KR101304092B1 - Method and apparatus for buffering and decoding received data in a receiver of digital video broadcasting system - Google Patents

Abstract

The present invention relates to a method and an apparatus for buffering and decoding received data at a receiver of a digital broadcasting system, and a method of buffering received data at a receiver of a digital broadcasting system transmitting a transport stream (TS) packet includes an error in the TS packet. Checking the detection flag to determine whether the TS packet is in an error state; detecting at least one TS packet belonging to the same section; and continuous counter information from header information of at least one TS packet belonging to the same section; And calculating and buffering a buffering position of a normal TS packet using the buffer. In the present invention, the method for decoding the buffered data, when an error occurs as a result of the error detection of the TS packet, performs a correlation on the header information of the TS packet to satisfy the condition of similarity or reliability, the TS packet It is determined that the error does not occur and performs repeated decoding.

Therefore, according to the present invention, MPE-FEC decoding can improve the performance of MPE-FEC decoding because buffering of section data is performed in units of TS packets, and decoding is performed by deleting only data of an errored TS packet. By performing iterative decoding on the data of the TS packet in which the error occurs, the MPE-FEC decoding performance can be further improved.

TS packet, DVB-H, buffering, section, MPE-FEC, RS decoding

Description

Method and apparatus for buffering and decoding received data in a receiver of a digital broadcasting system {METHOD AND APPARATUS FOR BUFFERING AND DECODING RECEIVED DATA IN A RECEIVER OF DIGITAL VIDEO BROADCASTING SYSTEM}

1 is a block diagram showing a configuration of a receiver in a general digital broadcasting system using a TS packet as a transmission unit

FIG. 2 is a block diagram illustrating a configuration of a conventional section detection and buffering device included in the receiver of FIG. 1.

3 is a diagram illustrating a detection and buffering process of a section including a TS packet in which a conventional error occurs;

4 is a flowchart illustrating a conventional section detection and buffering method.

5 is a block diagram illustrating a configuration of a section detection and buffering apparatus in a digital broadcasting system according to a first embodiment of the present invention.

6 is a diagram illustrating a detection and buffering process of a section including an error TS packet according to the first embodiment of the present invention.

7 is a flowchart illustrating a section detection and buffering method according to a first embodiment of the present invention.

8 is a diagram illustrating a header structure of a TS packet in a general DVB-H system.

9 illustrates a correlation apparatus of a TS packet header according to a second embodiment of the present invention.

10 is a diagram illustrating a first decoding process in an iterative decoding method according to a second embodiment of the present invention.

11 is a diagram illustrating a second decoding process in an iterative decoding method according to a second embodiment of the present invention.

12 is a diagram illustrating a detection and buffering process of a section in an iterative decoding method according to a second embodiment of the present invention.

13 is a flowchart showing an iterative decoding method according to a second embodiment of the present invention.

The present invention relates to a method and apparatus for receiving a transport stream (hereinafter referred to as "TS") packet in a digital broadcasting system, and in particular, a receiver of a digital video broadcasting-handheld (DVB-H) system. The present invention relates to a method and apparatus for decoding received data.

Recently, with the development of data compression technologies such as audio and video and communication technologies, digital broadcasting, which can provide high quality voice and video services anywhere through a fixed or mobile terminal, has been realized. Examples of such digital broadcasting include digital audio broadcasting (DAB), digital radio broadcasting (DRS), digital audio radio system, and audio, video, and data services. So-called digital multimedia broadcasting (DMB) systems. In addition, the DVB-H system, which enhances the mobility and portability of the European digital audio broadcasting system Eureka 147 (European Research Coordination Agency project-147) system and the DVB-T (Terrestrial) system, which is one of the digital broadcasting standards, has recently received attention. have.

The physical layer specification of the DVB-H system follows most of the specifications of the DVB-T system and multi-protocol encapsulation-forward error to ensure stable reception of data at the receiver while moving. Additional error correction coding techniques such as Correction (MPE-FEC) are supported. That is, the DVB-H system, which is a mobile broadcasting system for Europe, uses MPE-FEC technology to improve channel decoding performance in the DVB-T system, which is a fixed broadcast reception technology. The MPE-FEC technique proposes to obtain more channel coding gains by forming bursts with IP datagrams and adding (255, 191) Reed-Solomon (RS) coding for each row component. Technology has become.

In the DVB-H system using the MPE-FEC technology, broadcast data is made into an IP datagram, and at least one IP datagram constitutes one burst. The bursts configured as described above are then (255, 191) RS encoded. The section data is divided into an MPE section carrying an IP datagram and an MPE-FEC section carrying parity data generated by the RS encoding. Hereinafter, for convenience of description, the MPE section and the MPE-FEC section will be referred to as sections without distinguishing them.

