Apparatus and method for generating broadcast signal frame

Abstract

An apparatus and method for generating a broadcast signal frame are disclosed. An apparatus for generating a broadcast signal frame according to an embodiment of the present invention includes a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhancement layer signal, a power normalizer configured to reduce power of the multiplexed signal to a power level corresponding to the core layer signal, a time interleaver configured to generate a time-interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, and a frame builder configured to generate a broadcast signal frame, wherein the broadcast signal frame includes a preamble for signaling time interleaver information corresponding to the time interleaver, and wherein the preamble includes a field indicating a start position of a first complete FEC block corresponding to each of physical layer pipes.

Description

[0001] This application is a divisional application of the patent application with the application number "201780056062.6", the title of "Apparatus for generating broadcast signal frame including preamble indicating start position of first complete FEC block and method for generating broadcast signal frame", the filing date of September 8, 2017. TECHNICAL FIELD

[0002] The present application relates to a broadcast signal transmission / reception technology used in a broadcast system, and more particularly, to a broadcast signal transmission / reception system that multiplexes / demultiplexes and then transmits / receives two or more signals. BACKGROUND

[0003] Bit interleaved coded modulation (BICM) is a bandwidth-efficient transmission technology, and is implemented in such a way that an error correction encoder, a bit-wise interleaver, and a high-order modulator are combined with each other.

[0004] Because BICM uses a low-density parity-check (LDPC) encoder or a Turbo encoder as an error correction encoder, BICM can provide excellent performance using a simple structure. In addition, because BICM can select a modulation order and a length and a code rate of an error correction code in various forms, BICM can provide high-level flexibility. Due to these advantages, BICM has been applied to broadcast standards such as DVB-T2 and DVB-NGH, and has a high possibility of being used for other next-generation broadcast systems.

[0005] In order to support multiple services at the same time, a multiplexing, i.e., a process of mixing multiple signals, is required. Among multiplexing technologies, currently widely used technologies include time division multiplexing (TDM) suitable for dividing and using time resources and frequency division multiplexing (FDM) suitable for dividing and using frequency resources. That is, TDM is a method of allocating time periods for each service, and FDM is a technology of allocating frequency resource periods for each service and then using them. Recently, there is an urgent need for a new multiplexing technology suitable for a next-generation broadcast system and providing greater flexibility and performance than TDM and FDM. SUMMARY

[0006] TECHNICAL PROBLEM

[0007] An object of the present application is to provide a broadcast signal frame structure in which a new signal multiplexing technology capable of providing greater flexibility and performance than TDM and FDM is applied.

[0008] In addition, an object of the present application is to efficiently perform signaling related to time interleaving, especially when convolutional time interleaving is used.

[0009] Further, it is an object of the present application to effectively signal a field indicating a start position of a first complete FEC block of a physical layer pipe in a subframe.

[0010] Technical Solution

[0011] To achieve the above objects, the present application provides an apparatus for generating a broadcast signal frame, including a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhancement layer signal, a power normalizer configured to reduce a power of the multiplexed signal to a power level corresponding to the core layer signal, a time interleaver configured to generate a time interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, and a frame builder configured to generate a broadcast signal frame, wherein the broadcast signal frame includes a preamble for signaling time interleaver information corresponding to the time interleaver. In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to each of physical layer pipes.

[0012] In this case, the start position of the first complete FEC block can be designated with respect to a first cell of each of the physical layer pipes.

[0013] In this case, when an operation mode of the time interleaver is a mode corresponding to convolutional time interleaving, the start position of the first complete FEC block can indicate a first cell of the first complete FEC block before the convolutional time interleaving, and a position of the first cell of the first complete FEC block after the convolutional time interleaving can be signaled.

[0014] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after the convolutional time interleaving, which is calculated by adding a position (C) before the convolutional time interleaving and a delay caused by the convolutional time interleaving.

[0015] In this case, the delay caused by the convolutional time interleaving can be calculated by using a position (L1D_plp_CTI_start_row) of an interleaver selector corresponding to the convolutional time interleaving.

[0016] In this case, the delay caused by the convolutional time interleaving can be calculated by using a modulo operation of a sum (L1D_plp_CTI_start_row+C) of a position of an interleaver selector corresponding to the convolutional time interleaving and a position before the convolutional time interleaving and a number (N_row) of delay lines corresponding to the convolutional time interleaving.

[0017] In this case, the position of the interleaver selector can be signaled only for the core layer physical layer channel corresponding to the core layer, and the position of the interleaver selector can not be signaled for the enhancement layer physical layer channel corresponding to the enhancement layer.

[0018] In this case, the position of the interleaver selector for the enhancement layer physical layer channel can be calculated by using the position of the interleaver selector signaled for the core layer physical layer channel corresponding to the enhancement layer physical layer channel.

[0019] In this case, the length of the field indicating the start position of the first complete FEC block can be 22 bits.

[0020] In this case, the field indicating the start position of the first complete FEC block can be signaled for each of the core layer physical layer channel and the enhancement layer physical layer channel.

[0021] Further, an embodiment of the present application provides a method of generating a broadcast signal frame, including generating a multiplexed signal by combining a core layer signal and an enhancement layer signal, reducing power of the multiplexed signal to a power level corresponding to the core layer signal, generating a time-interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, and generating a broadcast signal frame including a preamble for signaling time-interleaver information corresponding to interleaving. In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to each of physical layer channels.

[0022] In this case, the start position of the first complete FEC block can be designated with respect to a first unit of each of the physical layer channels.

[0023] In this case, when the interleaving corresponds to convolutional time interleaving, the start position of the first complete FEC block can indicate a first unit of the first complete FEC block before the convolutional time interleaving, and a position of the first unit of the first complete FEC block can be signaled after the convolutional time interleaving.

[0024] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after the convolutional time interleaving, which is calculated by adding a position (C) before the convolutional time interleaving and a delay caused by the convolutional time interleaving.

[0025] In this case, the delay caused by the convolution time interleaving can be calculated by using the position of the interleaver selector corresponding to the convolution time interleaving (L1D_plp_CTI_start_row).

[0026] In this case, the delay caused by the convolution time interleaving can be calculated by using the sum of the position of the interleaver selector corresponding to the convolution time interleaving and the position before the convolution time interleaving (L1D_plp_CTI_start_row+C) and the modulo operation of the number of delay lines corresponding to the convolution time interleaving (N_row).

[0027] In this case, the position of the interleaver selector can be signaled only for the core layer physical layer pipes corresponding to the core layer, and the position of the interleaver selector can not be signaled for the enhancement layer physical layer pipes corresponding to the enhancement layer.

[0028] In this case, the position of the interleaver selector for the enhancement layer physical layer pipes can be calculated by using the position of the interleaver selector signaled for the core layer physical layer pipes corresponding to the enhancement layer physical layer pipes.

[0029] In this case, the length of the field indicating the start position of the first complete FEC block can be 22 bits.

[0030] In this case, the field indicating the start position of the first complete FEC block can be signaled for each of the core layer physical layer pipes and the enhancement layer physical layer pipes.

[0031] Advantageous Effects

[0032] According to the present application, a frame structure is provided, in which the frame structure provides a new signal multiplexing technique capable of providing greater flexibility and performance than TDM and FDM.

[0033] Further, according to the present application, signaling operations related to time interleaving can be effectively performed, particularly when convolution time interleaving is used.

