaver 240 interleaves the encoded multi-transport stream. That is, the data interleaver 240 interleaves the multi-transport stream according to the interleaving rule according to the VSB standard.

The trellis encoder 250 trellis encodes the interleaved multi-transport stream.

The multiplexer 260 multiplexes the segment sync signal and the field sync signal added to the trellis encoded multi-transport stream.

The modulator 270 performs channel modulation on the multiplexed multi-transport stream and up-converts the multi-transport stream into an RF channel signal. The multi-transport stream transmitted by the modulating unit 270 is transmitted to the receiving apparatus 300 through a channel.

Although not shown in the present embodiment, the modulating unit 270 further includes a pilot inserting unit (not shown), a pre-equalizing unit (not shown), a VSB modulating unit (not shown), and an RF modulating unit As shown in FIG.

The pilot inserting unit inserts a pilot by adding a predetermined DC value to the multi-transport stream to which the synchronization signal is added.

The pre-equalizer equalizes the multi-transport stream in which the pilot is inserted, so that inter-symbol interference is minimized.

The VSB modulation unit VSB-modulates the equalized multi-transport stream.

The RF modulator modulates the VSB-modulated multi-transport stream into a signal in the RF channel band and transmits it.

The turbo processor 220 is located at the rear end of the randomizer 210 in the transmitting apparatus 200. However, the positions of the randomizer 210 and the turbo processor 220 may be changed.

The configuration of the randomizer 210 and the turbo processor 220 may be implemented by combining the transport stream generating apparatus of FIG. 10 and the transmitting apparatus of FIG. 12.

8 is a block diagram showing a configuration of a transmitting apparatus according to another embodiment of the present invention.

8, the transmitting apparatus includes a randomizing unit 210, a parity area generating unit 280, a first interleaver 285, a turbo processing unit 290, a deinterleaver 295, an RS encoder 230, 2 interleaver 240, a trellis encoder 250, a multiplexer 260, and a modulator 270.

The randomizer 210 randomizes the multi-transport stream received from the transport stream generating apparatus 100 and provides the multi-transport stream to the parity area generator 280.

The parity area generating unit 280 serves to provide a parity insertion area for a multi-transport stream including a normal stream and a turbo stream. The parity insertion area means an area where a parity bit calculated for a multi-transport stream can be inserted, i.e., recorded.

The first data interleaver 285 interleaves the multi-transport stream processed by the parity area generating unit 280.

The turbo processor 290 demodulates the interleaved multi-transport stream to detect the turbo stream, encodes it in units of turbo, and multiplexes the multi-transport stream with the multi-transport stream, thereby performing turbo encoding to robustly process the turbo stream.

An example of the configuration of the turbo processor 290 is shown in Fig. Referring to FIG. 9, the turbo processing unit 290 includes a demux 291, an outer encoder 223, an outer interleaver 225, and a multiplexer 293.

The demux 291 demultiplexes the interleaved multi-transport stream to detect the turbo stream.

The outer encoder 223 calculates the parity for the detected turbo stream and inserts the parity into the parity insertion region provided in the turbo stream, thereby encoding the turbo stream in units of turbos. At this time, the outer encoder 223 can perform encoding based on the coding information.

The outer interleaver 225 outer-interleaves the encoded turbo stream.

Mux 293 multiplexes the interleaved turbo stream and the multi-transport stream. Accordingly, the turbo stream can be robustly processed.

The turbo processor 290 may be replaced with the turbo processor 220 of FIG. Accordingly, the turbo stream among the multi-transport streams distributed by the second interleaver 240 is configured to be densified, so that the turbo-based operation can be performed.

Referring back to FIG. 8, the data deinterleaver 295 deinterleaves the multi-transport stream output from the turbo processor 290.

The RS encoder 230 performs parity addition on the multi-transport stream provided from the data deinterleaver 295 and encodes the multi-transport stream. Specifically, the RS encoder 230 inserts the calculated parity for the multi-transport stream into the parity insertion area provided by the parity area generator 280. [

The second data interleaver 240 interleaves the multi-transport stream inserted with the parity.