The section data is carried in a payload of a TS packet, which is a transmission unit of a DVB-H system, and transmitted through a physical layer. The TS packet has a fixed length of, for example, 188 bytes and is (204, 188) RS encoded, then convolutionally coded and transmitted. One section is transmitted through one or more TS packets.

Hereinafter, an operation of a receiver for detecting section data and performing decoding for MPE-FEC RS decoding in a general DVB-H system transmitting a TS packet will be described.

1 is a block diagram illustrating a configuration of a receiver in a general digital broadcasting system using a TS packet as a transmission unit.

In FIG. 1, the TS packet received from the wireless network is received by the RF demodulator 103 through the antenna 101, and down-converted and demodulated by the RF demodulator 103 and converted into a digital signal. The converted digital signals are OFDM symbols, and are converted into signals in the frequency domain by the fast fourier transform (FFT) processor 105. The symbol deinterleaver 107 deinterleaves the signal converted into the signal in the frequency domain in units of symbols and outputs the deinterleaving unit. The symbol demapper 109 demaps the deinterleaved signal based on a predetermined modulation scheme such as QPSK, 16-QAM, or 64-QAM, and outputs the deinterleaved signal to the bit deinterleaver 111. Then, the bit deinterleaver 111 performs deinterleaving in units of bits, respectively.

In addition, in FIG. 1, the channel decoder 113 includes a Viterbi decoder (not shown) and an RS decoder (204, 188), and performs channel decoding and (204, 188) RS decoding. The decoded signal is synchronized with the TS packet synchronizer 115 and descrambled by the descrambler 117. In FIG. 1, the MPE-FEC decoder 119 performs packet identifier filtering on the descrambled signal, analyzes header information of the TS packet, and detects a section by detecting the packet. The original broadcast data is restored by performing buffering, MPE-FEC decoding, and RS decoding for one section.

Hereinafter, a section detection and buffering process for conventional MPE-FEC decoding will be described with reference to FIG. 2.

The prior art uses cyclic redundancy check (CRC) results to detect sections. In FIG. 1, the descrambler 117 transmits TS packets of 188 bytes. The TS packet includes information indicating the starting point of a section and PID information. The PID is called a packet identifier and is used to classify different service program information. One section includes header information, data information, and CRC information. However, the starting point of the header in the section is irregular in the TS packet. Therefore, information indicating the header start point of the section exists in the header information of the TS packet. It also tells whether there is header information or section information in the TS packet.

2 is a block diagram illustrating a configuration of a conventional section detection and buffering device 200 provided in the receiver of FIG. 1.

When the operation of extracting sections from TS packets is defined as section detection, in FIG. 2, the TS packet header analyzer 201 extracts the header information of the TS packet and transmits the header information of the TS packet to the first register 203. The payload carrying the data of the TS packet is delivered to the section header analyzer 205. The section header analyzer 205 receives the information from the first register 203 in which the header information of the TS packet is stored, and distinguishes the header information of the section from the payload section of the TS packet and the payload information of the section. If the payload of the section includes the header information of the section, the header information of the section is extracted and transferred to the second register 207. If the payload of the TS packet contains the section data, the payload of the TS packet is Pass to section buffer and CRC block 209.

In FIG. 2, the section buffer and CRC block 209 buffer the payload of the section and perform a CRC check for validity test of the buffered section data. The section buffer and the CRC block 209 transfer the section data and the validity result information on which the validity of the section data has been tested to the MPE-FEC buffer 211. In addition, the section buffer and the CRC block 209 receives the size information of the section from the second register 207, and outputs a decoding start signal to the MPE-FEC RS decoder 213. Accordingly, the MPE-FEC RS decoder 213 restores the original broadcast data by performing RS decoding on the section data based on the validity result information transmitted from the MPE-FEC buffer 211. In the above operation, the section buffer and the CRC block 209 determine whether to buffer the MPE-FEC buffer 211 based on the CRC check result of the buffered section data.

In general, in the case of MPE-FEC erasure RS decoding including the deletion information, the more valid section data or the more information of the erasure result, the more likely the RS decoding of the section data is successful. The validity result information is input from the MPE-FEC buffer 211 to the MPE-FEC RS decoder 213, and the deletion information indicates that an error exists at any position of the section data. Knowing the location of the error doubles the ability to correct the error. However, looking at the process of detecting and buffering the actual section, since one section may be composed of multiple TS packets, even if only one of the TS packets included in one section fails, the CRC check for the section fails. You get a result. As a result, when a section is composed of two or more TS packets, even if an error exists in only one TS packet among a plurality of TS packets, the TS packet (s) without any error are discarded together. Therefore, the conventional section detection and buffering method is inefficient. can do. That is, the longer the length of a section is, even if only one TS packet fails, all data of the remaining TS packets included in the section are treated as invalid. Therefore, in the conventional section detection and buffering method, processing occurs due to ineffectiveness even for a normal TS packet, thereby substantially reducing error correction capability of MPE-FEC decoding.