[0034] Further, according to the present application, a field indicating the start position of the first complete FEC block of a physical layer pipe in a subframe can be effectively signaled. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a block diagram illustrating a broadcast signal transmitting / receiving system according to an embodiment of the present application;

[0036] Figure 2 is an operational flowchart illustrating a broadcast signal transmitting / receiving method according to an embodiment of the present application;

[0037] Figure 3 is a block diagram illustrating an example of an apparatus for generating a broadcast signal frame in Figure 1 ;

[0038] Figure 4 is a diagram illustrating an example of a structure of a broadcast signal frame;

[0039] Figure 5 is a block diagram illustrating an example of a receiving process of a broadcast signal frame shown in Figure 4 ;

[0040] Figure 6 is a diagram illustrating another example of a receiving process of a broadcast signal frame shown in Figure 4 ;

[0041] Figure 7 is a block diagram illustrating another example of an apparatus for generating a broadcast signal frame shown in Figure 1 ;

[0042] Figure 8 is a block diagram illustrating an example of a signal demultiplexer shown in Figure 1 ;

[0043] Figure 9 is a block diagram illustrating an example of a core layer BICM decoder and an enhancement layer symbol extractor shown in Figure 8 ;

[0044] Figure 10 is a block diagram illustrating another example of a core layer BICM decoder and an enhancement layer symbol extractor shown in Figure 8 ;

[0045] Figure 11 is a block diagram illustrating another example of a core layer BICM decoder and an enhancement layer symbol extractor shown in Figure 8 ;

[0046] Figure 12 is a block diagram illustrating another example of a signal demultiplexer shown in Figure 1 ;

[0047] Figure 13 is a diagram illustrating a power increase due to a combination of a core layer signal and an enhancement layer signal;

[0048] Figure 14 is an operational flowchart illustrating a method of generating a broadcast signal frame according to an embodiment of the present application;

[0049] Figure 15 is a diagram illustrating a structure of a superframe including a broadcast signal frame according to an embodiment of the present application;

[0050] Figure 16 is a diagram illustrating an example of an LDM frame including multiple physical layer pipes and using two layers of LDM;

[0051] Figure 17 is a diagram illustrating a further example of an LDM frame including multiple physical layer pipes and using two layers of LDM;

[0052] Figure 18 is a diagram illustrating an application example of an LDM frame using multiple physical layer pipes and two layers of LDM;

[0053] Figure 19 is a diagram illustrating a further application example of an LDM frame using multiple physical layer pipes and two layers of LDM;

[0054] Figure 20 is a diagram illustrating an example of using a convolutional time interleaver;

[0055] Figure 21 is a diagram illustrating a further example of using a convolutional time interleaver;

[0056] Figure 22 is a diagram illustrating an example of using a hybrid time interleaver;

[0057] Figure 23 is a diagram illustrating Figure 22 a time interleaver packet in an example of

[0058] Figure 24 to 26 is a diagram illustrating a process for calculating the size of an incomplete FEC block in an example of Figure 23

[0059] Figure 27 is a diagram for explaining the number of bits required for L1D_plp_fec_block_start when L1D_plp_TI_mode = "00";

[0060] Figure 28 and Figure 29 is a diagram for explaining the number of bits required for L1D_plp_CTI_fec_block_start when L1D_plp_TI_mode = "01";

[0061] Figure 30 is a diagram illustrating an example of L1D_plp_fec_block_start for an enhancement layer;

[0062] Figure 31 is a diagram illustrating a relationship between before convolutional time interleaving and after convolutional time interleaving;

[0063] Figure 32 ​is a diagram illustrating a single physical layer channel case where a convolutional time interleaving with a depth of 0 is applied;

[0064] Figure 33 is a diagram illustrating an operation of a receiver side in a single physical layer channel case; and

[0065] Figure 34 and 35 is a diagram illustrating a multiple enhanced physical layer channel case. DETAILED DESCRIPTION

[0066] Hereinafter, the present application will be described in detail with reference to the accompanying drawings. In the description, redundant descriptions and descriptions of well-known functions and configurations which have been deemed to make the gist of the present application unnecessarily obscure will be omitted. The embodiments of the present application are provided in order to sufficiently describe the present application to those of ordinary skill in the art to which the present application pertains. Therefore, the shape, size, etc. of components in the accompanying drawings can be exaggerated so that the description is apparent.

[0067] Hereinafter, preferred embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0068] Figure 1 is a block diagram illustrating a broadcast signal transmitting / receiving system according to an embodiment of the present application.

[0069] Referring to Figure 1 , a broadcast signal transmitting / receiving system according to an embodiment of the present application includes a broadcast signal transmitting apparatus 110, a wireless channel 120, and a broadcast signal receiving apparatus 130.

[0070] The broadcast signal transmitting apparatus 110 includes a device 111 for generating a broadcast signal frame by multiplexing core layer data and enhancement layer data, and an OFDM transmitter 113.

[0071] The device 111 combines a core layer signal corresponding to the core layer data and an enhancement layer signal corresponding to the enhancement layer data at different power levels, and generates a multiplexed signal by performing interleaving applied to both the core layer signal and the enhancement layer signal. In this case, the device 111 can generate a broadcast signal frame including a bootstrap and a preamble using a time interleaved signal. In this case, the broadcast signal frame can be an ATSC 3.0 frame.

[0072] In this case, the time interleaving can use one of time interleaver packets, and a boundary between the time interleaver packets can be a boundary between physical layer channels (PLPs) of the core layer corresponding to the core layer signal. That is, one of the boundaries between the physical layer channels of the core layer can be a boundary between the time interleaver packets.

[0073] The OFDM transmitter 113 transmits a multiplexed signal using an OFDM communication method via the antenna 117, thereby allowing the transmitted OFDM signal to be received via the antenna 137 of the broadcast signal receiving apparatus 130 over the wireless channel 120.

[0074] The broadcast signal receiving apparatus 130 includes an OFDM receiver 133 and a signal demultiplexer 131. When a signal transmitted over the wireless channel 120 is received via the antenna 137, the OFDM receiver 133 receives the OFDM signal via synchronization, channel estimation, and equalization.

[0075] In this case, the OFDM receiver 133 can detect and demodulate a bootstrap code from the OFDM signal, demodulate a preamble using information included in the bootstrap code, and demodulate a superposed payload using information included in the preamble.

[0076] The signal demultiplexer 131 first recovers core layer data from a signal (a superposed payload) received via the OFDM receiver 133, and then recovers enhancement layer data via cancellation corresponding to the recovered core layer data. In this case, the signal demultiplexer 131 can first generate a broadcast signal frame, can recover a bootstrap code, can recover a preamble using information included in the bootstrap code, and can recover a data signal using signaling information included in the preamble. In this case, the signaling information can be L1 signaling information, and can include injection level information, normalization factor information, etc.

[0077] In this case, the preamble can include PLP identification information for identifying a physical layer pipe (PLP); and layer identification information for identifying a layer corresponding to a hierarchy.

[0078] In this case, the PLP identification information and the layer identification information can be included in the preamble as different fields from each other.

[0079] In this case, the time interleaver information can be included in the preamble based on the core layer.

[0080] In this case, based on a comparison result of the layer identification information with a predetermined value, the preamble can selectively include injection level information corresponding to an injection level controller for each physical layer pipe (PLP).

[0081] In this case, the preamble can include type information, start position information, and size information of a physical layer pipe.

[0082] In this case, the type information can be used to identify one of a first type corresponding to a non-scattered physical layer pipe and a second type corresponding to a scattered physical layer pipe.

[0083] In this case, non-scattered physical layer channels can be allocated for continuous data unit indexes, and scattered physical layer channels can include two or more subslices.

[0084] In this case, type information can be selectively signaled for each physical layer channel (PLP) according to a comparison result of layer identification information and a predetermined value.

[0085] In this case, type information can be signaled only for a core layer.

[0086] In this case, start position information can be the same as an index of a first data unit corresponding to a physical layer channel.

[0087] In this case, start position information can indicate a start position of a physical layer channel using a unit addressing scheme.

[0088] In this case, start position information can be included in a preamble for each physical layer channel (PLP) without verifying a condition of a conditional statement corresponding to layer identification information.

