KR20190039490A - Apparatus and method for transmitting and receiving packet in broadcasting and communication system - Google Patents

Abstract

According to one embodiment of the present invention, a method of a signal transmitting apparatus for transmitting a packet by in a broadcasting and communication system comprises the steps of: generating a forward error correction (FEC) packet including an FEC parity packet and an FEC source packet; and transmitting the FEC packet to a signal receiving apparatus, wherein the FEC parity packet includes a parity block and a plurality of parity sub-blocks based on a source block, wherein the plurality of parity sub-blocks are generated by encoding information sub-blocks generated from a plurality of source sub-blocks using an FEC encoding scheme, wherein the plurality of source sub-blocks are generated by using second source payloads selected based on a preset source sub-block generation scheme among first source payloads included in the source block, and wherein the FEC source packet is generated by using the source block.

Description

[0001] APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING PACKET IN BROADCASTING AND COMMUNICATION SYSTEM [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for transmitting / receiving packets in a broadcast and communication system, and more particularly to an apparatus and a method for transmitting / receiving packets using a source sub- will be.

Broadcasting and communication systems, such as MMT (Moving Picture Experts Group) media transport systems, for example, are expected to provide high definition (HD) content, , And Ultra High Definition (UHD) content.

In the broadcasting and communication system, data congestion on a network is becoming more and more intense due to diversification of contents, increase of high-capacity contents such as HD contents and UHD contents. In this situation, the content transmitted by the signal transmitting apparatus, for example, the host A, is not normally transmitted to the signal receiving apparatus, for example, the host B, and a part or all of the content transmitted by the signal transmitting apparatus is transmitted through the route ). ≪ / RTI >

On the other hand, since data is generally transmitted in units of packets, data loss occurs in units of transmission packets. Accordingly, if the transmission packet is lost on the network, the signal receiving apparatus can not receive the lost transmission packet, so that the data included in the lost transmission packet can not be known. Therefore, various types of users' inconveniences such as deterioration of audio quality, deterioration of image quality of video (video), screen breakage, drop of a caption, loss of a file and the like may occur.

Therefore, there is a need for a method for recovering data loss caused on the network for this reason.

One of the ways to support the recovery of lost data in a signal receiving device when data is lost on the network is to use a predetermined number of packets that can have various lengths, A source block is composed of data packets and a parity data or a repair packet such as a forward error correction (FEC) And the recovery information is added to the source block.

In this manner, when the signal receiving apparatus detects that a data loss has occurred, the signal receiving apparatus can perform a decoding operation using the recovery information. At this time, packets including a plurality of contents requiring different transmission reliability may be included in one source block. In this case, if the amount of recovery packets is determined based on a packet requiring the highest transmission reliability for one source block, packets requiring low transmission reliability are overprotected to reduce the efficiency of the network. On the other hand, when determining the amount of recovery packets based on a packet requiring the lowest transmission reliability for one source block, it is not possible to restore a packet requiring high transmission reliability.

However, in the current broadcasting and communication system, a method of effectively recovering data loss is not specifically proposed, while efficiently considering transmission reliability for packets included in a source block.

Therefore, in broadcasting and communication systems, there is a need to efficiently recover data loss while efficiently considering transmission reliability for packets included in a source block.

The present invention provides a method and apparatus for transmitting / receiving packets in a broadcasting and communication system.

The present invention also provides a method and apparatus for transmitting / receiving a packet using a source sub-block in a broadcasting and communication system.

The present invention also provides a packet transmission / reception method and apparatus for increasing data restoration efficiency in a broadcast and communication system.

The present invention also provides a packet transmission / reception method and apparatus capable of obtaining an efficient transmission reliability in a broadcasting and communication system.

The method according to one embodiment includes: A method for transmitting a packet in a broadcasting and communication system, the method comprising: generating a FEC packet including a Forward Error Correction (FEC) parity packet and an FEC source packet; And transmitting the FEC packet to a signal receiving apparatus, wherein the FEC parity packet includes a parity block and a plurality of parity block blocks based on a source block, and the plurality of parity block blocks include a plurality of The source subblocks are generated by encoding the information subblocks generated from the source subblocks by using the FEC coding scheme, and the plurality of source subblocks are generated from among the first source payloads included in the source block Wherein the FEC source packet is generated using second source payloads selected based on a predefined source subblock generation scheme, Characterized by the generated by using the source block.

The present invention is effective in enabling transmission and reception of packets using source subblocks in broadcast and communication systems.

In addition, the present invention has an effect of enabling packet transmission / reception to increase data restoration efficiency in a broadcast and communication system.

In addition, the present invention has an effect of enabling packet transmission / reception that can acquire efficient transmission reliability in a broadcast and communication system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically illustrates the structure of a broadcast and communication system according to an embodiment of the present invention; FIG.
2 schematically illustrates an example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention.
FIG. 3 schematically shows a process of generating a source block in the source block generator 201 of FIG. 2; FIG.
4 schematically shows another example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention.
5 schematically illustrates an example of a source subblock generation process of the source subblock generator 402 of FIG.
6 schematically shows another example of a source sub-block generation process of the source sub-block generator 402 of FIG.
FIG. 7 schematically illustrates an internal structure of an FEC decoding block 113 of the signal receiving apparatus 110 of FIG. 1 according to an embodiment of the present invention. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

The present invention proposes an apparatus and method for transmitting / receiving packets in a broadcast and communication system.