3 is a diagram illustrating a detection and buffering process of a section including a TS packet in which a conventional error occurs. In FIG. 3, reference numeral 310 denotes a sequence of received TS packets, and 330 denotes a sequence of received TS packets. Reorganized into sections. In addition, reference numeral 350 denotes a process of buffering by treating the invalid section in the MPE-FEC buffer 211 of FIG. 2 as invalid. In the sequence 310 of TS packets of FIG. 3, a TS packet indicated by "O" in the upper right corner shows a TS packet 311 that is normally received, and a TS packet indicated by "X" indicates a TS packet 313 in which an error has occurred. ). When the TS packet 313, which has an error in the process of reconstructing the TS packets in the unit of section, is included, the section buffer and the CRC block 209 are invalid in the entire section data as shown by reference numeral 351 of FIG. And only the section data where no error occurred, such as 353, is buffered.

4 is a flowchart illustrating a method of detecting and buffering a section in a conventional receiver. In step 401, the receiver checks whether an error occurs in a TS packet and then performs PID filtering in step 403 to detect a TS packet of a desired program. Thereafter, in step 405, the receiver analyzes the header information of the TS packet to find the header start position of the section data. In step 407, the receiver analyzes the header information of the section, and in step 409, the receiver buffers the corresponding section data in the section buffer. . In step 411, the receiver performs a CRC check on the buffered section. In step 413, the receiver buffers the data of the section having the CRC check result as “Good” in the MPE-FEC buffer 211. Treat all as invalid. Thereafter, in step 415, when the receiver receives all of the bursts, the receiver performs MPE-FEC RS decoding to perform error correction. As described above, the detection and decoding method of the conventional section includes TS packets that are normally received in one section that is composed of two or more TS packets. If present, the entire data of the section shall be treated as invalid. Therefore, it can be seen that inefficient MPE-FEC decoding is performed.

Accordingly, the present invention provides a method and apparatus for decoding received data capable of improving MPE-FEC decoding performance in a receiver of a digital broadcasting system.

The present invention provides a method and apparatus for decoding section data using an error detection flag of a TS packet in a receiver of a digital broadcasting system.

The present invention provides a method and apparatus for decoding section data including error information in a receiver of a digital broadcasting system.

In a method of buffering and decoding section data in a receiver of a digital broadcasting system transmitting a transport stream (TS) packet according to the present invention, checking whether an error of the TS packet is confirmed by checking an error detection flag from header information of the TS packet. Analyzing the header information of the TS packet to find the header start position of the section, and then detecting at least one TS packet belonging to the same section, and header information of at least one TS packet belonging to the same section Checking the number of TS packets in error by using the continuous counter information, and calculating and buffering buffering positions of the data of the remaining TS packets except the data of the TS packets in error; MPE-FEC decoding process using the buffered data and the erase information All.

An apparatus for buffering and decoding section data in a receiver of a digital broadcasting system for transmitting a transport stream (TS) packet according to the present invention includes a TS packet header analyzer for extracting header information of the TS packet, and extracts header information of the section. An error detection flag by checking a section header analyzer, a register for storing the TS packet and header information of the section, a buffer for buffering the data of the section, and header information of the TS packet stored in the register to check the corresponding TS. After checking whether there is an error of the packet, finding the header start position of the section, checking the number of TS packets in which the error occurred, and calculating buffering positions of the normal TS packets except the data of the TS packet in which the error occurred. A section buffer and an error checking block for buffering data of the section in the buffer; Using the buffered data and the erasure information is characterized in that it comprises an MPE-FEC decoding block for performing MPE-FEC decoding.

The decoding method according to the present invention is a method of decoding received data in a receiver of a system for transmitting a transport stream (TS) packet, and determines whether the received TS packet is an error, and generates error information indicating whether the error is an error. And a process of performing RS decoding using the received TS packet and valid information; and if the RS decoding fails as a result of the RS decoding, a synchronization information field and a packet of header information of a TS packet with respect to an errored TS packet. Performing a correlation check of the header using an ID field and continuous counter information, updating the error information using a result of the correlation check of the header, and receiving the received TS packet and the updated error information. It includes the process of performing RS decoding using.

