KR20100015287A - Transmitting/receiving system and method of processing broadcast signal in transmitting/receiving system - Google Patents

Abstract

PURPOSE: A transmitting/receiving system and a method of processing broadcast signal are provided to additionally encode mobile service data, and transmit the encoded data to the receiving system thereby improving a receiving performance of the receiving system. CONSTITUTION: A reliability adjusting unit adjusts the reliability of mobile service data based on the position of mobile service data within data group which is trellis-decoded. An outer decoder(5018) symbol-decodes the mobile service data outputted from the reliability adjusting unit. The outer decoder feeds back the decoded mobile service data into an inner decoder(5012). An error correction unit corrects the error created in the mobile service data outputted from the outer decoder.

Description

Transmitting / receiving system and method of processing broadcast signal in transmitting / receiving system}

The present invention relates to a digital broadcasting system for transmitting and receiving digital broadcasting, and more particularly, to a transmission system for processing and transmitting digital broadcasting, a receiving system for receiving and processing digital broadcasting, and a processing method of a broadcast signal. .

In the digital broadcasting, VSB (Vestigial Sideband) transmission method adopted as a digital broadcasting standard in North America and Korea is a single carrier method, so the reception performance of the receiving system may be degraded in a poor channel environment. In particular, in the case of a portable or mobile broadcast receiver, since the robustness against channel change and noise is further required, when the mobile service data is transmitted through the VSB transmission method, the reception performance is further deteriorated.

Accordingly, an object of the present invention is to provide a transmission system, a reception system, and a broadcast signal processing method that are resistant to channel changes and noise.

Another object of the present invention is to provide a transmission system, a reception system, and a broadcast signal processing method for improving the reception performance of a reception system by performing additional encoding on mobile service data in a transmission system and transmitting the same to a reception system. have.

Still another object of the present invention is to provide a transmission system, a reception system, and a broadcast signal for improving the reception performance of a reception system by inserting and transmitting known data known by a promise of a transmission / reception side into a predetermined area of a data area. To provide a treatment method.

It is still another object of the present invention to provide a receiving system and a broadcast signal processing method for improving turbo decoding performance by performing turbo decoding by weighting the data according to data positions in a data group.

In order to achieve the above object, a transmission system according to an embodiment of the present invention may include a service multiplexer and a transmitter. The service multiplexer may multiplex the mobile service data and the main service data at a preset data rate and transmit them to the transmitter. The transmitter may perform additional encoding on the mobile service data transmitted from the service multiplexer, and collect a plurality of mobile service data packets on which the encoding is performed to form a data group. The transmitter may multiplex the mobile service data packet including the mobile service data and the main service data packet including the main service data and transmit the multiplexed service to the receiving system.

The data group may be divided into a plurality of areas according to the degree of interference of the main service data. Long known data streams may be inserted periodically in an area free of interference of the main service data.

A receiving system according to an embodiment of the present invention may use the known data stream for demodulation and channel equalization.

A reception system according to another embodiment of the present invention includes a signal receiver, an equalizer, an inner decoder, a reliability controller, an outer decoder, and an error correction unit. The signal receiver receives and demodulates a broadcast signal including a data group including a mobile service data and a plurality of known data streams. The equalizer channel equalizes the data group included in the demodulated broadcast signal using the known data sequence. The inner decoder performs trellis decoding by matching the mobile service data in the data group inputted with the block size for turbo decoding by the equalizer with the mobile service data which is symbol-decoded and fed back. The reliability adjustment unit adjusts the reliability of the mobile service data according to the position in the data group of the trellis decoded mobile service data. The outer decoder performs symbol decoding on the mobile service data output from the reliability adjuster and feeds back the inner decoder. The error correcting unit corrects an error generated in the mobile service data output from the outer decoding unit.

The inner decoding unit performs trellis decoding on the mobile service data in symbol units, and outputs a soft decision value of each symbol.

The reliability adjustment unit lowers the reliability of the soft decision value of the symbol by multiplying the soft decision value of the symbol by a weight less than 1 according to the position of the mobile service data in the data group.

According to another aspect of the present invention, there is provided a method of processing a broadcast signal in a receiving system, the method including receiving and demodulating a broadcast signal including a data group including a mobile service data and a plurality of known data streams, Channel equalizing the data group included in the demodulated broadcast signal, matching the mobile service data in the data group inputted to the block size for turbo decoding after the channel equalization with the mobile service data that is symbol-decoded and fed back, and trellis An inner decoding step of performing the decoding, a reliability adjustment step of adjusting the reliability of the mobile service data according to a position in the data group of the trellis-decoded mobile service data, and the mobile service data output from the reliability adjustment step. Trellis box after performing symbol decoding An outer decoding step for feeding to, and may comprise a step of correcting an error occurred in the mobile data service decoding the symbol.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

The transmission / reception system and the broadcast signal processing method according to the present invention have advantages in that they are resistant to errors and compatible with existing receivers when transmitting mobile service data through a channel.

The present invention has the advantage that the mobile service data can be received without error even in a ghost and noisy channel. The present invention can improve the reception performance of the reception system in an environment with a high channel change by inserting and transmitting known data in a specific position of the data area.

In addition, the present invention provides turbo decoding by giving a weight less than 1 to data obtained from an M / H block (or region) in a data group that is not equalized well when turbo decoding data transmitted in a poor channel environment such as a mobile channel. By doing this, turbo decoding performance can be improved.

The present invention is more effective when applied to portable and mobile receivers in which channel variation is severe and robustness to noise is required.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. At this time, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, by which the technical spirit of the present invention and its core configuration and operation is not limited.

Definition of terms used in the present invention

The terms used in the present invention were selected as widely used general terms as possible in consideration of the functions in the present invention, but may vary according to the intention or custom of the person skilled in the art or the emergence of new technologies. In addition, in certain cases, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the corresponding description of the invention. Therefore, it is intended that the terms used in the present invention should be defined based on the meanings of the terms and the general contents of the present invention rather than the names of the simple terms.

Among the terms used in the present invention, the main service data is data that can be received by the fixed receiving system and may include audio / video (A / V) data. That is, the main service data may include A / V data of a high definition (HD) or standard definition (SD) level, and may include various data for data broadcasting. Known data is data known in advance by an appointment of the transmitting / receiving side.

Among the terms used in the present invention, M / H (or MH) is the first letter of each of a mobile and a handheld, and is a concept opposite to a fixed form. The M / H service data includes at least one of mobile service data and handheld service data, and for convenience of description, the M / H service data may be referred to as mobile service data. In this case, the mobile service data may include not only M / H service data but also any service data indicating movement or portability, and thus the mobile service data will not be limited to the M / H service data.

The mobile service data defined as described above may be data having information such as a program execution file, stock information, or the like, or may be A / V data. In particular, the mobile service data may be A / V data having a smaller resolution and a smaller data rate than the main service data as service data for a portable or mobile terminal (or broadcast receiver). For example, if the A / V codec used for the existing main service is an MPEG-2 codec, the MPEG-4 codec that has better image compression efficiency as the A / V codec for mobile services. AVC (Advanced Video Coding), SVC (Scalable Video Coding), or the like may be used. In addition, any kind of data may be transmitted as the mobile service data. For example, TPEG (Transport Protocol Expert Group) data for broadcasting traffic information in real time may be transmitted as mobile service data.

In addition, data services using the mobile service data include weather services, transportation services, securities services, viewer participation quiz program, real-time polls, interactive educational broadcasting, game services, drama plot, characters, background music, shooting location, etc. Informational services, information on past sports history, profile and performance of athletes, and information on programs by media, time, or subject that enables product information and ordering. Etc., but the present invention is not limited thereto.

The transmission system of the present invention enables multiplexing of main service data and mobile service data on the same physical channel without any influence on receiving main service data from an existing receiving system.

The transmission system of the present invention performs additional encoding on mobile service data, and inserts and transmits data that is known in advance to both the transmitting and receiving sides, that is, known data.

When the transmission system according to the present invention is used, the reception system enables mobile reception of mobile service data, and also enables stable reception of mobile service data against various distortions and noises generated in a channel.

M / H frame structure

According to an embodiment of the present invention, the mobile service data is multiplexed with main service data in units of M / H frames, and then modulated in a VSB scheme and transmitted to a receiving system.

In this case, one M / H frame may consist of K1 subframes, and one subframe may consist of K2 slots. In addition, one slot may consist of K3 data packets. In the present invention, K1 is set to 5, K2 is set to 16, and K3 is set to 156 according to one embodiment. The values of K1, K2, and K3 presented in the present invention are preferred embodiments or simple examples, and the scope of the present invention is not limited to the above numerical values.

1 illustrates an embodiment of an M / H frame structure for transmitting and receiving mobile service data according to the present invention. FIG. 1 shows an example in which one M / H frame consists of five subframes and one subframe consists of 16 slots. In this case, one M / H frame means five subframes and 80 slots.

One slot consists of 156 data packets (ie, transport stream packets) at the packet level and 156 data segments at the symbol level. Or half of the VSB field. That is, since one data packet of 207 bytes has the same amount of data as one data segment, the data packet before data interleaving can be used as the concept of the data segment.

At this time, two VSB fields are combined to form one VSB frame.

2 shows an example of a VSB frame structure, in which one VSB frame includes two VSB fields (ie, odd field and even field). Each VSB field consists of one field sync segment and 312 data segments.

The slot is a basic time period for multiplexing the mobile service data and the main service data. One slot may include mobile service data or may consist only of main service data.

If a data group containing mobile service data is transmitted during one slot, the first 118 data packets in the slot correspond to one data group and the remaining 38 packets become the main service data packet. As another example, if there is no data group in one slot, the slot is composed of 156 main service data packets.

On the other hand, when the slots are assigned to VSB frames, they have offsets in their positions.

3 shows an example of mapping of the first four slot positions of a subframe to a VSB frame in a spatial domain. 4 shows an example of mapping of the first four slot positions of a subframe to one VSB frame in the time domain.

3 and 4, the 38 th data packet (# 37) of the first slot (Slot # 0) is mapped to the first data packet of the odd VSB field and the 38 th data of the second slot (Slot # 1). Packet # 37 is mapped to the 157th data packet of the order VSB field. In addition, the 38th data packet (# 37) of the third slot (Slot # 2) is mapped to the first data packet of the even VSB field, and the 38th data packet (# 37) of the fourth slot (Slot # 3) is It is mapped to the 157th data packet of the even VSB field. Similarly, the remaining 12 slots in that subframe are mapped in the same way to subsequent VSB frames.

Meanwhile, one data group may be divided into one or more layered areas, and the type of mobile service data inserted into each area may vary according to characteristics of each layered area. For example, each region in the data group may be classified based on reception performance in the data group.

According to an embodiment of the present invention, one data group is divided into A, B, C, and D regions in a data configuration after data interleaving.

FIG. 5 is a diagram in which data after data interleaving is arranged separately, and FIG. 6 is an enlarged part of the data group of FIG. 5 for better understanding of the present invention. FIG. 7 is a diagram in which data before data interleaving is arranged separately, and FIG. 8 is an enlarged part of the data group of FIG. 7 for better understanding of the present invention. That is, the data structure as shown in FIG. 5 is transmitted to the receiving system. In other words, one data packet is data interleaved and distributed to several data segments and transmitted to a receiving system. 5 shows an example in which one data group is distributed to 170 data segments. In this case, since one data packet of 207 bytes has the same amount of data as one data segment, the packet before data interleaving may be used as a concept of a segment.

5 shows an example of dividing a data group into 10 M / H blocks (MH blocks B1 to B10) in a data configuration after data interleaving. Each M / H block has a length of 16 segments. In FIG. 5, the first five segments of the M / H block B1 and the five segments after the M / H block B10 are allocated only RS parity data to a portion of the data segment, and are excluded from the areas A to D of the data group.

In other words, assuming that one data group includes at least A, B, C, and D regions, each M / H block may be one of A to D regions according to characteristics of each M / H block in the data group. Can be included in At this time, according to an embodiment of the present invention, each M / H block is included in any one of the A region and the D region according to the interference level of the main service data.

Here, the reason why the data group is divided into a plurality of areas is used for different purposes. That is, an area where there is no or little interference of the main service data may exhibit stronger reception performance than an area that is not. In addition, in case of applying a system for inserting and transmitting known data known to the data group by the transmission / reception side's promise, when the long service data is to be inserted periodically in the mobile service data, the main service It is possible to periodically insert known data of a certain length into an area where data does not interfere (that is, an area where main service data is not mixed). However, it is difficult to periodically insert known data into the area where the main service data interferes with the interference of the main service data, and also to insert long known data continuously.

The M / H blocks B4 to M / H block B7 in the data group of FIG. 5 show an example in which long known data strings are inserted before and after each M / H block as an area without interference of main service data. In the present invention, the M / H blocks B4 to M / H block B7 are referred to as an A region (= B4 + B5 + B6 + B7). As described above, in the case of the area A having a known data sequence back and forth for each M / H block, the receiving system can perform equalization using channel information obtained from the known data, and thus the strongest equalization among the areas A to D. You can get performance.

The M / H block B3 and the M / H block B8 in the data group of FIG. 5 are regions in which main service data has little interference, and a long known data string is inserted into only one side of both M / H blocks. That is, due to the interference of the main service data, M / H block B3 is inserted with a long known data column only after the M / H block, and M / H block B8 is inserted with a long known data column only before the corresponding M / H block. Can be. In the present invention, the M / H block B3 and the M / H block B8 will be referred to as a B region (= B3 + B8). As described above, in the case of the B area having only one known data string in each M / H block, the receiving system can perform equalization using channel information obtained from the known data, which is more robust than the C / D area. Equalization performance can be obtained.

The M / H block B2 and the M / H block B9 in the data group of FIG. 5 have more interference of the main service data than the B area, and both M / H blocks cannot insert a long known data stream back and forth. In the present invention, the M / H block B2 and the M / H block B9 are referred to as a C region (= B2 + B9).

The M / H block B1 and the M / H block B10 in the data group of FIG. 5 have more interference of the main service data than the C region, and likewise, both M / H blocks cannot insert a long known data string back and forth. In the present invention, the M / H block B1 and the M / H block B10 will be referred to as a D region (= B1 + B10). Since the C / D region is far from the known data stream, the reception performance may be poor when the channel changes rapidly.

7 shows an example in which 118 packets are allocated to one data group as a data structure before data interleaving. The data group of FIG. 7 includes 37 packets forward based on a reference packet when allocating to a VSB frame, for example, the first packet (or data segment) or the 157th packet (or data segment) after field synchronization, An example of configuring 118 packets including 81 packets (including the reference packet) to the rear is shown.

That is, with reference to FIG. 5, field synchronization is located between M / H block B2 and M / H block B3, which means that the slot has an offset of 37 data packets for the corresponding VSB field.

The size of the data group described above, the number of layered regions in the data group and the size of each region, the number of M / H blocks included in each region, the size of each M / H block, and the like are one for describing the present invention. The present invention is not limited to the above-described example only because it is an embodiment of.

FIG. 9 shows an example of a data group allocation order allocated to one subframe among five subframes constituting an M / H frame. For example, the method of allocating data groups may be equally applied to all M / H frames or may be different for each M / H frame. In addition, the same may be applied to all subframes in one M / H frame or may be differently applied to each subframe. In this case, it is assumed that the data group allocation is equally applied to all subframes in the M / H frame, and the number of data groups allocated to one M / H frame is a multiple of five.

According to an embodiment of the present invention, a plurality of consecutive data groups are allocated as far apart from each other as possible in a subframe. This makes it possible to respond strongly to burst errors that can occur within one subframe.

For example, assuming that three groups are allocated to one subframe, the first slot (Slot # 0), the fifth slot (Slot # 4), and the ninth slot (Slot # 8) in the subframe. Is assigned. FIG. 9 shows an example of allocating 16 data groups to one subframe by applying such an allocation rule, and includes 0, 8, 4, 12, 1, 9, 5, 13, 2, 10, 6, It can be seen that the slots are allocated to 16 slots in the order of 14,3,11,7,15.

Equation 1 below expresses a rule for allocating data groups to one subframe as described above.

j = (4i + O) mod 16

Where O = 0 if i <4,

O = 2 else if i <8,

O = 1 else if i <12,

O = 3 else.

In addition, j is a slot number in one subframe and may have a value between 0 and 15. I is a group number and may have a value between 0 and 15.

In the present invention, a collection of data groups included in one M / H frame will be referred to as a parade. The parade transmits data of one or more specific RS frames according to the RS frame mode.

Mobile service data in one RS frame may be allocated to all of the A / B / C / D areas in the data group or may be allocated to at least one of the A / B / C / D areas. According to an embodiment of the present invention, mobile service data in one RS frame is allocated to all of the A / B / C / D areas or only to one of the A / B areas and the C / D areas. That is, in the latter case, the RS frame allocated to the A / B area in the data group and the RS frame allocated to the C / D area are different. In the present invention, for convenience of description, the RS frame allocated to the A / B area in the data group is called a primary RS frame, and the RS frame allocated to the C / D area is referred to as a secondary RS frame. frame). The primary RS frame and the secondary RS frame form one parade. That is, if the mobile service data in one RS frame are all allocated to the A / B / C / D areas in the data group, one parade transmits one RS frame. In contrast, if the mobile service data in one RS frame is allocated to the A / B area in the data group and the mobile service data in the other RS frame is allocated to the C / D area in the data group, Up to RS frames can be transmitted.

That is, the RS frame mode indicates whether one parade transmits one RS frame or two RS frames.

Table 1 below shows an example of an RS frame mode.

RS Frame mode Description 00 There is only a primary RS Frame for all Group Regions 01 There are two separate RS Frames-Primary RS Frame for Group Region A and B-Secondary RS Frame for Group Region C and D 10 Reserved 11 Reserved

In Table 1, 2 bits are allocated to indicate an RS frame mode. Referring to Table 1, when the RS frame mode value is 00, one parade transmits one RS frame. If the RS frame mode value is 01, one parade is two RS frames, that is, primary RS. Indicates that a frame (Primary RS frame) and a secondary RS frame (Secondary RS frame) is transmitted. That is, when the RS frame mode value is 01, data of a primary RS frame for region A / B is allocated to the A / B area of the data group and transmitted, and a secondary RS frame for region is transmitted. Data of the C / D) is allocated to the C / D area of the corresponding data group and transmitted.

Like the data group allocation, the parades may be allocated as far apart from each other as possible in the subframe. This makes it possible to respond strongly to burst errors that can occur within one subframe.

In addition, the method of allocating parades may be differently applied to every M / H frame based on the M / H frame, and may be equally applied to all M / H frames. In addition, the same may be applied to all subframes in one M / H frame or may be differently applied to each subframe. The present invention may vary for each M / H frame, and the same applies to all subframes in one M / H frame. That is, the M / H frame structure may vary in units of M / H frames, which allows the ensemble data rate to be adjusted frequently and flexibly.

FIG. 10 is a diagram illustrating an example of allocating a single parade to one M / H frame. That is, FIG. 10 illustrates an embodiment when a single parade having a number of data groups included in one subframe is assigned to one M / H frame.

Referring to FIG. 10, if three data groups are sequentially allocated to one subframe in four slot periods, and this process is performed for five subframes in the corresponding M / H frame, 15 data in one M / H frame The data group is assigned. The 15 data groups are data groups included in one parade. Therefore, one subframe is composed of four VSB frames, but one subframe includes three data groups. Therefore, one VSB frame among four VSB frames in one subframe is not assigned a data group of the corresponding parade. Do not.

For example, suppose that one parade transmits one RS frame, RS encoding is performed in a later RS frame encoder for the RS frame, and 24 bytes of parity data is added to the RS frame. In this case, the parity data occupies about 11.37% (= 24 / (187 + 24) x 100) of the length of all RS code words. Meanwhile, when three data groups are included in one subframe, and 15 data groups form one RS frame when data groups in one parade are allocated as shown in FIG. 10, one data is generated due to burst noise generated in a channel. Even if all of the groups had errors, the proportion would be 6.67% (= 1/15 x 100). Therefore, in the receiving system, all errors can be corrected by erasure RS decoding. That is, since erasure RS decoding can correct channel errors as many as the number of RS parities, all byte errors less than or equal to the number of RS parities in one RS codeword can be corrected. This allows the receiving system to correct errors in at least one data group in one parade. As such, the minimum burst noise length correctable by a RS frame is over 1 VSB frame.

Meanwhile, when data groups for one parade are allocated as shown in FIG. 10, main service data may be allocated between the data group and the data group, or data groups of another parade may be allocated. That is, data groups for a plurality of parades may be allocated to one M / H frame.

Basically, the allocation of data groups for multiple parades is no different than for a single parade. That is, data groups in different parades allocated to one M / H frame are also allocated in four slot periods.

In this case, the data group of another parade may be allocated in a circular manner from a slot to which the data group of the previous parade is not allocated.

For example, assuming that data group allocation for one parade is performed as shown in FIG. 10, the data group for the next parade is allocated from the 12th slot in one subframe. This is one embodiment, and for example, the data group of the next parade may be sequentially assigned to another slot, for example, the third slot to the four slot period, in one subframe.

FIG. 11 shows an example of transmitting three parades (Parade # 0, Parade # 1, Parade # 2) in one M / H frame. In particular, one subframe among five subframes constituting the M / H frame is illustrated in FIG. An example of parade transmission of frames is shown.

If the first parade includes three data groups per subframe, the positions of the groups in the subframe can be obtained by substituting 0 to 2 for the i value of Equation 1 above. That is, data groups of the first parade are sequentially allocated to the first, fifth, and ninth slots (Slot # 0, Slot # 4, Slot # 8) in the subframe.

If the second parade includes two data groups per subframe, the positions of the groups in the subframe can be obtained by substituting 3 to 4 into the i value of Equation 1 above. That is, data groups of the second parade are sequentially allocated to the second and twelfth slots #Slot # 11 in the subframe.

In addition, if the third parade includes two groups per subframe, the positions of the groups in the subframe can be obtained by substituting 5 to 6 into the i value of Equation 1 above. That is, data groups of the third parade are sequentially allocated to the seventh and eleventh slots (Slot # 6 and Slot # 10) in the subframe.

As such, data groups for a plurality of parades may be allocated to one M / H frame, and data group allocation in one subframe is performed serially from left to right with a group space of 4 slots.

Therefore, the number of groups of one parade per a sub-frame (NOG) that may be allocated to one subframe may be any one of integers from 1 to 8. Since one M / H frame includes five subframes, this means that the number of data groups of one parade that can be allocated to one M / H frame may be any one of multiples of 5 to 40. That means you can.

FIG. 12 illustrates an example in which the allocation process of the three parades of FIG. 11 is extended to five subframes within one M / H frame.

FIG. 13 is a diagram illustrating a data transmission structure according to an embodiment of the present invention and illustrates a state in which signaling data is included and transmitted in a data group.

As described above, the M / H frame is divided into five subframes, and data groups corresponding to several parades are mixed in each subframe. In addition, data groups corresponding to each parade are grouped into M / H frame units to form one parade.

In FIG. 13, three parades (Parade # 0, Parade # 1, and Parade # 2) exist in one M / H frame. At this time, a certain portion (e.g. 37 bytes / data group) of each data group is used for delivering fast information channel (FIC) information encoded separately from RS encoding for mobile service data. The FIC region allocated to each data group constitutes one FIC segment.

Meanwhile, in the present embodiment, the concept of M / H ensemble is introduced to define a set of services. One M / H ensemble has the same QoS and is coded with the same FEC code. In addition, one M / H ensemble has the same unique identifier (ie, ensemble id) and corresponds to consecutive RS frames.

As shown in FIG. 13, the FIC segment corresponding to each data group describes service information of an M / H ensemble to which the data group belongs.

Schematic description of the transmission system

14 is a schematic diagram illustrating an embodiment of a transmission system for applying the present invention having the above-described structure, and may include a service multiplexer 100 and a transmitter or exciter 200. .