In addition, the present invention proposes an apparatus and method for transmitting / receiving a packet using a source sub-block in a broadcast and communication system.

Also, the present invention proposes a packet transmitting / receiving apparatus and method for increasing data restoration efficiency in a broadcasting and communication system.

In addition, the present invention proposes a packet transmission / reception apparatus and method capable of obtaining efficient transmission reliability in a broadcasting and communication system.

Embodiments of the present invention to be described below are referred to as high definition (HD) content, ultra high definition (UHD), or UHD ) Content, as well as loss of data packets in all electronic devices such as cell phones, TVs, computers, electronic boards, tablets and e-books that can provide a variety of multimedia services such as video conferencing / The present invention proposes a packet transmitting / receiving apparatus and method for efficiently recovering a packet.

Particularly, in the embodiments of the present invention, when a forward error correction (FEC) scheme is applied to data packets, a source block is divided into a plurality of source subblocks source sub-blocks, and efficiently generates an information block and an information sub-block to improve FEC decoding performance, or to increase transmission efficiency. .

In the embodiments of the present invention, the FEC encoding method is not described, but in the embodiments of the present invention, the FEC encoding method is a Reed-Solomon (RS) Code, a Low Density Parity Check (LDPC) code, a Turbo code, a Raptor code, a Raptor Q code, an XOR (Single Parity-Check) code, Code, a Pro-MPEG (Moving Picture Experts Group) FEC code, and the like.

FIG. 1 is a diagram schematically illustrating a structure of a broadcasting and communication system according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, the broadcasting and communication system includes a signal transmission apparatus 100 and a signal reception apparatus 110.

The signal transmission apparatus 100 includes a protocol A processing block 101 (hereinafter referred to as a protocol A processing block 101) for performing a protocol A processing operation corresponding to a protocol A corresponding to a forward error correction (FEC) A FEC coding block 102 and a protocol B processing block 103 and a transmitter physical layer processing block 104 which perform a protocol B processing operation corresponding to the protocol B corresponding to the FEC lower protocol.

The protocol A processing block 101 performs a protocol A processing operation on the transmission data to generate source payloads 130 and transmits the generated source payloads 130 to the FEC encoding block 130. [ (102). The FEC coding block 102 constitutes a source block including at least one source payload and performs an FEC coding operation corresponding to a FEC coding scheme set in advance for the configured source block to generate parity payloads 131).

In addition, the FEC encoding block 102 constructs an FEC source packet by adding FEC headers 132 to the source payloads 130, and transmits the FEC source packet to the protocol B processing block 103 . Here, the FEC source packet represents an FEC packet including a source payload and an FEC header.

The FEC encoding block 102 constructs an FEC parity packet by adding the FEC header 132 to the parity payloads 131 and transmits the FEC parity packet to the protocol B processing block 103 . Here, the FEC parity packet represents a FEC packet including a parity payload and an FEC header. Here, one FEC parity packet may include a plurality of parity payloads. For convenience of explanation, it is assumed that one FEC parity packet includes one parity payload.

The protocol B processing block 103 generates a protocol B signal by performing a protocol B processing operation corresponding to the protocol B on the FEC source packet or the FEC parity packet transmitted from the FEC encoding block 102, Signal to the transmitter physical layer processing block 104.

The transmitter physical layer processing block 104 converts the protocol B signal received from the protocol B processing block 103 into a physical layer signal suitable for physical layer transmission and outputs the converted physical layer signal to the signal receiving apparatus 110).

1, various processing blocks may exist between the protocol B processing block 103 and the transmitter physical layer processing block 104, and in FIG. 1, the protocol B processing block 103 and the transmitter A detailed description of various processing blocks that may exist between the physical layer processing blocks 104 will be omitted.

The signal receiving apparatus 110 includes a receiver physical layer processing block 111, a protocol B processing block 112 and an FEC decoding block 113 that perform a protocol B processing operation corresponding to the protocol B corresponding to the FEC lower protocol, And a protocol A processing block 114 that performs protocol A processing operations corresponding to protocol A corresponding to the FEC upper protocol.

The receiver physical layer processing block 111 converts a physical layer signal received from the signal transmission apparatus 100 to the signal reception apparatus 110 through a transmission channel 120 into a protocol B signal, B signal to the protocol B processing block 112. There may be various processing blocks between the protocol B processing block 112 and the receiver physical layer processing block 111 as described in the signal transmission apparatus 100. The protocol B processing block 112 and the receiver The detailed description of the various processing blocks existing between the physical layer processing block 111 will be omitted.

The protocol B processing block 112 performs protocol B processing on the physical layer signal received by the protocol B processing block 112 to generate a protocol B signal and then transmits the protocol B signal to the FEC decoding block 113). Here, the protocol B signal may be an FEC packet, that is, an FEC source packet or an FEC parity packet. At this time, some of the FEC packets transmitted from the signal transmitting apparatus 100 are lost due to congestion of the network and errors generated in the physical layer, and thus are not transmitted to the FEC decoding block 113. The FEC decoding block 113 performs an FEC decoding operation on the FEC packet transmitted from the protocol B processing block 112 to detect the source payloads transmitted from the signal transmitting apparatus 100, And passes the payloads to the protocol A processing block 114. The protocol A processing block 114 performs a protocol A processing operation on the source payloads received from the FEC decoding block 113 to detect transmission data.