In the decoding apparatus according to the present invention, a device for buffering and decoding section data in a receiver of a digital broadcasting system transmitting a TS (Transport Stream) packet divides user information into sections, and each section is divided into two or more packets for transmission. Wherein the sections have a section header, the packet has a predetermined fixed value, a value indicating the type of the information, and an identifier indicating the continuity of the information, and the channel information and the Reed-Solomon (RS) An apparatus for decoding a received packet from a receiver of a system for encoding and including an error detection bit, the packet header analyzer extracting header information of the packet, and the section header analyzer extracting header information of the section. And a register for storing header information of the packet and the section, and included in the packet. A buffer buffering user information, a correlator for checking a correlation of the packet header and providing a validity value, error information of a packet from an error detection flag from header information of the packet stored in the register, and header start of the section From the position, the buffering position is determined according to the number of packets in which an error is generated, and is received from the section buffer and the error checking block for updating the error information according to the validity value during repeated decoding, and from the buffer and the section buffer and the error checking block. And a decoder that performs RS decoding using the received information.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention. Prior to explaining the basic concept of the first embodiment of the present invention, the present invention is proposed to improve the performance of MPE-FEC decoding by using the error detection flag of the TS packet. That is, in the conventional decoding method, the section detection and buffering method determines whether to buffer based on the CRC test result of the section data. The section detection and buffering scheme proposed by the present invention is based on the error detection flag of the TS packet, that is, the result value of the RS decoding performed by the channel decoder and the continuity counter information to be described later between the TS packets. You decide whether to buffer. The channel decoder located at the front of the block where the detection and buffering of the section and the RS decoding in the receiver of the DVB-H system is performed includes a Viterbi decoder as described above and other RS decoders of the (204, 188) standard, for example.

In the first embodiment of the present invention, the 1-bit result value of RS decoding performed in the channel decoder is set as an error detection flag of a TS packet, and the error detection flag is included in a TS packet header output from the channel decoder to provide MPE-. It is used in the FEC buffering process and used for MPE-FEC decoding. Therefore, in the first embodiment proposed by the present invention, an error detection flag of a TS packet is used for section detection and buffering of a TS packet unit for MPE-FEC decoding.

According to the experiments of the present applicant, applying the first embodiment according to the present invention, it was confirmed that the decoding accuracy of the (204,188) RS decoding performed in the channel decoder is very high, so that the probability of misjudgment is very low, such as 10-6. . When buffering section data in units of TS packets according to the present invention, the number of TS packets having an error must be determined, which can be determined using continuity counter information included in header information of a TS packet. have. Therefore, by using the section data detection method of the present invention, it is possible to prevent the loss of the normal section data, thereby improving the performance of MPE-FEC decoding.

Hereinafter, the header structure of the TS packet including the error detection flag and the continuity counter information will be described with reference to Table 1 and FIG. 8, and then the first embodiment of the present invention will be described with reference to FIGS. 5 to 7. An embodiment will be described in detail.

8 is a diagram illustrating a header structure of a TS packet in a general DVB-H system. Referring to the header 803 structure of the TS packet 801, the header of the TS packet is a "sync byte" field 805 for synchronization. (Hereinafter referred to as a "synchronous information field"), a "transport error indicator" field 807 indicating the error detection flag, and a "payload unit start indicator" field indicating whether a section header is included in the TS packet. 809, a " PID " field 811 indicating an identifier of a program transmitted through the TS packet, and a " continuity counter " indicating a serial number of TS packets circulated from 0 to 15 in the stream of TS packets, for example. continuity counter) field 813 and an "adaption field" field 815 including a pointer byte indicating the location of the section header information. The pointer byte is contained in the "adaption field length" field 817 in the "adaption field" field 815.

The receiver of the present invention for receiving the TS packet having the header structure has the same configuration as the receiver of FIG. 1 except that the section data detection and buffering apparatus for decoding according to the first embodiment of the present invention is the MPE of FIG. 1. Is provided in the FEC decoder 119. Therefore, a detailed description of the same configuration as in FIG. 1 will be omitted, and the decoder according to the first embodiment of the present invention will be described below.

5 is a block diagram showing a detailed configuration of a decoder in a receiver of a digital broadcasting system according to the first embodiment of the present invention.