Here, the service multiplexer 100 is located in a studio of each broadcasting station, and the transmitter 200 is located in a site away from the studio. In this case, the transmitter 200 may be located in a plurality of different areas. In one embodiment, the plurality of transmitters may share the same frequency, in which case the plurality of transmitters all transmit the same signal. This corresponds to data transmission using a single frequency network (SFN). In the receiving system, the channel equalizer can then recover the original signal by compensating for the signal distortion caused by the reflected wave. In another embodiment, the plurality of transmitters may have different frequencies for the same channel. This corresponds to data transmission using a multi frequency network (MFN).

Various methods may be used for data communication between the service multiplexer and each transmitter located at a remote location, and as an example, an interface standard such as Synchronous Serial Interface for transport of MPEG-2 data (SMPTE-310M) may be used. . In the SMPTE-310M interface standard, the output data rate of the service multiplexer is determined to be a constant data rate. For example, it is set at 19.39 Mbps for 8VSB, and 38.78 Mbps for 16VSB. In addition, the existing 8VSB transmission system can transmit a transport stream (TS) packet having a data rate of about 19.39 Mbps on one physical channel. In the transmitter according to the present invention having backward compatibility with the existing transmission system, the mobile service data is further encoded and then multiplexed in the form of the main service data and the TS packet, and the multiplexed TS packet data is transmitted. The rate is about 19.39 Mbps.

In this case, the service multiplexer 100 receives at least one kind of main service data and table information for each main service, for example, PSI / PSIP table data, and encapsulates them into TS packets.

In addition, the service multiplexer 100 is, in one embodiment, at least one type of mobile service data and table information for each mobile service, for example, program specific information (PSI) / program and system information protocol (PSIP) table data. Receive encapsulation is encapsulated in each mobile service data packet in the form of a transport stream (TS) packet.

In another embodiment, the service multiplexer 100 receives an RS frame including at least one type of mobile service data and table information for each mobile service, and transmits a mobile service data packet in the form of a transport stream (TS) packet. You can encapsulate with.

The service multiplexer 100 multiplexes the encapsulated TS packets according to a preset multiplexing rule and outputs the TS packets to the transmitter 200.

Meanwhile, the RS frame has a size of N (row) x 187 (column) bytes as shown in FIG. N is the length of a row (ie, the number of columns), and 187 is the length of a column (ie, the number of rows).

In the present invention, each row of N bytes will be referred to as an M / H service data packet for convenience of description. The M / H service data packet may consist of an M / H header of 2 bytes and an M / H payload of N-2 bytes. In this case, the allocation of the M / H header area to two bytes is just one embodiment, and the present invention will not be limited to the above embodiment because it may be changed by a designer.

The RS frame is generated by collecting table information and / or IP datagrams having a size of N-2 (row) x 187 (column) bytes. In addition, one RS frame may include table information and IP datagram corresponding to one or more mobile services. For example, IP datagrams and table information of two kinds of mobile services, such as news (for example, IP datagram for mobile service 1) and securities (for example, IP datagram for mobile service 2), are stored in one RS frame. May be included.

That is, the M / H payload in the M / H service data packet constituting the RS frame may be assigned table information of a section structure or an IP datagram of mobile service data.

Alternatively, an IP datagram of table information or an IP datagram of mobile service data may be allocated to an M / H payload in an M / H service data packet constituting the RS frame.

In this case, the M / H service data packet may not be N bytes including the M / H header.

In this case, stuffing bytes may be allocated to the remaining payload portion of the corresponding M / H service data packet. For example, after assigning program table information to one M / H service data packet, if the length of the M / H service data packet is N-20 bytes including the M / H header, stuffing the remaining 20 bytes You can allocate bytes.

FIG. 16 illustrates an example of fields allocated to an M / H header area in an M / H service data packet according to the present invention, and may include a type_indicator field, an error_indicator field, a stuff_indicator field, and a pointer field.

The type_indicator field may allocate 3 bits in one embodiment, and indicates a type of data allocated to a payload in a corresponding M / H service data packet. That is, it indicates whether the data of the M / H payload is an IP datagram or signaling information including table information. Each data type constitutes one logical channel. In the logical channel carrying IP datagram, multiple mobile services are multiplexed and transmitted, and each mobile service is demultiplexed in the IP layer.

The error_indicator field may allocate 1 bit in one embodiment, and indicates whether an error of the corresponding M / H service data packet occurs. For example, when the error_indicator field value is 0, it means that there is no error in the corresponding M / H service data packet, and when 1, there is an error.

The stuff_indicator field may allocate 1 bit as an embodiment and indicates whether a stuffing byte is present in the payload of the corresponding M / H service data packet. For example, if the value of the stuff_indicator field is 0, it means that there is no stuffing byte in the corresponding M / H service data packet, and 1 means that there is a stuffing byte.

In one embodiment, the pointer field may allocate 11 bits, and indicates location information at which new data (ie, new signaling information or new IP datagram) starts in a corresponding M / H service data packet.

For example, if an IP datagram for mobile service 1 and an IP datagram for mobile service 2 are allocated to the first M / H service data packet in an RS frame as shown in FIG. 15, the pointer field value corresponds to the corresponding M / H. Indicates the start position of the IP datagram for mobile service 2 in the service data packet.

In addition, if there is no new data in the corresponding M / H service data packet, the corresponding pointer field value is displayed as the maximum value according to an embodiment. According to an embodiment of the present invention, 11 bits are allocated to the pointer field. Therefore, if 2047 is displayed in the pointer field value, it means that the packet has no new data. If the pointer field is 0, the point indicated may vary according to the type_indicator field value and the stuff_indicator field value.

The order, location, and meaning of the fields allocated to the M / H headers in the M / H service data packet shown in FIG. 16 are merely an example for helping understanding of the present invention. The order, location, meaning of the fields to be allocated, and the number of additional fields to be allocated may be easily changed by those skilled in the art, and thus the present invention will not be limited to the above embodiments.

17 (a) and 17 (b) show another embodiment of an RS frame according to the present invention, and FIG. 17 (a) shows an example of an RS frame to be allocated to an A / B area within a data group. (B) shows an example of the configuration of the RS frame to be allocated to the C / D area in the data group.

In FIGS. 17A and 17B, the column length (ie, number of rows) of the RS frame to be allocated to the A / B area and the column length (ie, number of rows) of the RS frame to be allocated to the C / D area are 187. Are the same, but the row lengths (ie, the number of columns) may be different.

The present invention satisfies the condition N1> N2 when the row length of the primary RS frame to be allocated to the A / B area of the data group is N1 byte and the row length of the secondary RS frame to be allocated to the C / D area is N2 byte. In one embodiment. Here, N1 and N2 may vary according to transmission parameters or to which region in the data group the RS frame is transmitted.

Each row of the N1 and N2 bytes is also referred to as an M / H service data packet in the present invention for convenience of description. The M / H service data packet in the RS frame to be allocated to the A / B area in the data group may be composed of an M / H header of 2 bytes and an M / H payload of N1-2 bytes. The M / H service data packet in the RS frame to be allocated to the C / D area of the data group may be composed of a 2-byte M / H header and an N2-2 byte M / H payload.

In the present invention, the primary RS frame for the A / B region in the data group and the secondary RS frame for the C / D region may include at least one of the table information and the IP datagram. In addition, one RS frame may include an IP datagram corresponding to one or more mobile services.

Parts not described in FIGS. 17A and 17B can be applied to FIG. 15 as they are.

Meanwhile, N, the number of columns in one RS frame, is determined according to Equation 2 below.

는 X 이하의 가장 큰 정수이다. In Equation 2, NoG denotes the number of data groups allocated to one subframe, PL denotes the number of SCCC (Serial Concatenated Convolution Code) payload bytes allocated to one data group, and P denotes each column of the RS frame. The number of RS parity bytes added. And

Is the largest integer below X.

That is, in Equation 2, the PL (Portion Length) is an RS frame portion length, which is equal to the number of SCCC payload bytes allocated to the corresponding data group. The PL may vary according to an RS frame mode, an SCCC block mode, and an SCCC outer code mode. Tables 2 to 5 below show embodiments of PL values depending on RS frame mode, SCCC block mode, and SCCC outer code mode. Detailed description of the SCCC block mode, SCCC outer code mode will be described later.

SCCC outer code mode PL for Region A for Region B for Region C for Region D 00 00 00 00 9624 00 00 00 01 9372 00 00 01 00 8886 00 00 01 01 8634 00 01 00 00 8403 00 01 00 01 8151 00 01 01 00 7665 00 01 01 01 7413 01 00 00 00 7023 01 00 00 01 6771 01 00 01 00 6285 01 00 01 01 6033 01 01 00 00 5802 01 01 00 01 5550 01 01 01 00 5064 01 01 01 01 4812 Other Reserved

Table 2 shows an example of the PL value of each data group in the RS frame that depends on the SCCC outer code mode value when the RS frame mode value is 00 and the SCCC block mode value is 00.

For example, assuming that the SCCC outer code mode values of the A / B / C / D areas in the data group are each 00 (that is, encoding at a 1/2 code rate is performed by the block processor 302 at the later stage), The PL value in each data group of the RS frame may be 9624 bytes. That is, 9624 bytes of mobile service data in one RS frame may be allocated to the A / B / C / D region of the corresponding data group.

SCCC outer code mode PL 00 9624 01 4812 Other Reserved

Table 3 shows an example of the PL value of each data group in the RS frame that depends on the SCCC outer code mode value when the RS frame mode value is 00 and the SCCC block mode value is 01.

SCCC outer code mode PL For Region A for Region B 00 00 7644 00 01 6423 01 00 5043 01 01 3822 Other Reserved

Table 4 shows an example of the PL value of the primary RS frame that depends on the SCCC outer code mode value when the RS frame mode value is 01 and the SCCC block mode value is 00. For example, if the SCCC outer code mode values of the A / B area are each 00, 7644 bytes of mobile service data in the primary RS frame may be allocated to the A / B area of the corresponding data group.

SCCC outer code mode PL For Region C for Region D 00 00 1980 00 01 1728 01 00 1242 01 01 990 Others Reserved

Table 5 shows an example of the PL value of the secondary RS frame that depends on the SCCC outer code mode value when the RS frame mode value is 01 and the SCCC block mode value is 00. For example, if the SCCC outer code mode values of the C / D area are each 00, 1980 bytes of mobile service data in the secondary RS frame may be allocated to the C / D area of the corresponding data group.

Service multiplexer

FIG. 18 is a detailed block diagram illustrating an embodiment of the service multiplexer. The controller 110 controls the overall operation of the service multiplexer, a table information generator 120 for a main service, and a null packet generator. 130, mobile service multiplexer 150, and transport multiplexer 160.

The transport multiplexer 160 may include a main service multiplexer 161 and a transport stream (TS) packet multiplexer 162.

Referring to FIG. 18, at least one type of compressed coded main service data and table data generated by the table information generator 120 for the main service are input to the main service multiplexer 161 of the transport multiplexer 160. do. According to an embodiment of the present invention, the table information generator 120 generates PSI / PSIP table data in the form of MPEG-2 Private Section.

The main service multiplexer 161 encapsulates input main service data and PSI / PSIP table data in the form of MPEG-2 TS packets, respectively, and multiplexes these TS packets to TS packet multiplexer 162. Will output The data packet output from the main service multiplexer 161 will be referred to as a main service data packet for convenience of description.

The mobile service multiplexer 150 receives at least one type of compression-coded mobile service data and table information for the mobile service, for example, PSI / PSIP table data, and encapsulates each in an MPEG-2 TS packet form. (encapsulation), and these TS packets may be multiplexed and output to the TS packet multiplexer 162. The data packet output from the mobile service multiplexer 150 will be referred to as a mobile service data packet for convenience of description.

Alternatively, the mobile service multiplexer 150 receives an RS frame generated using at least one type of compression-coded mobile service data and table information for the mobile service, and encapsulates it into an MPEG-2 TS packet. And output these TS packets to the TS packet multiplexer 162. The data packet output from the mobile service multiplexer 150 will be referred to as a mobile service data packet for convenience of description.

According to an embodiment of the present invention, the mobile service multiplexer 150 encapsulates an RS frame input in one of FIGS. 15 or 17 (a) and (b) into a TS packet.

In this case, identification information is required for the transmitter 200 to process the main service data packet and the mobile service data packet separately. The identification information may use a predetermined value by an appointment of a transmitting / receiving side, may be configured as separate data, or may be used by modifying a value of a predetermined position in the data packet.

According to an embodiment of the present invention, different PIDs (Packet Identifiers) may be allocated to the main service data packet and the mobile service data packet. That is, by assigning a PID (or null PID) not used for the main service to the mobile service, the transmitter 200 may distinguish the main service data packet from the mobile service data packet by referring to the PID of the input data packet.

In another embodiment, by modifying the sync byte in the header of the mobile service data packet, the sync byte value of the corresponding service data packet may be used to distinguish. For example, the sync byte of the main service data packet outputs the value defined in ISO / IEC13818-1 (for example, 0x47) without modification, and the sync byte of the mobile service data packet is modified and outputted. The data packet and the mobile service data packet can be distinguished. On the contrary, by modifying the sync byte of the main service data packet and outputting the sync byte of the mobile service data packet as it is, the main service data packet and the mobile service data packet can be distinguished.

There may be various ways to modify the sync byte. For example, the sync byte may be inverted bit by bit or only some bits may be inverted.

As such, any identification information capable of distinguishing the main service data packet from the mobile service data packet may be used. Thus, the present invention will not be limited to the above-described embodiments.

Meanwhile, the transport multiplexer 160 may use the transport multiplexer used in the existing digital broadcasting system. That is, in order to transmit the mobile service data multiplexed with the main service data, the data rate of the main service is limited to a data rate of 19 (19.39-K) Mbps, and K Mbps corresponding to the remaining data rate is allocated to the mobile service. This allows you to use the transport multiplexer that is already in use without changing it.

The transport multiplexer 160 multiplexes the main service data packet output from the main service multiplexer 161 and the mobile service data packet output from the mobile service multiplexer 150 to transmit to the transmitter 200.

However, there may occur a case where the output data rate of the mobile service multiplexer 150 is not K Mbps. For example, if the service multiplexer 100 allocates K Mbps of 19.39 Mbps to mobile service data and allocates the remaining (19.39-K) Mbps to main service data, the service multiplexer 100 is actually assigned. The data rate of the mobile service data multiplexed at &lt; RTI ID = 0.0 &gt; This is because, in the case of the mobile service data, the amount of data is increased by performing additional encoding in a pre-processor of the transmitter 200. As a result, the data rate of mobile service data that can be transmitted by the service multiplexer 100 becomes smaller than K Mbps.

As an example, since the preprocessor of the transmitter 200 performs encoding at least 1/2 of the code rate on the mobile service data, the amount of output data of the preprocessor is more than twice the amount of input data. Therefore, the sum of the data rate of the main service data multiplexed in the service multiplexer 100 and the data rate of the mobile service data is always less than or equal to 19.39 Mbps.

The service multiplexer 100 of the present invention may perform various embodiments to adjust the final output data rate of the mobile service multiplexer 150 to K Mbps.

In one embodiment, the null packet generator 130 generates a null data packet and outputs it to the mobile service multiplexer 150, and the mobile service multiplexer 150 multiplexes and outputs a null data packet and a mobile service data packet. The data rate can be set to K Mbps.

At this time, the null data packet is discarded after being transmitted to the transmitter 200. That is, it is not transmitted to the receiving system. To this end, identification information for distinguishing the null data is also required. Identification information for distinguishing the null data packet may also use a predetermined value by an appointment of a transmitting / receiving side, may be configured as separate data, or may be used by modifying a value of a predetermined position in the null data packet. It may be. For example, the null packet generator 130 may modify the sync byte value in the header of the null data packet as identification information, or may set the transport_error_indicator flag to 1 and use it as identification information. According to an embodiment of the present invention, a transport_error_indicator flag of a header in a null data packet is used as identification information for distinguishing a null data packet. In this case, the transport_error_indicator flag of the null data packet is set to 1, and the transport_error_indicator flag of all data packets other than the null data packet is reset to 0 to distinguish the null data packet. That is, when the null packet generator 130 generates a null data packet, if the transport_error_indicator flag is set to '1' in the field of the header of the null data packet and transmitted, the transmitter 200 may separate it. The identification information for distinguishing the null data packet may be any value capable of distinguishing the null data packet, and thus the present invention will not be limited to the above-described embodiment.

As another embodiment for adjusting the final output data rate of the mobile service multiplexer 150 to K Mbps, an OM packet (also referred to as OMP) may be used. In this case, the mobile service multiplexer 150 may set the output data rate to K Mbps by multiplexing the mobile service data packet, the null data packet, and the OM packet.

Meanwhile, signaling data such as a transmission parameter is required to process mobile service data in the transmitter 200.

According to an embodiment of the present invention, the transmission parameter is inserted into the payload region of the OM packet and transmitted to the transmitter 200.

In this case, in order for the transmitter 200 to identify that the transmission parameter is inserted in the OM packet, identification information indicating that the transmission parameter is inserted in the type field (= OM_type field) of the corresponding OM packet is displayed. In one embodiment.

That is, for the purpose of operation and management of the transmission system, a packet called OMP (Operations and Maintenance Packet) is defined. As an example, the OMP follows the format of an MPEG-2 TS packet and its PID has a value of 0x1FFA. The OMP consists of a header of 4 bytes and a payload of 184 bytes. The first byte of the 184 bytes indicates an OM packet type as an OM_type field, and the remaining 183 bytes are inserted with actual data as an OM_payload field.

In the present invention, it is possible to know that a transmission parameter is inserted into a corresponding OM packet by using a predetermined value among unused field values of the OM_type field. Then, the transmitter 200 may find the OMP by looking at the PID, and parse the OM_type field in the OMP to know whether a transmission parameter is inserted into the corresponding OM packet.

Transmission parameters that can be transmitted in the OM packet include M / H frame information (eg, M / H frame_index), FIC information (eg, next_FIC_version_number), parade information (eg, number_of_parades, parade_id, parade_repetition_cycle, ensemble_id), group information (e.g., number_of_group, start_group_number), SCCC information (e.g., SCCC_block_mode, SCCC_outer_code_mode), RS frame information (e.g., RS_Frame_mode, RS_frame_continuity_counter), RS encoding information (e.g., RS_code_mode) Etc.

In this case, the OM packet in which the transmission parameter is inserted may be generated at regular intervals and multiplexed with the mobile service data packet.

The multiplexing rule of the mobile service multiplexer 150, the main service multiplexer 161, and the TS packet multiplexer 160 and generation of null data packets are controlled by the controller 110.

The TS packet multiplexer 162 multiplexes the data packet output from the main service multiplexer 161 at (19.39-K) Mbps and the data packet multiplexed and output from the mobile service multiplexer 150 at K Mbps, The multiplexed data packet is transmitted to the transmitter 200 at a 19.39 Mbps data rate.

transmitter

19 is a block diagram illustrating a transmitter 200 according to an embodiment of the present invention. The controller 201, the demultiplexer 210, a packet jitter mitigator 220, and a pre-processor are illustrated in FIG. A processor 230, a packet multiplexer 240, a post-processor 250, a sync multiplexer 260, and a transmission unit 270.

When the data packet is received from the service multiplexer 100, the demultiplexer 210 must distinguish whether the received data packet is a main service data packet, a mobile service data packet, or a null data packet.

In one embodiment, the demultiplexer 210 may distinguish between the mobile service data packet and the main service data packet using a PID in the received data packet, and may distinguish a null data packet using a transport_error_indicator field.

If the OM packet is included in the received data packet, the OM packet may also be classified using a PID in the received data packet. At this time, if the OM_type field in the divided OM packet is used, it can be known whether the transmission parameter is included in the payload region of the corresponding OM packet.

The main service data packet separated by the demultiplexer 210 is output to the packet jitter reducer 220, the mobile service data packet is output to the preprocessor 230, and the null data packet is discarded. If the transmission parameter is included in the OM packet, the transmission parameter is extracted and output to the corresponding block, and then the OM packet is discarded. According to an embodiment of the present invention, the transmission parameter extracted from the OM packet is output to the corresponding block through the control unit 201.

The preprocessor 230 may be located at any specific location according to the purpose of data to be transmitted on the additional encoding and transmission frame for the mobile service data in the mobile service data packet which is demultiplexed and output from the demultiplexer 210. Perform the data group formation process to make it possible. This is to allow the mobile service data to respond quickly and strongly to noise and channel changes. The preprocessor 230 may refer to the transmission parameter extracted from the OM packet upon further encoding. In addition, the preprocessor 230 collects a plurality of mobile service data packets to form a data group, and allocates known data, mobile service data, RS parity data, MPEG header, and the like to a predetermined region in the data group.

Preprocessor in the transmitter

20 is a block diagram showing an embodiment of the preprocessor 230 according to the present invention. The M / H frame encoder 301, the block processor 302, the group formatter 303, the signaling encoder 305, And a packet formatter 305.

The M / H frame encoder 301 in the preprocessor 230 configured as described above performs data randomization on mobile service data input through the demultiplexer 210 and forms an RS frame corresponding to the ensemble, and in units of RS frames. Encoding for error correction is performed. The M / H frame encoder 301 may include one or more RS frame encoders. That is, the RS frame encoder may be provided in parallel by the number of parades in the M / H frame. As mentioned above, an M / H frame is a basic time period for transmitting one or more parades. Each parade is made of one or two RS frames.

21 is a conceptual block diagram illustrating an embodiment of the M / H frame encoder 301. The M / H frame coder 301 may include an input demux 309, M RS frame coders 310 ˜ 31M−1, and a multiplexer 320. Where M is the number of parades in one M / H frame.

The demultiplexer 309 outputs the input mobile service data to a corresponding RS frame encoder among M RS frame encoders in an ensemble unit.

In this case, the ensemble may be mapped to an RS frame encoder or parade. For example, if one parade is composed of one RS frame, the ensemble, RS frame, and parade may be mapped to 1: 1: 1, respectively.

The RS frame encoder forms an RS frame corresponding to the mobile service data of the input ensemble, and performs an error correction encoding process in units of RS frames. Subsequently, RS frames in which error correction encoding is performed to be allocated to a plurality of data groups are divided into a plurality of portions. At this time, according to the RS frame mode of Table 1, the data of one RS frame may be allocated to all of the A / B / C / D region in the plurality of data groups, or may be allocated to the A / B region or C / D region have.

If the RS frame mode value is 01, that is, if the data of the primary RS frame is allocated to the A / B area in the data group and the data of the secondary RS frame is allocated to the C / D area in the data group, each RS The frame encoder forms a primary RS frame and a secondary RS frame for each parade. On the contrary, if the RS frame mode value is 00, that is, a mode in which the data of the primary RS frame is allotted to the A / B / C / D areas in the data group, each RS frame encoder is one RS frame for each parade, Form a primary RS frame.

Each RS frame encoder separates each RS frame into a plurality of portions. Each portion of the RS frame corresponds to the amount of data that can be transmitted by one data group. The multiplexer 320 multiplexes the portions of the M RS frames 310 to 31M-1 and outputs them to the block processor 302.

For example, if one parade transmits two RS frames, the portions of primary RS frames in M RS frames 310-31M-1 are multiplexed and output, and the portions of secondary RS frames are multiplexed. Is sent.

The demultiplexer 309 and the multiplexer 320 operate according to the control signal of the controller 201. The control unit 201 may provide the necessary FEC modes to each RS frame encoder. Examples of the FEC mode include an RS code mode and the like, which will be described in detail later.

FIG. 22 is a detailed block diagram illustrating an embodiment of one RS frame encoder among a plurality of RS frame encoders in an M / H frame encoder.

One RS frame encoder may include a primary encoder 410 and a secondary encoder 420. Here, the secondary encoder 420 may or may not operate according to the RS frame mode. For example, if the RS frame mode is 00 as shown in Table 1, the secondary encoder 420 does not operate.

The primary encoder 410 may include a data randomizer 411, an RS-CRC encoder 412, and an RS frame divider 413. The secondary encoder 420 may include a data randomizer 421, an RS-CRC encoder 422, and an RS frame divider 423.