FIG. 1 illustrates a structure of a broadcast and communication system according to an embodiment of the present invention. Referring to FIG. 2, the structure of the internal structure of the FEC encoding block 102 of the signal transmission apparatus 100 of FIG. An example will be described.

FIG. 2 is a diagram schematically illustrating an example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention.

2, the FEC encoding block 102 includes a source block generator 201, an information block generator 202, a parity block generator 203, an FEC parity packet generator 204 and an FEC source packet generator 202. [ (205).

When the source payloads 221 are inputted, the source block generator 201 composes the source payloads 221 as source blocks and transmits them to the information block generator 202 and the FEC source packet generator 205 do. In this case, the number of source payloads 221 included in the source block can be changed, and the lengths of the source payloads 221 may be different from each other. A detailed description of the number of source payloads 221 included in the source block and the length of the source payloads 221 will be omitted.

The information block generator 202 receives the source block output from the source block generator 201 and outputs the source payloads 221 included in the source block to the information block generator 221 having the preset setting width T And outputs the generated information word block 211 to the parity block generator 203. The parity block generator 203 generates an information word block 211 by arranging the information word block 211 in a two-dimensional array. Here, each row included in the two-dimensional array is an information payload 222, and the width T is a 'payload size'. Here, the payload size is typically expressed in units of bytes or bits.

The parity block generator 203 receives the information word block 211 output from the information block generator 202 and performs an FEC encoding operation on the information word block 221 to generate a parity block 212 And transmits the parity block 212 to the FEC parity packet generator 204. Here, the parity block 212 includes a parity payload 223 having a size equal to that of the information payload 222.

The FEC parity packet generator 204 adds the FEC header 224 to each of the parity payloads 223 included in the parity block 212 output from the parity block generator 203 to generate FEC parity packets And generates an FEC parity packet block 213 including the generated FEC parity packets. Then, the FEC parity packet generator 204 outputs the FEC parity packet block 213 to the protocol B processing block 103.

The FEC source packet generator 205 generates the FEC source packets by adding the FEC header 224 to each of the source payloads 221 included in the source block output from the source block generator 201 And generates the generated FEC source packets in the FEC source packet block 214. The FEC source packet generator 205 then outputs the FEC source packet block 214. In this case, the FEC header added to each of the FEC source packet and the FEC parity packet may have the same form or may have a different form.

2 illustrates an example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention. Referring to FIG. 3, A process of generating a source block in the generator 201 will be described.

FIG. 3 is a diagram schematically illustrating a process of generating a source block in the source block generator 201 of FIG.

Referring to FIG. 3, the source block generator 201 divides a two-dimensional array having a symbol size T into m regions in units of T / m columns. It should be noted that the source block generation process shown in FIG. 3 is a source block generation process when m is 4 (m = 4). Here, when the symbol size T is not a multiple of m, the two-dimensional array may be divided into regions each including [T / m] + 1 columns and regions each including [T / m] . Here, for any real number A, [A] means the maximum integer less than or equal to A.

The regions each including [T / m] + 1 columns and the regions each including [T / m] columns are defined by predetermined commitments between the signal transmitting apparatus and the signal receiving apparatus, And the number of columns for the area of the area. For example, assuming that the remainder obtained by dividing T by m is n (n <m), the first n regions are divided into [T / m] +1 columns and the remaining mn Can be defined to be divided into [T / m] columns. It should be noted that the number of columns included in each region may be arbitrarily set differently according to the promise of the signal transmitting apparatus and the signal receiving apparatus, in addition to the regular region sorting method as described above.

Meanwhile, if necessary, the source block generator 201 generates a flow identifier (ID) (hereinafter referred to as "ID"), a User Datagram Protocol (UDP) To the source payload, information 302 indicating the characteristic information 301 of the packet and the length of the source payload, such as a flow ID. Each of the source payloads having the packet characteristic information, that is, the UDP flow ID 301 and the source payload length information 302, has a symbol size from the first column of the first row, T &lt; / RTI &gt;

At this time, the source block generator 201 generates the last data of the corresponding source payload in the last row in which the additional information, i.e., the packet characteristic information 301 and the arbitrary source payload appended with the source payload length information 302, (Or sets) the remaining part in the area to which the data is allocated. Note that the predetermined value may be set to a value of &quot; 0 &quot; for convenience, but it is not necessarily set to a value of &quot; 0 &quot;. For example, since the last data of the second source payload is allocated to the second area among the four areas in FIG. 3, the source block generator 201 determines that the remaining part 305 of the second area is &quot; 0 Quot; value. For convenience of explanation, the packet characteristic information 301 and the source payload length information 302 will be referred to as &quot; additional information &quot;.

In addition, since the one source payload to which the additional information is attached is arranged, the next source payload is always positioned at the starting point of the next area of the area to which the last data is allocated in the last row in which the previous source payload is placed . In other words, all source payloads must be placed at the beginning of an area. For example, in FIG. 3, the second source payload begins to be placed at the beginning of the third region following the portion 305 assigned with a value of &quot; 0 &quot;. Hereinafter, for the sake of convenience of explanation, it is referred to as being &quot; zero padded &quot; If a zero-padded portion, such as the zero-padded portion 306 of the fourth source payload, is assigned to the last region of the source payload, the fifth source payload, which is the next source payload, Th region.