In FIG. 5, the TS packet header analyzer 501 extracts the header information of the TS packet and transmits the header information of the TS packet to the first register 503, and the payload including the TS packet data is transferred to the section header analyzer 505. To pass. The section header analyzer 505 receives information from the first register 203 in which the header information of the TS packet is stored, and divides the header information of the section and the payload information of the section into the payload of the TS packet. If the payload of the section includes the header information of the section, the header information of the section is extracted and transferred to the second register 507. If the payload of the TS packet contains the section data, the payload of the TS packet is Pass to section buffer and error checking block 509. The section buffer and error check block 509 buffers section data in units of TS packets. The first register 503 provides the error detection flag and continuous counter information to the section buffer and error check block 509 from header information of a TS packet in accordance with the present invention. Accordingly, the section buffer and error check block 509 according to the present invention checks the error detection flag to check whether an error occurs in the corresponding TS packet, and checks the continuous counter information to continuously receive the TS packet stream. The number of TS packets having an error is checked. As described above, the section buffer and error check block 509 checks the number of TS packets in which an error has occurred, and then calculates buffering positions of the remaining normal TS packets.

In FIG. 5, the section buffer and error checking block 509 receives the size information of the section from the second register 507, outputs a decoding start signal to the MPE-FEC RS decoder 513, and checks for errors. The MPE-FEC buffer 511 transfers the completed section data and error information indicating whether or not the data is valid. Section data stored in the MPE-FEC buffer 511 is buffered in units of TS packets. The MPE-FEC RS decoder 513 restores the original broadcast data by performing MPE-FEC RS decoding on the section data based on the error information transmitted from the MPE-FEC buffer 511. As described above, the section buffer and error check block 509 according to the present invention does not determine whether to buffer the MPE-FEC buffer 211 based on the CRC check result of the buffered section data as in the prior art. Based on the error detection flag and the continuous counter information, whether or not an error occurs in the TS packet and the number of TS packets in which an error has occurred is determined, and a buffering position of a normal TS packet except for the TS packet in which an error occurs is calculated. Therefore, in the present invention, when the MPE-FEC RS decoding, the amount of the buffered section data is increased compared to the prior art, so that the performance of the MPE-FEC RS decoding can be improved by performing accurate decoding.

FIG. 6 is a diagram illustrating a detection and buffering process of a section including an error TS packet according to the first embodiment of the present invention. In FIG. The detailed description thereof will be omitted.

In FIG. 6, reference numeral 610 illustrates a buffering process when a TS packet in which an error occurs in the MPE-FEC buffer 511 of FIG. 5 and a normally received TS packet are divided by using error information according to the present invention. In the sequence 310 of TS packets of FIG. 6, a TS packet indicated by "O" in the upper right corner shows a TS packet 311 that is normally received, and a TS packet indicated by "X" indicates a TS packet 313 in which an error has occurred. ). When the TS packet 313 having an error is included in the process of reconstructing the section data in units of TS packets, the section buffer and the error checking block 509 may be configured as shown by reference numeral 611 of FIG. 6. Only data is treated as an error, and data of normally received TS packets as shown by reference numerals 613 and 615 are buffered within the same section. As such, only the payload of the TS packet having an error is treated as an error, thereby improving the performance of decoding the entire section.

FIG. 7 is a flowchart illustrating a section detection and buffering method according to a first embodiment of the present invention. In step 701, a receiver checks an error detection flag described in Table 1 above from header information of a TS packet to determine an error of a TS packet. After checking whether or not, in step 703, PID filtering is performed to detect TS packets of a desired program. Thereafter, in step 705, the receiver analyzes the header information of the TS packet to find the header start position of the section, and then in step 707, the receiver obtains the continuous counter information described in Table 1 from the header information of the at least one TS packet belonging to the same section. The number of TS packets having an error in the stream of TS packets continuously received is checked. In operation 709, the receiver analyzes the number information of the TS packet in which the error occurs and the header information of the section, and calculates buffering positions of the normal TS packets except for the TS packet in which the error occurs in step 711. In step 713, the receiver buffers section data in units of TS packets according to the buffering position calculated in step 711. In step 715, the receiver restores the original broadcast data by performing MPE-FEC RS decoding when buffering section data of one burst. As described above, the MPE-FEC decoding can improve the performance of MPE-FEC decoding because buffering of section data is performed in units of TS packets and decoding is performed by deleting only data of an errored TS packet. have.

Second Embodiment

Before explaining the second embodiment of the present invention, the basic concept of the second embodiment of the present invention will be described. In the first embodiment of the present invention, MPE-FEC buffering is performed in units of TS packets by using a result value of (204,188) RS decoding performed in a channel decoder. (204, 188) In the case of RS decoding, error correction is possible for an error of up to 8 bytes, and an error has been set for more errors. Although this error is set to occur even in an error situation slightly larger than 8 bytes of the 188 bytes of the TS packet, it cannot be utilized during the MPE-FEC decoding process, but many data portions of 188 bytes can be assumed to be data without errors.