[0089] In this case, size information can be generated based on a number of data units allocated to a physical layer channel.

[0090] In this case, size information can be included in a preamble for each physical layer channel (PLP) without verifying a condition of a conditional statement corresponding to layer identification information.

[0091] In this case, time interleaver information can be signaled based on a core layer.

[0092] In this case, a time interleaver can correspond to a hybrid time interleaver. In this case, physical layer channels (PLPs) of the core layer and the enhancement layer can include only complete FEC blocks.

[0093] In this case, in a case where a boundary between time interleaver packets does not correspond to a boundary between FEC blocks in the enhancement layer, a preamble can be used to signal information for identifying a portion of an FEC block in the enhancement layer, wherein the FEC block corresponds to the boundary between the time interleaver packets.

[0094] In this case, the information for identifying a portion of an FEC block can include at least one of start position information of a physical layer channel (PLP) in the core layer, start position information of a physical layer channel (PLP) in the enhancement layer, modulation information corresponding to the enhancement layer, and FEC type information corresponding to the enhancement layer.

[0095] In this case, the start position information of the physical layer pipe (PLP) can correspond to an index of a first data unit of the physical layer pipe (PLP).

[0096] In this case, the modulation information can be signaled only if the FEC type information satisfies a predetermined condition.

[0097] In this case, the enhancement layer signal can correspond to enhancement layer data recovered based on cancellation corresponding to recovery of core layer data corresponding to the core layer signal.

[0098] In this case, the time interleaver can correspond to a convolutional time interleaver, the time interleaver packet can include a physical layer pipe (PLP) including an incomplete FEC block, and the preamble can be used to signal start position information of a first complete FEC block in the physical layer pipe (PLP).

[0099] In this case, the time interleaver can perform interleaving by using one of a plurality of operation modes.

[0100] In this case, the operation modes can include a first mode corresponding to no time interleaving, a second mode for performing convolutional time interleaving, and a third mode for performing hybrid time interleaving.

[0101] In this case, the preamble can include a field indicating a start position of a first complete FEC block for the first and second modes corresponding to a current physical layer pipe, and can not include a field indicating a start position of a first FEC block for the third mode. In this case, the field indicating the start position can indicate a start position of a first FEC block starting in the current physical layer pipe during a current subframe.

[0102] In this case, the field indicating the start position of the first FEC block can be one of a first field used in the first mode and a second field used in the second mode, and the first field and the second field can have different lengths.

[0103] In this case, the length of the second field can be longer than the length of the first field.

[0104] In this case, the length of the first field can be determined based on a length of an LDPC codeword and a modulation order, and the length of the second field can be determined further considering a depth of a convolutional time interleaver in addition to the length of the LDPC codeword and the modulation order.

[0105] In this case, the length of the first field can be 15 bits, and the length of the second field can be 22 bits.

[0106] In this case, the first field and the second field can be respectively signaled for each of a core layer corresponding to a core layer signal and an enhancement layer corresponding to an enhancement layer signal.

[0107] In this case, the preamble can include a field indicating a start position of the first complete FEC block corresponding to each of the physical layer channels.

[0108] In this case, the start position of the first complete FEC block can be designated with respect to a first unit of each of the physical layer channels.

[0109] In this case, when the operation mode of the time interleaver is a mode corresponding to convolutional time interleaving, the start position of the first complete FEC block can indicate a position of a first unit of the first complete FEC block before the convolutional time interleaving, and the position of the first unit of the first complete FEC block can be signaled after the convolutional time interleaving.

[0110] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after the convolutional time interleaving, which is calculated by adding a position (C) before the convolutional time interleaving and a delay caused by the convolutional time interleaving.

[0111] In this case, the delay caused by the convolutional time interleaving can be calculated by using a position (L1D_plp_CTI_start_row) of an interleaver selector corresponding to the convolutional time interleaving.

[0112] In this case, the delay caused by the convolutional time interleaving can be calculated by using a sum (L1D_plp_CTI_start_row+C) of a position of an interleaver selector corresponding to the convolutional time interleaving and a position before the convolutional time interleaving, and a modulo operation of a number (N_row) of delay lines corresponding to the convolutional time interleaving.

[0113] In this case, the position of the interleaver selector can be signaled only for a core layer physical layer channel corresponding to a core layer, and the position of the interleaver selector can not be signaled for an enhancement layer physical layer channel corresponding to an enhancement layer.

[0114] In this case, the position of the interleaver selector for the enhancement layer physical layer channel can be calculated by using the position of the interleaver selector signaled for a core layer physical layer channel corresponding to the enhancement layer physical layer channel.

[0115] In this case, the length of the field indicating the start position of the first complete FEC block can be 22 bits.

[0116] In this case, the field indicating the start position of the first complete FEC block can be signaled for each of the core layer physical layer channel and the enhancement layer physical layer channel.

[0117] As will be described in detail later, Figure 1 The apparatus 111 shown in FIG. 1 can include a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhancement layer signal, a power normalizer configured to reduce the power of the multiplexed signal to a power level corresponding to the core layer signal, a time interleaver configured to generate a time interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, and a frame builder configured to generate a broadcast signal frame, wherein the broadcast signal frame includes a preamble for signaling time interleaver information corresponding to the time interleaver. In this case, the combiner can combine the core layer signal and the enhancement layer signal at different power levels. In this case, the preamble can include a field indicating the start position of the first complete FEC block corresponding to each of the physical layer channels. In this case, Figure 1 The broadcast signal transmitting apparatus 110 shown in FIG. 1 can be considered to include a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhancement layer signal, a power normalizer configured to reduce the power of the multiplexed signal to a power level corresponding to the core layer signal, a time interleaver configured to generate a time interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, a frame builder configured to generate a broadcast signal frame, wherein the broadcast signal frame includes a preamble for signaling time interleaver information corresponding to the time interleaver, and an OFDM transmitter configured to transmit the broadcast signal frame through an antenna using an OFDM communication scheme. In this case, the combiner can combine the core layer signal and the enhancement layer signal at different power levels. In this case, the preamble can include a field indicating the start position of the first complete FEC block corresponding to each of the physical layer channels.

[0118] As will be described in detail later, Figure 1The signal demultiplexer shown in the middle can include a time de-interleaver configured to generate a time de-interleaved signal by applying time de-interleaving to a received signal corresponding to a broadcast signal frame, a de-normalizer configured to increase a power of the received signal or the time de-interleaved signal to a level corresponding to a power decreased by the power normalizer of the transmitter, a core layer BICM decoder configured to recover core layer data from a signal power-adjusted by the de-normalizer, an enhancement layer symbol extractor configured to extract an enhancement layer signal by performing cancellation corresponding to the core layer data on a signal power-adjusted by the de-normalizer using an output signal of a core layer FEC decoder of the core layer BICM decoder, a de-injection level controller configured to increase a power of the enhancement layer signal to a level corresponding to a power decreased by the injection level controller of the transmitter, and an enhancement layer BICM decoder configured to recover enhancement layer data using an output signal of the de-injection level controller. In this case, Figure 1 The broadcast signal receiving apparatus 130 shown in the middle can be regarded as including an OFDM receiver configured to generate a received signal by performing any one or more of synchronization, channel estimation, and equalization on a transmitted signal corresponding to a broadcast signal frame, a time de-interleaver configured to generate a time de-interleaved signal by applying time de-interleaving to the received signal, a de-normalizer configured to increase a power of the received signal or the time de-interleaved signal to a level corresponding to a power decreased by the power normalizer of the transmitter, a core layer BICM decoder configured to recover core layer data from a signal power-adjusted by the de-normalizer, an enhancement layer symbol extractor configured to extract an enhancement layer signal by performing cancellation corresponding to the core layer data on a signal power-adjusted by the de-normalizer using an output signal of a core layer FEC decoder of the core layer BICM decoder, a de-injection level controller configured to increase a power of the enhancement layer signal to a level corresponding to a power decreased by the injection level controller of the transmitter, and an enhancement layer BICM decoder configured to recover enhancement layer data using an output signal of the de-injection level controller.