The trellis encoder 250 Trellis encodes the interleaved multi-transport stream by the second data interleaver 220.

The mux 260 adds and multiplexes a segment sync signal and a field sync signal to a trellis encoded multi transport stream.

The modulator 270 performs channel modulation on the multiplexed multi-transport stream and up-converts the multi-transport stream into an RF channel signal.

10 is a block diagram illustrating a configuration of a transport stream generation apparatus according to another embodiment of the present invention.

Referring to FIG. 10, the transport stream generating apparatus includes an RS encoder 110, a duplicator 120, an outer encoder 140, an outer interleaver 150, a data deinterleaver 160, and a MUX 130 .

Meanwhile, the outer encoder 140, the outer interleaver 150, and the data deinterleaver 160 perform the same operations as the outer encoder 223, the outer interleaver 225, and the data deinterleaver 227 of FIG. 7. can do. A duplicate description will be omitted.

The RS encoder 110 removes a sync signal from the turbo stream, calculates a parity for the turbo data area, and adds parity of 20 bytes in size.

The duplicator 120 prepares a parity insertion area according to the coding rate in the encoded turbo stream.

The outer encoder 140 performs encoding by convolutionally encoding the turbo stream and then inserting the encoded value into the parity insertion area provided through the duplicator 120. [

The outer interleaver 150 outer-interleaves the encoded turbo stream.

The data deinterleaver 160 deinterleaves the interleaved turbo stream.

The mux 130 muxes the separately received normal stream and the turbo stream processed by the duplicator 120. Thus, a multi-transport stream in which the normal stream and the turbo stream are mixed can be generated.

Meanwhile, the MUX 130 may provide an area for inserting the turbo stream into the stuffing area included in the adaptation field for each packet of the multi-transport stream.

Meanwhile, the MUX 130 may generate a multi-transport stream including a turbo stream having a different coding rate in units of turbo, in order to transmit a turbo stream having various coding rates and various data rates. Here, the turbo unit is preferably a multiple of 52 packet units.

11 is a block diagram illustrating a configuration of a transport stream generation apparatus according to another embodiment of the present invention.

Referring to FIG. 11, an RS encoder 110, a duplicator 120, a MUX 130, a randomizer 170, a turbo processor 180, and a reverse randomizer 190 are included. Here, the RS encoder 110, the duplicator 120, and the MUX 130 may perform the same operations as those having the same reference numerals in FIG. A duplicate description will be omitted.

The randomizer 170 randomizes the generated multi-transport stream.

The turbo processor 180 detects only the turbo stream from the randomized multi-transport stream, and then robustly processes the detected turbo stream by encoding and interleaving. Then, the interleaved turbo stream is deinterleaved and inserted into the multi transmission stream to reconstruct the multi transport stream.

Here, the turbo processor 180 may be configured as shown in FIG.

The reverse randomizer 190 de-randomizes the reconstructed multi-transport stream.

12 is a block diagram showing the configuration of a transmitting apparatus according to another embodiment of the present invention.

12, the transmitting apparatus includes a randomizer 210, an RS encoder 230, a data interleaver 240, a trellis encoder 250, a multiplexer 260, and a modulator 270 .

The transmitter receives the robust multicast streams from the transport stream generating apparatuses of FIGS. 10 and 11, performs randomization, RS encoding, interleaving, trellis encoding, and then performs a segment synchronization signal and a field synchronization signal. Add multiplexing, channel modulation, and transmit. The configuration of this embodiment performs the same operation as that of the configuration shown in Fig. A duplicate description will be omitted.

13 is a block diagram showing the configuration of the receiving apparatus of FIG. 3 according to an embodiment of the present invention.

Referring to FIG. 13, the receiver 300 includes a demodulator 310, an equalizer 320, a first processor 330, and a second processor 340.

The demodulator 310 detects the synchronization and demodulates the received multi-transport stream in accordance with the synchronization signal added to the baseband signal of the received multi-transport stream when the multi-transport stream modulated in the RF signal form is received through the antenna.