Therefore, in the second embodiment of the present invention, first, MPE-FEC decoding is performed according to the first embodiment of the present invention. As mentioned above, in the MPE-FEC decoding process according to the first embodiment, a TS packet in which an error is detected is not used. Thereafter, the header part is correlated with the header part of the TS packet before or after the error is detected, and the similarity or reliability is determined, and when the similarity or reliability condition is satisfied, the TS packet is not detected. If not, MPE-FEC decoding is performed once more. As described above, MPE-FEC RS decoding may be repeatedly performed on two cases in which there is an error in the TS packet in which an error is detected, and the probability of error correction may be further improved.

FIG. 9 is a diagram illustrating a correlation apparatus of a TS packet header according to a second embodiment of the present invention. In FIG. 9, the same elements as in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted. .

In FIG. 9, parts that can be easily detected for a sequence of consecutive TS packets are information on a synchronization information field 805, a "PID" field 811, and a "continuity counter" field 813. .25 bits of the synchronization information field 805, the "PID" field 811, and the "continuity counter" field 813, even if the TS packet has an error and the error detection flag is set to "1". Comparing the information, the receiver can roughly determine whether or not it is a TS packet to be received.

9 shows information of a header input for determining similarity or reliability of the above-described header information. Since the synchronization information field field 805 is a predetermined value, it may be determined whether the received value and the predetermined value match to determine similarity or reliability of the received TS packet. In addition, since the "PID" field 811 includes broadcast information, it is possible to determine whether the receiver is a PID of a broadcast to be received. The "previous continuity counter" field 901 is a value of the continuity counter field of the previously received TS packet. That is, to check the continuity of the packet by comparing the "continuity counter" field 813 and the "previous continuity counter" field 901. In more detail, the continuity of the currently received packet may be checked using a previous continuity counter value according to the cyclic repetition characteristic of the continuity counter. Therefore, through this, it is possible to determine whether the TS packet in which the current error has occurred is a packet to be originally received.

The TS packet header correlator 903 is provided according to the present invention. When applied to the first embodiment of the present invention, the TS packet header correlator 903 receives information from the first register 503 of FIG. May be provided to the section buffer and error check block 509 or / and the MPE-FEC buffer 511. Therefore, in the iterative decoding according to the present invention, the MPE-FEC RS decoder 513 can perform the iterative decoding using the result of the correlation checked in the correlator 903.

10 is a diagram illustrating a first decoding process in an iterative decoding method according to a second embodiment of the present invention.

The data shown in FIG. 10 are divided into reliable data and data in which an error exists. Therefore, in the case of reliable data, it is indicated as "reliable" in FIG. 10, and an error exists, that is, in the case of unreliable data, it is indicated as "erasure" in FIG. Such information is set for each TS packet, which is information detected according to an error check result, and correspondingly, data is stored in the MPE-REC buffer 511 in the form shown in FIG. 10. have. The "reliable" and "erasure" information shown in FIG. 10 are stored separately from the data and input to the MPE-FEC RS decoder 513.

TS packets received by the receiver are buffered in the MPE-FEC buffer 511 in units of one burst 1001 having a vertical axis of 256, 512, or 1024 bytes and a horizontal axis of 255 bytes. At this time, the order in which the TS packets are stored in the MPE-FEC buffer 511 is stored from the upper right side of the burst to the lower side. When one row is all stored, the TS packets are stored in the next row. After each row has been stored in this manner, RS decoding is performed. As is well known, RS decoding reads stored data row by row and performs decoding. Accordingly, the portion indicated by 191 in FIG. 10 becomes information necessary for broadcasting, and the portion indicated by 64 becomes parity information generated during RS encoding. The information is read on the horizontal axis and RS decoding is performed using the validity result information (255, 191). That is, TS packets marked as "reliable" in FIG. 10 are packets without errors in which an error detection flag is set to "0", and TS packets marked as "erasure" are packets in which an error is set with an error detection flag set to "1". to be. Therefore, the above information can be used to correct an error of information of the portion marked "erasure".

Next, a process 1003 of reading data from one row and performing RS decoding using the validity result information (255, 191) will be described in more detail. During RS decoding, not only the data of the TS packet but also the reliable / erasure information 1005 are read from the MPE-FEC buffer 511 to perform decoding. Accordingly, FIG. 10 illustrates decoding performed using the error detection flag as it is according to the first embodiment of the present invention. If error correction is not performed in the first decoding process, a second decoding process is performed according to the second embodiment of the present invention. As described above, if there is an error in the section even after performing the primary RS decoding, the present invention performs the secondary RS decoding according to the second embodiment.