[0119] In this case, the broadcast signal frame can include a preamble, and the preamble can include a start position of a first complete FEC block corresponding to each of the physical layer channels, wherein the start position of the first complete FEC block corresponding to each of the physical layer channels can be used to calculate a position of a first unit before convolutional time interleaving.

[0120] Although in the above description, the broadcast signal receiving apparatus 130 is described as including the OFDM receiver, the time de-interleaver, the de-normalizer, the core layer BICM decoder, the enhancement layer symbol extractor, the de-injection level controller, and the enhancement layer BICM decoder, the broadcast signal receiving apparatus 130 can include only the OFDM receiver, the time de-interleaver, the de-normalizer, the core layer BICM decoder, the enhancement layer symbol extractor, the de-injection level controller, and the enhancement layer BICM decoder. Figure 1Although not explicitly shown, the broadcast signal transmitting / receiving system according to the embodiment of the present application can multiplex / demultiplex one or more pieces of extension layer data in addition to the core layer data and the enhancement layer data. In this case, the extension layer data can be multiplexed at a power level lower than that of the core layer data and the enhancement layer data. Further, when two or more extension layers are included, an injection power level of a second extension layer can be lower than that of a first extension layer, and an injection power level of a third extension layer can be lower than that of the second extension layer.

[0121] Figure 2 is a flowchart illustrating an operation of a broadcast signal transmitting / receiving method according to an embodiment of the present application.

[0122] Referring to Figure 2 In the broadcast signal transmitting / receiving method according to the embodiment of the present application, in step S210, the core layer signal and the enhancement layer signal are combined at different power levels and then multiplexed to generate a broadcast signal frame including time interleaver information shared by the core layer signal and the enhancement layer signal and a preamble for signaling the time interleaver information.

[0123] In this case, the broadcast signal frame generated in step S210 can include a bootstrap, a preamble, and a superposed payload. In this case, at least the bootstrap and the preamble can include L1 signaling information. In this case, the L1 signaling information can include injection level information and a normalization factor information.

[0124] In this case, the preamble can include PLP identification information for identifying a physical layer pipe (PLP) and layer identification information for identifying a layer corresponding to a hierarchy.

[0125] In this case, the PLP identification information and the layer identification information can be included in the preamble as different fields from each other.

[0126] In this case, the time interleaver information can be included in the preamble based on the core layer.

[0127] In this case, based on a comparison result of the layer identification information with a predetermined value, the preamble can selectively include injection level information corresponding to an injection level controller for each physical layer pipe (PLP).

[0128] In this case, the preamble can include type information, start position information, and size information of a physical layer pipe.

[0129] In this case, the type information can be used to identify one of a first type corresponding to a non-scattered physical layer channel and a second type corresponding to a scattered physical layer channel.

[0130] In this case, a non-scattered physical layer channel can be allocated for a continuous data unit index, and a scattered physical layer channel can include two or more sub-slices.

[0131] In this case, the type information can be selectively signaled according to a comparison result of the layer identification information with a predetermined value for each physical layer channel (PLP).

[0132] In this case, the type information can be signaled only for a core layer.

[0133] In this case, the start position information can be the same as an index of a first data unit corresponding to the physical layer channel.

[0134] In this case, the start position information can indicate a start position of the physical layer channel using a unit addressing scheme.

[0135] In this case, the start position information can be included in a preamble for each physical layer channel (PLP) without verifying a condition of a conditional statement corresponding to the layer identification information.

[0136] In this case, the size information can be generated based on a number of data units allocated to the physical layer channel.

[0137] In this case, the size information can be included in a preamble for each physical layer channel (PLP) without verifying a condition of a conditional statement corresponding to the layer identification information.

[0138] In this case, the time interleaver information can be signaled based on a core layer.

[0139] In this case, generating a time-interleaved signal can perform interleaving using a hybrid time interleaver.

[0140] In this case, the physical layer channels (PLPs) of the core layer and the enhancement layer can include only complete FEC blocks.

[0141] In this case, in a case where a boundary between time interleaver packets does not correspond to a boundary between FEC blocks in the enhancement layer, the preamble can be used to signal information for identifying a portion of the FEC blocks in the enhancement layer, wherein the FEC blocks correspond to the boundary between the time interleaver packets.

[0142] In this case, the information for identifying a portion of the FEC block can include at least one of start position information of a physical layer pipe (PLP) in the core layer, start position information of a physical layer pipe (PLP) in the enhancement layer, modulation information corresponding to the enhancement layer, and FEC type information corresponding to the enhancement layer.

[0143] In this case, the start position information of the physical layer pipe (PLP) can correspond to an index of a first data unit of the physical layer pipe (PLP).

[0144] In this case, the modulation information can be signaled only in the case where the FEC type information satisfies a predetermined condition.

[0145] In this case, the enhancement layer signal corresponds to enhancement layer data, wherein the enhancement layer data can be recovered based on cancellation corresponding to recovery of core layer data corresponding to the core layer signal.

[0146] In this case, generating the time-interleaved signal can perform interleaving using a convolutional time interleaver, the time interleaver grouping can include a physical layer pipe (PLP) including an incomplete FEC block, and a preamble can be used to signal start position information of a first complete FEC block in the physical layer pipe (PLP).

[0147] In this case, the interleaving can be performed by using one of a plurality of operation modes.

[0148] In this case, the operation modes can include a first mode corresponding to no time interleaving, a second mode for performing convolutional time interleaving, and a third mode for performing hybrid time interleaving.

[0149] In this case, the preamble can include a field indicating a start position of a first complete FEC block for the first and second modes corresponding to a current physical layer pipe, and can not include a field indicating a start position of a first FEC block for the third mode.

[0150] In this case, the field indicating the start position of the first FEC block can be one of a first field used in the first mode and a second field used in the second mode, and the first field and the second field can have different lengths.

[0151] In this case, the length of the second field can be longer than the length of the first field.

[0152] In this case, the length of the first field can be determined based on the length of the LDPC codeword and the modulation order, and the length of the second field can be determined not only by the length of the LDPC codeword and the modulation order but also further considering the depth of the convolutional time interleaver.

[0153] In this case, the length of the first field can be 15 bits, and the length of the second field can be 22 bits.

[0154] In this case, the first field and the second field can be respectively signaled for each of a core layer corresponding to a core layer signal and an enhancement layer corresponding to an enhancement layer signal.

[0155] In this case, the preamble can include a field indicating a start position of a first complete FEC block corresponding to each of the physical layer channels.

[0156] In this case, the start position of the first complete FEC block can be designated with respect to a first unit of each of the physical layer channels.

[0157] In this case, when the operation mode of the time interleaver is a mode corresponding to convolutional time interleaving, the start position of the first complete FEC block can indicate a position of a first unit of the first complete FEC block before the convolutional time interleaving, and the position of the first unit of the first complete FEC block can be signaled after the convolutional time interleaving.

[0158] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after the convolutional time interleaving, which is calculated by adding a position (C) before the convolutional time interleaving and a delay caused by the convolutional time interleaving.

[0159] In this case, the delay caused by the convolutional time interleaving can be calculated by using a position (L1D_plp_CTI_start_row) of an interleaver selector corresponding to the convolutional time interleaving.

[0160] In this case, the delay caused by the convolutional time interleaving can be calculated by using a sum (L1D_plp_CTI_start_row+C) of a position of an interleaver selector corresponding to the convolutional time interleaving and a position before the convolutional time interleaving, and a modulo operation of a number (N_row) of delay lines corresponding to the convolutional time interleaving.