That is, the data randomizer 411 of the primary encoder 410 receives and renders the mobile service data of the primary ensemble output from the demultiplexer 309 and outputs it to the RS-CRC encoder 412. In this case, by performing the rendering on the mobile service data in the data randomizer 411, the data rendering 251 of the post processor 250 may omit the rendering process on the mobile service data. The data randomizer 411 may perform randomizing by discarding sync bytes in the mobile service data packet. Alternatively, rendering may be performed without discarding the sync byte, which is a system designer's option. According to an embodiment of the present invention, the rendering is performed without discarding the sync byte in the corresponding mobile service data packet.

The RS-CRC encoder 412 forms an RS frame corresponding to the randomized primary ensemble, and uses FEC (Reed-Solomon) and CRC (Cyclic Redundancy Check) codes in units of RS frames. Forward Error Correction) and outputs the RS frame divider 413.

That is, the RS-CRC encoder 412 configures an RS frame by collecting a plurality of randomized and input mobile service data packets, and performs at least one of an error correction encoding process and an error detection encoding process in units of RS frames. Do this. This makes it possible to cope with extremely poor and rapidly changing propagation environment by giving robustness to mobile service data and distracting clustering errors that can be caused by the propagation environment change.

In addition, the RS-CRC encoder 412 may configure a super frame by collecting a plurality of RS frames, and perform row permutation in units of super frames. The row permutation is also referred to as row interleaving, and in the present invention, it is referred to as row mixing for convenience of description. The row mixing process may be omitted.

In this case, when the RS-CRC encoder 412 mixes each row of the super frame with a predetermined rule, the positions of the rows before and after row mixing in the super frame are changed. When the row mixing is performed in the unit of the super frame, even if a large amount of error occurs in a single RS frame to be decoded, the errors are distributed in the entire super frame, so that these errors are distributed throughout the super frame. The decryption ability is improved.

In the RS-CRC coder 412, RS correction is applied to RS coding, and error detection encoding is applied to cyclic redundancy check (CRC) coding. Parity data to be used for error correction is generated when the RS encoding is performed, and CRC data to be used for error detection is generated when CRC encoding is performed.

The CRC data generated by the CRC encoding may be used to indicate whether mobile service data is damaged by an error while being transmitted through a channel. The present invention may use other error detection encoding methods in addition to CRC encoding, or may increase the overall error correction capability at the receiving end by using an error correction encoding method.

Here, the RS-CRC encoder 412 may perform RS frame configuration, RS encoding, CRC encoding, super frame configuration, row mixing in units of super frames by referring to a transmission parameter provided through the control unit 201. have.

23 (a) and 23 (b) show a process of allocating one or two RS frames into a plurality of portions according to RS frame mode values, and assigning each portion to a corresponding region in a corresponding data group. According to an embodiment of the present invention, data allocation of the data group is performed by the group formatter 303 at the rear side.

That is, FIG. 23A illustrates a case in which the RS frame mode is 00. In FIG. 22, only the primary encoder 410 operates to form one RS frame for one parade. One RS frame is divided into a plurality of portions, and the data of each portion is allocated to the A / B / C / D region in the corresponding data group.

FIG. 23B illustrates a case in which the RS frame mode is 01. In FIG. 22, both the primary encoder 410 and the secondary encoder 420 operate to operate two RS frames, that is, a primary RS frame for one parade. And a secondary RS frame. The primary RS frame is also divided into a plurality of potions, and the secondary RS frame is also divided into a plurality of potions. In this case, data of each primary RS frame portion is allocated to the A / B region in the corresponding data group, and data of each secondary RS frame portion is allocated to the C / D region in the corresponding data group.

RS  Detailed description of the frame

24A illustrates an example of an RS frame generated by the RS-CRC encoder 412 of the present invention.

The RS-CRC encoder 412 generates Nc-Kc (= P) parity bytes by performing (Nc, Kc) -RS encoding on each column when an RS frame is formed as shown in FIG. Then, you can create a column of (187 + P) bytes by adding the generated P parity bytes after the last byte of the column. Here, Kc is 187 as in FIG. 24A and Nc is 187 + P.

Here, the P value may vary depending on the RS code mode value.

Table 6 below shows an example of an RS code mode which is one of RS encoding information.

RS code mode RS code Number of parity bytes (P) 00 (211,187) 24 01 (223,187) 36 10 (235,187) 48 11 Reserved Reserved

In Table 6, 2 bits are allocated to indicate an RS code mode. The RS code mode indicates the parity number of the corresponding RS frame.

For example, if the RS code mode value is 10, 48 parity bytes are generated by performing (235,187) -RS encoding on the RS frame of FIG. 24 (a), and 48 parity bytes are stored at the end of the corresponding column. Create a column of 235 bytes after the bytes.

When the RS frame mode of Table 1 indicates 00, that is, a single RS frame, only the RS code mode for the corresponding RS frame needs to be displayed. However, when the RS frame mode of Table 1 indicates 01, that is, a plurality of separate RS frames, the RS code mode is displayed corresponding to the primary and secondary RS frames, respectively. That is, the RS code mode is preferably applied independently to the primary RS frame and the secondary RS frame.

If the RS encoding process is performed on all N columns, an RS frame having a size of N (row) x (187 + P) (column) bytes can be generated as shown in (b) of FIG. 24.

At this time, each row of the RS frame consists of N bytes. However, an error may be included in the RS frame according to the channel condition between the transmission and reception. When an error occurs in this way, it is possible to use CRC data (or CRC code or CRC checksum) to check an error for each row.

The RS-CRC encoder 412 may perform CRC encoding on the RS coded mobile service data to generate the CRC data. The CRC data generated by the CRC encoding may be used to indicate whether mobile service data is damaged by an error while being transmitted through a channel.

The present invention may use other error detection encoding methods in addition to CRC encoding, or may increase the overall error correction capability at the receiving end by using an error correction encoding method.

24 (c) shows an example of using a 2-byte (i.e. 16-bit) CRC checksum as CRC data, and after generating a 2-byte CRC checksum for N bytes of each row, an N-byte rear end is generated. It is adding. By doing this, each row is expanded to N + 2 bytes.

Equation 3 below shows an example of a polynomial that generates a 2-byte CRC checksum for each row of N bytes.

g (x) = x ¹⁶ + x ¹² + x ⁵ + 1

Since adding a 2-byte CRC checksum to each row is an embodiment, the present invention will not be limited to the example described above.

After all the RS coding and CRC coding described above, an RS frame of N × 187 bytes is extended to an RS frame of (N + 2) × (187 + P) bytes.

Looking at the error correction scenario of this extended RS frame, the bytes in the RS frame is transmitted on the channel in the row direction. At this time, if a large amount of error occurs in the limited transmission time, the error occurs in the row direction in the RS frame of the decoding process of the receiving system. However, in view of the RS code performed in the column direction, an error is distributed, and thus an effective error correction can be performed. In this case, although a parity byte (P) is increased as a method for more robust error correction, an appropriate compromise is required because it decreases the transmission efficiency. In addition, erasure decoding can be used to improve the error correction capability.

In addition, in the RS-CRC encoder 412 of the present invention, in order to further improve the error correction capability of the RS frame, row permutation may be performed in a super frame unit.

25A to 25D illustrate an embodiment of a row mixing process in units of super frames.

That is, G-frames of RS-CRC coded RS frames are collected as shown in FIG. At this time, since each RS frame is composed of (N + 2) x (187 + P) bytes, one super frame is composed of (N + 2) x (187 + P) xG bytes.

When the rows of the super frame configured as described above are mixed according to a predetermined rule, the positions of the rows before and after row mixing in the super frame are changed. That is, as shown in (b) of FIG. 25, the i-th row of the super frame before row mixing is located in the j-th row of the same super frame as shown in (c) of FIG. This relationship between i and j can be known through a row mixing rule as shown in Equation 4 below.

Even after row mixing in the super frame unit is performed, each row of the super frame is composed of N + 2 bytes.

After all the row mixing in the super frame unit is performed, the R frame divider is divided into G row mixed RS frames and provided to the RS frame divider 413 as shown in (d) of FIG. 25.

Note that the RS parity and the number of columns of each RS frame constituting one super frame must be the same.

Similar to the error correction scenario of the RS frame described above, in the case of a super frame, since a large amount of error occurs, the error frame is distributed throughout the super frame even though an error that cannot be corrected is included in one RS frame to be decoded. The decoding capability is further improved compared to the RS frame.

So far, RS frame formation and encoding process when allocating data of one RS frame to A / B / C / D area in data group when dividing one data group into A / B / C / D area Explained. That is, as an embodiment when transmitting one RS frame in one parade, in this case, the secondary encoder 420 is not operated.

Meanwhile, when transmitting two RS frames in one parade, data of the primary RS frame may be allocated to the A / B area of the data group and data of the secondary RS frame may be allocated to the C / D area of the data group. At this time, the primary encoder 410 receives the mobile service data to be allocated to the A / B area in the data group, forms a primary RS frame, and performs RS encoding and CRC encoding. The secondary encoder 420 receives the mobile service data to be allocated to the C / D region in the data group, forms a secondary RS frame, and performs RS encoding and CRC encoding. That is, encoding of the primary RS frame and the secondary RS frame is performed independently of each other.

(A) and (b) of FIG. 26 configure a primary RS frame by receiving mobile service data to be allocated to the A / B area in the data group, and collect the mobile service data to be allocated to the C / D area. Shows an example in which error correction encoding and error detection encoding are performed.

That is, (a) of FIG. 26 receives N1 (row) x mobile service data of a primary ensemble to be allocated to an A / B area within a data group from the RS-CRC encoder 412 of the primary encoder 410. An RS frame having a size of 187 (column) bytes is configured, RS coding is performed on each column of the RS frame thus configured, P1 parity data is added to each column, and CRC coding is performed on each row. An example of adding a 2-byte CRC checksum per row is shown.

FIG. 26 (b) shows N2 (row) × 187 (column) bytes of the secondary ensemble's mobile service data to be allocated to the C / D area in the data group from the RS-CRC encoder 422 of the secondary encoder 420. An RS frame having a size of? Is configured, RS coding is performed on each column of the RS frame thus configured, P2 parity data is added to each column, and CRC coding is performed on each row, thereby performing 2-byte CRC for each row. An example of adding a checksum is shown.

In this case, the RS-CRC encoders 412 and 422 refer to M / H frame information, FIC information, RS frame information (including RS frame mode), and RS encoding information (RS code mode) by referring to transmission parameters provided through the control unit 201. ), SCCC information (including SCCC block mode information, SCCC outer code mode information), data group information, area information in the data group, and the like. The transmission parameters are not only referred to for RS frame configuration, error correction encoding, and error detection encoding in each RS-CRC encoder 412 and 422, but must be transmitted to the receiving system for normal decoding in the receiving system. According to an embodiment of the present invention, the transmission parameter is transmitted to a receiving system through a transmission parameter channel (TPC). The TPC will be described in detail later.

In the RS-CRC encoder 412 of the primary encoder 410, data of a primary RS frame in which encoding in units of RS frames and row mixing in units of super frames is performed is output to the RS frame divider 413. If the secondary encoder 420 is operated, the data of the secondary RS frame in which the RS-CRC encoder 422 of the secondary encoder 420 performs the mixing of the RS frame unit and the raw mixing of the super frame unit is RS frame divider. It is output to 423.

The RS frame divider 413 of the primary encoder 410 separates the primary RS frame into a plurality of portions and outputs the same to the multiplexer 320. Each portion of the primary RS frame corresponds to the amount of data that can be transmitted by one data group. Similarly, the RS frame divider 423 of the secondary encoder 420 divides the secondary RS frame into a plurality of portions and outputs the secondary RS frame to the multiplexer 320.

The present invention will be described in detail with respect to the RS frame divider 413 of the primary encoder 410. For convenience of description, an RS frame having a size of N (row) x 187 (column) bytes is formed as shown in FIGS. 24A to 24C, and the RS frame is assigned to each column through RS encoding. Assume that P bytes of parity data are added and 2 bytes of CRC checksums are added to each row through CRC encoding.

The RS frame divider 413 then converts the encoded RS frame having a size of N + 2 (row) x 187 + P (column) bytes into a plurality of portions having a PL size, where PL is the RS frame portion length. Partition

In this case, the PL value may vary according to RS frame mode, SCCC block mode, and SCCC outer code mode as shown in Tables 2 to 5. In addition, the total number of bytes of the RS frame in which RS and CRC encoding is performed is equal to or slightly smaller than 5 x NoG x PL. In this case, the RS frame is divided into ((5 x NoG)-1) portions of PL size and one portion of PL size or smaller size. That is, the size of each portion except the last portion among the portions divided from one RS frame is equal to PL.

If the size of the last potion is smaller than PL, stuffing bytes (or dummy bytes) are inserted into the last potion by the number of insufficient bytes so that the size of the last potion is finally PL.

Each portion divided from one RS frame corresponds to an amount of data for SCCC encoding and mapping into a single data group in one parade. (Each portion of a RS frame corresponds to the amount of data to be SCCC-encoded and mapped into a single data group of a Parade).

27 (a) and 27 (b) show the last stuffing of S stuffing bytes when a RS frame of size (N + 2) x (187 + P) is divided into (5 x NoG) potions having a PL size An example is added to the drawing.

That is, RS and CRC coded RS frames as shown in FIG. 27A are divided into a plurality of portions as shown in FIG. 27B. The number of portions divided from the RS frame is (5 x NoG). And the first ((5 x NoG)-1) potions contain a PL size, but the last one potion can be less than or equal to the PL size. If the size is smaller than the PL size, the last portion may be filled by obtaining S stuffing bytes as shown in Equation 5 below to make the PL size.

S = (5 x NoG x PL)-((N + 2) x (187 + P))

Each portion including the PL size data is output to the block processor 302 via the multiplexer 320 of the M / H frame encoder 301.

The mapping order of the RS Frame Portions to a Parade of Groups is not identical in order of mapping the RS frame portions to data groups of a parade. with the Group assignment order defined in Equation 1). In other words, given the data group position of the parade within one M / H frame, the SCCC coded RS frame portions are allocated in time order (Given the Group positions of a Parade in an M / H Frame, the SCCC-encoded RS Frame Portions shall be mapped in time order).

Referring to FIG. 11, the data groups of parade # 1 (the second Parade that is allocated) are first allocated to the 13th slot (Slot # 12), and then to the third slot (Slot # 2). However, if data is placed in these allocated slots, the data is placed in chronological order from left to right. That is, the first data group of parade # 1 is placed in the third slot (Slot # 2), and the second data group of parade # 1 is placed in the 13th slot (Slot # 13).

Block handler

Meanwhile, the block processor 302 performs SCCC outer coding on the output of the M / H frame encoder 301. That is, the block processor 302 encodes the data of each portion inputted by error correction encoding at a code rate of 1 / H (where H is a natural number of 2 or more) and outputs the encoded data to the group formatter 303. The present invention encodes and outputs input data using either one of half code rate encoding (or half encoding) and one quarter code rate encoding (or quarter encoding). It is set as an Example. The data of each portion output from the M / H frame encoder 301 includes at least one of pure mobile service data, RS parity data, CRC data, and stuffing data, but broadly, they are data for mobile service. Therefore, the data of each portion will be described as all mobile service data.

The group formatter 303 inserts mobile service data, which is SCCC outer coded and output from the block processor 302, into a corresponding region in a data group formed according to a predefined rule, and also has various positions in relation to data deinterleaving. Holders or known data (or known data position holders) are also inserted into the corresponding area in the data group. The group formatter 303 then deinterleaves the data and position holders in the data group.

In the present invention, as shown in FIG. 5, the data group is composed of ten M / H blocks B1 to B10 on the basis of data interleaving, and is divided into four regions A, B, C, and D.

Further, as shown in FIG. 5, it is assumed that a data group is divided into a plurality of layered areas, and the block processor 302 may encode mobile service data to be inserted into each area at a different code rate according to the characteristics of the layered area.

For example, the mobile service data to be inserted into the A / B area in the data group is encoded by the block processor 302 at a 1/2 code rate, and the encoded mobile service data is encoded by the group formatter 303. It can be inserted into the A / B area. In addition, the mobile service data to be inserted into the C / D area of the data group is encoded by the block processor 302 at a 1/4 code rate which is higher in error correction capability than the 1/2 code rate. May be inserted into the C / D area by the group formatter 303. As another example, the mobile service data to be inserted into the C / D region is encoded by the block processor 302 at a code rate having a stronger error correction capability than that of the 1/4 code rate, and the encoded data is then grouped. The formatter 303 may be inserted into the C / D region, or may be left as a reserved region for later use.

In another embodiment, the block processor 302 may perform 1 / H encoding on a SCCC block basis. The SCCC block includes at least one M / H block.

In this case, if 1 / H encoding is performed in one M / H block unit, the M / H blocks B1 to B10 and the SCCC blocks SCB1 to SCB10 are the same (SCB1 = B1, SCB2 = B2, SCB3 = B3, SCB4 = B4, SCB5 = B5, SCB6 = B6, SCB7 = B7, SCB8 = B8, SCB9 = B9, SCB10 = B10). For example, M / H block B1 may be encoded at 1/2 code rate, M / H block B2 at 1/4 code rate, and M / H block B3 at 1/2 code rate. The same applies to the remaining M / H blocks.

Alternatively, a plurality of M / H blocks in the A, B, C, and D regions may be bundled into one SCCC block, and 1 / H encoding may be performed in units of SCCC blocks. This can improve the reception performance of the C / D domain. For example, 1/2 coding is performed by combining M / H blocks B1 to M / H blocks B5 into one SCCC block, and the mobile service data encoded as described above is converted into M / H of the data group in the group formatter 303. It is possible to insert from H block B1 to M / H block B5.

In addition, 1/4 encoding is performed by binding M / H blocks B6 to M / H block B10 with other SCCC blocks, and the mobile service data encoded in the group formatter 303 starts from M / H blocks B6 of the data group. Up to M / H block B10 can be inserted. In this case, one data group consists of two SCCC blocks.

As another embodiment, two M / H blocks may be bundled and configured as one SCCC block. For example, one SCCC (SCB1) block may be configured by combining the M / H block B1 and the M / H block B6. Similarly, tie M / H block B2 and M / H block B7 to tie another SCCC (SCB2) block, tie M / H block B3 and block B8 to another SCCC (SCB3) block, M / H block B4 and block B9 may be bundled to bind another SCCC (SCB4) block, M / H block B5, and M / H block B10 to configure another SCCC (SCB5) block. In this case, 10 M / H blocks are composed of 5 SCCC blocks. This can compensate for the reception performance of the C and D areas where the reception performance is relatively lower than that of the A area in a reception environment with a severe channel change. In addition, as the number of main service data symbols increases from the A area to the D area, this causes a performance degradation of the error correction code. As described above, the performance degradation is achieved by configuring a plurality of M / H blocks into one SCCC block. Can reduce

When 1 / H encoding is performed in the block processor 302 as described above, SCCC related information should be transmitted to the receiving system in order to correctly restore the mobile service data.

Table 7 below shows an example of an SCCC block mode showing a relationship between an M / H block and an SCCC block among SCCC related information.

SCCC Block Mode 00 01 10 11 Description One M / H Block per SCCC block Two M / H Blocks per SCCC block reserved reserved SCB SCB input, M / H Block SCB input, M / H Blocks SCB1 B1 B1 + B6 SCB2 B2 B2 + B7 SCB3 B3 B3 + B8 SCB4 B4 B4 + B9 SCB5 B5 B5 + B10 SCB6 B6 - SCB7 B7 - SCB8 B8 - SCB9 B9 - SCB10 B10 -

Table 7 according to an embodiment shows that two bits are allocated to indicate the SCCC block mode. For example, if the SCCC block mode value is 00, this indicates that the SCCC block and the M / H block are the same. In addition, if the SCCC block mode value is 01, this indicates that each SCCC block is composed of two M / H blocks.

As described above, if one data group is composed of two SCCC blocks, this information may also be displayed in SCCC block mode although not shown in Table 7. For example, when the SCCC block mode value is 10, this may indicate that each SCCC block is composed of five M / H blocks and one data group is composed of two SCCC blocks. Here, the number of M / H blocks included in the SCCC block and the position of the M / H block may be changed by the system designer, and thus, the present invention is not limited to the above embodiment, and the SCCC mode information may be extended.

Table 8 below shows an example of code rate information of the SCCC block, that is, the SCCC outer code mode among SCCC related information.

SCCC outer code mode Description 00 The outer code rate of a SCCC Block is 1/2 rate 01 The outer code rate of a SCCC Block is 1/4 rate 10 Reserved 11 Reserved

In Table 8, 2 bits are allocated to indicate the code rate information of the SCCC block. For example, if the SCCC outer code mode value is 00, the code rate of the corresponding SCCC block indicates 1/2, and if 01, 1/4 indicates.

If the SCCC block mode value of Table 7 indicates 00, the SCCC outer code mode may display a code rate of each M / H block corresponding to each M / H block. In this case, since one data group includes 10 M / H blocks and each SCCC block mode is assumed to have 2 bits, 20 bits are required to indicate the SCCC block mode for 10 M / H blocks. .

As another example, when the SCCC block mode value of Table 7 indicates 00, the SCCC outer code mode may display the code rate of each region corresponding to each region in the data group. In this case, since one data group includes four areas A, B, C, and D, and each SCCC block mode is assumed to have 2 bits, 8 bits are required to indicate the SCCC block mode for the four areas. Do.

As another example, when the SCCC block mode value of Table 7 indicates 01, the A, B, C, and D areas in the data group have the same SCCC outer code mode.

Meanwhile, Table 9 below shows an example of an SCCC output block length (SOBL) for each SCCC block when the SCCC block mode value is 00.

SCCC Block SOBL SIBL 1/2 rate 1/4 rate SCB1 (B1) 528 264 132 SCB2 (B2) 1536 768 384 SCB3 (B3) 2376 1188 594 SCB4 (B4) 2388 1194 597 SCB5 (B5) 2772 1386 693 SCB6 (B6) 2472 1236 618 SCB7 (B7) 2772 1386 693 SCB8 (B8) 2508 1254 627 SCB9 (B9) 1416 708 354 SCB10 (B10) 480 240 120

That is, if the SCCC Output Block Length (SOBL) is known for each SCCC block, the SCCC Input Block Length (SIBL) for the corresponding SCCC block is determined according to the outer code rate of each SCCC block. Can be. The SOBL is equal to the number of SCCC output (or outer encoded) bytes for each SCCC block, and the SIBL is equal to the number of SCCC or payload bytes for each SCCC block.

Table 10 below shows an example of SOBL and SIBL for each SCCC block when the SCCC block mode value is 01.

SCCC Block SOBL SIBL 1/2 rate 1/4 rate SCB1 (B1 + B6) 3000 1500 750 SCB2 (B2 + B7) 4308 2154 1077 SCB3 (B3 + B8) 4884 2442 1221 SCB4 (B4 + B9) 3804 1902 951 SCB5 (B5 + B10) 3252 1626 813

To this end, the block processor 302 uses an RS frame portion-SCCC block converter 511, a byte-bit converter 512, a convolutional encoder 513, a symbol interleaver 514, and a symbol-byte converter (Fig. 28). 515, and SCCC block-MH block converter 516.

The convolutional encoder 513 and the symbol interleaver 514 are virtually concatenated with the trellis coding module 256 to form an SCCC.The convolutional encoder 513 and the symbol interleaver 514 are virtually concatenated with the trellis encoder in the post-processor to construct the SCCC).

That is, the RS frame potion-SCCC block converter 511 uses the SIBLs of Tables 9 and 10 according to RS frame mode, SCCC block mode, and SCCC outer code mode to input a plurality of SCCC blocks. Divide. The M / H frame encoder 301 outputs a primary RS frame portion or a primary RS frame portion and a secondary RS frame portion according to the RS frame mode.