The equalizer 320 equalizes the demodulated multi transport stream to compensate for channel distortion due to the multipath of the channel. The equalized multi-transport stream by the equalizer 320 is provided to the first processor 330 and the second processor 340.

The first processing unit 330 processes the normal stream among the multi-transport streams to restore the normal data.

The first processor 330 includes a Viterbi decoder 331, a data deinterleaver 333, an RS decoder 335, and a first Randomizer 337.

The Viterbi decoder 331 performs error correction on the normal stream of the equalized multi-transport stream and decodes the error-corrected symbols to output a symbol packet.

The data deinterleaver 333 deinterleaves the decoded packets and rearranges the distributed packets.

The RS decoder 335 performs Reed-Solomon decoding on the deinterleaved normal stream packet to correct the error.

The first Randomizer 337 derandomizes the Reed-Solomon decoded Normal Stream packet to recover normal data.

Meanwhile, the second processing unit 340 processes the turbo stream among the multi-transport streams to recover the turbo data.

The second processing unit 340 includes a turbo decoder 341, a second reverse randomizer 343, and a turbo stream extractor 345.

The turbo decoder 341 selectively performs turbo decoding only on the turbo stream among the equalized multi-transport streams. Turbo decoding means a decoding process for a turbo stream.

The turbo decoder 341 may perform turbo decoding by detecting a turbo stream from some or all of the packet adaptation fields of the multi-transport stream.

At this time, the turbo decoder 341 can decode only the data desired by the user based on the coding information.

That is, since the turbo stream to which various coding rates are applied is turbo-encoded and de-interleaved on a turbo-basis basis, the turbo stream is not dispersed and turbo decoding can be easily performed on a turbo-by-turbo basis.

Thus, the user can only decode the desired data. That is, the decoding of only the data desired by the user means that the turbo decoding is selectively performed on all or part of the received turbo stream.

The second Randomizer 343 de-randomizes the turbo decoded multi-transport stream.

The turbo stream extracting unit 345 retrieves the turbo stream from the multi-transport stream that has been randomized and restores the turbo data.

Specifically, the turbo stream extracting unit 345 may retrieve the turbo data after extracting the turbo stream, collecting information data only for the turbo stream, and then performing an RS decoder (not shown) for performing Reed Solomon decoding.

14 is a block diagram showing a configuration of the turbo decoder 341. In Fig.

Referring to FIG. 14, the turbo decoder 341 includes a trellis map decoder 410, an outer deinterleaver 420, an outer map decoder 430, and an outer interleaver 440.

The trellis map decoder 410 trellis-decodes the turbo stream among the equalized multi-transport streams and provides it to the outer deinterleaver 420. At this time, it is possible to selectively decode only the data of the channel desired by the user based on the coding information.

This is because the turbo stream of the distributed multi-transport stream is densely packed by passing through the de-interleaving process in the turbo processing unit 220 of the transmitting apparatus 200, so that the turbo stream can be processed in units of turbo.

The outer deinterleaver 420 outer deinterleaves the trellis-decoded turbo stream.

The outer map decoder 430 may convolutionally decode the deinterleaved turbo stream. Accordingly, the outer map decoder 430 outputs a soft decision and a hard decision output value according to the result of the convolution decoding. Here, the soft decision and the hard decision are determined according to the metric of the turbo stream.

For example, when the turbo stream metric is "0.8", a soft decision value of "0.8" is output. When the turbo stream metric is "1", hard decision is output.

The hard decision output value of the outer map decoder 430 is provided to the reverse randomizer 343. In this case, the hard decision output value means a turbo stream.

Meanwhile, when the outer map decoder 430 outputs a soft decision, the outer interleaver 440 interleaves the turbo stream and provides it to the trellis map decoder 410.

The trellis map decoder 410 provides the interleaved turbo stream to the outer deinterleaver 420 by re-running trellis decoding, and the outer deinterleaver 420 again deinterleaves the outer map to the outer map decoder 430. To provide.

Operations of the trellis map decoder 410, the outer deinterleaver 420 and the outer interleaver 440 can be repeatedly performed until a hard decision is output. Thus, a reliable decryption level can be obtained.