[0161] In this case, the position of the interleaver selector can be signaled only for the core layer physical layer channel corresponding to the core layer, and the position of the interleaver selector can not be signaled for the enhancement layer physical layer channel corresponding to the enhancement layer.

[0162] In this case, the position of the interleaver selector for the enhancement layer physical layer channel can be calculated by using the position of the interleaver selector signaled for the core layer physical layer channel corresponding to the enhancement layer physical layer channel.

[0163] In this case, the length of the field indicating the start position of the first complete FEC block can be 22 bits.

[0164] In this case, the field indicating the start position of the first complete FEC block can be signaled for each of the core layer physical layer channel and the enhancement layer physical layer channel.

[0165] Further, in the broadcast signal transmitting / receiving method according to an embodiment of the present application, in step S220, the broadcast signal frame is OFDM transmitted.

[0166] Further, in the broadcast signal transmitting / receiving method according to an embodiment of the present application, in step S230, the signal is OFDM received.

[0167] In this case, in step S230, synchronization, channel estimation, and equalization can be performed.

[0168] In this case, in step S230, the pilot code can be recovered, the preamble can be recovered using the signal included in the recovered pilot code, and the data signal can be recovered using the signaling information included in the preamble.

[0169] Further, in the broadcast signal transmitting / receiving method according to an embodiment of the present application, in step S240, the core layer data is recovered from the received signal.

[0170] Further, in the broadcast signal transmitting / receiving method according to an embodiment of the present application, in step S250, the enhancement layer data is recovered through cancellation of the core layer signal.

[0171] Specifically, Figure 2 Steps S240 and S250 shown in FIG. 2B can correspond to a demultiplexing operation corresponding to step S210.

[0172] As will be described in detail later, Figure 2The step S210 illustrated in FIG. 2 can include generating a multiplexed signal by combining the core layer signal and the enhancement layer signal, reducing power of the multiplexed signal to a power level corresponding to the core layer signal, generating a time-interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, and generating a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the interleaving. In this case, the operation of generating a multiplexed signal can include combining the core layer signal and the enhancement layer signal at different power levels. In this case, the preamble can include a field indicating a start position of a first complete FEC block corresponding to each of the physical layer channels. In this case, the broadcast signal transmission method of steps S210 and S220 can be regarded as including generating a multiplexed signal by combining the core layer signal and the enhancement layer signal, reducing power of the multiplexed signal to a power level corresponding to the core layer signal, generating a time-interleaved signal by performing interleaving applied to both the core layer signal and the enhancement layer signal, generating a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the interleaving, and transmitting the broadcast signal frame through the antennas using an OFDM communication scheme. In this case, the operation of generating a multiplexed signal can include combining the core layer signal and the enhancement layer signal at different power levels. In this case, the preamble can include a field indicating a start position of a first complete FEC block corresponding to each of the physical layer channels.

[0173] As will be described in detail later, Figure 2The steps S240 and S250 shown in FIG. 10 can include generating a time deinterleaved signal by applying time deinterleaving to a received signal corresponding to a broadcast signal frame, increasing a power of the received signal or the time deinterleaved signal to a level corresponding to a power reduced by a power normalizer of a transmitter, recovering core layer data from the power-adjusted signal, extracting an enhanced layer signal by performing cancellation corresponding to the core layer data on the power-adjusted signal, increasing a power of the enhanced layer signal to a level corresponding to a power reduced by an injection level controller of the transmitter, and recovering enhanced layer data using the power-adjusted enhanced layer signal. In this case, the broadcast signal receiving method according to an embodiment of the present application can be considered to include generating a received signal by performing any one or more of synchronization, channel estimation, and equalization on a transmitted signal corresponding to a broadcast signal frame, generating a time deinterleaved signal by applying time deinterleaving to the received signal, increasing a power of the received signal or the time deinterleaved signal to a level corresponding to a power reduced by a power normalizer of a transmitter, recovering core layer data from the power-adjusted signal, extracting an enhanced layer signal by performing cancellation corresponding to the core layer data on the power-adjusted signal, increasing a power of the enhanced layer signal to a level corresponding to a power reduced by an injection level controller of the transmitter, and recovering enhanced layer data using the power-adjusted enhanced layer signal.

[0174] In this case, the broadcast signal frame can include a preamble, and the preamble can include a start position of a first complete FEC block corresponding to each of the physical layer channels, and the start position of the first complete FEC block corresponding to each of the physical layer channels can be used to calculate a position of a first unit before convolutional time interleaving.

[0175] Figure 3 is a block diagram illustrating an example of an apparatus for generating a broadcast signal frame in Figure 1 .

[0176] Referring to Figure 3 , the apparatus for generating a broadcast signal frame according to an embodiment of the present application can include a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, a power normalizer 345, and a time interleaver 350, a signaling generation unit 360, and a frame builder 370.

[0177] Generally, a BICM device includes an error correction encoder, a bit interleaver, and a symbol mapper. Figure 3 Each of the core layer BICM unit 310 and the enhanced layer BICM unit 320 shown in FIG. 11 can include an error correction encoder, a bit interleaver, and a symbol mapper. Specifically, Figure 3Each of the error correction encoders (the core layer FEC encoder and the enhancement layer FEC encoder) shown in FIG. 1 can be formed by connecting a BCH encoder and an LDPC encoder in series. In this case, the input of the error correction encoder is input to the BCH encoder, the output of the BCH encoder is input to the LDPC encoder, and the output of the LDPC encoder can be the output of the error correction encoder.

[0178] As shown in FIG. 1, the core layer data and the enhancement layer data pass through respective different BICM units, and then are combined by the combiner 340. That is, the term "layer division multiplexing (LDM)" used herein can refer to combining a plurality of pieces of data of a plurality of layers into a single piece of data using power difference, and then transmitting the combined data. Figure 3

[0179] That is, the core layer data passes through the core layer BICM unit 310, the enhancement layer data passes through the enhancement layer BICM unit 320, and then passes through the injection level controller 330, and the core layer data and the enhancement layer data are combined by the combiner 340. In this case, the enhancement layer BICM unit 320 can perform BICM encoding different from that of the core layer BICM unit 310. That is, the enhancement layer BICM unit 320 can perform error correction encoding or symbol mapping of a higher bit rate than the core layer BICM unit 310. In addition, the enhancement layer BICM unit 320 can perform error correction encoding or symbol mapping that is less robust than the core layer BICM unit 310.

[0180] For example, the core layer error correction encoder can exhibit a lower bit rate than the enhancement layer error correction encoder. In this case, the enhancement layer symbol mapper can be less robust than the core layer symbol mapper.

[0181] The combiner 340 can be regarded as functioning to combine the core layer signal and the enhancement layer signal at different power levels. In one embodiment, power level adjustment can be performed on the core layer signal but not on the enhancement layer signal. In this case, the power of the core layer signal can be adjusted to be higher than that of the enhancement layer signal.

[0182] The core layer data can use a forward error correction (FEC) code having a low coding rate to perform robust reception, and the enhancement layer data can use an FEC code having a high coding rate to achieve a high data transmission rate.

[0183] That is, in the same reception environment, the core layer data can have a wider coverage than the enhancement layer data.

[0184] The enhancement layer data that has passed through the enhancement layer BICM unit 320 is adjusted in gain (or power) by the injection level controller 330, and is combined with the core layer data by the combiner 340. ​

[0185] That is, the injection level controller 330 generates a power-reduced enhancement layer signal by reducing the power of the enhancement layer signal. In this case, the amplitude of the signal adjusted by the injection level controller 330 can be determined based on the injection level. In this case, in the case where the signal B is inserted into the signal A, the injection level can be defined by Equation 1 below:

[0186]

[0187] For example, when the enhancement layer signal is inserted into the core layer signal, assuming that the injection level is 3dB, Equation 1 means that the enhancement layer signal has a power corresponding to half the power of the core layer signal.