Thus, after performing all of the above-described processes for a given source payload, the completed two-dimensional array 212 results in an information block.

On the other hand, packets containing a plurality of contents requiring different transmission reliability may be included in one source block. In this case, if the amount of recovery packets required for one source block is determined based on a packet that requires the highest reliability among the packets included in the one source block, Packets that require low reliability are overprotected, which reduces network efficiency.

On the contrary, when determining the amount of recovery packets necessary for one source block based on a packet requesting the lowest reliability among the packets included in the one source block, Packets requiring reliability can not be restored.

Therefore, in the embodiment of the present invention described below, a method of dividing a source block into source sub-blocks and efficiently configuring information blocks and information sub-blocks to improve decoding performance or increase transmission efficiency is provided do.

FIG. 4 is a diagram schematically showing another example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention.

4, the FEC encoding block 102 includes a source block generator 401, a source sub-block generator 402, and S information sub-block generators, that is, an information sub-block generator # 1 403-1 2, an information subblock generator # 2 403-2, ..., S parity part block generators, i.e., parity part block generator # 1 404-1, parity part block generator # 2 404-2, ..., and parity part block generator # A parity block generator 405, a parity block generator 407, and a FEC source packet generator 408. The parity block generator 404 includes a parity block generator #S 404-S, an information block generator 405, a parity block generator 406,

The source block generator 401 generates a source block 410 including the input source payloads and outputs the generated source block 410 to the source subblock generator 402, And the information block generator 405 and the FEC source packet generator 408, respectively.

The source sub block generator 402 receives the source block output from the source block generator 401 and selects the source payloads included in the source block to generate S source sub blocks, 1 411-1, a source subblock # 2 411-2, ..., , And the source subblock # S 411-S, and the source subblock # 1 411-1, the source subblock # 2 411-2, , And outputs the source subblock #S (411-S) to the information subblock generator. That is, the source subblock generator 402 outputs the source subblock # 1 411-1 to the information subblock generator # 1 403-1, the source subblock # 2 411-2, To the information subblock generator # 2 403-2, , And outputs the source subblock #S (411-S) to the information subblock generator #S (403-S).

The information subblock generator # 1 403-1, the information subblock generator # 2 403-2, , Each of the information subblock generators #S (403-S) inputs the corresponding source subblock output from the source subblock generator 402, and generates an information subblock generating method To generate an information sub-block.

At this time, the information subblock generator # 1 403-1, the information subblock generator # 2 403-2, And the information sub-block generator #S 403-S perform the same operations as those performed by the information block generator 202 described in FIG. 2, and will be described in detail as follows.

The information subblock generator # 1 403-1, the information subblock generator # 2 403-2, , The information sub-block generator #S (403-S) may use a different payload size T and the number of areas m, and the details will be described below.

Assume that the payload size T and the number m of regions used in the i-th information subblock generator, that is, the information subblock generator #i 403-i are T (i) and m (i) Assume that the number of information payloads included in the i &lt; th &gt; information subblock is K (i).

Next, the S parity part block generators, i.e., parity part block generator # 1 404-1, parity part block generator # 2 404-2, , And parity block generator #S (404-S) perform a FEC encoding operation corresponding to the FEC encoding scheme preset in the input information sub-block to generate a parity block. Here, a codeword generated according to the FEC coding scheme will be referred to as an FEC codeword. Assume that the FEC code applied to the i-th parity block generator, that is, the parity block generator #i (404-i) is C (i). Here, the FEC code C (i) may define the association of the K (i) information payloads and the K (i) parity payloads.

The information block generator 405 receives the source block output from the source block generator 401 and performs an information block generating operation corresponding to the information block generating method preset for the source block, Block, and outputs the generated information block to the parity block generator 406. Here, the information block generating method may exist in various ways, and a detailed description of the information block generating method itself will be omitted.

The parity block generator 406 receives an information block output from the information block generator 405 and performs a parity block generating operation corresponding to a predetermined parity block generating method for the information block to generate a parity block And outputs the generated parity block to the FEC parity packet generator 407. Here, the parity block generation method may exist in various ways, and a detailed description of the parity block generation method itself will be omitted.

The FEC parity packet generator 407 includes the parity part block generator # 1 404-1, the parity part block generator # 2 404-2, S parity block blocks output from the parity block generator #S 404-S and the parity block output from the parity block generator 406, and outputs the S parity block blocks and the parity block The parity payloads included in the block are used to generate FEC parity packets. ]

The FEC source packet generator 408 receives the source block 410 output from the source block generator 401 and outputs the FEC source packet using the source payloads included in the source block 410 . Here, the FEC source packet generator 408 generates an FEC source packet in accordance with a preset FEC source packet generation scheme, and a detailed description of the established FEC source packet generation scheme will be omitted.

4, another example of the internal structure of the FEC encoding block 102 of the signal transmitting apparatus 100 of FIG. 1 according to an embodiment of the present invention is described. Next, referring to FIG. 5, An example of a source subblock generation process of the block generator 402 will be described.

FIG. 5 is a diagram schematically illustrating an example of a source subblock generation process of the source subblock generator 402 of FIG.

Referring to FIG. 5, the source subblock generator 402 inputs a source block 501 output from the source block generator 401. In FIG. 4, the source block 501 is shown as &quot; 410 &quot;, and in FIG. 5, the source block 410 is changed to reference numeral 501 for convenience.