15 is a flowchart illustrating a process of transmitting a multi-transport stream according to an embodiment of the present invention.

Referring to FIG. 15, a multi-transport stream including a turbo stream and a normal stream having a variable coding rate is generated (S510). Specifically, a parity insertion region according to various coding rates is provided in a turbo stream, an adaptive field is provided in a normal stream, and then two streams are multiplexed to generate a multi transport stream.

Next, after randomizing the generated multi-transport stream (S520), the turbo process is performed (S530). A specific method of turbo processing is described in detail in Fig.

After the turbo process is completed, the multi-transport stream is subjected to Reed-Solomon encoding (S540) and interleaving (S550).

The interleaved multi-transport stream is Trellis-encoded, and a segment sync signal and a field sync signal are added to the Trellis-encoded multi-transport stream and multiplexed (S570).

Thereafter, channel modulation is performed and transmitted (S580). A detailed description thereof has been given above, so that redundant description and illustration are omitted.

16 is a flowchart illustrating a turbo process according to an embodiment of the present invention.

Referring to FIG. 16, a multi-transport stream is received and only a turbo stream is detected (S610). The detected turbo stream is encoded in units of Turbo (S620). At this time, after performing convolutional encoding based on the coding information, the encoding is performed by inserting the encoded value into the parity insertion region provided in the turbo stream.

When the encoding is completed, the encoded turbo stream is subjected to outer interleaving (S630), and the interleaved turbo stream is deinterleaved (S640).

Accordingly, when interleaving the multi transport streams later, the turbo streams among the multi transport streams may be output in a dense configuration. In other words, when viewed from the side of the receiving apparatus, the turbo stream is not dispersed but dense, so that selective restoration is possible. Thus, the power consumption of the receiving apparatus can be reduced.

For example, in the case where the user desires to view only the program 2, only the turbo 2 can be operated without needing to operate on all the data, so that the power consumption can be reduced.

The turbo stream is inserted into the multi-transport stream again, and the multi-transport stream is reconstructed (S650).

17 is a flowchart illustrating a process of receiving a multi-transport stream according to an embodiment of the present invention.

Referring to FIG. 17, a multi-transport stream is received and demodulated (S710). Then, the demodulated stream is equalized (S715).

Then, Viterbi decoding is performed on the normal stream in the equalized stream (S720), deinterleaving (S725), and Reed Solomon decoding is performed (S730). Next, the normalized data is restored by performing the reverse randomization (S735).

On the other hand, turbo decoding is first performed for the turbo stream among the equalized streams (S740), and then the de-randomization is performed (S745). Next, the turbo stream is detected from the de-randomized dual transport stream (S750), and the turbo data is recovered.

18 is a flowchart for explaining a turbo decoding method. Referring to FIG. 18, trellis decoding is performed on a turbo stream in a multi-transport stream (S810). At this time, it is possible to selectively decode only the data of the channel desired by the user based on the coding information.

Then, the trellis-decoded turbo stream is outer-deinterleaved (S820), and outer decoding is performed (S830).

Meanwhile, when the soft decision output value is outputted through outer decoding, outer interleaving (S840) is performed, and the outer interleaved turbo stream is subjected to trellis decoding and outer de-interleaving (S810 and S820). This makes it possible to obtain a lightly-judged turbo stream at a reliable level.

As described above, according to the present invention, it is possible to efficiently transmit and receive a multi-transport stream including a turbo stream and a normal stream having various coding rates.

In particular, it is possible to perform encoding and decoding on a turbo basis for a turbo stream having a variable coding rate, thereby transmitting / receiving various performance turbo streams having various coding rates.

In addition, since the user can perform a process on a desired turbo stream, power consumption can be reduced in terms of the receiving apparatus.