[0188] In this case, the injection level controller 330 can adjust the power level of the enhancement layer signal from 0dB to 25.0dB in steps of 0.5dB or 1dB.

[0189] Generally, the transmission power allocated to the core layer is higher than the transmission power allocated to the enhancement layer, which enables the receiver to first decode the core layer data.

[0190] In this case, the combiner 340 can be regarded as generating a multiplexed signal by combining the core layer signal with the power-reduced enhancement layer signal.

[0191] The signal obtained through the combination of the combiner 340 is provided to the power normalizer 345 so that the power of the signal can be reduced by a power level corresponding to the power increase caused by the combination of the core layer signal and the enhancement layer signal, and then power adjustment is performed. That is, the power normalizer 345 reduces the power of the signal obtained through the multiplexing of the combiner 340 to a power level corresponding to the core layer signal. Since the level of the combined signal is higher than the level of the one-layer signal, power normalization of the power normalizer 345 is required in order to prevent amplitude clipping or the like in the remaining part of the broadcast signal transmitting / receiving system.

[0192] In this case, the power normalizer 345 can adjust the amplitude of the combined signal to an appropriate value by multiplying the amplitude of the combined signal by the normalization factor of Equation 2 below. The injection level information used to calculate Equation 2 below can be transmitted to the power normalizer 345 via a signaling stream:

[0193]

[0194] Assuming that when the enhancement layer signal S E is injected into the core layer signal S C with a preset injection level, the power levels of the core layer signal and the enhancement layer signal are normalized to 1, the combined signal can be represented by S C+ αS E represents.

[0195] In this case, α is a scale factor corresponding to various injection levels. That is, the injection level controller 330 can correspond to the scale factor.

[0196] For example, when the injection level of the enhancement layer is 3dB, the combined signal can be represented by represents.

[0197] Since the power of the combined signal (multiplexed signal) is increased compared to the power of the core layer signal, the power normalizer 345 needs to mitigate the increase in power.

[0198] The output of the power normalizer 345 can be represented by β(S C + αS E ).

[0199] In this case, β is a normalization factor based on various injection levels of the enhancement layer.

[0200] When the injection level of the enhancement layer is 3dB, the power of the combined signal is increased by 50% compared to the power of the core layer signal. Accordingly, the output of the power normalizer 345 can be represented by

[0201] represents.

[0202] Table 1 below lists the scale factor α and the normalization factor β for various injection levels (CL: core layer, EL: enhancement layer). The relationship between the injection level, the scale factor α, and the normalization factor β can be defined by Equation 3 below:

[0203]

[0204] Table 1

[0205]

[0206]

[0207] That is, the power normalizer 345 corresponds to the normalization factor and reduces the power of the multiplexed signal by the level at which the combiner 340 has increased the power.

[0208] In this case, each of the normalization factor and the scale factor can be a rational number greater than 0 and less than 1.

[0209] In this case, the scale factor can decrease as the power reduction corresponding to the injection level controller 330 becomes greater, and the normalization factor can increase as the power reduction corresponding to the injection level controller 330 becomes greater.

[0210] The power-normalized signal passes through the time interleaver 350 to distribute burst errors occurring on a channel.

[0211] In this case, the time interleaver 350 can be regarded as performing interleaving applied to both the core layer signal and the enhancement layer signal. That is, the core layer and the enhancement layer share the time interleaver, thereby preventing unnecessary use of memory, and also reducing a delay at the receiver.

[0212] Although this will be described in more detail later, the enhancement layer signal can correspond to enhancement layer data recovered based on cancellation corresponding to recovery of core layer data, wherein the core layer data corresponds to the core layer signal. The combiner 340 can combine one or more extension layer signals having a power level lower than a power level of the core layer signal and the enhancement layer signal with the core layer signal and the enhancement layer signal.

[0213] Meanwhile, L1 signaling information including the injection level information is encoded by a signaling generation unit 360 including signaling-specific BICM. In this case, the signaling generation unit 360 can receive the injection level information IL INFO from the injection level controller 330, and can generate an L1 signaling signal.

[0214] In the L1 signaling, L1 refers to Layer 1 in the lowest layer of an ISO 7 layer model. In this case, the L1 signaling can be included in a preamble.

[0215] In general, the L1 signaling can include an FFT size, a guard interval size, etc. (i.e., important parameters of an OFDM transmitter), a channel code rate, modulation information, etc. (i.e., BICM important parameters). This L1 signaling signal is combined with a data signal into a broadcast signal frame.

[0216] The frame builder 370 generates a broadcast signal frame by combining the L1 signaling signal with the data signal. In this case, the frame builder 370 can generate a broadcast signal frame using the time-interleaved signal, wherein the broadcast signal frame includes a preamble for signaling size information of a physical layer pipe (PLP), and time interleaver information shared by the core layer signal and the enhancement layer signal. In this case, the broadcast signal frame can further include a bootstrap code.

[0217] In this case, the frame builder 370 can generate a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the time interleaver 350.

[0218] In this case, the time interleaver 350 can use one of the time interleaver packets, and a boundary between the time interleaver packets can be a boundary between physical layer pipes (PLPs) of the core layer corresponding to the core layer signal. That is, one of the boundaries between the physical layer pipes (PLPs) of the core layer can be the boundary between the time interleaver packets.

[0219] In this case, the time interleaver information can be signaled based on the core layer.

[0220] According to one embodiment, a part of the time interleaver information can be signaled based on the core layer, and another part of the time interleaver information can be signaled regardless of the layer.

[0221] That is, the time interleaver information can be signaled based on layer identification information corresponding to the core layer.

[0222] In this case, the time interleaver 350 can correspond to a hybrid time interleaver. In this case, the physical layer pipes (PLPs) of the core layer and the enhancement layer can include only complete FEC blocks.

[0223] In this case, in a case where a boundary between the time interleaver packets does not correspond to a boundary between FEC blocks in the enhancement layer, a preamble can be used to signal information for identifying a part of the FEC blocks in the enhancement layer, wherein the FEC blocks correspond to the boundary between the time interleaver packets.

[0224] In this case, the information for identifying the part of the FEC blocks can include at least one of the following information: start position information of a physical layer pipe (PLP) in the core layer, start position information of a physical layer pipe (PLP) in the enhancement layer, modulation information corresponding to the enhancement layer, and FEC type information corresponding to the enhancement layer.

[0225] In this case, the start position information of the physical layer pipe (PLP) can correspond to an index of a first data unit of the physical layer pipe (PLP).

[0226] In this case, the modulation information can be signaled only when the FEC type information satisfies a predetermined condition.

[0227] In this case, the enhancement layer signal can correspond to enhancement layer data recovered based on cancellation corresponding to recovery of core layer data corresponding to the core layer signal.

[0228] In this case, the time interleaver 350 can correspond to a convolution time interleaver, the time interleaver packet can include a physical layer pipe (PLP) including an incomplete FEC block, and the preamble can be used to signal the start position information of the first complete FEC block in the physical layer pipe (PLP).

[0229] In this case, the start position of the first complete FEC block can be designated with respect to a first cell of each of the physical layer pipes.

[0230] In this case, when the operation mode of the time interleaver is a mode corresponding to convolution time interleaving, the start position of the first complete FEC block can indicate a first cell of the first complete FEC block before convolution time interleaving, and a position of the first cell of the first complete FEC block after convolution time interleaving can be signaled.

[0231] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after convolution time interleaving, which is calculated by adding a position (C) before convolution time interleaving and a delay caused by convolution time interleaving.

[0232] In this case, the delay caused by convolution time interleaving can be calculated by using a position (L1D_plp_CTI_start_row) of an interleaver selector corresponding to convolution time interleaving.