If the RS frame mode is 00, the portion of the primary RS frame is equal to the amount of data mapped to 10 M / H blocks in one data group by SCCC outer coding in the block processor 302. If the SCCC block mode is 00, the primary RS frame is divided into 10 SCCC blocks according to Table 9. If the SCCC block mode is 01, the primary RS frame portion is divided into five SCCC blocks according to Table 10. Meanwhile, if the RS frame mode is 01, the block processor 302 receives two RS frame portions. If the RS frame mode is 01, 01 is not used as the SCCC block mode value. The primary portion divided from the primary RS frame is SCCC outer coded as the SCCC blocks SCB3, SCB4, SCB5, SCB6, SCB7, and SCB8 in the block processor 302. The SCCC blocks SCB3 and SCB8 are mapped to the region B in the data group in the group formatter 303, and the SCCC blocks SCB4, SCB5, SCB6 and SCB7 are mapped to the region A. The secondary portion divided from the secondary RS frame is SCCC outer coded by the block processor 302 as SCCC blocks SCB1, SCB2, SCB9, and SCB10. The group formatter 303 maps the SCCC blocks SCB1 and SCB10 to the region D in the data group, and maps the SCCC blocks SCB2 and SCB9 to the region C. FIG.

The byte-bit converter 512 divides the mobile service data byte of each SCCC block output from the RS frame portion-SCCC block converter 511 into bits and outputs the bits to the convolutional encoder 513.

The convolutional encoder 513 performs 1/2 encoding or 1/4 encoding on the input mobile service data bit.

FIG. 29 is a detailed block diagram showing an embodiment of the convolutional encoder 513. The delay block 521 is composed of two delayers 521 and 523 and three adders 522, 524 and 525. output as ~ u4). At this time, the input data bit U is output as it is as the most significant bit u0 and is encoded and output as the lower bits u1u2u3u4.

That is, the input data bits U are output as the most significant bit u0 and output to the first and third adders 522 and 525. The first adder 522 adds the input data bit U and the output of the first delayer 521 and outputs the result to the second delayer 523. The delayed data is outputted to the lower bit u1 and fed back to the first delayer 521. The first delayer 521 delays the data fed back from the second delayer 523 by a predetermined time (for example, one clock) and outputs the lower bit u2 to the first adder 522 and the first adder 522. 2 is output to the adder 524.

The second adder 524 adds outputs of the first and second delayers 521 and 523 to output the lower bit u3. The third adder 525 adds the input data bit U and the output of the second adder 524 and outputs the least significant bit u4.

At this time, the first and second delayers 521 and 523 are reset to zero at the start of each SCCC block. The convolution encoder 513 of FIG. 29 may be used as a 1/2 encoder, or may be used as a 1/4 encoder.

That is, when some output bits of the convolutional encoder 513 of FIG. 29 are selected and outputted, they can be used as 1/2 encoder or 1/4 encoder.

Table 11 below shows an example of an output symbol of the convolution encoder 513.

Region 1/2 rate 1/4 rate SCCC Block mode = ‘00’ SCCC Block mode = ‘01’ A, B (u0, u1) (u0, u2), (u1, u4) (u0, u2), (u1, u4) C, D (u0, u1), (u3, u4)

For example, in the case of 1/2 code rate, one output symbol, i.e., u0, u1 bits, may be selected and output. In the case of the 1/4 code rate, two output symbols, that is, four bits, may be selected and output according to the SCCC block mode. For example, if the SCCC block mode is 01, selecting and outputting an output symbol of u0, u2 and an output symbol of u1, u4 results in quarter coding.

The mobile service data symbols encoded by the convolutional encoder 513 at 1/2 or 1/4 code rates are output to the symbol interleaver 514.

The symbol interleaver 514 performs block interleaving on a symbol unit basis for the output data symbols of the convolutional encoder 513. That is, symbol interleaver 514 is a type of block interleaver. The symbol interleaver 514 may be applied to any interleaver as long as the interleaver is structurally arranged in any order. According to an embodiment of the present invention, the use of a variable length symbol interleaver applicable to a case in which the lengths of symbols to be rearranged are various will be described.

30 shows an embodiment of a symbol interleaver according to the present invention, where B is 2112 and L is 4096 an example of symbol interleaving.

Here, B is a block length in symbols output from the convolutional encoder 513 for symbol interleaving, and L is a block length in symbol units actually interleaved in the symbol interleaver 514. At this time, the block length B in symbol units input to the symbol interleaver 514 is equal to 4 × SOBL. That is, since one symbol consists of 2 bits, B can be set to 4 x SOBL.

In symbol interleaving, L = 2 ^m (where m is a natural number) while satisfying the condition L ≥ B. If the values of B and L differ, a null (or null) symbol is added by the number of differences (= LB), thereby creating an interleaving pattern as shown in P '(i) of FIG.

Therefore, B is a block size of actual symbols input to the symbol interleaver 514 for interleaving, and L is an interleaving unit in which actual interleaving is performed by an interleaving pattern generated by the symbol interleaver 514.

Equation 6 below receives the B symbols to be rearranged in the symbol interleaver 514 in order, finds L = 2 ^m and satisfies the condition L? Is a mathematical expression of the process.

For all positions 0 ≤ i ≤ B-1

P '(i) = {89 x i x (i + 1) / 2} mod L

Where L ≧ B, L = 2 ^m and m is a natural number.

After rearranging the order of the B input symbols and the (LB) null symbols in units of L symbols as shown in Equation 6 and P '(i) of FIG. 30, the position of the null symbol is shown as P (i) of FIG. Remove and reorder. That is, starting with the lowest i, shift the P (i) entries to the left to fill the empty entry locations). The symbols of the aligned interleaving pattern P (i) are sequentially output to the symbol-byte converter 515.

The symbol-byte converter 515 converts the mobile service data symbols outputted after the sequence rearrangement is completed in the symbol interleaver 514 to bytes and outputs the converted bytes to the SCCC block-MH block converter 516. The SCCC block-MH block converter 516 converts the symbol interleaved SCCC block into an M / H block and outputs the result to the group formatter 303.

If the SCCC block mode is 00, the SCCC block is mapped 1: 1 to each M / H block in the data group. As another example, if the SCCC block mode is 01, the SCCC block is mapped to two corresponding M / H blocks in the data group. For example, the SCCC block SCB1 is in (B1, B6), SCB2 is in (B2, B7), SCB3 is in (B3, B8), SCB4 is in (B4, B9), and SCB5 is in (B5, B10) Is mapped to. The M / H block output from the SCCC block-MH block converter 516 is composed of mobile service data and FEC redundancy. The present invention considers not only mobile service data of M / H block but also FEC redundancy as mobile service data.

group Formatter

The group formatter 303 inserts data of the M / H block output from the block processor 302 into a corresponding M / H block in a data group formed according to a predefined rule, and also relates to data deinterleaving. Various position holders or known data (or known data position holders) are also inserted into the corresponding area in the data group.

That is, in the group formatter 303, in addition to the encoded mobile service data output from the block processor 302, an MPEG header position holder, an unstructured RS parity position holder, Insert the main service data location holder into the corresponding area of the data group. The reason for inserting the main service data location holder is that the mobile service data and the main service data are intermingled in the areas B to D based on the data interleaving as shown in FIG. 5. As an example, the position holder for the MPEG header may be assigned to the front of each packet based on the output data after the data deinterleaving. It is also possible to insert dummy bytes to construct the intended group format. In addition, the group formatter 303 inserts a position holder for initializing the trellis encoding module 256 into the corresponding region. In one embodiment, the initialization data location holder may be inserted before the known data stream.

The group formatter 303 may also insert signaling information encoded and output by the signaling encoder 304 into a corresponding region of the data group.

In this case, the signaling information may be referenced when inserting each data and position holder into the data group in the group formatter 303. Encoding of the signaling information and insertion into the data group will be described later in detail.

The group formatter 303 inserts various data and position holders into a corresponding region of the data group, and then deinterleaves the data and position holders in the data group in a reverse process of data interleaving and outputs the data to the packet formatter 305. That is, when the data and position holder in the data group configured as shown in FIG. 5 are deinterleaved by the group formatter 303, the data group output to the packet formatter 305 has the structure as shown in FIG. 7. To this end, the group formatter 303 may include a group format organizer 527 and a data deinterleaver 529 as shown in FIG. 31. The group format forming unit 527 inserts data and position holders into the corresponding regions in the data group as described above, and the data deinterleaver 529 deinterleaves the data and position holders in the data group in a reverse process of data interleaving. .

The packet formatter 305 removes the main service data location holder and the RS parity location holder which have been allocated for deinterleaving among the deinterleaved input data, collects the remaining parts, and then collects null packets in the 3-byte MPEG header location holder. Insert an MPEG header with a PID (or a PID not used in the main service data packet). A sync byte is added at the beginning of each 187 byte data packet.

Also, the packet formatter 305 may insert actual known data into the known data position holder when the group formatter 303 inserts the known data position holder, or later inserts the known data position holder for replacement insertion. You can output as is without adjustment.

Then, the packet formatter 305 divides the data in the packet-formatted data group into mobile service data packets (ie, MPEG TS packets) in units of 188 bytes and provides them to the packet multiplexer 240.

The packet multiplexer 240 multiplexes the data group output from the packet formatter 305 and the main service data packet output from the packet jitter reducer 220 under the control of the control unit 201. The data is output to the data renderer 251 of (Post-Processor) 250. That is, the controller 201 controls the time multiplexing of the packet multiplexer 240. If the packet multiplexer 240 receives 118 mobile service data packets from the packet formatter 305, 37 of the 118 mobile service data packets are placed before the VSB field sync insertion position, and another A 81 mobile service data packet is placed after the VSB field sync insertion position. The multiplexing method can be adjusted by various variables of the system design. The multiplexing method and multiplexing rule in the packet multiplexer 240 will be described in detail later.

In the packet multiplexing process, since a data group including mobile service data is multiplexed (or allocated) between main service data, the temporal position of the main service data packet is relatively moved. However, the system target decoder (i.e., MPEG decoder) for main service data processing of the receiving system receives and decodes only main service data and recognizes the mobile service data packet as a null data packet.

Therefore, when the system target decoder of the receiving system receives the main service data packet multiplexed with the data group, packet jitter occurs.

In this case, since there are various buffers for the video data in the system target decoder and the size thereof is quite large, the packet jitter generated by the packet multiplexer 240 is not a big problem in the case of video data. However, the size of the buffer for audio data in the system target decoder can be problematic.

That is, the packet jitter may cause overflow or underflow in a buffer for main service data of the receiving system, for example, a buffer for audio data.

Accordingly, the packet jitter reducer 220 readjusts the relative position of the main service data packet so that no overflow or underflow occurs in the buffer of the system target decoder.

The present invention describes embodiments of relocating the audio data packet of the main service data in order to minimize the influence on the operation of the audio buffer. The packet jitter reducer 220 rearranges the audio data packets in the main service data section so that the audio data packets of the main service are as uniform as possible.

In addition, when the location of the main service data packet is relatively readjusted, the PCR value must be corrected accordingly. The PCR value is a time reference value to match the time of the MPEG decoder and is inserted into a specific area of the TS packet and transmitted. In one embodiment, the packet jitter reducer 220 also performs PCR value correction.

The output of the packet jitter reducer 220 is input to the packet multiplexer 240. The packet multiplexer 240 multiplexes the main service data packet output from the packet jitter reducer 220 and the mobile service data packet output from the preprocessor 230 according to a preset multiplexing rule as described above. The data is output to the data randomizer 251 of 250.

If the input data is a main service data packet, the data randomizer 251 performs rendering in the same way as the existing renderer. That is, the sync byte in the main service data packet is discarded and the remaining 187 bytes are randomly generated using pseudo random bytes generated therein, and then output to the RS encoder / unstructured RS encoder 252.

However, if the input data is a mobile service data packet, only a part of the packet may be rendered. For example, assuming that the preprocessor 230 has previously performed rendering on mobile service data, the data renderer 251 may select a sync byte of a 4-byte MPEG header included in the mobile service data packet. Discard it and perform rendering for only the remaining 3 bytes to output to the RS encoder / unstructured RS encoder 252. That is, the rest of the mobile service data except the MPEG header is output to the RS encoder / unstructured RS encoder 252 without performing rendering. The data randomizer 251 may or may not perform the randomization of the known data (or known data location holder) and the initialization data location holder included in the mobile service data packet.

The RS encoder / unstructured RS encoder 252 adds 20 bytes of RS parity by performing RS encoding on the data to be rendered or bypassed by the data randomizer 251, and then the data interleaver 253. Will output In this case, the RS encoder / unstructured RS encoder 252 adds 20 bytes of RS parity to 187 bytes of data after performing systematic RS encoding in the same manner as the existing broadcasting system when the input data is a main service data packet. In case of a mobile service data packet, unsystematic RS coding is performed, and the 20-byte RS parity obtained at this time is inserted at a predetermined parity byte position in the packet.

The data interleaver 253 is a convolutional interleaver in bytes.

The output of the data interleaver 253 is input to a parity substituent 254 and an unstructured RS encoder 255.

On the other hand, in order to make the output data of the trellis encoder 256 located at the rear end of the parity substituter 254 into known data defined by appointment on the transmitting / receiving side, the memory in the trellis encoder 256 is first initialized. Is needed. That is, before the input known data string is trellis encoded, the memory of the trellis encoder 256 must be initialized.

At this time, the start of the known data stream is not the actual known data but the initialization data position holder inserted by the group formatter in the preprocessor 230. Therefore, a process of generating initialization data immediately before the input known data string is trellis encoded and replacing the corresponding trellis memory initialization data position holder is required.

The trellis memory initialization data is generated by determining a value thereof according to the memory state of the trellis encoder 256. In addition, a process of recalculating RS parity under the influence of the replaced initialization data and replacing the RS parity with the RS parity output from the data interleaver 253 is necessary.

Accordingly, the unstructured RS encoder 255 receives a mobile service data packet including an initialization data position holder to be replaced with initialization data from the data interleaver 253 and inputs initialization data from the trellis encoder 256. Receive. The initialization data position holder of the input mobile service data packet is replaced with the initialization data, and the RS parity data added to the mobile service data packet is removed, and then unstructured RS encoding is performed. The RS parity obtained by the unsystematic RS coding is output to the parity substituent 255. Then, the parity substituent 255 selects the output of the data interleaver 253 for the data in the mobile service data packet, and selects the output of the unstructured RS encoder 255 for the RS parity. Will output

Meanwhile, when the main service data packet is input or the mobile service data packet including the initialization data location holder to be replaced is input, the parity substituter 254 selects data and RS parity output from the data interleaver 253 as it is. The trellis encoder 256 outputs the trellis encoder.

The trellis encoder 256 converts the data of the byte unit output from the parity substituent 254 into symbol units, performs 12-way interleaving, trellis-codes, and outputs the trellis to the synchronous multiplexer 260.

32 is a detailed diagram of one trellis encoder out of twelve trellis encoders in the trellis encoder 256. FIG. The trellis coder may include two multiplexers 531, 541, two adders 532, 543, and three memories 533, 542, 544.

That is, the first to third memories 533, 542, and 544 are initialized by trellis initialization data inserted into the initialization data position holder by the parity substituent 254. In other words, when the first two symbols (i.e., 4 bits) converted from each trellis initialization data byte are input, the input bits of the trellis encoder are rewritten by the memory values of the trellis encoder as shown in FIG. (More specifically, when the first two 2-bit symbols converted from each trellis initialization byte are inputted, the input bits of the trellis encoder shall be replaced by the memory values of the trellis encoder, as shown in Figure 28).

And since two symbols (i.e. 4 bits) are required for trellis initialization, the last two symbols of trellis initialization data bytes are not used for trellis initialization and are treated as symbols of known data bytes ( Since 2 symbols (4 bits) are required for trellis initialization, the last 2 symbols (4 bits) from trellis initialization bytes are not used for trellis initialization and are treated like a symbol from a known data byte).

When the trellis encoder of FIG. 32 is in initialization mode, the input of the trellis encoder is in the internal trellis state instead of the output of the parity substituent 254. internal trellis state instead of from the parity replacer 254). When the trellis encoder is in the normal mode, the input symbol from the parity replacer 254 shall be processed. The trellis encoder provides the modified input data for trellis initialization to the non-systematic RS encoder 255 for trellis initialization.

That is, the first multiplexer 531 selects the upper bit X2 of the input symbol when the selection signal indicates the normal mode, and outputs the first memory 533 when the initialization signal indicates the initialization mode. Is selected and output to the first adder 532. The first adder 532 adds the output of the first multiplexer 531 and the output of the first memory 533 to the first memory 533 and outputs the most significant bit Z2. The first memory 533 delays the output data of the first adder 532 by one clock and then outputs the same to the first multiplexer 531 and the first adder 532. On the other hand, the second multiplexer 541 selects the lower bit X1 of the input symbol when the selection signal indicates the normal mode, and outputs the output of the second memory 542 when the selection signal indicates the initialization mode. It selects and outputs to the second adder 543 and to the lower bit Z1. The second adder 543 adds the output of the second multiplexer 541 and the output of the second memory 542 and outputs the output to the third memory 544. The third memory 544 delays the output of the second adder 543 by one clock, outputs the result to the second memory 542, and outputs the least significant bit Z0. The second memory 542 delays the output of the third memory 544 by one clock and outputs the result to the second adder 543 and the second multiplexer 541.

The synchronous multiplexer 260 inserts field sync and segment sync into the output of the trellis encoder 256 and outputs the field sync and segment sync to the pilot inserter 271 of the transmitter 270.

Data in which the pilot is inserted in the pilot inserter 271 is modulated by a modulator 272, for example, a VSB method, and then transmitted to each receiving system through the RF up converter 273.

Multiplexing Method of Packet Multiplexer 240

That is, the data of the error correction encoding and 1 / H coded primary RS frame (ie, RS frame mode is 00) or primary / secondary RS frame (ie, RS frame mode is 01) is plural in the group formatter 303. It is divided into three data groups and allocated to at least one of the areas A to D of each data group, or assigned to at least one M / H block of the M / H blocks B1 to B10 and deinterleaved. The deinterleaved data group is multiplexed according to a predetermined multiplexing rule with the main service data in the packet multiplexer 240 via the packet formatter 305.

The packet multiplexer 240 multiplexes and outputs a plurality of consecutive data groups as far as possible from each other in a subframe. For example, assuming that three data groups are multiplexed and transmitted in one subframe, the three data groups include the first slot (Slot # 0), the fifth slot (Slot # 4), and the ninth in the subframe. Slots # 8 are sequentially assigned and output.

Like the data group allocation, the parades are output as multiplexed as far as possible from each other in the subframe. The method of allocating the data group and the parades may be differently applied to each M / H frame based on the M / H frame, and the same may be applied to all subframes in one M / H frame.

FIG. 10 shows an embodiment when the packet multiplexer 240 allocates a single parade having the number of data groups included in one subframe to one M / H frame. Referring to FIG. 10, if three data groups are sequentially allocated to one subframe in four slot periods, and this process is performed for five subframes in the corresponding M / H frame, 15 data in one M / H frame You can see that a data group is assigned. The 15 data groups are data groups included in one parade.

When data groups for one parade are allocated to M / H frames as shown in FIG. 10, the packet multiplexer 240 may allocate main service data between the data group and the data group, and data of another parade. You can also assign groups. That is, the packet multiplexer 240 may allocate data groups for a plurality of parades in one M / H frame.

Basically, the method of assigning data groups for multiple parades is also no different from that of a single parade. That is, the packet multiplexer 240 also allocates data groups in another parade allocated to one M / H frame in four slot periods.

In this case, the data group of another parade may be allocated in a circular manner from a slot to which the data group of the previous parade is not allocated.

For example, assuming that data group allocation for one parade is performed as shown in FIG. 10, the data group for the next parade may be allocated from the 12th slot in one subframe.

FIG. 11 shows an example of allocating three parades (Parade # 0, Parade # 1, Parade # 2) to one M / H frame in the packet multiplexer 240 and transmitting the same.

For example, assuming that the first parade (Parade # 0) includes three groups of data per subframe, the packet multiplexer 240 substitutes 0 to 2 for the i value of Equation 1 to allow the user to enter the subframe. The location of the data groups can be found. That is, data groups of the first parade are sequentially allocated to the first, fifth, and ninth slots (Slot # 0, Slot # 4, Slot # 8) in the subframe and output.

If a second parade (Parade # 1) includes two data groups per subframe, the packet multiplexer 240 assigns 3 to 4 to the i value of Equation 1 to locate the data groups in the subframe. Can be obtained. That is, data groups of the second parade are sequentially allocated to the second and twelfth slots (Slot # 1, Slot # 11) in the subframe and output.

In addition, if the third parade (Parade # 2) includes two groups per subframe, the packet multiplexer 240 substitutes 5 to 6 for the i value of Equation 1 to locate the data groups in the subframe. Can be obtained. That is, data groups of the third parade are sequentially allocated to the seventh and eleventh slots (Slot # 6, Slot # 10) in the subframe and output.

As such, the packet multiplexer 240 may multiplex and output data groups for a plurality of parades in one M / H frame, and the multiplexing of data groups in one subframe has a group space of 4 slots and is left. To the right from the serial. Therefore, the number of groups of one parade per a sub-frame (NOG) that can be multiplexed into one subframe may be any one of integers from 1 to 8. Since one M / H frame includes five subframes, this means that the number of data groups of one parade that can be multiplexed into one M / H frame may be any one of multiples of 5 to 40. Means that you can.

Signaling  Information processing

According to an embodiment of the present invention, a signaling information area for inserting signaling information is allocated to some areas in each data group.

33 shows an example in which a signaling information area for inserting signaling information is allocated from a first segment to a part of a second segment of an M / H block B4 in a data group. That is, 276 (= 207 + 69) bytes of the M / H block B4 of each data group are allocated as an area for inserting signaling information. In other words, the signaling information area is composed of 207 bytes, which is the first segment of M / H block B4, and the first 69 bytes of the second segment. For example, the first segment of the M / H block B4 corresponds to the 17th or 173th segment of the VSB field.

The signaling information to be inserted into the signaling information region is FEC coded by the signaling encoder 304 and input to the group formatter 303. The signaling information may include a transmission parameter inserted into the payload region of the OM packet and received by the demultiplexer 210.

The group formatter 303 inserts signaling information, which is FEC coded and output by the signaling encoder 304, into a signaling information region of a data group.

The signaling information can be largely divided into two types of signaling channels. One is a Transmission Parameter Channel (TPC) and the other is a Fast Information Channel (FIC).

The TPC data is signaling information including transmission parameters such as RS frame information, RS coding information, FIC information, data group information, SCCC information, M / H frame information, and the like. The TPC data is only an embodiment for better understanding of the present invention, and the present invention will not be limited to the above embodiment since addition and deletion of signaling information included in the TPC can be easily changed by those skilled in the art.

The FIC data is provided to enable fast service acquisition in a receiver, and includes cross layer information between a physical layer and a higher layer.The FIC is provided to enable the fast service acquisition of receivers and it contains cross layer information between the physical layer and the upper layer (s)).

34 is a detailed block diagram of one embodiment of a signaling encoder 304.

The signaling encoder 304 includes a TPC encoder 561, an FIC encoder 562, a block interleaver 563, a multiplexer 564, a signaling randomizer 565, and an iterative turbo encoder 566. ) May be included.

The TPC encoder 561 receives 10 bytes of TPC data and performs (18,10) -RS encoding to add 8 bytes of parity data to the 10 bytes of TPC data. The RS-coded 18 bytes of TPC data is output to multiplexer 564.

The FIC encoder 562 receives 37 bytes of FIC data and performs (51,37) -RS encoding to add 14 bytes of parity data to 37 bytes of FIC data. The RS-encoded 51-byte FIC data is input to the block interleaver 563 and interleaved in predetermined block units. For example, the block interleaver 563 is a variable length block interleaver, and interleaves FIC data in each subframe input by RS coding in units of TNoG (column) x 51 (row) blocks and outputs the result to the multiplexer 564. do. Here, the TNoG is the number of all data groups allocated to one subframe. The block interleaver 563 is synchronized to the first FIC data of each subframe.

The block interleaver 563 writes an RS codeword of 51 bytes from left to right, top to bottom in row units, and reads from top to bottom in columns and from left to right in units of 51 bytes (The Block interleaver shall write the incoming RS codewords of 51 bytes row-by-row from left to right and top-to-bottom and shall output the data in units of 51 bytes by reading column by column from top-to-bottom and left-to-right ).