11 is a diagram illustrating a second decoding process in an iterative decoding method according to a second embodiment of the present invention.

In FIG. 11, a similarity or reliability is determined by performing a correlation test of the TS packet header described with reference to FIG. 9 with respect to a TS packet in which an error occurs. Referring to this update process, as described above with reference to FIG. 9, even if an error exists as a result of CRC check of the TS packet, the received packet is set again using the header information of the TS packet. That is, the correlation of the headers of the packets marked as erasure at the first RS decoding is checked by the method described with reference to FIG. 9. If the result of the correlation check is that there is no error in the header, it is assumed that there is no error in the payload of the actual TS packet. This is to take advantage of the fact that even if there is an error in the payload of the TS packet, only a small amount of error exists, so the effect on the whole session is very small. Therefore, in the second RS decoding, the correlation is checked again only for information in which an error exists using the header of the TS packet, and then newly determined "erasure" and "relable". Accordingly, the TS packet 1107 indicated by erasure in FIG. 11 is still in error as a result of checking the header correlation, and some packets 1109-a, 1109-b, and 1109-c of the existing packets have an error. As a result of performing header correlation, it is determined that there is similarity or reliability and can be estimated as valid data. Accordingly, RS decoding is performed in the secondary RS decoding process as shown in FIG. 11. That is, referring to (255, 191) RS decoding process 1103 in FIG. 11, it can be seen that updated reliable / erasure information 1105 is used for TS packets that are not valid in the same manner as described in FIG. 9. .

FIG. 12 illustrates a process of detecting and buffering a section in an iterative decoding method according to a second embodiment of the present invention. In FIG. 12, the same components as in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted. Let's do it.

In the TS packet 1211 denoted as erasure & reliable in FIG. 12, as described in the second embodiment of the present invention, an error detection flag is indicated by “1”, but TS is determined to have similarity or reliability by performing correlation of headers. Packet. In performing the MPE-FEC (255, 191) RS decoding process on the packet, the packet is determined to be an invalid packet and the first decoding process is performed. If the decoding of the session fails, the header correlation check is passed. In one case, it is determined as a reliable packet and a second decoding process is performed.

13 is a flowchart illustrating a iterative decoding method according to a second embodiment of the present invention.

When decoding the received packet, the receiver reads payload data and validity information from the MPE-FEC buffer stored in units of TS packets in step 1301, and performs MPE-FEC RS decoding using the read information in step 1303. . This decoding method means a decoding method according to the first embodiment described above. After performing the decoding as described above, the receiver checks whether the MPE-FEC RS decoding succeeds in step 1305. If the decoding succeeds in step 1305, the decoding process ends. If the decoding of the test result of step 1305 is not successful, the receiver moves to step 1307 to perform the second decoding as described in the second embodiment of the present invention. Therefore, when the receiver proceeds to step 1307, the receiver calculates the correlation using the header information of the packet of the TS packet (s) determined to have an error in the first decoding. The receiver then determines whether the result of the correlation calculated in step 1309 is similar or reliable. The error information indicating the validity is updated using the value determined as described above. At this time, if it is determined that there is no similarity or reliability for all TS packets that are not valid, the decoding process ends. However, if one TS packet among TS packets determined to be invalid in the first decoding process has similarity or reliability, the receiver proceeds to step 311 to update the second error information. In this case, the second error information refers to error information updated through correlation checking in step 1307. Thereafter, the receiver proceeds to step 1311 to perform the MPE-FEC RS decoding process once again using the updated error information.

As described above, MPE-FEC decoding may be repeatedly performed on two cases in which there is an error in the TS packet in which an error is detected, and the probability of error correction may be further improved.

As described above, according to the present invention, MPE-FEC decoding is performed because buffering of section data is performed in units of TS packets during MPE-FEC decoding, and decoding is performed by processing only data of TS packets in which an error occurs as an error exists. Can improve the performance.

In addition, it is possible to further improve the error correction probability by repeatedly performing MPE-FEC RS decoding by taking the correlation of the header of the TS packet with respect to the TS packet in which the error is detected. Further, according to the present invention, the MPE The performance improvement of FEC decoding can increase the reception rate of broadcast data, and as a result, broadcast coverage can be extended.