[0233] In this case, the delay caused by convolution time interleaving can be calculated by using a sum (L1D_plp_CTI_start_row+C) of a position of an interleaver selector corresponding to convolution time interleaving and a position before convolution time interleaving, and a modulo operation of a number (N_row) of delay lines corresponding to convolution time interleaving.

[0234] In this case, the position of the interleaver selector can be signaled only for a core layer physical layer pipe corresponding to a core layer, and the position of the interleaver selector can not be signaled for an enhancement layer physical layer pipe corresponding to an enhancement layer.

[0235] In this case, the position of the interleaver selector for the enhancement layer physical layer pipe can be calculated by using the position of the interleaver selector signaled for a core layer physical layer pipe corresponding to the enhancement layer physical layer pipe.

[0236] In this case, the length of the field indicating the start position of the first complete FEC block can be 22 bits.

[0237] In this case, a field indicating a start position of a first complete FEC block can be signaled for each of the core layer physical layer channel and the enhancement layer physical layer channel.

[0238] In this case, the time interleaver 350 can perform interleaving by using one of a plurality of operation modes.

[0239] In this case, the operation modes can include a first mode (L1D_plp_TI_mode=00) corresponding to no time interleaving, a second mode (L1D_plp_TI_mode=01) for performing convolution time interleaving, and a third mode (L1D_plp_TI_mode=10) for performing hybrid time interleaving.

[0240] In this case, the preamble can include a field indicating a start position of a first complete FEC block for the first mode and the second mode corresponding to the current physical layer channel, and can not include a field indicating a start position of a first FEC block for the third mode.

[0241] In this case, the field indicating the start position of the first FEC block can be one of a first field (L1D_plp_fec_block_start) used in the first mode (L1D_plp_TI_mode=00) and a second field (L1D_plp_CTI_fec_block_start) used in the second mode (L1D_plp_TI_mode=01), and the first field and the second field can have different lengths. In this case, the first field (L1D_plp_fec_block_start) can indicate a start position of a first FEC block starting in the current physical layer channel during a current subframe, and the second field (L1D_plp_CTI_fec_block_start) can indicate a start position of a first complete FEC block of the current physical layer channel exiting the convolution time interleaver in the current subframe or a subsequent subframe. In this case, both the first field (L1D_plp_fec_block_start) and the second field (L1D_plp_CTI_fec_block_start) can be signaled based on interleaving. Specifically, in the case of the second field (L1D_plp_CTI_fec_block_start), when signaling is performed based on interleaving, the number of bits required for signaling can increase.

[0242] In this case, the length of the second field can be longer than the length of the first field.

[0243] In this case, the length of the first field can be determined based on the length of the LDPC codeword and the modulation order, and the length of the second field can be determined not only by the length of the LDPC codeword and the modulation order but also further considering the depth of the convolutional time interleaver.

[0244] In this case, the length of the first field can be 15 bits, and the length of the second field can be 22 bits.

[0245] In this case, the first field and the second field can be respectively signaled for each of a core layer corresponding to a core layer signal and an enhancement layer corresponding to an enhancement layer signal.

[0246] In this case, the frame builder 370 can include a preamble generator configured to generate a preamble, a bootstrap generator configured to generate a bootstrap, and a superposition payload generator configured to generate a superposition payload corresponding to a time-interleaved signal.

[0247] In this case, the bootstrap can be shorter than the preamble and have a fixed length.

[0248] In this case, the bootstrap can include a symbol representing a structure of the preamble, wherein the symbol corresponds to a fixed-length bit string representing a combination of a modulation scheme / coding rate, an FFT size, a guard interval length, and a pilot pattern of the preamble.

[0249] In this case, the symbol can correspond to a look-up table in which a preamble structure corresponding to a second FFT size is allocated before a preamble structure corresponding to a first FFT size, the second FFT size being smaller than the first FFT size when a modulation scheme / coding rate is the same, and a preamble structure corresponding to a second guard interval length is allocated before a preamble structure corresponding to a first guard interval length, the second guard interval length being longer than the first guard interval length when a modulation scheme / coding rate is the same and an FFT size is the same.

[0250] The broadcast signal frame can be transmitted via an OFDM transmitter robust to multipath and Doppler phenomena. In this case, the OFDM transmitter can be regarded as being responsible for a transmission signal generation of a next-generation broadcast system.

[0251] In this case, the preamble can include PLP identification information for identifying a physical layer pipe (PLP), and layer identification information for identifying a layer corresponding to a hierarchy.

[0252] In this case, the PLP identification information and the layer identification information can be included in the preamble as fields different from each other.

[0253] In this case, the time interleaver information can be included in the preamble based on the core layer.

[0254] In this case, based on a comparison result of the layer identification information with a predetermined value (IF(j>0)), the preamble can selectively include the injection level information corresponding to the injection level controller for each physical layer pipe (PLP).

[0255] In this case, the preamble can include type information, start position information, and size information of the physical layer pipe.

[0256] In this case, the type information can be used to identify one of a first type corresponding to a non-scattered physical layer pipe and a second type corresponding to a scattered physical layer pipe.

[0257] In this case, the non-scattered physical layer pipe can be allocated for a continuous data unit index, and the scattered physical layer pipe can include two or more sub-slices.

[0258] In this case, the type information can be selectively signaled according to a comparison result of the layer identification information with a predetermined value for each physical layer pipe (PLP).

[0259] In this case, the type information can be signaled only for the core layer.

[0260] In this case, the start position information can be the same as an index of a first data unit corresponding to the physical layer pipe.

[0261] In this case, the start position information can indicate a start position of the physical layer pipe using a unit addressing scheme.

[0262] In this case, the start position information can be included in the preamble for each physical layer pipe (PLP) without verifying a condition of a conditional statement corresponding to the layer identification information.

[0263] In this case, the size information can be generated based on a number of data units allocated to the physical layer pipe.

[0264] In this case, the size information can be included in the preamble for each physical layer pipe (PLP) without verifying a condition of a conditional statement corresponding to the layer identification information.

[0265] Figure 4 FIG. 1 is a diagram illustrating an example of a structure of a broadcast signal frame.

[0266] Referring to Figure 4 , the broadcast signal frame includes a bootstrap code 4410, a preamble 4420, and a superposed payload 4430.

[0267] Figure 4 The frame shown in FIG. 4A can be included in a superframe.

[0268] In this case, the broadcast signal frame can include at least one OFDM symbol. The broadcast signal frame can include a reference symbol or a pilot symbol.

[0269] A frame structure in which layer division multiplexing (LDM) is applied includes a bootstrap code 4410, a preamble code 4420, and a superposed payload 4430 as shown in FIG. 4B. Figure 4

[0270] In this case, the bootstrap code 4410 and the preamble code 4420 can be regarded as two levels of preamble codes.

[0271] In this case, the bootstrap code 4410 can have a shorter length than the preamble code 4420 for fast acquisition and detection. In this case, the bootstrap code 4410 can have a fixed length. In this case, the bootstrap code can include a fixed length symbol. For example, the bootstrap code 4410 can be composed of four OFDM symbols each having a length of 0.5 ms, such that the bootstrap code 4410 can correspond to a fixed time length of 2 ms.

[0272] In this case, the bootstrap code 4410 can have a fixed bandwidth, and the preamble code 4420 and the superposed payload 4430 can have a variable bandwidth wider than the bootstrap code 4410.

[0273] The preamble code 4420 can transmit detailed signaling information using a robust LDPC code. In this case, the length of the preamble code 4420 can vary according to the signaling information.

[0274] In this case, both the bootstrap code 4410 and the superposed payload 4430 can be regarded as common signals shared by a plurality of layers.

[0275] The superposed payload 4430 can correspond to a multiplexed signal of at least two layer signals. In this case, the superposed payload 4430 can be generated by combining a core layer payload and an enhancement layer payload at different power levels. In this case, the core layer payload can include an in-band signaling part. In this case, the in-band signaling part can include signaling information for an enhancement layer service.