The multiplexer 564 multiplexes the TPC data encoded by the TPC encoder 561 with the FIC data block interleaved by the block interleaver 563 on a time axis, and signals the multiplexed 69 bytes of data by the randomization signal 565. Will output

The signaling randomizer 565 randomizes the multiplexed data and outputs the same to the recursive turbo coder 566. The signaling randomizer 565 may use the generated polynomial of the randomizer for mobile service data as it is. Initialization also occurs in every data group (occur).

The recursive turbo coder 566 is an inner coder that performs recursive turbo coding on randomized data, that is, signaling information data, using the PCCC scheme. The recursive turbo encoder 566 may be composed of six even component encoders and six odd component encoders.

FIG. 35 is a diagram illustrating an embodiment of a syntax structure of TPC data input to the TPC encoder 561. The TPC data is inserted into the signaling information area of each data group and transmitted.

The TPC data includes Sub-Frame_number field, Slot_number field, Parade_id field, starting_Group_number (SGN) field, number_of_Group (NoG) field, Parade_repetition_cycle (PRC) field, RS_Frame_mode field, RS_code_mode_primary field, RS_code_mode_secondary field, SCCC_Block_mode field, SC_CC__lock_mode field, SC_CC__lock_mode field It may include a SCCC_outer_code_mode_C field, a SCCC_outer_code_mode_D field, a FIC_version field, a Parade_continuity_counter field, a TNoG field, and the like.

The Sub-frame_number field indicates the number of current subframes in the corresponding M / H frame and is transmitted for M / H frame synchronization. The Sub-Frame_number field shall be the current Sub-Frame number within the M / H Frame, which is transmitted for M / H Frame synchronization.Its value shall range from 0 to 4).

The Slot_number field indicates the number of current slots in a corresponding subframe and is transmitted for M / H frame synchronization. The Slot_number field value may have a value between 0 and 15 (The Slot_number field is the current Slot number within the Sub-Frame, which is transmitted for M / H Frame synchronization. Its value shall range from 0 to 15).

The Parade_id field indicates an identifier for identifying a parade to which the corresponding data group belongs. The Parade_id field value may be represented by 7 bits. The Parade_id field identifies the Parade to which this Group belongs.The value of this field may be any 7-bit value. Each Parade in a M / H transmission shall have a unique Parade_id). Communication of the Parade_id between the physical layer and the upper layer is made by Ensemble_id formed by adding 1 bit to the left of the Parade_id (Communication of the Parade_id between the physical layer and the management layer shall be by means of an Ensemble_id formed by adding one bit to the left of the Parade_id). Ensemble_id for identifying the primary ensemble transmitted through the parade may be formed by displaying 0 in the added MSB, and Ensemble_id for distinguishing the secondary ensemble may be formed by displaying 1 in the added MSB. the Ensemble_id is for the primary Ensemble delivered through this Parade, the added MSB shall be '0'.Otherwise, if it is for the secondary Ensemble, the added MSB shall be' 1 ').

The starting_Group_number (SGN) field shall be the first Slot_number for a Parade to which this Group belongs, as determined by Equation 1 (after the Slot numbers For all preceding Parades have been calculated).) The SGN and NoG fields are used to obtain a slot number assigned to one parade in the corresponding subframe by applying Equation 1.

The number_of_Groups (NoG) field shall be the number of Groups in a Sub-Frame assigned to the Parade to which this Group belongs, minus 1, eg, NoG = 0 implies that one Group is allocated to this Parade in a Sub-Frame). The NoG field value may have a value between 0 and 7. Slot numbers assigned to the corresponding parade may be calculated from SGN and NoG using Equation 1.

The PRC field indicates a repetition period of a parade transmitted in M / H frame units as shown in Table 12 below. (The Parade_repetition_cycle (PRC) field shall be the cycle time over which the Parade is transmitted, minus 1, specified in units of M / H Frames, as described in Table 12).

PRC Description 000 This Parade shall be transmitted once every M / H Frame. 001 This Parade shall be transmitted once every 2 M / H Frames. 010 This Parade shall be transmitted once every 3 M / H Frames. 011 This Parade shall be transmitted once every 4 M / H Frames. 100 This Parade shall be transmitted once every 5 M / H Frames. 101 This Parade shall be transmitted once every 6 M / H Frames. 110 This Parade shall be transmitted once every 7 M / H Frames. 111 Reserved

For example, if the PRC field value is 001, the parade indicates that transmission is performed once every 2 M / H frames.

The RS_Frame_mode field indicates whether one RS frame or two RS frames are transmitted in one parade, and is defined as shown in Table 1 below.

The RS_code_mode_primary field indicates an RS code mode for a primary RS frame and may be defined as shown in Table 6.

The RS_code_mode_secondary field indicates an RS code mode for a secondary RS frame and may be defined as shown in Table 6.

The SCCC_Block_mode indicates how M / H blocks in the data group are allocated to the SCCC block and may be defined as shown in Table 7.

The SCCC_outer_code_mode_A field indicates the SCCC outer code mode for the area A in the data group and may be defined as shown in Table 8.

The SCCC_outer_code_mode_B field indicates the SCCC outer code mode for the area B in the data group.

The SCCC_outer_code_mode_C field indicates the SCCC outer code mode for the area C in the data group.

The SCCC_outer_code_mode_D field indicates the SCCC outer code mode for the area D in the data group.

The FIC_version field indicates a version of FIC data.

The Parade_continuity_counter field increases from 0 to 15, and increases by 1 for each (PRC + 1) M / H frame. For example, if PRC = 011, the Parade_continuity_counter field is incremented every fourth M / H frame.

The TNoG field indicates the number of all data groups allocated in one subframe.

The information included in the TPC data is only an embodiment for better understanding of the present invention, and the present invention is not limited to the above embodiments because addition and deletion of the information included in the TPC data can be easily changed by those skilled in the art. Will not.

At this time, the TPC data for each parade (except for the Sub-Frame_number field and the Slot_number field) does not change their values during one M / H frame. The same information is repeatedly transmitted through all data groups in the parade for one M / H frame. By doing so, reception of TPC data is extremely robust, and reception performance can be improved. Since the Sub-Frame_number field and the Slot_number field values are incremented counter values, the fields are robust due to transmission of values that are regularly expected (Since the TPC parameters (except Sub-Frame_number and Slot_number) for each Parade do not change their values during an M / H Frame, the same information is transmitted repeatedly through all M / H Groups belonging to that Parade during an M / H Frame.This allows very robust and reliable reception of the TPC data.Because the Sub- Frame_number and the Slot_number are increasing counter values, they also are robust due to the transmission of regularly expected values).

The FIC data transmits cross layer information for fast mobile service acquisition. The FIC data may include channel combining information between the ensemble and the mobile service.

36 is a diagram illustrating an example of a transmission scenario of TPC data and FIC data. The Sub-Frame_number, Slot_number, Parade_id, Parade_repetition_cycle, and Parade_continuity_counter information of FIG. 35 have their values corresponding to the current M / H frame through five subframes within a specific M / H frame (Sub-Frame_number, Slot_number, Parade_id , Parade_repetition_cycle, and Parade_continuity_counter shall have their values corresponding to the current M / H Frame throughout the 5 Sub-Frames within a particular M / H Frame). Some of the TPC parameters and FIC data are signaled in advance.

The SGN, NoG, and all FEC modes have values corresponding to the current M / H frame in the first two subframes. The SGN, NoG, and all FEC modes have values corresponding to the M / H frame in which the next parade appears in the third, fourth, and fifth subframes of the current M / H frame. By doing so, the receiver can obtain reliable transmission parameters in advance (SGN, NoG and all FEC modes shall have values corresponding to the current M / H Frame in the first two Sub-Frames.SGN, NoG and all FEC modes shall have values corresponding to the Frame in which the Parade next appears throughout the 3 ^rd , 4 ^th and 5 ^th Sub-Frames of the current M / H Frame. This enables the M / H receivers to get the transmission parameters in advance very reliably.).

For example, if Parade_repetition_cycle = '000', the values of the third, fourth, and fifth subframes of the current M / H frame correspond to the next M / H frame. If Parade_repetition_cycle = '011', the values of the third, fourth, and fifth subframes of the current M / H frame correspond to the fourth and subsequent M / H frames.

The FIC_version and FIC_data have a value applied to the current M / H frame during the first and second subframes of the current M / H frame. The FIC_version and FIC_data have a value applied to the next M / H frame during the 3rd, 4th, and 5th subframes of the current M / H frame (FIC_version and FIC_data shall have values that apply to the current M / H Frame during the 1 ^st Sub-Frame and the 2 ^nd Sub-Frame, and they shall have value s corresponding to the immediately following M / H Frame during the 3 ^rd , 4 ^th and 5 ^th Sub-Frames of the current M / H Frame.).

On the other hand, the receiving system can reduce power consumption of the receiving system by turning on the power only in a section to which a data group of a desired parade is allocated to receive data and turning off the power in other sections. This feature is particularly useful in portable receivers that require low power consumption. For example, assume that data groups of the first parade with NOG 3, the second parade with NOG 2, and the third parade with NOG 2 are allocated to one M / H frame as shown in FIG. 37. In addition, it is assumed that the user selects the mobile service included in the first parade through a remote controller or a keypad provided in the terminal. In this case, the power consumption can be reduced by turning on the power in the slot to which the data group of the first parade is allocated and turning off the power in the remaining slots as shown in FIG. 37. In this case, the actual data group to be received needs to be powered on a little earlier than the allocated slot so that the tuner or demodulator converges in advance.

Known data ( known data or training signal Zone allocation

The transmission system inserts a long, regular length of training sequence into each data group. In one embodiment, each data group includes six training sequences. The training sequences are specified before trellis coding. The training sequence is trellis coded, and the trellis coded sequences become known data sequences. This is because the memories of the trellis encoder are initialized according to the values set at the beginning of each sequence. 38 shows an example of inserting six training sequences at the byte level before trellis coding. 38 is an example of the arrangement of training sequences performed in the group formatter 303.

The first training sequence is inserted into the last two segments of M / H block B3. The second training sequence is inserted into the second and third segments of the M / H block B4. The second training sequence is next to the signaling information region as shown in FIG. 5. The third to sixth training sequences are inserted into the last two segments of the M / H blocks B4, B5, B6 and B7, respectively.

As in FIG. 38, the first, third to sixth training sequences are spaced 16 segments apart. In FIG. 38, a dotted area indicates a trellis data byte, and a lined area indicates a training data byte. And the white area indicates other data, such as FEC encoded mobile service data bytes or dummy data bytes.

39 shows an example of inserting training sequences at a symbol level after trellis coding by a trellis encoder. In FIG. 39, a dotted area indicates a segment sync symbol, and a lined area indicates training data symbols. And the white area is for FEC coded mobile service data symbols, FEC coded signaling data symbols, main service data symbols, RS parity data symbols, dummy data symbols, trellis initialization symbols and / or initial training sequence. Indicates other data symbols, such as data symbols.

After the trellis coding, the last 1416 (= 588 + 828) symbols of the first, third, fourth, fifth, and sixth training sequences may normally have the same data pattern.

The second training sequence may have a first 528-symbol sequence and a second 528-symbol sequence, the two sequences being the same pattern. That is, the 528-symbol sequence is repeated after the 4-symbol data segment sync signal. And at the end of each training sequence, the memory values of the 12 trellis encoders are reset to zero.

Receiving system

40 is a block diagram illustrating a receiving system according to an embodiment of the present invention.

The receiving system of FIG. 40 includes a tuner 1301, a demodulator 1302, a demultiplexer 1303, a program table buffer 1304, a program table decoder 1305, a program table storage 1306, and a data handler. 1307, middleware engine 1308, A / V decoder 1311, A / V post processor 1310, application manager 1313, and user interface 1314. The application manager 1313 may include a channel manager 1312 and a service manager 1313.

In FIG. 40, the flow of data is indicated by a solid line, and the flow of control is indicated by a dotted line.

The tuner 1301 tunes the frequency of a specific channel through any one of an antenna, a cable, and a satellite to down-convert to an intermediate frequency (IF) signal and outputs the demodulator 1302. At this time, the tuner 1301 is controlled by the channel manager 1312 in the application manager 1313 and also reports the result and strength of the broadcast signal of the channel being tuned to the channel manager 1312. . The data received at the frequency of the specific channel includes main service data, mobile service data, program table information data for decoding of the main service data and mobile service data, and transmission parameters.

The demodulator 1302 performs VSB demodulation, channel equalization, etc. on the signal output from the tuner 1301, and outputs the main service data and the mobile service data. The demodulator 1302 will be described in detail later.

 Meanwhile, the transmitter may insert and transmit signaling information (or TPC information) including a transmission parameter in at least one of the signaling information area, the field synchronization area, the known data area, and the mobile service data area. Accordingly, the demodulator 1302 can extract a transmission parameter from at least one of a signaling information area, a field synchronization area, a known data area, and a mobile service data area.

The transmission parameters include M / H frame information, subframe information, slot information, parade related information (for example, parade ID, parade repetition period, etc.), data group information in subframe, RS frame mode information, RS code mode information, SCCC block information, SCCC outer code mode information, FIC version information, and the like may be included.

The demodulator 1302 performs block decoding, RS frame decoding, etc. using the extracted transmission parameters. For example, referring to SCCC related information (eg, SCCC block information, SCCC outer code mode) in a transmission parameter, block decoding of each area in the data group is performed, and RS related information (eg, RS code mode). RS frame decoding of each region in the data group is performed with reference to.

In the present invention, an RS frame including the mobile service data demodulated by the demodulator 1302 is input to the demultiplexer 1303 according to an embodiment.

That is, the data input to the demultiplexer 1303 is in the form of RS frame data as shown in FIGS. 17A and 17B. In other words, the RS frame decoder in the demodulator 1302 performs an inverse process in the RS frame encoder of the transmission system, corrects errors in the RS frame, and outputs the errors in the RS. When de-rendering is performed in the reverse process of the transmission system with respect to an error-corrected RS frame in the data derandomizer, an RS frame such as (a) or (b) of FIG. 17 is obtained.

The demultiplexer 1303 may receive RS frames of all parades or may receive only RS frames of a parade including a mobile service desired to be received by power control. For example, if the demultiplexer 1303 receives the RS frames of all parades, the demultiplexer 1303 may demultiplex a parade including a mobile service to be received using parade_id.

In addition, since one parade transmits one or two RS frames and one ensemble is mapped to one RS frame, the demultiplexer 1303 may receive a mobile service if one parade transmits two RS frames. It is necessary to distinguish an RS frame for transmitting an ensemble including mobile service data to be decoded from a parade including a. That is, the demultiplexer 1303 selects one of the inputted parade or a plurality of parade if the demultiplexed parade transmits the primary ensemble and the secondary ensemble.

In one embodiment, the demultiplexer 1303 may demultiplex an RS frame that transmits an ensemble including mobile service data to be decoded by using an ensemble_id created by adding one bit to the left side of the parade_id.

The demultiplexer 1303 refers to the M / H header of the M / H service data packet in the RS frame corresponding to the ensemble containing the mobile service data to be decoded, and determines whether the corresponding M / H service data packet is program table information. It can be identified whether it is an IP datagram of service data. Alternatively, if both the program table information and the mobile service data are in the form of IP datagrams, the IP datagrams of the program table information and the mobile service data may be distinguished using an IP address.

In this case, the divided program table information is output to the program table buffer 1304. The audio / video / data streams are separated from the IP datagrams of the mobile service data to be received among the separated IP datagrams of the mobile service data and output to the A / V decoder 1309 and / or the data handler 1307, respectively. .

At this time, the demultiplexer 1303 indicates that the stuff_indicator field in the M / H header of the M / H service data packet indicates that a stuffing byte is inserted into the payload of the corresponding M / H service data packet. According to an embodiment of the present invention, after removing the stuffing byte from the payload of the packet, program table information and mobile service data are distinguished, and A / V / D is classified from the separated mobile service data.

The program table buffer 1304 temporarily stores program table information in a section form and outputs the program table decoder 1305 to the program table decoder 1305.

The program table decoder 1305 classifies the tables using the table id and the section length in the program table information. The program table decoder 1305 parses the sections of the divided tables and databases the parsing results in the program table storage unit 1306. As an example, the program table decoder 1305 collects sections having the same table identifier (table_id), constructs a table, parses the database, and stores the parsing result in the program table storage unit 1306.

The A / V decoder 1309 decodes the audio and video streams output from the demultiplexer 1303 through respective decoding algorithms, and outputs the decoded audio and video streams to the A / V postprocessor 1310. For example, the audio decoding algorithm may include an AC-3 decoding algorithm, an MPEG 2 audio decoding algorithm, an MPEG 4 audio decoding algorithm, an AAC decoding algorithm, an AAC + decoding algorithm, an HE AAC decoding algorithm, an AAC SBR decoding algorithm, an MPEG surround decoding algorithm, and a BSAC decoding. At least one of the algorithm may be applied, and the video decoding algorithm may apply at least one of the MPEG 2 video decoding algorithm, the MPEG 4 video decoding algorithm, the H.264 decoding algorithm, the SVC decoding algorithm, and the VC-1 decoding algorithm.

The data handler 1307 processes the data stream packets necessary for data broadcasting among the data stream packets separated by the demultiplexer 1303 and then mixes the A / V data through the middleware engine 1308. In an embodiment, the middleware engine 1308 is a JAVA middleware engine.

The application manager 1311 receives a key input of a TV viewer through a user interface (UI) and responds to a viewer's request with a graphical user interface (GUI) on a TV screen. It also saves and restores the GUI control, user requests and TV system state of the entire TV in memory (e.g. NVRAM or Flash). In addition, the application manager 1311 may control the demultiplexer 1303 to receive parade-related information, for example, parade_id from the demodulator 1302, and select an RS frame of a parade in which a required mobile service exists. In addition, the demultiplexer 1303 may be controlled to receive an ensemble_id and select an RS frame of an ensemble including mobile service data to be decoded from the parade. The channel manager 1312 is controlled to perform channel related operations (channel MAP management and program table decoder operation).

The channel manager 1312 manages a physical channel and a logical channel map, and controls a tuner 1301 and a program table decoder 1305 to respond to a viewer's channel request. Also, the program table decoder 1305 receives a parsing request and a result of a channel related table of a channel to be tuned.

Within the receiving system Demodulator

FIG. 41 is a block diagram illustrating an embodiment of a demodulator in a reception system according to the present invention. FIG. In the demodulation unit of FIG. 41, the reception performance can be improved by performing carrier synchronization recovery, frame synchronization recovery, channel equalization, etc. using known data information inserted and transmitted in a mobile service data section by a transmission system. In addition, the demodulator may reduce power consumption of the reception system by turning on the power only in the slot to which the data group of the parade including the mobile service desired to be received is allocated.

The demodulator according to the present invention may include an operation controller 2000, a demodulator 2002, an equalizer 2003, a known data detector 2004, a block decoder 2005, and an RS frame decoder 2006. have. The demodulator may further include a main service data processor 2008. The main service data processor may include a data deinterleaver, an RS decoder, and a data derandomizer. The demodulator may further include a signaling decoder 2013. In addition, the receiving system may further include a power controller 5000 for controlling the power supply of the demodulator.

That is, the frequency of a specific channel tuned through the tuner is down converted to an intermediate frequency (IF) signal, and the down converted data 2001 is output to the demodulator 2002 and the known data detector 2004. The down-converted data 2001 is a demodulator 2002 and a known data detector 2004 through an analog / digital converter (ADC, not shown) which converts an analog IF signal of a passband into a digital IF signal. In an embodiment, the input is performed by

The demodulator 2002 performs automatic gain control, carrier recovery, and timing recovery on the digital IF signal of the input passband to form a baseband signal and outputs the same to the equalizer 2003 and the known data detector 2004. .

The equalizer 2003 compensates for the distortion on the channel included in the demodulated signal and outputs the same to the block decoder 2005.

At this time, the known data detector 2004 detects the known data position inserted by the transmitting side from the input / output data of the demodulator 2002, that is, the data before the demodulation is performed or the data which has been partially demodulated, A symbol sequence of known data generated at the position is output to the demodulator 2002, the equalizer 2003, the signaling decoder 2013, and the operation controller 2000. In addition, the known data detector 2004 may provide information for allowing the transmitting decoder to distinguish mobile service data that has undergone additional encoding and main service data that does not undergo additional encoding by the block decoder 2005. Will output

Although the connection state is not illustrated in the diagram of FIG. 41, the information detected by the known data detector 2004 may be used in the reception system as a whole and may be used in the RS frame decoder 2006.

Data demodulated by the demodulator 2002 or channel equalized data by the equalizer 2003 are also input to the signaling decoder 2013. In addition, the known data position information detected by the known data detector 2004 is also input to the signaling decoder 2013.

The signaling decoder 2013 extracts and decodes the signaling information (for example, TPC information) inserted and transmitted by the transmitter from the input data, and provides the decoded signaling information as a necessary block.

That is, the signaling decoder 2013 extracts and decodes the TPC data and the FIC data inserted and transmitted by the transmitter from the equalized data to the operation controller 2000, the known data detector 2004, and the power controller 5000. Output For example, the TPC data and the FIC data are inserted and received in the signaling information region of each data group.

The signaling decoder 2013 performs signaling decoding in a reverse process of the signaling encoder of FIG. 34 to extract TPC data and FIC data. For example, the input data is decoded by the PCCC scheme, de-randomized, and separated into TPC data and FIC data. In this case, RS decoding is performed on the separated TPC data to correct an error generated in the TPC. After the deinterleaving is performed on the separated FIC data, RS decoding is performed to correct an error generated in the FIC data. The error corrected TPC data is output to the operation controller 2000, the known data detector 2004, and the power controller 5000.

The TPC data may include a transmission parameter transmitted by the service multiplexer 100 to the transmitter 200 by inserting the payload region of the OM packet.

Here, the TPC data may include RS frame information, SCCC information, M / H frame information, and the like as shown in FIG. 35. The RS frame information may include RS frame mode information and RS code mode information. The SCCC information may include SCCC block mode information and SCCC outer code mode information. The M / H frame information may include M / H frame index information. The TPC data may include subframe count information, slot count information, parade_id information, SGN information, NOG information, and the like.

In this case, if the known data information output from the known data detector 2004 is used, the signaling information region in the data group can be known. That is, the first known data sequence (or training sequence) is inserted into the last two segments of M / H block B3 in the data group, and the second known data column is inserted into the second and three of the M / H block B4. Is inserted between the first segment. In this case, since the second known data stream is inserted and received after the signaling information area, the signaling decoder 2013 extracts signaling information of the signaling information area from data output from the demodulator 2002 or the channel equalizer 2003. It can be decoded.

The power controller 5000 receives M / H frame related information from the signaling decoder 2013 to control power of the tuner and the demodulator. The power controller 5000 may control the power of the tuner and the demodulator by receiving power control information from the operation controller 2000.

According to an embodiment of the present invention, the power controller 5000 receives data by turning on power in a slot to which a data group of a parade including a mobile service desired by a user is allocated, and turns off power in other slots.

For example, assume that data groups of the first parade having NOG 3, the second parade having NOG 2, and the third parade having NOG 2 are allocated to one M / H frame as shown in FIG. 37. In addition, it is assumed that the user selects the mobile service included in the first parade through a remote controller or a keypad provided in the terminal. In this case, the power controller 5000 may reduce power consumption by turning on the power in the slot to which the data group of the first parade is allocated as shown in FIG. 37 and turning off the power in the remaining sections. In this case, the actual data group to be received needs to be powered on a little earlier than the allocated slot so that the tuner or demodulator converges in advance.

The demodulator 2002 can improve the demodulation performance by using the known data symbol string at the time of timing recovery or carrier recovery, and the equalization performance can be improved using the known data in the equalizer 2003 as well. . In addition, the equalization performance may be improved by feeding back the decoding result of the block decoder 2005 to the equalizer 2003.

Demodulator and known data detector

In this case, as shown in FIG. 5, the reception system may receive a data frame (or VSB frame) including a data group in which a known data string is periodically inserted. The data group is divided into areas A through D as shown in FIG. 5, where area A is M / H blocks B4 to M / H block B7, area B is M / H blocks B3 and M / H block B8, and area C According to the embodiment of the present invention, M includes an M / H block B2 and an M / H block B9, and a D region includes an M / H block B1 and an M / H block B10.