First, the source block 501 includes 12 source payloads: source payload SP0, source payload SP1, ..., and source payload SP11. The source subblock generator 402 divides the 12 source payloads into three source subblocks: source subblock 1 502, source subblock 2 503, and source subblock 3 504 ). Here, the source subblock 1 502 includes four source payloads: a source payload SP0, a source payload SP1, a source payload SP2, and a source payload SP3, and the source subblock 2 (503) comprises four source payloads: a source payload SP4, a source payload SP5, a source payload SP6, and a source payload SP7, (Source subblock 1 (502) = {SP0, SP1, SP2, SP3}, source payload SP8, source payload SP9, source payload SP10 and source payload SP11 SP5, SP6, SP7}, and the source sub-block 3 (504) = {SP8, SP9, SP10, SP11}.

The case where the source subblock generator 402 mathematically represents the process of generating the source subblocks is considered as follows.

First, when the source block SB is divided into S source subblocks SSB (1), SSB (2), ..., SSB (S), a relationship corresponding to the following "source subblock creation rule 1" do.

[Source Subblock Generation Rule 1]

1) The intersection of SSB (i) and SSB (j) for an integer i, j among all integers between 1 and S is an empty set.

2) The union of SSB (1), SSB (2), ..., SSB (S) is a subset of SB.

5, an example of a source subblock generation process of the source subblock generator 402 of FIG. 4 has been described. Referring to FIG. 6, a source subblock generation process of the source subblock generator 402 of FIG. Other examples of the above will be described.

FIG. 6 is a diagram schematically showing another example of a source subblock generation process of the source subblock generator 402 of FIG.

Referring to FIG. 6, the source subblock generator 402 inputs a source block 601 output from the source block generator 401. In FIG. 4, the source block 601 is shown as &quot; 410 &quot;, and in FIG. 6, the source block 410 is changed to &quot; 601 &quot;

First, the source block 601 includes twelve source payloads: source payload SP0, source payload SP1, ..., and source payload SP11. The source subblock generator 402 divides the 12 source payloads into two source subblocks, i.e., a source subblock 1 602 and a source subblock 2 603. Here, the source subblock 1 602 includes four source payloads: source payload SP0, source payload SP1, source payload SP2, and source payload SP3, and the source subblock 2 The source payload SP1, the source payload SP2, the source payload SP3, the source payload SP4, the source payload SP5, and the source payload SP5. SP5, SP2, SP3, SP4, SP5, SP6, and a source payload SP7 (source subblock 1 602 = {SP0, SP1, SP2, SP3} , SP6, SP7}).

The case where the source subblock generator 402 mathematically represents the process of generating the source subblocks is considered as follows.

First, when a source block SB is divided into S source subblocks SSB (1), SSB (2), ..., SSB (S), a relation corresponding to the following "source subblock creation rule 2" do.

[Source Subblock Generation Rule 2]

1) The intersection of SSB (i) and SSB (i + 1) is SSB (i) for all integers between 1 and S - 1.

2) SSB (S) is a subset of SB.

3 and 4, the information block generator 405 proposed in the present invention inputs a source block 410 and outputs the input source block 410 to the source block 410 as described with reference to FIG. 3 And generates an information block having a format. In this case, T, T (1), ..., T (S) in FIG. 4 may have different values.

Another example of the information block generator 405 proposed by the present invention includes S information subblock generators, that is, information subblock generator # 1 403-1, information subblock generator # 2 403-2, ... , And S information sub-blocks generated in the information sub-block generator #S (403-S) are concatenated to generate one information block. When one information block is generated by concatenating S information sub-blocks in this way, there is a constraint condition that T = T (1) = ... = T (S).

The payload size T and the number of regions m used in the information block generator 405 proposed by embodiments of the present invention are determined based on the reliability condition requested by the contents included in the source block input to the information block generator 405 A memory constraint of the FEC decoder, a constraint of the FEC decoding delay time, and the like.

Similarly, T (i) and m (i) used in the i-th information sub-block generator are also stored in the memory of the FEC decoder and the reliability conditions required by the contents included in the source sub- Constraints of the FEC decoding delay time, and the like. Here, when the contents included in the source subblock are contents requiring high reliability, it is required to use FEC codes having strong error correction coding capability.

First, the error correction capability of the FEC code is usually improved as the FEC codeword length increases. If the value of T is reduced when a given source block or source sub-block is converted into an information block, the number of information payloads included in the information block is increased. In this way, when the number of information payloads included in the information block is increased, more powerful FEC codes can be used.

On the other hand, since each source subblock is a subset of the source block, it contains a smaller amount of data than the source block. Therefore, in the case of T = T (1) = ... = T (S), K (i), i = 1, ..., S,

In one embodiment of the present invention, T (i) can be expressed by the following equation (1).

In Equation (1), T < a > denotes a power of T.

In another embodiment proposed in the present invention, T (i) can be expressed by the following equation (2).

6 illustrates another example of the source subblock generation process of the source subblock generator 402 of FIG. 4. Referring to FIG. 7, the signal receiving apparatus 110 of FIG. 1 according to an embodiment of the present invention ) Of the FEC decoding block 113 will be described.

7 is a diagram schematically illustrating the internal structure of an FEC decoding block 113 of the signal receiving apparatus 110 of FIG. 1 according to an embodiment of the present invention.