Claims (15)

A method for detecting and buffering a section in a receiver of a digital broadcasting system transmitting a transport stream (TS) packet, Checking an error detection flag from header information of the TS packet to determine whether the TS packet is in error; Analyzing header information of the TS packet to find a header start position of a section to which the TS packet belongs, and then detecting at least one TS packet belonging to the section; Checking the number of TS packets having an error by checking continuous counter information from header information of at least one TS packet belonging to the section; And calculating the buffering position of the data of the normal TS packet except for the data of the TS packet in which the error occurs, and buffering the section data belonging to the section. The method of claim 1, And the buffering position is calculated based on the information on the number of TS packets having an error and the header information of the section. The method of claim 1, And the buffering is performed in units of TS packets. The method of claim 1, And the digital broadcasting system is a digital video broadcasting-handheld (DVB-H) system. The method of claim 1, Checking the correlation using the header information of the TS packet when decoding of the section fails; And updating the error information according to the correlation test result and buffering data of the TS packet in which the error exists. The method of claim 5, wherein the checking of the correlation comprises: If the synchronization information field and the packet identifier field in the header of the TS packet match a preset value, and there is a correlation between the continuity counter value of the previously received TS packet and the continuity counter value of the currently received TS packet, the reliability is reliable. And determine that the error information is updated. An apparatus for detecting and buffering a section in a receiver of a digital broadcasting system for transmitting a transport stream (TS) packet, A TS packet header analyzer for extracting header information of the TS packet; A section header analyzer for extracting header information of the section; A register for storing header information of the TS packet and header information of the section; A buffer for buffering the data in the section; Check the error detection flag from the header information of the TS packet stored in the register to determine whether the corresponding TS packet is error, find the header start position of the section to which the TS packet belongs, and then at least one TS packet belonging to the section. To check the number of TS packets in error by checking the continuous counter information from the header information of at least one TS packet belonging to the section. And a section buffer and an error check block for calculating a buffering position to buffer section data belonging to the section in the buffer. The method of claim 7, wherein And the section buffer and the error checking block calculate the buffering position by analyzing information about the number of TS packets in which an error occurs and header information of the section. The method of claim 7, wherein And the section buffer and the error check block perform buffering of the section on a TS packet basis. The method of claim 7, wherein And the digital broadcasting system is a digital video broadcasting-handheld (DVB-H) system. The method of claim 7, wherein A TS packet header correlator for checking a correlation using header information of the TS packet when decoding of the section fails; And the section buffer and the error check block update the error information according to the correlation check result and calculate and buffer the data of the TS packet in which the error exists. The method of claim 11, wherein the correlation test, If the synchronization information field and the packet identifier field in the header of the TS packet match a preset value, and there is a correlation between the continuity counter value of the previously received TS packet and the continuity counter value of the currently received TS packet, the reliability is reliable. And determine to update the error information. A method of decoding received data in a receiver of a system for transmitting a transport stream (TS) packet, Determining whether the received TS packet is in error and generating error information indicating the error; Performing RS decoding by using the received TS packet and the error information; If the RS decoding fails, performing a header correlation check on a TS packet having an error by using a synchronization information field, a packet ID field, and continuous counter information among header information of the TS packet; Updating the error information by using a correlation test result of the header; And performing RS decoding by using the received TS packet and the updated error information. Transmission information is divided into two or more packets, the packet has a predetermined fixed value, a value indicating the type of the transmission information, an identifier indicating the continuity of the transmission information as a packet header, and the divided transmission information as a channel. In a method of decoding a received packet in a receiver of a system for encoding and transmitting Reed-Solomon (RS) encoding, Generating error information by checking an error after decoding the received packet, and sequentially storing the error information and the transmission information included in the packet; Performing RS decoding using the error information when the stored information is stored in an RS decoding unit; If the RS decoding fails, checking a correlation using information of the packet header; Determining that a packet having correlation exists as a valid packet to update the error information; And performing RS decoding by using the updated error information. Transmission information is divided into sections, and each of the sections is divided into two or more packets and transmitted, the sections have a section header, the packet has a predetermined fixed value and a value indicating the type of the transmission information, and the transmission information. An apparatus for decoding a received packet in a receiver of a system having an identifier indicating a continuity of the packet header, channel encoding and Reed-Solomon (RS) encoding the information to be transmitted, and including an error detection bit, A packet header analyzer for extracting header information of the packet; A section header analyzer for extracting header information of the section; A register for storing header information of the packet and header information of the section; A packet buffer for buffering transmission information included in the packet; A correlator for checking a correlation of the packet header and providing a validity value; From the header information of the packet stored in the register, the error information of the packet and the number of packets in which an error has occurred are determined, and a buffering position is determined according to the confirmed result, and the error information is determined according to the validity value during repeated decoding. The section buffer and error check block to update, And a decoder for performing RS decoding using information received from the packet buffer, the section buffer, and the error check block.

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