As shown in FIGS. 38 and 39, the known data section in which the known data columns are periodically inserted includes the known data columns of the same pattern. The known data columns of the same pattern and the total known data columns of the known data sections may have the same length. May be different. In other cases, the entire known data columns are longer than the known data columns of the same pattern, and the entire known data columns contain the same pattern of known data columns.

When the known data is periodically inserted between the mobile service data, the channel equalizer of the receiving system can use the known data as a training sequence and use it as an accurate determination value. In another embodiment, the channel equalizer may use the known data to estimate the impulse response of the channel. In another embodiment, the channel equalizer may use the known data to update filter coefficients (ie, equalization filters).

Meanwhile, when known data of the same pattern is inserted periodically, each known data section may be used as a guard interval in the channel equalizer according to the present invention. The guard interval serves to prevent interference between blocks generated by the multipath channel. This is because known data behind the mobile service data section (i.e., data block) can be considered copied in front of the mobile service data section.

Such a structure is also called a cyclic prefix, which allows the impulse response of data blocks and channels transmitted from a transmission system to be circular convolution in the time domain. Therefore, in the channel equalizer of the receiving system, it is easy to perform channel equalization in the frequency domain using fast fourier transform (FFT) and inverse FFT (IFFT).

That is, since the data block received from the receiving system is expressed as the product of the data block and the channel impulse response (CIR) in the frequency domain, the channel equalization is simply performed by multiplying the inverse of the channel in the frequency domain during channel equalization. It is possible.

The known data detector 2004 may detect the known data position periodically inserted and transmitted, and may estimate an initial frequency offset in the process of detecting the known data. In this case, the demodulator 2002 may more accurately estimate and compensate carrier frequency offset from the known data position information and the initial frequency offset estimate.

On the other hand, when the known data is transmitted in the structure as shown in FIG. 5, the known data detector 2004 first determines the position of the second known data area using the known data of the second known data area where the same pattern is repeated twice. Detect.

In this case, since the known data detector 2004 knows the structure of the data group, when the location of the second known data area is detected, the symbol or segment is counted based on the location of the second known data area, and thus the known data detector 2004 is located in the data group. The first, third to sixth known data area positions can be estimated. If the data group is a data group including field synchronization, the symbol or segment is counted based on the position of the second known data area to estimate the position of the field sync in the corresponding data group located temporally before the second known data area. can do. In addition, the known data detector 2004 may output the known data position information and the field sync position information in the parade including the mobile service selected by the user with reference to the M / H frame related information input from the signaling decoder 2013. .

At least one of the estimated known data position information and the field sync position information is provided to the demodulator 2002, the channel equalizer 2003, the signaling decoder 2013, and the operation controller 2000.

In addition, the known data detector 2004 may estimate an initial frequency offset using known data inserted into the second known data area, that is, the ACQ known data area. In this case, the demodulator 2002 may more accurately estimate and compensate carrier frequency offset from the known data position information and the initial frequency offset estimate.

Operation Controller

The operation controller 2000 receives the known data position information and transmission parameter information, and outputs M / H frame time information, presence or absence of a data group of a selected Parade, position information of known data in a data group, power control information, and the like. Pass in each block. The operation controller 2000 controls the operations of the demodulator 2002, the equalizer 2003, the block decoder 2005 and the RS frame decoder 2006 as shown in FIG. 41, but is not illustrated. The operation of the entire demodulator can be controlled. The operation controller 8000 may be implemented as a separate block or may be included in the demodulator as shown in FIG. 41.

42 is an overall block diagram of the operation controller 2000.

The Operation Controller 2000 indicates a Parade ID Checker 3101, a Frame Synchronizer 3102, a Parade Mapper 3103, a Group Controller 3104, and known sequence instructions. It may include a controller (Known Sequence Indication Controller) 3105.

The operation controller 2000 receives the known data position information from the known data detector 2004 and the transmission parameter information from the signaling decoder 2013 to generate a control signal necessary for the demodulation unit of the receiving system. For example, the known data position information detected by the known data detector 2004 is input to a known sequence indication controller 3105 and transmitted parameter information (ie, TPC data) decoded by the signaling decoder 2013. ) Is entered into the Parade ID Checker 3101.

The Parade ID Checker 3101 compares a Parade ID (parade ID selected by a user) included in the user control signal with a Parade ID input from the signaling decoder 2013. If the two Parade IDs are not the same, the Parade ID Checker 3101 waits until the next transmission parameter is input from the signaling decoder 2013.

Meanwhile, when two Parade IDs are the same, the Parade ID Checker 3101 outputs transmission parameter information to a block inside the Operation Controller 2000 and the system as a whole.

That is, when the Parade ID of the transmission parameter information input to the Parade ID checker 3101 is determined to be the same as the Parade ID selected by the user, the Parade ID Checker 3101 starts the group_number_number (parade Mapper 3103) with a Parade Mapper 3103. SGN) and number_of_groups (NoG) are printed. In addition, the Parade ID Checker 3101 outputs sub_frame_number, slot_number, parade_repetition_cycle (PRC) to the frame synchronizer 3102, and outputs SCCC_block_mode, SCCC_outer_code_mode_A, SCCC_outer_codemode_B, SCCC_out_code_code_outer_code_outer_code to the block decoder 2005. RS_frame_mode, RS_code_mode_primary, and RS_code_mode_secondary are output to the RS frame decoder 2006.

The parade mapper 3103 receives SGN and NoG as inputs from the Parade ID Checker 3101 and determines which slot among the 16 slots in the sub-frame is transmitted to output the corresponding information. The data group number transmitted for each sub-frame is determined by a continuous integer from SGN to (SGN + NoG-1). For example, if SGN = 3 and NoG = 4, four data groups with group numbers 3, 4, 5, and 6 will be transmitted for each sub-frame. The Parade Mapper 3103 calculates the slot number j through which the data group is transmitted according to Equation 1 with Group number i obtained from SGN and NoG.

In the case of SGN = 3 and NoG = 4 as in the above example, by substituting this in Equation 1, the slot number of the transmitted data group becomes 12, 2, 6, 10 in order.

The Parade Mapper 3103 outputs the obtained slot number information.

As an embodiment of outputting the slot number, a bit vector having 16 bits may be used.

Bit vector SNi (i = 0 ~ 15) can be set to 1 if there is a data group to be transmitted in the i th slot and 0 if not, and this bit vector can be output as slot number information.

The Frame Synchronizer 3102 receives sub_frame_number, slot_number, and PRC from the Parade ID Checker 3101 to calculate slot_counter and frame_mask signals and output them to the output. The slot_counter represents a slot_number at the present time of operation of the receiver, and the frame_mask is a signal indicating whether the corresponding Parade is transmitted to the current Frame. The Frame Synchronizer 3102 initializes slot_counter, sub_frame_counter, and frame_counter when first receiving signaling information. In addition, the counter value at the present time is generated by adding the slot number L which is delayed according to the time taken from the demodulation to the signaling is decoded together with the signaling information input in this process. After the initialization process, the slot_counter is updated at every slot period, the sub_frame_counter is updated at every cycle of the slot_counter value, and the frame_counter is updated at every cycle of the sub_frame_counter. The frame_mask signal is generated with reference to the frame_counter information and the PRC information. In an embodiment, if a corresponding Parade is transmitted in the current frame, 1 may be output as a frame_mask, and 0 may be output if not.

The Group Controller 3104 receives Slot number information from the Parade Mapper 3103, receives slot_counter and frame_mask information from the Frame Synchronizer 3102, and outputs a group_presence_indicator indicating whether a current data group is transmitted. do. For example, if the slot number information input from the Parade Mapper 3103 is 12, 2, 6, 10, the frame_mask information input from the Frame Synchronizer 3102 is 1 and the slot_counter is 2, 6, 10, 12. You can output 1 as the group_presence_indicator, and 0 otherwise.

The Known Sequence Indication Controller 3105 outputs position information of other known data, data group start position information, etc. with position information of specific known data inputted. In this case, since the known data exists in a predetermined position in the data group, when the position information of one known data column of the plurality of known data columns is known, the data position information and the data group start position information of another known column can be known. The Known Sequence Indication Controller 3105 may output the known data and the data group position information required by the demodulator of the receiving system only when the data group is transmitted using the group_presence_indicator information. The role of the Known Sequence Indication Controller 3105 may be performed by the known data detector 2004.

Channel equalizer

The demodulated data using the known data in the demodulator 2002 is input to the equalizer 2003. The demodulated data may also be input to a known data detector 2004.

At this time, one data group input for equalization is divided into areas A to D, as shown in FIG. 5, where A is an M / H block B4 to M / H block B7, and B is an M / H block B3 and M. In an embodiment, the / H block B8, the C region includes the M / H block B2 and the M / H block B9, and the D region includes the M / H block B1 and the M / H block B10. That is, one data group is divided into M / H blocks each 16 segments long from B1 to B10, and a long training sequence (that is, a known data sequence) is inserted at the beginning of the M / H blocks B4 to B8. do. In addition, two data groups may be allocated to one VSB field. In this case, one of the two data groups has a field synchronization after the 37th segment of the data group.

The present invention can utilize known data and / or field synchronization for knowing the position and contents by the transmission / reception side's promise for channel equalization.

The present invention will be described as an embodiment of a channel equalizer for estimating CIR using known data and / or field synchronization.

The channel equalizer 2003 may perform channel equalization in various ways. In the present invention, channel equalization is performed by estimating a channel impulse response (CIR) using known data and / or field synchronization. It will be described in an embodiment.

In particular, the present invention describes that the estimation and application of the channel impulse response (CIR) are different according to each region in the data group layered and transmitted in the transmission system.

In this case, up to four data groups may be allocated and transmitted in one VSB frame. In this case, not all data groups include field synchronization. According to an embodiment of the present invention, a data group including field synchronization estimates a CIR using field synchronization and known data, and a data group not including field synchronization estimates CIR using only known data.

For example, in the case of a data group including field synchronization, the data of the M / H block B3 may be channel equalized using the CIR obtained from the field synchronization and the CIR obtained from the known data of the first known data area. The data of the M / H blocks B1 and B2 can also be compensated for the channel distortion by using the CIR obtained from the field synchronization and the CIR obtained from the known data of the first known data area. However, in the case of the data group that does not include the field synchronization, the CIR cannot be obtained from the field synchronization. Therefore, the data of the M / H blocks B1 to B3 are used to correct the channel distortion using the CIR obtained from the first known data region and the third known data region. You can compensate.

The present invention performs channel equalization on data in a data group using the CIR estimated in the known data region, wherein one of the estimated CIRs may be used as it is, depending on the characteristics of each region of the data group. A CIR generated by interpolating or extrapolating a plurality of CIRs may be used.

Here, interpolation is a function value at some point between Q and S when the function value F (Q) at point Q and the function value F (S) at point S are known for a function F (x). It is meant to estimate, and the simplest example of the interpolation is linear interpolation. 43 shows an example of linear interpolation.

는 다음의 수학식 7과 같이 추정할 수 있다. 다시 말해, 시점 Q, S에서의 함수값 F(Q), F(S)를 알고 있으므로 두 지점을 지나는 직선을 구해서 P시점에서의 함수값의 근사값

를 구할 수 있다. 이때, (Q,F(Q)), (S,F(S))를 지나는 직선의 수식은 다음의 수학식 7과 같다. In other words, given a function value F (Q) of x = Q and a function value F (S) of x = S in any function F (x), the estimate of the function value at x = P

Can be estimated as in Equation 7 below. In other words, since we know the function values F (Q) and F (S) at time points Q and S, we find a straight line passing through two points and approximate the function value at point P.

Can be obtained. At this time, the equation of the straight line passing through (Q, F (Q)), (S, F (S)) is expressed by the following equation (7).

의 근사값 을 구하면 다음의 수학식 8과 같다. Therefore, by substituting P into x in Equation 7, the function value at the time point P

The approximation of is given by Equation 8 below.

The linear interpolation technique of Equation 8 is the simplest of many interpolation techniques, and various other interpolation techniques may be used in addition to the above-described methods, and thus the present invention will not be limited to the examples described above.

Also, extrapolation means that when a function value F (Q) at time Q and a function value F (S) at time S are known for a function F (x), It means to estimate the function value at the time point. The simplest example of such extrapolation is linear extrapolation.

를 구할 수 있다.44 shows an example of linear extrapolation. Similar to the linear interpolation example, in the case of the linear extrapolation, if a function value F (Q) and F (S) at the point of time Q and S are known at any function F (x), a straight line passing through two points is obtained and P is obtained. Approximation of function values at the time

Can be obtained.

The linear extrapolation technique is the simplest of many extrapolation techniques, and various other extrapolation techniques may be used in addition to the above-described methods, and thus the present invention will not be limited to the examples described above.

45 is an embodiment of a channel equalizer in accordance with the present invention.

45 is a block diagram illustrating an embodiment of a channel equalizer according to the present invention, wherein a first frequency domain transform unit 4100, a channel estimator 4110, a second frequency domain transform unit 4121, and coefficient calculations are shown. The unit 4122, the distortion compensator 4130, and the time domain converter 4140 are configured.

The channel equalizer may further include a residual carrier phase error canceller, a noise canceller (NC), and a decision section.

The first frequency domain transform unit 4100 includes an overlap unit 4101 that overlaps input data, and a fast fourier transform unit 4102 that converts output data of the overlap unit 4101 into a frequency domain. It is configured to include.

The channel estimator 4110 may include a CIR estimator 4111, a first cleaner (Pre-CIR Cleaner) 4113, a CIR calculator 4114, and a first estimator for estimating a channel impulse response (CIR) from input data. Post-CIR cleaner 4115, and a zero-padding unit 4116.

The channel estimator 4110 may further include a phase compensator for compensating the phase of the CIR estimated by the CIR estimator 4111.

The second frequency domain converter 4121 includes an FFT unit for converting the CIR output from the channel estimator 4110 into a frequency domain.

The time domain converter 4140 extracts only valid data from the IFFT unit 4141 and the output data of the IFFT unit 4141 to convert the data whose distortion is compensated by the distortion compensation unit 4130 into the time domain. It includes a save unit (4142). The output data of the save unit 4422 is channel equalized data.

In this case, a residual carrier phase error removing unit may be further provided at an output terminal of the time domain converter 4140 to estimate and remove the residual carrier phase error included in the channel equalized data.

In addition, a noise removing unit may be further provided at an output terminal of the time domain converter 4140 to estimate and remove noise included in channel equalized data.

The distortion compensator 4130 may be any element that performs a complex multiplication role.

That is, referring to FIG. 45, the demodulated data is superimposed at the overlapping ratio 4101 of the first frequency domain transforming unit 4100 at a preset overlap ratio and output to the FFT unit 4102. The FFT unit 4102 converts the overlapped data in the time domain into overlapped data in the frequency domain through an FFT and outputs the overlapped data in the distortion compensator 4130.

The distortion compensator 4130 complexly multiplies the equalization coefficient calculated by the coefficient calculator 4122 with the overlapped data of the frequency domain output from the FFT unit 4102 of the first frequency domain transform unit 4100. After compensating for the channel distortion of the superimposed data output at 4102, the channel distortion is output to the IFFT unit 4141 of the time domain transform unit 4140. The IFFT unit 4141 IFFTs the overlapped data whose distortion of the channel is compensated, converts the data into a time domain, and outputs the converted data to the save unit 4422. The save unit 4422 extracts and outputs only valid data from the overlapped data of the channel equalized time domain.

On the other hand, the demodulated received data is input to the overlapping portion 4101 of the first frequency domain transformer 4100 in the channel equalizer and also to the CIR estimator 4111 of the channel estimator 4110.

The CIR estimator 4111 estimates the CIR using the training sequence. If the data to be channel equalized is data in a data group including field synchronization, the training sequence used in the CIR estimator 4111 may be field synchronization data and known data. However, if the data to be channel equalized is data in a data group that does not include field synchronization, the training sequence may be known data only.

As an example, the CIR estimator 4111 estimates a channel impulse response (CIR) using data received during a known data interval and reference known data generated at a receiving side by an appointment of the transmitting / receiving side. To this end, the CIR estimator 4111 is provided with known data position information from the known data detector 2004.

In addition, if the CIR estimator 4111 is a data group including field synchronization, an impulse response (CIR_FS) of the channel using data received during the field synchronization period and reference field synchronization data generated at the receiving side by the promise of the transmitting / receiving side. ) Can be estimated. To this end, the CIR estimator 4111 may be provided with field sync position information from the known data detector 2004.

The estimated CIR is input to the CIR calculator 4114 via the first cleaner 4113 or bypasses the first cleaner 4113. The CIR operator 4114 interpolates or extrapolates the estimated CIR to the second cleaner 4115.

Depending on whether the CIR operator 4114 interpolates or extrapolates the estimated CIR, the first cleaner 4113 may or may not operate. For example, when the interpolation is performed on the estimated CIR, the first cleaner 4113 is not operated. When the extrapolation is performed on the estimated CIR, the first cleaner 4113 is operated.

That is, the CIR estimated from the known data includes not only the channel component to be obtained but also the jitter component due to noise. Since this jitter component is a factor that degrades the equalizer performance, it is preferable to remove the jitter component before using the CIR in the coefficient calculator 4122. Therefore, in the embodiment, the first and second cleaners 4113 and 4115 remove a portion of the input CIR component whose power is equal to or less than a predetermined threshold (ie, make it '0'). do. This removal process is called CIR cleaning.

That is, CIR interpolation in the CIR calculator 4114 is performed by multiplying and adding a coefficient to two CIRs estimated by the CIR estimator 4112, respectively. At this time, some of the noise components of the CIR are added to each other to cancel. Accordingly, when CIR interpolation is performed in the CIR calculator 4114, the original CIR in which the noise component remains is used. That is, when CIR interpolation is performed in the CIR calculator 4114, the estimated CIR bypasses the first cleaner 4113 and is input to the CIR calculator 4114. The CIR interpolated by the CIR calculator 4114 cleans the second cleaner 4115.

On the other hand, the CIR extrapolation in the CIR calculator 4114 is performed by estimating the CIR located outside the two CIRs by using the difference between the two CIRs estimated by the CIR estimator 4112. Therefore, the noise component of the CIR is amplified at this time. Accordingly, when CIR extrapolation is performed in the CIR calculator 4114, the CIR cleaned by the first cleaner 4113 is used. That is, when CIR extrapolation is performed by the CIR calculator 4114, the extrapolated CIR is input to the zero padding unit 4116 via the second cleaner 4115.

On the other hand, the length of the CIR input and the FFT size do not coincide when the CIR, which is clinked and output by the second cleaner 4115, is converted into the frequency domain by the second frequency domain converter 4121. May occur. That is, a case where the length of the CIR is smaller than the FFT size may occur. In this case, the zero padding unit 4116 adds '0' to the CIR by the difference between the FFT size and the input CIR length and outputs the same to the second frequency domain transforming unit 4121. The zero-padded CIR may be one of interpolated CIRs, extrapolated CIRs, and CIRs estimated from a base data interval.

The second frequency domain converter 4121 converts the input CIR of the time domain into FIR by converting the received CIR into the CIR of the frequency domain, and outputs the CIR to the coefficient calculator 4122.

The coefficient calculator 4122 calculates an equalization coefficient by using the CIR of the frequency domain output from the second frequency domain converter 4121 and outputs the equalization coefficient to the distortion compensator 4130. In this example, the coefficient calculator 4122 obtains an equalization coefficient of a frequency domain that minimizes a mean square error (MMSE) from the CIR of the frequency domain and outputs the equalization coefficient to the distortion compensator 4130. .

The distortion compensator 4130 complexly multiplies the equalization coefficient calculated by the coefficient calculator 4122 with the overlapped data of the frequency domain output from the FFT unit 4102 of the first frequency domain transform unit 4100. Compensate for the channel distortion of the overlapping data output at 4102.

Block decoder

On the other hand, if the data inputted to the block decoder 2005 after channel equalization in the equalizer 2003 is data in which both block coding and trellis coding are performed at the transmitting side (for example, data in an RS frame), the transmitting side is performed. In contrast, if trellis decoding and block decoding are performed, and block encoding is not performed and only trellis encoding is performed (for example, main service data), only trellis decoding is performed.

The trellis decoded and block decoded data by the block decoder 2005 is output to the RS frame decoder 2006. That is, the block decoder 2005 may be configured in the known data, the data used for trellis initialization, the signaling information data, the MPEG header, and the RS encoder / unstructured RS encoder or unstructured RS encoder of the transmission group. The added RS parity data is removed and output to the RS frame decoder 2006. Here, data removal may be performed before block decoding, or may be performed during or after block decoding.

Meanwhile, the trellis decoded data by the block decoder 2005 is output to the data deinterleaver of the main service data processor 2008. In this case, the data trellis decoded by the block decoder 2005 and output to the data deinterleaver may include not only main service data but also data in RS frames and signaling information. In addition, RS parity data added after the preprocessor 230 may be included in the data output to the data deinterleaver.

In another embodiment, the block encoding is not performed at the transmitting side, and the data having only trellis encoding may be bypassed in the block decoder 2005 as it is and output to the data deinterleaver. In this case, a trellis decoder must be further provided in front of the data deinterleaver.

The block decoder 2005 performs a Viterbi (or trellis) decoding on the input data to obtain a hard decision value if the input data is data which is not performed by the block encoding but only the trellis encoding. Alternatively, the soft decision value may be hard determined and the result may be output.

The block decoder 2005 outputs a soft decision value with respect to the input data if the input data is data in which both block coding and trellis coding are performed at the transmitting side.

That is, if the input data is block encoding performed by the block processor 302 on the transmitting side and trellis encoding is performed by the trellis coding unit 256, Conversely, trellis decoding and block decoding are performed. At this time, the block processor on the transmitting side can be seen as an external encoder, and the trellis encoder can be seen as an internal encoder.

In order to maximize the decoding performance of the outer code at the time of decoding the concatenated code, it is preferable to output the soft decision value from the decoder of the inner code.

46 is a detailed block diagram illustrating an embodiment of a block decoder 2005 according to the present invention, and includes a feedback controller 5010, an input buffer 5011, a trellis decoder 5012, and a symbol-byte converter 5013. ), Outer block extractor 5014, feedback deformatter 5015, symbol deinterleaver 5016, outer symbol mapper 5017, symbol decoder 5018, internal symbol mapper ( An inner symbol mapper 5019, a symbol interleaver 5020, a feedback formatter 5021, and an output buffer 5022 may be included. Like the transmitting side, the trellis decoder 5012 can be viewed as an internal decoder, and the symbol decoder 5018 can be viewed as an external decoder.

The input buffer 5011 temporarily stores block coded mobile service data symbols (including RS parity data symbols and CRC data symbols added during RS frame encoding) among symbol values output by channel equalization by the equalizer 2003. The stored symbol values are repeatedly output M times to the trellis decoder 5012 in turbo decoding size (TDL) for turbo decoding. The turbo decoding size (TDL) is also called a turbo block. Here, the TDL should be able to include at least one SCCC block size. Therefore, as defined in FIG. 5, assuming that one M / H block is 16 segment units, and one SCCC block is configured by a combination of ten M / H blocks, the TDL is larger than the maximum possible combination size. Should be the same. For example, assuming that two M / H blocks constitute one SCCC block, the TDL may be 32 segments or more (828x32 = 26496 symbols).

M is a repetition number of turbo decoding predetermined by the feedback controller 5010.

In addition, the input buffer 5011 does not include a mobile service data symbol (including RS parity data symbols and CRC data symbols added at the time of RS frame encoding) among symbol values output by channel equalization by the equalizer 2003. Input symbol values in the section are bypassed without being stored. That is, since the trellis decoding is performed only on the input symbol value of the section in which the SCCC block encoding is not performed, the input buffer 5011 does not perform the storing and repetitive output process on the input. ).

The storage, repetition, and output of the input buffer 5011 is performed by the control of the feedback controller 5010. The feedback controller 5010 stores and outputs the input buffer 5011 with reference to SCCC related information output from the operation controller 2000 or the signaling decoder 2013, for example, the SCCC block mode and the SCCC outer code mode. Can be controlled.