7, the FEC decoding block 113 includes a reception source block reconstructor 701, a reception source subblock reconstructor 702, and S reception information subblock reconstructors, that is, a reception information subblock The restoration device # 1 703-1, the reception information subblock restoration device # 2 703-2, The reception information subblock restorer #S 703-S, the S FEC decoders, that is, the FEC decoder # 1 704-1, the FEC decoder # 2 704-2, An FEC decoder #S 704-S, a received information block reconstructor 705, and an FEC decoder 706.

The reception source block reconstructor 701 analyzes the FEC header included in the FEC source packet received through the signal reception apparatus 110 to reconstruct the reception source block 710 and reconstructs the reconstructed reception source block 710 ) To the reception source subblock reconstructor 702 and the reception information block reconstructor 705.

The reception source block restorer 702 receives the reception source block 710 output from the reception source block restructurer 701, selects the source payloads included in the reception source block 710, (711-1), a receiving source subblock # 2 (711-2), and a receiving source subblock block , Generates the reception source subblock #S (711-S), and outputs the generated S reception source subblocks to the reception information subblock reconstructor. That is, the reception source subblock reconstructor 702 outputs the reception source subblock # 1 711-1 to the reception information subblock reconstructor # 1 703-1, 2 711-2 to the reception information subblock reconstructor # 2 703-2, , And outputs the reception source subblock #S (711-S) to the reception information subblock reconstructor #S (703-S). Here, the information used for detecting the reception source block and the reception source sub-block including the source payload can be obtained from the FEC header to be described later, and the reception source block including the source payload and the reception source block A method of acquiring information used for detecting a block from the FEC header will be described later, and a detailed description thereof will be omitted here.

On the other hand, the reception information subblock reconstructor # 1 703-1, the reception information subblock reconstructor # 2 703-2, , The reception information subblock reconstructor #i 703-i, which is the i-th reception information blocker reconstructor of the reception information subblock block reconstructor #S 703-S, i &lt; th &gt; reception source subblock, that is, the reception source subblock #i, performs a reception information subblock restoration operation corresponding to the reception subblock restoration method preset for the reception source subblock #i, And outputs the restored received information subblock #i to the corresponding FEC decoder, that is, the FEC decoder #i 704-i. At this time, the reception information subblock reconstructor #i 703-i performs the same operation as that performed by the information subblock generator #i 403-i described in FIG. 4, The size of the payload and the number of areas required for the operation of the restoration device #i 703-i can be obtained through a separate protocol for transmitting FEC header or control information to be described later, A method of acquiring the size of the payload and the number of areas necessary for the operation 703-i through a separate protocol for transmitting the FEC header and the control information will be described below, and a detailed description thereof will be omitted here.

On the other hand, some of the transmission FEC packets transmitted from the signal transmission apparatus 100 may be lost due to congestion of the network and errors caused in the physical layer, The transmission FEC packets lost to the FEC decoding block 113 can not be transmitted to the FEC decoding block 113. [ Therefore, unlike the signal transmission apparatus 100, the reception source block 710 and the S reception source subblocks, i.e., the reception source subblock # 1 711-1 and the reception source subblock # 2 711 -2) and ... , The receiving source subblock #S (711-S) may not be aware of the values of some payloads. Therefore, the area where data is not normally obtained in the generation of the reception information sub-blocks is processed as loss, and the S FEC decoders, that is, the FEC decoder # 1 704-1 and the FEC decoder # 2 704-2 ), ... , And is transmitted to the FEC decoder #S (704-S).

Therefore, the FEC decoder # 1 704-1, the FEC decoder # 2 704-2, , The FEC decoder #i (704-i), which is the i-th FEC decoder among the FEC decoders #S (704-S), receives the i-th received information subblock, An attempt is made to recover a lost transmission FEC packet using the parity payload for the information subblock, i.e., the information subblock #i, i.e., the i-th received parity subblock, i.e., the received parity subblock #i. In this case, the relationship between the parity payload and the FEC code included in the FEC parity packet can be obtained from the FEC header, which will be described later, and the relationship between the parity payload and the FEC code included in the FEC parity packet is The detailed description thereof will be omitted here.

The RB block reconstructor 706 receives the RB block 710 output from the RB block reconstructor 701 and generates a RB block 710 for the RB block 710, And restores the received information block, and outputs the received received information block to the FEC decoder 706. The FEC decoder 706 decodes the received information block.

The FEC decoder 706 restores the lost part using the parity payload of the information block obtained from the received information block and the FEC parity packet, that is, the received parity block, And outputs the reconstructed information block.

In the case of applying the FEC scheme using the division of the source block proposed in the embodiment of the present invention, the signal transmission apparatus 100 transmits information indicating which source sub-block is included in which source sub-block, Information about the number of divided areas included in the information subblock and information about how many of the source payloads are started in which area of the information payload should be transmitted to the signal receiving apparatus 110. If the signal reception apparatus 110 determines that the source payload is included in a certain source sub-block, the number of divided sub-regions included in the information sub-block and the information sub-block, If it is not possible to obtain information as to which area of the information payload the loads are started from, it is impossible to know at which position the FEC source packets are placed in the source block when any FEC source packets are lost. It becomes difficult to perform the operation.