In addition, the above turbo stream may be named additional data stream or additional stream in the sense that it is added to the normal data stream and transmitted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

1 is a block diagram showing a configuration of a conventional digital broadcast (ATSC VSB) system,

2 is an exemplary diagram showing a frame structure of conventional ATSC VSB data,

3 is a block diagram illustrating a configuration of a digital broadcasting system according to an embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a transport stream generating apparatus of FIG. 3 according to an embodiment of the present invention;

5 is a diagram illustrating a structure of a multi-transport stream according to an exemplary embodiment of the present invention.

6 is a block diagram showing a configuration of a transmitting apparatus of FIG. 3 according to an embodiment of the present invention;

FIG. 7 is a block diagram showing the configuration of the turbo processor of FIG. 6;

8 is a block diagram showing the configuration of a transmitting apparatus according to another embodiment of the present invention;

FIG. 9 is a block diagram showing the configuration of the turbo processor of FIG. 8;

10 is a block diagram illustrating a configuration of a transport stream generating apparatus according to another embodiment of the present invention.

11 is a block diagram illustrating a configuration of a transport stream generating apparatus according to another embodiment of the present invention.

12 is a block diagram showing a configuration of a transmitting apparatus according to another embodiment of the present invention;

FIG. 13 is a block diagram illustrating a configuration of a receiving apparatus of FIG. 3 according to an embodiment of the present invention;

FIG. 14 is a block diagram showing the configuration of the turbo decoder of FIG. 13;

FIG. 15 is a flowchart illustrating a process of transmitting a multi-transport stream according to an exemplary embodiment of the present invention;

16 is a flowchart illustrating a turbo process according to an embodiment of the present invention.

FIG. 17 is a flowchart illustrating a process of receiving a multi-transport stream according to an embodiment of the present invention,

18 is a flowchart illustrating a turbo decoding process according to an embodiment of the present invention.

[Description of Drawings]

100: Transport Stream Generation Device 200: Transmission Device

300: receiving apparatus 110, 230: RS encoder

120: Duplicator 130: Mux

140,223: outer encoder 150,225,440: outer interleaver

160, 227, 333: Data deinterleaver 170, 210:

180, 220 Turbo processing units 190, 337, 343, 337:

240,285: Data interleaver 250: Trellis encoder

260: Mux 270: Modulation unit

221,345: turbo stream detector 280: parity area generator

291: Di Mills 293: Mux

310 demodulation section 320 equalization section

330: first processing section 340: second processing section

331: Viterbi decoder 335: RS decoder

341: turbo decoder 410: trellis map decoder

420: outer deinterleaver 430: outer map decoder

Claims (8)

A demodulator for receiving and demodulating a transport stream including additional data and normal data; An equalizer for equalizing the demodulated transport stream; And And a decoder configured to decode additional data of the equalized transport stream. The transport stream is, A digital broadcasting transmitter encodes the additional data, codes the variable data according to a variable coding rate, and then multiplexes the normal data, The decoding unit, A trellis decoder for trellis decoding additional data in the equalized transport stream; An outer deinterleaver for deinterleaving the trellis decoded additional data; And And an outer decoder for decoding the deinterleaved additional data. The method of claim 1, The decoding unit, And performing decoding corresponding to the coding rate with respect to additional data in the equalized transport stream. 3. The method of claim 2, The decoding unit, And an outer interleaver for interleaving the decoded additional data and providing the decoded additional data to the trellis decoder. The method of claim 1, The variable coding rate may be determined by: Rate or a 1/4 rate. Receiving and demodulating a transport stream comprising additional data and normal data; Equalizing the demodulated transport stream; And Decoding the equalized transport stream; The transport stream is, The digital data transmitter encodes the additional data, codes the data according to a variable coding rate, and then multiplexes the normal data. Wherein the decoding comprises: Trellis decoding trellis decoding additional data in the equalized transport stream; Deinterleaving the trellis decoded additional data; And And decoding the deinterleaved additional data. The method of claim 5, Wherein the decoding comprises: And performing decoding corresponding to the coding rate with respect to additional data in the equalized transport stream. The method according to claim 6, Wherein the decoding comprises: Interleaving the decoded additional data and providing the decoded additional data to the trellis decoder. The method of claim 5, The variable coding rate may be determined by: Rate or a 1/4 rate.

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