The trellis decoder 5012 includes a 12-way Trellis Coded Modulation (TCM) decoder to correspond to the 12-way trellis encoder. The 12-way trellis decoding is performed on the input symbol value in a reverse process of the 12-way trellis encoder.

That is, the trellis decoder 5012 receives the output symbol value of the input buffer 5011 and the soft-decision value of the feedback formatter 5021 by TDL, and performs TCM decoding of each symbol. do.

In this case, the soft determination values output from the feedback formatter 5021 are matched one-to-one with symbol positions corresponding to the TDL output from the input buffer 5011 under the control of the feedback controller 5010, and thus the trellis decoder ( 5012). That is, the symbol value output from the input buffer 5011 and the data decoded by turbo decoding are matched to the same position in the corresponding turbo block TDL and output to the trellis decoder 5012. For example, if the turbo decoded data is the third symbol value in the turbo block, the turbo decoded data is matched with the third symbol value in the turbo block output from the input buffer 5011 and output to the trellis decoder 5012.

To this end, the feedback controller 5010 controls to store the corresponding turbo block data in the input buffer 5011 during recursive turbo decoding, and delays the soft decision value of the output symbol of the symbol interleaver 5020 through delay or the like. For example, the LLR and the symbol value of the input buffer 5011 corresponding to the same position in the block of the output symbol are controlled to be input to the TCM decoder of the corresponding path by one-to-one matching. In this case, if the symbol value is not a block coded symbol, since it is not turbo decoded, null is input to a matching output position in the feedback formatter 5021.

After this process is performed for a predetermined number of iterations of turbo decoding, data of the next turbo block is output from the input buffer 5011 to repeat the turbo decoding process.

The output of the trellis decoder 5012 means the reliability of symbols input to the transmitting trellis encoder with respect to the transmitted symbols. For example, since the input of the trellis encoder 256 on the transmitting side has two bits as one symbol, the log bit between the probability that the bit is '1' and the probability that the bit is '0' is higher than the log likelihood ratio (LLR). Output (bitwise output) can be done for and low bit respectively. The Log Likelihood Ratio (LLR) refers to a log value of a ratio between a probability value of 1 and a probability value of 0. Or outputs the logarithm ratio (LLR) of the probability values that two bits, i.e., a symbol is "00", "01", "10", or "11", for all four combinations (00,01,10,11) Symbol unit output). This is, in turn, a soft decision value for the received symbol, which represents the reliability of the bits that have been entered into the trellis encoder. As a decoding algorithm of each TCM decoder in the trellis decoder 5012, MAP (Maximum A posteriori Probability), SOVA (Soft-Out Viterbi Algorithm), and the like may be used.

The output of the trellis decoder 5012 is output to the symbol-byte converter 5013 and the external block extractor 5014.

The symbol-byte converter 5013 hard-decisions the soft decision value output by trellis decoding by the trellis decoder 5012, and then binds four symbols into one byte unit. The data is output to the data deinterleaver of the main service data processing unit 2008. That is, the symbol-byte converter 5013 performs a hard decision in bits on the soft decision value of the output symbol of the trellis decoder 5012. Therefore, data hard-determined by the symbol-byte converter 5013 and output in byte units include not only main service data but also mobile service data, known data, signaling information data, RS parity data, and MPEG header.

The outer block extractor 5014 corresponds to a mobile service data symbol (including RS parity data and CRC data symbols added at the time of RS frame encoding) among soft decision values equal to the TDL of the trellis decoder 5012. The B soft decision values are divided and output to the feedback deformatter 5015. That is, in the external block extractor 5014, soft decision values such as main service data, known data, signaling information data, RS parity data, and MPEG header are discarded without being output to the feedback deformatter 5015.

The feedback deformatter 5015 may perform an intermediate process (eg, a group formatter, a data deinterleaver, a packet formatter, and a data interleaver) in which an output symbol of the transmitting block processor 302 is input to the trellis encoder 256. In a reverse process of the processing order change of the mobile service data symbol generated in the Rx, the processing order of the soft decision value of the mobile service data symbol is reordered and output to the symbol deinterleaver 5016. This is because a plurality of blocks exist between the trellis encoders 256 of the block processor 302 on the transmitting side, and the order and trellis of the mobile service data symbols output from the block processor 302 due to these blocks. This is because the order of the mobile service data symbols input to the encoder 256 is different. Accordingly, the feedback deformatter 5015 is output from the external block extractor 5014 so that the order of the mobile service data symbols inputted to the symbol deinterleaver 5016 matches the output order of the block processor 302 on the transmitting side. Reorder the mobile service data symbols. This reordering process may be implemented in at least one of software, hardware, and middleware.

The symbol deinterleaver 5016 is a reverse process of symbol interleaving of the symbol interleaver 514 on the transmitting side. The symbol deinterleaver 5016 deinterleaves the soft decision value of the data symbols outputted after the order is changed by the feedback deformatter 5015. The block size used for deinterleaving in the symbol deinterleaver 5016 is equal to the interleaving size (ie, B) of the actual symbol of the symbol interleaver on the transmitting side, which is a turbo decoding trellis decoder 5012 and a symbol. This is because it is made between the decoders 5018.

Both the input and output of the symbol deinterleaver 5016 are soft decision values, and the deinterleaved soft decision values are output to an external symbol mapper 5017.

The operation of the external symbol mapper 5017 may vary depending on the configuration and the code rate of the convolutional encoder 513 of the transmitting side. For example, the external symbol mapper 5017 outputs the input data to the symbol decoder 5018 as it is if the data is ½ encoded by the convolutional encoder 513. As another example, if the data is coded by the convolutional encoder 513 and transmitted, the input data is converted to the symbol decoder 5018 according to the input format of the symbol decoder 5018. To this end, the external symbol mapper 5017 may receive SCCC-related information, for example, the SCCC block mode and the SCCC outer code mode, from the signaling decoder 2013.

The symbol decoder 5018 (that is, the external decoder) performs a symbol decoding on the output of the external symbol mapper 5017 as a reverse process of the convolutional encoder 513 of the transmitting side. At this time, the symbol decoder 5018 outputs two soft determination values. One is a soft decision value (hereinafter referred to as a first soft decision value) that matches the output symbol of the convolutional encoder 513 and the other is a soft decision value (hereinafter, referred to as a first soft decision value) that matches the input bit of the convolution encoder 513. Second soft determination value). The first soft decision value represents an output symbol of the convolutional encoder 513, that is, the reliability of two bits, and constitutes a log ratio (LLR) between a probability of '1' and a probability of '0' of one bit. Output (bitwise output) for the upper and lower bits respectively, or output the logarithm ratio (LLR) of the probability values that the 2 bits will be "00", "01", "10", and "11". (Symbol unit output) The first soft decision value is fed back to the trellis decoder 5012 through the internal symbol mapper 5019, the symbol interleaver 5020, and the feedback formatter 5021. The second soft decision value represents the reliability of the input bit of the convolutional encoder 513 of the transmitting side, and is expressed as a logarithm ratio (LLR) between a probability of '1' and a probability of '0' of one bit. Is output to 5022. As a decoding algorithm of the symbol decoder 5018, MAP (Maximum A posteriori Probability), SOVA (Soft-Out Viterbi Algorithm), or the like may be used.

The first soft decision value output from the symbol decoder 5018 is input to the internal symbol mapper 5019. The internal symbol mapper 5019 converts the first soft decision value according to the input format of the trellis decoder 5012 and outputs the converted soft signal to the symbol interleaver 5020. The operation of the internal symbol mapper 5019 may vary according to the structure and the code rate of the convolutional encoder 513 of the transmitting side.

The symbol interleaver 5020 performs symbol interleaving on the first soft decision value output from the internal symbol mapper 5019 and outputs the result to the feedback formatter 5021. The output of the symbol interleaver 5020 also becomes a soft determination value.

The feedback formatter 5021 is an intermediate process (eg, a group formatter, a data deinterleaver, a packet formatter, and a data interleaver) in which an output symbol of the block processor 302 on the transmitting side is input to the trellis encoder 256. The order of the output values of the symbol interleaver 5020 is changed in accordance with the change in the processing order of the symbols generated in the subfield, and then output to the trellis decoder 5012. The reordering process of the feedback formatter 5021 may also be implemented by at least one of software, hardware, and middleware.

The soft decision values output from the symbol interleaver 5020 are input to the trellis decoder 5012 in one-to-one correspondence with mobile service data symbol positions corresponding to the TDL output from the input buffer 5011. In this case, since the main service data symbol, the RS parity symbol of the main service data, the known data symbol, the signaling information data, etc. are not the mobile service data symbols, the feedback formatter 5021 inserts null data into the corresponding position and trellis decodes the data. Output to the part 5012. In addition, since there is no value fed back from the symbol interleaver 5020 at the first decoding start every time the turbo decoding of the TDL size symbols is performed, the feedback formatter 5021 is controlled by a feedback controller 5010 to provide mobile service data. Null data is inserted into all symbol positions including the symbol and outputted to the trellis decoder 5012.

The output buffer 5022 receives the second soft decision value from the symbol decoder 5018 under the control of the feedback controller 5010, temporarily stores the second soft decision value, and outputs the second soft decision value to the RS frame decoder 2006. For example, the output buffer 5022 is overwriting the second soft decision value of the symbol decoder 5018 until M turbo decoding is performed, and then M turbo decoding is performed for one TDL. If so, the second soft decision value at that time is output to the RS frame decoder 2006.

The feedback controller 5010 controls the number of times of turbo decoding and turbo decoding repetition of the entire block decoder as shown in FIG. 46.

That is, after turbo decoding is performed for a predetermined number of repetitions, the second soft decision value of the symbol decoder 5018 is output to the RS frame decoder 2006 through the output buffer 5022, and block decoding for one turbo block is performed. The process is complete.

This is referred to as a regressive turbo decoding process for convenience of description in the present invention.

At this time, the number of recursive turbo decoding between the trellis decoder 5012 and the symbol decoder 5018 may be defined in consideration of hardware complexity and error correction performance. It has the disadvantage of being complicated.

On the other hand, each M / H block may have different equalization performance depending on the known data position in the data group (or M / H group). That is, since the receiving system performs channel equalization using the channel information obtained from the known data, an area relatively far from the known data is faster than a region A having a long sequence of known data back and forth for each M / H block. Equalization performance can deteriorate.

In the present invention, the M / H blocks B4 to M / H blocks B7 in the data group are referred to as the A area (= B4 + B5 + B6 + B7), and the M / H blocks B3 and M / H block B8 are referred to as the B area (= B3). M / H block B2 and M / H block B9 are called C regions (= B2 + B9), and M / H block B1 and M / H block B10 are referred to as B regions (= B1 + B10). do.

The M / H blocks B4 to M / H block B7 in the area A are inserted with long known data strings before and after each M / H block without interference of main service data. Therefore, in the case of the area A, since the equalization can be performed using the channel information obtained from the known data, the reception system can obtain the strongest equalization performance among the areas A to D.

The M / H block B3 and the M / H block B8 in the region B have little interference with main service data, and a long known data string is inserted into only one side of both M / H blocks. As described above, in the case of the B area having only one known data string in each M / H block, the receiving system can perform equalization using channel information obtained from the known data, which is more robust than the C / D area. Equalization performance can be obtained.

In the M / H block B2 and the M / H block B9 of the C region, the interference of the main service data is greater than that of the B region, and both M / H blocks cannot insert a long known data string back and forth. In the M / H block B1 and the M / H block B10 of the D area, the interference of the main service data is more than that of the C area, and similarly, both M / H blocks cannot insert a long known data stream back and forth. Since the C / D region is far from the known data stream, the reception performance may be poor when the channel changes rapidly.

That is, the equalization performance is excellent in the order of A> B> C> D in the data group. As described above, an area relatively far from the known data may deteriorate the equalization performance due to a fast channel change.

In addition, the present invention supports two SCCC block modes as shown in Table 7. Referring to Table 7, if the SCCC block mode value is 00, the SCCC block and the M / H block are the same. However, if the SCCC block mode value is 01, each SCCC block is composed of two M / H blocks. That is, when the SCCC block mode value is 01, the symbols encoded by the SCCC block in the transmission system are transmitted through two M / H blocks.

47 shows an example of a combining rule of an M / H block when the SCCC block mode value is 01. That is, in the transmission system, SCCC encoding is performed by combining M / H block 1 and M / H block 6, and SCCC block encoding is performed by combining M / H block 2 and M / H block 7. In addition, SCCC encoding is performed by combining the 3rd M / H block and the 8th M / H block, and combining the 4th M / H block and the 9th M / H block by SCCC encoding. In addition, SCCC encoding is performed by combining the 5th M / H block and the 10th M / H block. When the SCCC coded data is transmitted by applying the combination rule, the reception system may improve the overall error correction capability by combining and decoding the symbols of the region having poor equalization performance with the symbols of the region having excellent equalization performance.

Then, the feedback controller 5010 in the block decoder of FIG. 46 adjusts the output order of the symbols stored in the input buffer 5011 according to the combining rule of the M / H block. The symbol output from the input buffer 5011 is input to the TCM decoder 5012. For example, 1st M / H block, 6th M / H block, 2nd M / H block, 7th M / H block, 3rd M / H block, 8th M / H block, 4th M / H block The H block, the M / H block 9, the M / H block 5, and the M / H block 10 are input to the TCM decoder 5012 in this order.

The TCM decoder 5012 decodes each input M / H block and outputs the decoded data to an external block extractor 5014. As described above, the data for the mobile service extracted by the external block extractor 5014 includes a feedback deformatter 5015, a symbol deinterleaver 5016, an external symbol mapper 5017, a symbol decoder 5018, and an internal symbol mapper. 5019, a symbol interleaver 5020, and a feedback formatter 5021 are fed back to the TCM decoder 5012.

When the data for the mobile service is fed back from the feedback formatter 5021 to the TCM decoder 5012, the feedback formatter 5021 may provide a mobile service for each M / H block output from the input buffer 5011. The TCM decoder 5012 is fed back to match the position of the data. In this case, if two M / H blocks encoded by one SCCC block are not sequentially decoded sequentially, a temporary buffer for adjusting the order of M / H blocks may be additionally required in the middle of input / output of each decoder during a feedback decoding process.

In addition, when the block decoding is performed by the combined mode, the symbol in the M / H block having poor equalization performance may be intertwined with the symbols in the M / H block having good equalization performance, and the error correction capability may be improved. A symbol in a block may adversely affect decoding of adjacent M / H symbols having good equalization capability.

Therefore, according to the present invention, by adding weights to the symbols of the data for the mobile service for each M / H block or for each region, the influence of the symbols having poor equalization capability during decoding can be reduced. The weight may be added to each symbol or multiplied by each symbol. According to an embodiment of the present invention, each symbol is multiplied.

According to an embodiment of the present invention, the soft decision value of the TCM decoded and output symbol is multiplied by a predetermined weight to be used in the symbol decoder 5018.

Here, the weight may be different for each region or may be different for each M / H block. Alternatively, some regions of the plurality of regions may have the same weight, and others may have different weights. Alternatively, some M / H blocks of the plurality of M / H blocks may have the same weight, and other M / H blocks may have different weights.

At this time, according to an embodiment of the present invention, the weight of the region (or M / H block) having poor equalization performance is smaller than the weight of the region (or M / H) having good equalization performance.

For example, the weights may be set in the order of A area <B area <C area <D area. As an example of this case, the weight of the region A may be set to 1, the weight of the region B to 0.5, the weight of the region C to 0.25, and the weight of the region D to 0.125. As another example, the weights of the A and B regions may be set to be the same, and the weights of the C and D regions are set to be the same, and the weights of the C and D regions may be set to be smaller than the weights of the A and B regions. As an example of this case, the weights of the A and B regions may be set to 1, and the weights of the C and D regions may be set to 0.25. As another example, 4th M / H block, 5th M / H block, 6th M / H block, 7th M / H block <3rd M / H block, 8th M / H block <1st M / The weights may be set in the order of the H block, the 2nd M / H block, the 9th M / H block, and the 10th M / H block.

The method of setting weights for each region or M / H block in the data group described above, and the numerical values set as weights are embodiments to help the understanding of the present invention. The scope of the present invention will not be limited to the above embodiments as it may be changed.

According to the present invention, the weights of the A and B regions are set equally (β1), and the weights of the C and D regions are equally set (β2), while the weights of the C and D regions (β2) are greater than the weights of the AB regions (β1). Is set to a smaller value (ie, β1 < β2) in one embodiment. In an embodiment, β1 is set to 1 and β2 is set to 0.25.

According to an embodiment of the present invention, the soft decision value of the TCM decoded symbol is multiplied by the weight in the TCM decoder 5012. More specifically, multiplying the TCM decoded symbol LLR by the weight is an embodiment.

That is, the output of the TCM decoder 5012 means the reliability of the symbols input to the transmitting trellis encoder for the transmitted symbols. At this time, since the two bits are one symbol of the input of the trellis encoder 256 on the transmitting side, in the present invention, one symbol in the TCM decoder 5012 is "00", "01", "10", or "11". According to an embodiment of the present invention, a logarithm ratio LLR of a probability value to be output is output and four LLRs are multiplied by a predetermined weight for each symbol.

The LLRs of the symbols multiplied by the weights are input to the symbol decoder 5018 while the symbol positions of the region having good equalization and the region of the region having poor equalization are mixed in the symbol deinterleaver 5016 to perform symbol decoding. In the symbol decoder 5018, the symbol decoding of a region having poor equalization ability when decoding in symbol units, the TCM decoded and the probability value of the front and back states in trellis state transition rather than the input symbol LLR. This increases the probability of symbol decoding, so that the influence of symbols in regions with poor equalization ability can be reduced.

That is, the symbol LLR input to the symbol decoder 5018 is a result of performing TCM decoding for each M / H block, but there are many differences in equalization capability for each M / H block, and thus the symbol LLRs are affected accordingly. Accordingly, the present invention provides symbol LLRs obtained from M / H blocks (eg, 1,2,9,10th M / H blocks) that are not equalized well when decoding symbols transmitted in a poor channel environment such as a mobile channel. By using symbol LLRs obtained from well-equalized M / H blocks (eg, 3rd to 8th M / H blocks) in the symbol decoding process, the error correction capability of the symbol decoder 5018 can be improved.

FIG. 48 is a block diagram illustrating another embodiment of a block decoder according to the present invention. In an embodiment, the reliability adjusting unit 5200 is further provided between the TCM decoder and the symbol decoder of FIG. 46.

More specifically, the reliability adjusting unit 5200 is provided between the feedback deformatter 5015 and the symbol deinterleaver 5016 according to an embodiment.

The reliability adjuster 5200 includes a first multiplier 5201, a second multiplier 5202, and a selector 5203. In one embodiment, the selector 5203 is a multiplexer.

The first multiplier 5201 multiplies the output of the feedback deformatter 5015 by a first weight β1, and the second multiplier 5202 multiplies the output of the feedback deformatter 5015 by a second weight β2. Multiplying by an embodiment. In this embodiment, β1 is set to 1 and β2 is set to 0.25.

The selector 5203 may select an output of the first multiplier 5201 according to a selection signal and output the result to the symbol deinterleaver 5016, or select an output of the second multiplier 5202 to the symbol deinterleaver 5016. Output

The selector 5203 has a symbol LLR obtained by multiplying weights in the first and second multipliers 5201 and 5202, respectively, in an A / B region (or 3,4,5,6,7,8th M / H block). Selects the output of the first multiplier 5201 if the symbol LLR of, and selects the output of the second multiplier 5202 if the symbol LLR of the C / D region (or 1,2,9,10th M / H block) In one embodiment. In the present invention, it is known that the symbol LLR decoded and outputted by the TCM is a symbol LLR of which area of the A / B / C / D area in the data group or a M / H block of 10 M / H blocks. In one embodiment.

In this case, the first and second multipliers 5201 and 5202 may multiply four LLRs in one symbol by weights β1 and β2, respectively. For example, in the first multiplier 5201, four LLRs for the A symbol (that is, the logarithmic ratio (LLR) of the probability values that will be "00", "01", "10", and "11") may be used. The weights β1 are each multiplied, and in the second multiplier 5202, the second weights β2 are respectively multiplied.

The symbol LLR selected and output by the selector 5203 is inputted to the symbol decoder 5018 through the symbol deinterleaver 5016 and the external symbol mapper 5017 and decoded.

For example, suppose that the symbol decoder 5018 uses the Max-log MAP decoding algorithm. In this case, the forward metric calculation process will be described as follows.

The block processor in the transmission system performs block encoding using two memories as shown in FIG. Therefore, there are four memory states '00', '01', '10', and '11' for each time index. If block encoding is performed using three memories in the block processor, eight memory states ('000' to '111') exist for each time index.

That is, based on FIG. 29, for example, FIGS. 49 and 50, '00', '01', '10', and '11' states are generated for each time index (or also referred to as a section or a stage). In the state, two passes meet.

For example, in the '00' state, the paths of the '00' state and the '01' state of the previous time index meet. In the '01' state, the paths of the '10' state and the '11' state of the previous time index meet, In the '10' state, the paths of the '00' state and the '01' state of the previous time index meet. In the '11' state, the paths of the '10' state and the '11' state of the previous time index meet.

49 illustrates an example of obtaining a confidence value of the forward metric for each state when the weight according to the present invention is not applied. FIG. 50 illustrates a confidence value of the forward metric for each state when the weight according to the present invention is applied. Shows an example of obtaining.

49 and 50, at time index n, the confidence value of the forward metric in the '00' state is 0.0, the confidence value of the forward metric in the '01' state is 0.21, and the confidence value of the forward metric in the '10' state is Assume that the confidence value of the forward metric with a state of -0.7 and '11' is -0.15. And, the log ratio of the probability value that the TCM decoded symbol will be "00" (i.e. symbol LLR (0)) is 0.5, and the log ratio of the probability value that will be "01" (i.e. symbol LLR (1)) is 1.3, " Suppose that the log ratio of the probability value to be 10 "(i.e. symbol LLR (2)) is 0.3, and the log ratio of the probability value to be" 11 "(i.e. symbol LLR (3)) is 0.4.

In this case, for each state, the forward metric confidence value of the corresponding state at time index n and the symbol LLR of each pass for the corresponding state transition are added, and at time index n + 1, the two paths for each state are added. Select the larger of the results as the confidence value of the forward metric of the state. The symbol LLR for the state transition is a TCM decoded symbol LLR.

Taking the '00' state of time index n + 1 of FIG. 49 as an example, the confidence value (ie, 0.0) of the forward metric of the '00' state of the previous time index n and the symbol of the path for transition to the '00' state LLR (0) (i.e. 0.5) is added to obtain a confidence value (i.e. 0.5) of the first forward metric, and a confidence value (i.e. 0.21) and '00' of the forward metric of the state '01' of the previous time index n. The confidence value of the second forward metric (i.e., 0.51) is obtained by adding the symbol LLR 2 (i.e., 0.3) of the path for transition to the state, and the confidence values of the first and second forward metrics are compared. As a result of the comparison, the confidence value of the second forward metric (i.e., 0.51) among the confidence values of the first and second forward metrics is selected as the confidence value of the forward metric of the '00' state of the time index n + 1. .

When this process is performed for the remaining states of time index n + 1, the confidence value of the forward metric of the '01' state of the time index n + 1 becomes 0.6, and the confidence value of the forward metric of the '10' state is 0.71. The confidence value of the forward metric in the '11' state is 1.15.

That is, the confidence value of the forward metric for the states '00', '01', '10', and '11' is updated to 0.51, 0.6, 0.71, and 1.15 at time index n + 1. In this case, the confidence value of the forward metric in the '11' state is updated to the largest value.

In other words, in the case of FIG. 49, the confidence values of the forward metrics of the states' 00 ',' 01 ',' 10 ', and' 11 'of the time index n + 1 are' 00 ',' 01 ',' The effect of the symbol LLRs (i.e. symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) on each pass is more than the confidence value of the forward metric of the 10 'and' 11 'states. I receive a lot.