Signaling information on the symbol size T and the number m of the divided regions is transmitted to each source packet and transmitted through a separate packet Lt; / RTI &gt; Hereinafter, a description will be made of a method of transmitting information indicating which source payload is contained in which source sub-block and signaling information on the symbol size T and the number m of divided areas through a separate packet. Respectively.

First, the signal transmission apparatus 100 transmits a Content Delivery Protocol (CDP), such as a Session Description Protocol (SDP) (1), ..., T (S) and m, m (1), ..., m (1), which represent the relationship between the source block and the source sub- (1), ..., T (S) and m, m (1) to the signal receiving apparatus 110, or information indicating the relationship between the source block and the source sub- ), ..., m (S) to the signal receiving apparatus 110. Here, when T is not a multiple of m, a predetermined appointment (for example, an upper region includes [T / m] + 1 columns) between the signal transmitting apparatus 100 and the signal receiving apparatus 110, The signal receiving apparatus 110 can detect the number of columns included in each region by using the values of T and m by using [T / m] columns).

In the above description, information indicating which source sub-block is included in which source sub-block, signaling information on the symbol size T and the number m of divided sub-regions is added to each FEC source packet, or a separate packet A description will be given of a case in which the data is transmitted through the network.

Meanwhile, the signal transmitting apparatus 100 must transmit additional information so that the signal receiving apparatus 110 can grasp the form in which the source payload is arranged in the information block and the information sub-block. Specifically, First, in order that the source payload received from the signal receiving apparatus 110 can be grasped in an information block and an information sub-block, the signal transmitting apparatus 100 transmits the source payload Information indicating the position of the row where the arrangement is to be started, that is, the order of the FEC encoded symbols and the position of an area starting within the FEC encoded symbol, may be added to each FEC source packet and transmitted to the signal receiving apparatus 110.

Table 1 below shows an example of the signaling information added to the FEC source packet according to an embodiment of the present invention.

.... Source Block Number (SBN) Payload Type If (Payload type == Source Payload) {
Encoding Symbol ID (ESI)
Payload Start Position (PSP)
Number of associated Source Sub-Blocks (N)
For i = 1 to N {
Source Sub-Block Number (SSBN (i))
Encoding Symbol ID for SSBN (i) (ESI (i))
Packet Start Position for SSBN (i) (PSP (i))
}
} If (Payload type == Parity Payload for Source Block) {
Encoding Symbol ID (ESI)
Information Block Length (IBL)
T, m
} If (Payload type == Parity Payload for Source Sub-Block) {
Source Sub-Block Number (SSBN)
Encoding Symbol ID (ESI)
Information Sub-Block Length (ISBL)
T (SSBN), m (SSBN)
}

Referring to Table 1, the signaling information added to the FEC source packet includes a source block number (SBN) and a payload type.

The source block number (SBN) indicates a source block corresponding to the corresponding FEC packet. The payload type indicates the type of data that the payload included in the FEC packet includes, i.e., the type of the payload included in the FEC packet. Here, the type of the payload can be largely classified into three types: a source payload and a parity payload related to the source block and a parity payload related to the source sub-block.

In Table 1, the signaling information added to the FEC source packet may include additional information corresponding to the payload type.

First, when the payload type indicates a source payload (Payload type == Source Payload), the signaling information added to the FEC source packet includes an Encoding Symbol ID (ESI) The number of associated source subblocks (N), the source subblock number from 1 to N for the number N of the associated source subblocks, and the number of the corresponding source subblocks An encoded symbol identifier for the source subblock number, and a packet start position for the corresponding source subblock number. In Table 1, the source subblock number for the i-th source subblock is represented by a Source Sub-Block Number (SSBN (i)), the encoded symbol identifier for the i- (I) (ESI (i)), and the packet start position for the i-th source subblock is represented by the Packet Start Position for SSBN (i) (PSP (i)).

Secondly, when the payload type indicates a parity payload for a source block (Payload type == Parity Payload for Source Block), the signaling information added to the FEC source packet includes an encoded symbol identifier (ESI) (IBL), and T and m, as shown in FIG.

Thirdly, if the payload type indicates a parity payload for a source sub-block (Payload type == Parity Payload for Source Sub-Block), the signaling information added to the FEC source packet is a source sub- , An encoded symbol identifier (ESI), an information sub-block length (ISBL) (hereinafter referred to as "ISBL"), T (SSBN), and m (SSBN).

The payload type will be described with reference to FIG.

Referring to FIG. 1, in another embodiment of the present invention, a payload type is transferred to a protocol B processing block 103 in the form of control information, and in the protocol B processing block 103, Is included in the header of B. In this case, the payload type may be omitted from the signaling information added to the FEC source packet as described in Table 1.

In the case where the payload type of the FEC packet indicates the source payload, an Encoding Symbol ID (ESI) refers to an initial coded symbol at which the FEC source packet starts, that is, , And a payload start position (PSP) indicates an area in the information block where the source payload starts. For example, assuming m = 4 in FIG. 3, the pair of the ESI value and the PSP value of the first FEC source packet becomes (0, 0), and the ESI value of the second FEC source packet and the PSP The pair of values becomes (1, 2), the pair of ESI value and PSP value of the third FEC source packet becomes (3, 3), and the pair of ESI value and PSP value of the fourth FEC source packet becomes , 1).