By the way, the symbol LLR (i.e., symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) is obtained from an M / H block that is not equalized well through the poor channel. Assume that the symbol LLR (ie, symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) is '00', '01', '10' at time index n + 1. This can adversely affect the confidence value of a forward metric with a ', '11' state. That is, regardless of the state of '01' having the highest confidence value of the forward metric at time index n, the state of '11' is selected at time index n + 1, so the influence of symbol LLR is greatly affected. In other words, since the symbol LLR is incorrectly decisively affected, the symbol decoding performance may be degraded.

Therefore, in the present invention, the TCM decoded symbol LLR (i.e., symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) suffers from poor channel and is not equalized well. If determined to be from a block, the symbol LLR (i.e., symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) is multiplied by a weight less than zero, thereby It is to reduce the influence of the symbol LLR (ie, symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) when obtaining the confidence value of the forward metric of each state.

That is, at state transition, the symbol LLR (i.e. symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) is multiplied by a weight less than 1 and then the next time index (e.g. When the confidence value of the forward metric of each state is obtained at time index n + 1), the confidence value of the forward metric of each state at the next time index (e.g., time index n + 1) is equal to the previous time index ( For example, it is greatly affected by the confidence values of the forward metric of each state of time index n).

For example, the TCM decoded symbol LLR (i.e. symbol LLR (0), symbol LLR (1), symbol LLR (2), symbol LLR (3)) is multiplied by a weight of 0.25 and then each at the next time index n + 1. If the confidence value of the forward metric of the state is obtained, the confidence value of the forward metric for the states '00', '01', '10', and '11' is 0.285, -0.05, at time index n + 1 as shown in FIG. It is updated to 0.335 and 0.175, respectively. In this case, the confidence value of the forward metric in the '10' state is updated to the largest value. That is, it can be seen that the state '10' at time index n + 1 connected with the state '01' showing the highest forward metric confidence value at time index n has the highest forward metric confidence value.

In other words, in FIG. 50, the confidence value of the forward metric of the states '00', '01', '10', and '11' at the time index n + 1 is obtained from the symbol LLR obtained from each pass (that is, the symbol LLR (0). ), Rather than the symbol LLR (1), symbol LLR (2), and symbol LLR (3), the confidence value of the forward metric of the states '00', '01', '10', and '11' of time index n Receive more Therefore, even if the symbol LLR is obtained from an M / H block that is not equalized well while experiencing a poor channel, the symbol decoding performance is not significantly reduced.

In the weighting method according to the present invention, since the equalization capability and encoding method of each M / H block may be different, the symbol LLRs obtained therefrom may be given different weights according to M / H blocks. In addition, the present invention is more effective when applied when the SCCC block mode value is 01 as shown in Table 7.

In the present invention, when block decoding is performed on a block decoder with respect to channel equalized data, the M / H of any M / H of 10 M / H blocks or any area of the A / B / C / D areas of the data group is included. Suppose you know if it is data in a block.

So far, the present invention has been described as a method of assigning a weight to a TCM decoded symbol LLR, but the weight may be given before TCM decoding or a symbol decoded symbol LLR.

Meanwhile, the main service data processing unit 2008 of FIG. 41 is blocks necessary for receiving main service data, and may not be necessary in a reception system structure for receiving only mobile service data.

The data deinterleaver in the main service data processing unit 2008 deinterleaves the data output from the block decoder 2005 in the reverse process of the data interleaver on the transmitting side and outputs the data to the RS decoder. Data input to the data deinterleaver includes not only main service data but also mobile service data, known data, RS parity, MPEG header, and the like.

The RS decoder performs systematic RS decoding on the deinterleaved data and outputs it to the derandomizer.

The derandomizer receives the output of the RS decoder, generates pseudo random bytes identical to the transmitter's renderer, bitwise XORs them, and inserts an MPEG sync byte in front of every packet, thereby generating a 188-byte packet. Output in units.

RS  Frame decoder

The data output from the block decoder 2005 is a portion unit. That is, the RS frame is divided into a plurality of portions at the transmitting side, and the mobile service data of each portion is allocated to the A / B / C / D region in the data group, or at any one of the A / B region and the C / D region. It is assigned and sent to the receiver. Accordingly, the RS frame decoder 2006 collects a plurality of portions in one parade to form one RS frame or two RS frames, and performs error correction decoding in units of RS frames.

For example, if the RS frame mode is 00, one parade transmits one RS frame, where one RS frame is divided into a plurality of potions, and the mobile service data of each divided portion is A of the corresponding data group. It is allocated to / B / C / D area and transmitted. In this case, the RS frame decoder 2006 extracts the mobile service data from the A / B / C / D area in the data group and configures one portion as shown in FIG. 51 (a). A plurality of potions may be obtained by performing the data groups. In addition, mobile service data of a plurality of portions may be collected to configure one RS frame. If stuffing byte is added to the last potion, stuffing byte is removed and RS frame is composed.

As another example, if the RS frame mode is 01, one parade transmits two RS frames, that is, a primary RS frame and a secondary RS frame. In this case, the primary RS frame is divided into a plurality of primary portions, and the mobile service data of each divided primary portion is allocated to the A / B area in the corresponding data group and transmitted. The secondary RS frame is divided into a plurality of secondary portions, and the mobile service data of each divided secondary portion is allocated to the C / D area of the corresponding data group and transmitted. In this case, the RS frame decoder 2006 extracts the mobile service data from the A / B area in the data group as shown in FIG. 51 (b) and configures a primary portion of the plurality of data of one parade. A plurality of primary portions can be obtained by performing the A / B region of the group. In addition, a plurality of primary portions may be collected to construct a primary RS frame. If stuffing bytes are added to the last primary portion, stuffing bytes are removed and a primary RS frame is constructed. In addition, a plurality of secondary portions may be obtained by extracting mobile service data from a C / D region of a corresponding data group and configuring a single secondary portion for the C / D regions of a plurality of data groups in one parade. . In addition, a plurality of secondary portions may be collected to form a secondary RS frame. If stuffing bytes are added to the last secondary portion, stuffing bytes are removed and a secondary RS frame is constructed.

That is, the RS frame decoder 2006 receives the mobile service data of each portion encoded and / or CRC coded from the block decoder 2005, and receives the mobile service data from the operation controller 2000 (or the signaling decoder 2013). After a plurality of input potions are collected according to the output RS frame related information, an RS frame is configured and error correction is performed. Referring to the RS frame mode value in the RS frame related information, an RS frame may be configured, and information on the number and code size of parity of an RS code used to configure an RS frame may be known.

The RS frame decoder 2006 performs an inverse process in the RS frame encoder of the transmission system with reference to RS frame related information to correct errors in the RS frame. In addition, the de-rendering operation is performed after adding the MPEG sync byte of 1 byte that was removed in the RS frame encoding process to the error-corrected mobile service data packet.

FIG. 52 illustrates a process of forming one RS frame and an RS frame reliability map by collecting a plurality of potions transmitted in one parade when the RS frame mode value is 00.

That is, the RS frame decoder 2006 configures an RS frame by collecting the received mobile service data. According to an embodiment of the present invention, the mobile service data is RS encoded data in units of RS frames in a transmission system. In this case, for example, CRC encoding may be performed or may be omitted.

If, in the transmission system, RS frames having a size of (N + 2) x (187 + P) bytes are divided into M portions, mobile service data of M portions is divided into A / B / C / of M data groups. Assuming that the data is allocated to the D region and transmitted, the reception system collects mobile service data of each portion as shown in FIG. 52 (a) to form an RS frame having a size of (N + 2) x (187 + P) bytes.

At this time, if a stuffing byte S is added and transmitted to at least one portion of the RS frame, the stuffing byte is removed and an RS frame and an RS frame credit map are configured. For example, if S stuffing bytes are added as shown in FIG. 27, the RS frames and the RS frame credit map are configured after the S stuffing bytes are removed.

In addition, assuming that the block decoder 2005 outputs a decoding result as a soft decision value, the RS frame decoder 2006 may determine 0 and 1 of a corresponding bit as a sign of the soft decision value. We will collect eight and make up a byte. If all of these processes are performed on the soft decision values of a plurality of portions (or data groups) in one parade, an RS frame having a size of (N + 2) x (187 + P) bytes can be constructed.

In addition, the present invention not only uses the soft decision value to construct an RS frame, but also to construct a reliability map.

The credit map indicates whether or not the corresponding byte formed by collecting eight bits determined by the sign of the soft decision value is reliable.

In an embodiment, when the absolute value of the soft determination value exceeds a preset threshold, the corresponding bit value determined by the sign of the soft determination value is determined to be reliable, and when it is not exceeded, it is determined to be unreliable. Then, in the case where it is determined that even one bit in one byte composed of eight bits determined by the sign of the soft decision value is unreliable, the credit map indicates that the byte is unreliable. Here, one bit is an embodiment, and when a plurality of, for example, four or more bits are determined to be unreliable, it may indicate that the corresponding byte is not reliable in the credit map.

On the contrary, when all bits in one byte are determined to be reliable, that is, when the absolute value of the soft decision value of all bits of one byte exceeds a preset threshold, the corresponding map is marked as reliable. Likewise, if a plurality of bits in one byte, for example, four or more bits are determined to be reliable, the credit map indicates that the bytes are reliable.

The above-described numerical values are merely examples, and the scope of the present invention is not limited to the numerical values.

As described above, the RS frame decoder 2006 generates an RS frame and a credit map using soft decision values of symbols (or bits) turbo-decoded and output by the block decoder 2005. Therefore, when turbo decoding is correctly performed in the block decoder 2005, the reliability of the RS frame and the credit map is also increased.

Therefore, after performing turbo decoding by applying weights in the block decoder 2005, the reliability of the RS frame and credit map generated in the RS frame decoder 2006 is determined by performing turbo decoding without applying weights and then performing RS decoding. It can be seen that the reliability of the RS frame and the credit map generated in (2006) is higher. That is, when the turbo decoder performs weight decoding by applying the weight in the block decoder 2005, the performance of the RS frame decoder 2006 is also increased.

The configuration of the RS frame and the configuration of the credit map using the soft decision value can be performed simultaneously. At this time, the credit information in the credit map corresponds 1: 1 to each byte in the RS frame. For example, if one RS frame has a (N + 2) x (187 + P) byte size, the credit map has a (N + 2) x (187 + P) bit size. 52 (a ') and (b') show a process of forming a credit map according to the present invention.

Subsequently, error correction is performed on the RS frame using RS frame credit map information.

53 shows an embodiment of an error correction decoding process according to the present invention.

53 is a diagram illustrating an error correction process when both RS encoding and CRC encoding are performed on an RS frame in a transmission system.

Next, the error correction process illustrated in FIG. 53 will be described in detail.

That is, as shown in (a) and (a ') of FIG. 53, an RS frame having a (N + 2) x (187 + P) byte size and an RS frame credit map having a (N + 2) x (187 + P) bit size If configured, CRC syndrome check is performed on this RS frame to check whether an error occurs in each row. Next, as shown in (b) of FIG. 53, an RS frame having a size of Nx (187 + P) bytes is formed by removing the 2-byte CRC checksum, and an error flag corresponding to each row indicates whether an error occurs. Similarly, since the portion of the credit map corresponding to the CRC checksum is not utilized, this portion is removed to leave only Nx (187 + P) credit information as shown in FIG. 53 (b ').

After the CRC syndrome check is performed as described above, RS decoding is performed in the column direction. In this case, RS erasure correction may be performed according to the number of CRC error flags. That is, as shown in (c) of FIG. 53, the CRC error flag corresponding to each row in the RS frame is checked, so that the maximum number of RS erasure corrections can be performed when the number of rows having an error is performed in the RS direction column decoding. Determine if it is less than or equal to the number of errors. The maximum error number is a parity number P inserted during RS encoding.

In an embodiment of the present invention, it is assumed that the parity number P added to each column is 48.

In this case, if the number of rows having a CRC error is less than or equal to the maximum number of errors that can be corrected by RS erasure decoding (48 according to the embodiment), as shown in (d) of FIG. (235,187) -RS erasure decoding is performed in the column direction on an RS frame having 235 N byte rows, and as shown in (e) of FIG. 53, 48 bytes of parity data added to the end of each column are removed.

However, if the number of rows having a CRC error is larger than the maximum number of errors that can be corrected by RS erasure decoding (that is, 48), RS erasure decoding cannot be performed.

In this case, error correction may be performed through general RS decoding. In addition, the present invention can further improve error correction capability by using a credit map generated when constructing an RS frame from the soft decision value.

That is, in the RS frame decoder, the absolute value of the soft decision value of the block decoder 2005 is compared with a preset threshold to determine the credit of the bit value determined by the sign of the soft decision value. Credit information for the corresponding byte formed by collecting eight bits determined by the sign of the soft decision value was displayed on the credit map.

Accordingly, the present invention does not assume that all bytes of the row have an error even if it is determined that there is a CRC error as a result of the CRC syndrome check of the specific row as shown in FIG. Set to error only for bytes determined to be unreliable by reference. That is, only the bytes determined to be unreliable in the credit information of the credit map regardless of the CRC error of the corresponding row are set as erasure points.

Alternatively, the CRC syndrome check determines that there is a CRC error in the row, and sets an error only for bytes determined that the credit information of the credit map is unreliable. That is, only a byte having a CRC error in a corresponding row and determined to be unreliable in credit information of a credit map is set as an erasure point.

Then, if the number of error points in each column is less than or equal to the maximum number of errors that can be corrected by RS erasure decoding (that is, 48), RS erasure decoding is performed on the column. On the contrary, if the number of error points is larger than the maximum number that can be modified by RS erasure decoding (that is, 48), general RS decoding is performed on the column.

In other words, if the number of rows with CRC errors is greater than the maximum number of errors that can be corrected by RS erasure decoding (for example, 48), then the corresponding columns in accordance with the number of erasure points in the column determined by the credit information of the credit map RS erasure decoding is performed or general RS decoding is performed.

For example, the number of rows having a CRC error in the RS frame is greater than 48, and the number of erasure points determined by the credit information of the credit map is 40 in the first column and 50 in the second column. Suppose Then, (235,187) -RS erasure decoding is performed on the first column, and (235,187) -RS decoding is performed on the second column.

When error correction decoding is performed in all column directions in the RS frame by performing the above process, 48 bytes of parity data added to the end of each column are removed as shown in FIG.

As described above, in the present invention, even if the total number of CRC errors corresponding to each row in the RS frame is larger than the maximum error number that can be corrected by RS erasure decoding, the credit information of the corresponding credit map of the corresponding column is determined when the error correction decoding of the specific column is performed. Therefore, if the number of bytes with low credibility is equal to or smaller than the maximum error number correctable by RS erasure decoding, RS erasure decoding may be performed on the column.

Here, the difference between general RS decoding and RS erasure decoding is the number of correctable errors. That is, if general RS decoding is performed, errors can be corrected by the number (for example, 24) corresponding to (number of parity) / 2 inserted in the RS encoding process. If RS erasure decoding is performed, RS encoding process is performed. An error may be corrected by the number of parities inserted (e.g., 48).

After the error correction decoding is performed as described above, as shown in (e) of FIG. 53, an RS frame having 187 N-byte rows (that is, a packet) can be obtained. RS frames of size Nx187 bytes are output in the order of N 187 bytes, in which case, as shown in (f) of FIG. 53, 1-byte MPEG sync bytes deleted by the transmission system are added to each of the 187 bytes packets. Outputs a mobile service data packet in units of 188 bytes.

The RS frame-decoded mobile service data as described above is derandomized and output in the reverse process of the randomizer of the transmission system. In this way, mobile service data transmitted from the transmission system can be obtained.

The present invention provides an RS frame decoder in parallel by the number of parades in one M / H frame (= M), and a multiplexer for multiplexing a plurality of portions at an input of the M RS frame decoders. The output terminal may include a demultiplexer to configure an RS frame decoder.

The present invention described so far is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such modifications are the scope of the present invention. Belongs to.

1 illustrates an example of an M / H frame structure for transmitting and receiving mobile service data according to the present invention.

2 illustrates an example of a general VSB frame structure.

FIG. 3 is a diagram of the present invention showing an example of mapping of the first four slot positions of a subframe in a spatial domain, for one VSB frame; FIG.

4 is a diagram of the present invention showing an example of mapping of the first four slot positions of a subframe in a time domain, for one VSB frame;

5 illustrates an embodiment of a structure of a data group after data interleaving according to the present invention.

6 is an enlarged view of a portion of FIG. 5;

7 illustrates an embodiment of a structure of a data group before data interleaving according to the present invention.

8 is an enlarged view of a portion of FIG. 7;

9 illustrates an example of a data group order allocated to one subframe among five subframes constituting an M / H frame according to the present invention.

10 illustrates an example of allocating a single parade to one M / H frame according to the present invention.

11 illustrates an example of allocating three parades to one M / H frame according to the present invention.

FIG. 12 is a diagram illustrating an example in which the allocation process of three parades of FIG. 11 is extended to five subframes.

FIG. 13 is a diagram illustrating a data transmission structure according to an embodiment of the present invention, and illustrates a state in which signaling data is included and transmitted in a data group.

14 is a schematic structural block diagram of a transmission system according to an embodiment of the present invention;

15 illustrates an embodiment of an RS frame according to the present invention.

16 illustrates an example of an M / H header structure in an M / H service data packet according to the present invention.

17 (a) and 17 (b) show another embodiment of an RS frame according to the present invention.

18 is a block diagram illustrating an embodiment of the service multiplexer of FIG. 14.

19 is a block diagram showing an embodiment of the transmitter of FIG.

20 is a block diagram illustrating an embodiment of the preprocessor of FIG. 19.

FIG. 21 is a block diagram showing an embodiment of the M / H frame encoder of FIG. 20. FIG.

FIG. 22 is a detailed block diagram of an embodiment of the RS frame encoder of FIG. 21. FIG.

23A and 23B illustrate a process in which one or two RS frames are divided into a plurality of portions according to RS frame mode values according to the present invention, and each portion is assigned to each data group.

24 (a) to (c) illustrate an error correction encoding and error detection encoding process according to an embodiment of the present invention.

25 (a) to (d) are diagrams illustrating a low mixing process of a super frame unit according to an embodiment of the present invention;

(A) and (b) of FIG. 26 show an example in which one parade is composed of two RS frames.

27A and 27B illustrate an embodiment of a process of dividing an RS frame to form a data group according to the present invention.

28 is a block diagram showing an embodiment of a block processor according to the present invention;

29 illustrates an embodiment of a convolutional encoder in a block processor according to the present invention.

30 illustrates an example of symbol interleaving of a block processor according to the present invention.

31 is a block diagram illustrating an embodiment of the group formatter of FIG. 20.

32 is a block diagram showing an embodiment of a trellis encoder according to the present invention

33 is a diagram illustrating an example of allocating a signaling information region to a portion of a data group according to the present invention.

FIG. 34 is a block diagram showing an embodiment of the signaling encoder of FIG. 20. FIG.

35 is a diagram illustrating an embodiment of a syntax structure of TPC data according to the present invention.

36 shows an example of a transmission scenario of TPC data and FIC data according to the present invention.

37 is a view showing an example for controlling a power source in a parade unit according to the present invention.

38 illustrates an example of arrangement of training sequences in a data group before trellis coding according to the present invention.

39 is a view showing an example of arrangement of training sequences in a data group after trellis coding according to the present invention.

40 is a block diagram showing an embodiment of a receiving system according to the present invention;

FIG. 41 is a block diagram showing an embodiment of a demodulator in a reception system according to the present invention; FIG.

FIG. 42 is a detailed block diagram illustrating an embodiment of the operation controller of FIG. 41. FIG.

43 illustrates an example of linear interpolation according to the present invention.

44 shows an example of linear extrapolation according to the present invention.

45 is a block diagram illustrating an embodiment of a channel equalizer according to the present invention.

46 is a detailed block diagram showing an embodiment of a block decoder according to the present invention.

47 illustrates an example of a combining rule of an M / H block when an SCCC block mode value is 01 according to the present invention.

48 is a detailed block diagram showing another embodiment of a block decoder according to the present invention.

49 is a diagram illustrating an example of obtaining a confidence value of a forward metric for each state when a weight according to the present invention is not applied.

50 shows an example of obtaining a confidence value of a forward metric for each state when a weight according to the present invention is applied.

51 (a) and 51 (b) illustrate an example of a process of forming a plurality of potions and configuring one or two RS frames.

52 and 53 illustrate an embodiment of an error correction decoding process according to the present invention.

Claims (14)

A signal receiver configured to receive and demodulate a broadcast signal including a data group including a mobile service data and a plurality of known data streams; An equalizer for channel equalizing a data group included in the demodulated broadcast signal using the known data sequence; An inner decoder configured to perform trellis decoding by matching the mobile service data in the data group inputted to the block size for turbo decoding by the equalizer with the mobile service data which is symbol-decoded and fed back; A reliability adjusting unit for adjusting the reliability of the mobile service data according to a position in the data group of the trellis decoded mobile service data; An outer decoder for performing symbol decoding on the mobile service data output from the reliability controller to feed back to the inner decoder; And And an error correcting unit correcting an error generated in the mobile service data output from the outer decoding unit. The method of claim 1, The inner decoding unit performs trellis decoding on mobile service data in symbol units, and outputs a soft decision value of each symbol. The method of claim 2, The soft decision value of the symbol is a log ratio LLR (0) of the probability value that the symbol becomes "00", a log ratio LNK (1) of the probability value that becomes "01", and a log ratio of probability value that becomes "10". (LLR (2)) A receiving system which is the logarithmic ratio LLR (3) of the probability value to be "11". The method of claim 2, The data group is divided into ten M / H blocks (first M / H block to tenth M / H block) according to positions of known data columns. The method of claim 4, wherein The reliability adjustment unit is a weight that is preset to the soft decision value of the symbol if the soft decision value of the symbol is a soft decision value of a symbol obtained from the mobile service data of the 1,2,9, 10th M / H blocks in the data group. Multiplying to lower the reliability of the soft decision value of the symbol. The method of claim 5, wherein And the reliability adjustment unit lowers the reliability of the soft decision value of the symbol by multiplying the soft decision value of the symbol by a weight less than one. The method of claim 4, wherein The reliability adjustment unit adjusts the reliability of the trellis-decoded mobile service data when two M / H blocks are combined and transmitted by SCCC block coding in a transmission system. Receiving and demodulating a broadcast signal including a data group including a mobile service data and a plurality of known data streams; Channel equalizing a data group included in the demodulated broadcast signal using the known data sequence; Performing trellis decoding by matching the mobile service data in the data group inputted in the block size for turbo decoding with the channel equalization and the mobile service data which is symbol-decoded and fed back; Adjusting the reliability of the mobile service data according to the position in the data group of the trellis decoded mobile service data; Performing symbol decoding on the mobile service data output in the reliability adjustment step and then feeding back for trellis decoding; And And correcting an error generated in the symbol decoded mobile service data. The method of claim 8, The trellis decoding step performs trellis decoding on mobile service data in symbol units and outputs a soft decision value of each symbol. The method of claim 9, The soft decision value of the symbol is a log ratio LLR (0) of the probability value that the symbol becomes "00", a log ratio LNK (1) of the probability value that becomes "01", and a log ratio of probability value that becomes "10". (LLR (2)) A broadcast signal processing method of a reception system, which is a log ratio (LLR (3)) of a probability value to be "11". The method of claim 9, And the data group is divided into ten M / H blocks (first M / H block to tenth M / H block) according to positions of known data streams. The method of claim 11, If the soft decision value of the symbol is a soft decision value of a symbol obtained from the mobile service data of the first, second, ninth, and tenth M / H blocks in the data group, the reliability adjustment step is preset to the soft decision value of the symbol. And multiplying weights to lower the reliability of the soft decision value of the symbol. The method of claim 12, And adjusting the reliability by multiplying the soft decision value of the symbol by a weight less than 1 to reduce the reliability of the soft decision value of the symbol. The method of claim 11, When two M / H blocks are combined and transmitted by SCCC block coding in a transmission system, the reliability adjustment step includes broadcasting signal processing of a reception system that adjusts reliability of the trellis-decoded mobile service data. Way.

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