The number N of source subblocks indicates the number of source subblocks containing the corresponding FEC source packets. SSBN (i), which is a source sub-block number (SSBN) (hereinafter referred to as &quot; SSBN &quot;) for an integer i from 1 to N, indicates a source sub-block to which the corresponding FEC source packet corresponds , ESI (i) indicates the position of the first coded symbol, i.e., the row in the information subblock, in which the FEC source packet starts in the information subblock, and PSP (i) Indicates the area that was started. In another embodiment of the present invention, when the number N of source subblocks is a constant, the number N of source subblocks is not repeatedly transmitted every FEC packet, And the number N of the source subblocks may be omitted from Table 1. The number N of the source subblocks may be omitted from Table 1.

Also, when the payload type of the FEC packet indicates the parity payload related to the source block, the number N of the source subblocks is always 1, and the PSP is always 0, so that it can be omitted.

On the other hand, assuming that the number of information payloads included in the information block is K, the coding symbol identifiers (ESI) of the FEC source packets are generally 0, 1, 2, ..., (K - 1), but the encoded symbol identifier (ESI) of the FEC parity packet may be allocated according to the system requirements of the broadcasting and communication system. For example, the encoded symbol identifier (ESI) of the FEC parity packet may be sequentially allocated as 0, 1, 2, ... for each recovered symbol, like the encoded symbol identifier (ESI) of the FEC source packet have. In this case, there is an advantage in that the size of an octet necessary for the coded symbol identifier (ESI) of the recovery packet can be minimized.

In another embodiment of the present invention, the recovery symbol is regarded as a coded symbol concatenated after the source symbol, and the ESI for each parity symbol is calculated as K, (K + 1), (K + 2) And so on.

Further, as another embodiment of the present invention, when the source block is divided into m regions and each source symbol is regarded as m refined symbols, a total of m * K refined symbols . Thus, for each recovery symbol, the coded symbol identifier (ESI) for the FEC parity packet may be sequentially allocated as m * K, (m * K + 1), (m * K + 2) have.

In addition, the signal transmission apparatus 100 may determine a source block length (SBL), which indicates the total number of rows of the regions included in the source block, to the signal receiving apparatus 110 ) And T, m to indicate the structure of the correct source block, so that the signal receiving apparatus 110 can detect the correct structure of the source block transmitted from the signal transmitting apparatus 100. [

When the payload type of the FEC packet indicates a parity payload related to the source subblock, an identifier for the source subblock, that is, a source subblock number (SSBN) is added, and subsequent information is added to the information subblock Except that the payload type represents the parity payload associated with the source block.

It should be noted that the FEC header as shown in Table 1 includes only the minimum information necessary for carrying out the embodiments of the present invention and may include additional information according to the system requirements of the broadcasting and communication system Do.

Also, in the embodiment of the present invention, even if there are separate reliable means for transmitting control information, only a part of N, T, m, IBL and ISBL among the fields included in the FEC header transmit the control information And the FEC source packet header may be transmitted using a source block identifier (SBN), a source subblock identifier (SSBN), a coded symbol identifier (ESI) for the source block and a source subblock (ESI) of the coded symbol identifier. In addition, the FEC parity packet header MUST include a source block distinguisher (SBN) and a coded symbol identifier (ESI). When the payload type among the FEC parity packets refers to a parity payload related to the source subblock, the source subblock identifier (SSBN) must be included in the FEC packet header.

In the present invention, since the source payload is protected by one or more FEC codes, the signal receiving apparatus can update the reception source block dynamically in the FEC decoding process to obtain the decoding performance improvement.

7, the operation of the FEC decoding block 113 of the signal receiving apparatus 110 of FIG. 1 according to an embodiment of the present invention will be described.

7, in an embodiment of the present invention, the reception source block reconstructor 701 first generates only the first reception source sub-block, and the first reception source sub-block uses the FEC code C (1) That is, FEC decoded through the FEC decoder # 1 (704-1), thus attempting to restore the lost source payload. If there is a restored source payload, the receive source block reconstructor 701 updates the receive source block and restores the second receive source sub-block using the updated receive source block. In this manner, the same process as performed for the first reception source sub-block until the S-th reception source sub-block, which is the last reception source sub-block, i.e., the FEC code C (S) That is, FEC decoding through the FEC decoder #S (704-S), and thus restoration of the lost source payload is attempted.

The received information block reconstructor 705 then restores the received information block using the updated received source block using the result of decoding all the information sub-blocks, and uses the FEC code C, that is, FEC Decoder 706 to attempt to restore the lost source payload.

Unlike the above description, in another embodiment of the present invention, after the signal receiving apparatus 110 independently performs decoding on each source sub-block, a result obtained by decoding all information sub- It is also possible to update the reception source block once using the updated reception source block, to construct an information block again using the updated reception source block, and to attempt to recover the lost source payload using the FEC code C. [

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (1)

A method for transmitting a packet by a signal transmitting apparatus in a broadcasting and communication system,
Generating an FEC packet including a Forward Error Correction (FEC) parity packet and an FEC source packet;
And transmitting the FEC packet to a signal receiving apparatus,
The FEC parity packet includes a parity block and a plurality of parity block blocks based on a source block, and the plurality of parity block blocks include an information sub-block generated from a plurality of source sub-blocks, Wherein the plurality of source subblocks are generated by encoding using a second source payload based on a preset source subblock generation scheme among the first source payloads included in the source block, &Lt; / RTI &gt; loads,
Wherein the FEC source packet is generated using the source block.

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