[0276] In this case, the bootstrap code 4410 can include a symbol representing a preamble structure.

[0277] In this case, the symbol included in the bootstrap code for representing the preamble structure can be set as in Table 2 below. ​

[0278] Table 2

[0279]

[0280]

[0281]

[0282] For example, a fixed length code of 7 bits can be assigned to represent the preamble structure shown in Table 2.

[0283] L1-basic mode 1, L1-basic mode 2, and L1-basic mode 3 in Table 2 can correspond to QPSK and 3 / 15 LDPC.

[0284] L1-basic mode 4 in Table 2 can correspond to 16-NUC (Non-Uniform Constellation) and 3 / 15 LDPC.

[0285] L1-basic mode 5 in Table 2 can correspond to 64-NUC (Non-Uniform Constellation) and 3 / 15 LDPC.

[0286] L1-basic mode 6 and L1-basic mode 7 in Table 2 can correspond to 256-NUC (Non-Uniform Constellation) and 3 / 15 LDPC. Hereafter, the modulation scheme / coding rate represents a combination of a modulation scheme and a coding rate such as QPSK and 3 / 15 LDPC.

[0287] The FFT size in Table 2 can represent the size of a Fast Fourier Transform.

[0288] The GI length in Table 2 can represent a guard interval length, which can represent the length of a non-data guard interval in a time domain. In this case, the longer the guard interval, the more robust the system.

[0289] The pilot pattern in Table 2 can represent Dx of a pilot pattern. Although not explicitly shown in Table 2, in the example of Table 2, Dy can all be 1. For example, Dx = 3 can mean that one pilot for channel estimation is included in every three symbols in the x-axis direction. For example, Dy = 1 can mean that a pilot is included in every time in the y-axis direction.

[0290] As shown in Table 2, a preamble structure corresponding to a second modulation scheme / coding rate, which is more robust than a first modulation scheme / coding rate, can be assigned before a preamble structure corresponding to the first modulation scheme / coding rate in the look-up table.

[0291] In this case, being assigned before other preamble structures can mean being stored in the look-up table as a sequence number corresponding to a sequence number smaller than that of the other preamble structures.

[0292] Further, in the case of the same modulation scheme / coding rate, a preamble structure corresponding to a second FFT size shorter than the first FFT size can be allocated in the look-up table before a preamble structure corresponding to the first FFT size.

[0293] Further, in the case of the same modulation scheme / coding rate and the same FFT size, a preamble structure corresponding to a second guard interval longer than the first guard interval can be allocated in the look-up table before a preamble structure corresponding to the first guard interval.

[0294] As shown in Table 2, the setting of the order of allocating the preamble structures in the look-up table can make the identification of the preamble structure using the pilot code more efficient.

[0295] Figure 5 is a diagram illustrating an example of a reception process of the broadcast signal frame shown in Figure 4

[0296] Referring to Figure 5 , the pilot code 4510 is detected and demodulated, and the signaling information is reconstructed by demodulating the preamble 4520 using the demodulated information.

[0297] The core layer data 4530 is demodulated using the signaling information, and the enhancement layer signal is demodulated through a cancellation process corresponding to the core layer data. In this case, the cancellation corresponding to the core layer data will be described in detail later.

[0298] Figure 6 is a diagram illustrating another example of a reception process of the broadcast signal frame shown in Figure 4

[0299] Referring to Figure 6 , the pilot code 4610 is detected and demodulated, and the signaling information is reconstructed by demodulating the preamble 4620 using the demodulated information.

[0300] The core layer data 4630 is demodulated using the signaling information. In this case, the core layer data 4630 includes an in-band signaling part 4650. The in-band signaling part 4650 includes signaling information for the enhancement layer service. The bandwidth is more efficiently used through the in-band signaling part 4650. In this case, the in-band signaling part 4650 can be included in the core layer more robust than the enhancement layer.

[0301] In the example of Figure 6 , the basic signaling information and the information for the core layer service can be transmitted through the preamble 4620, and the signaling information for the enhancement layer service can be transmitted through the in-band signaling part 4650.

[0302] ​​The enhanced layer signal is demodulated through a cancellation process corresponding to the core layer data.

[0303] In this case, the signaling information can be L1 (Layer 1) signaling information. The L1 signaling information can include information for a physical layer parameter.

[0304] Reference Figure 4 , the broadcast signal frame includes an L1 signaling signal and a data signal. For example, the broadcast signal frame can be an ATSC 3.0 frame.

[0305] Figure 7 is a block diagram illustrating another example of the apparatus for generating a broadcast signal frame shown in Figure 1

[0306] Reference Figure 7 As can be seen, the apparatus for generating a broadcast signal frame multiplexes data corresponding to N (N is a natural number equal to or greater than 1) extension layers in addition to the core layer data and the enhanced layer data.

[0307] That is, in addition to the core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, the power normalizer 345, the time interleaver 350, the signaling generation unit 360, and the frame builder 370, Figure 7 the apparatus for generating a broadcast signal frame in

[0308] The core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, the power normalizer 345, the time interleaver 350, the signaling generation unit 360, and the frame builder 370 shown in Figure 3 have been described in detail with reference to Figure 7

[0309] Each of the N extension layer BICM units 410,..., 430 independently performs BICM encoding, and each of the injection level controllers 440,..., 460 performs power reduction corresponding to the respective extension layers, thereby enabling the power-reduced extension layer signals to be combined with other layer signals via the combiner 340.

[0310] In this case, each of the error correction encoders of the extension layer BICM units 410,..., 430 can be formed by connecting a BCH encoder and an LDPC encoder in series.

[0311] ​​Specifically, it is preferable that the power reduction corresponding to each of the injection level controllers 440,..., 460 is higher than the power reduction of the injection level controller 330. That is, the injection level controller 330 is the lowest one among the injection level controllers 330, 440,..., 460. Figure 7 The lower one among the injection level controllers 330, 440,..., 460 shown in FIG. 4 can correspond to a greater power reduction.

[0312] The injection level information provided by the injection level controllers 330, 440, and 460 shown in FIG. 4 is included in the broadcast signal frame of the frame builder 370 via the signaling generation unit 360, and then transmitted to the receiver. That is, the injection level of each layer is contained in the Ll signaling information, and then transmitted to the receiver. Figure 7

[0313] In the present application, the adjustment of the power can correspond to an increase or decrease in the power of the input signal, and can correspond to an increase or decrease in the gain of the input signal.

[0314] The power normalizer 345 alleviates an increase in the power caused by the combination of the plurality of layer signals by means of the combiner 340.

[0315] In the example shown in FIG. 4, the power normalizer 345 can adjust the power of the signal combined by the signals of the respective layers to an appropriate amplitude by multiplying the amplitude of the signal combined by the signals of the respective layers by the normalization factor obtained by using Equation 4 below: Figure 7

[0316] The time interleaver 350 performs interleaving equally applied to the signals of the plurality of layers by interleaving the signal combined by the combiner 340.

[0317]

[0318] is a block diagram showing another example of the signal demultiplexer shown in FIG. 5. Figure 8 Figure 1 Referring to FIG. 6, the signal demultiplexer according to an embodiment of the present application includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, an enhancement layer symbol extractor 530, a de-injection level controller 1020, and an enhancement layer BICM decoder 540.

[0319] Referring to FIG. 6, the signal demultiplexer according to an embodiment of the present application includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, an enhancement layer symbol extractor 530, a de-injection level controller 1020, and an enhancement layer BICM decoder 540. Figure 8 In this case, the signal demultiplexer shown in FIG. 6 can correspond to the apparatus for generating a broadcast signal frame shown in FIG. 5.

[0320] Figure 8 In this case, the signal demultiplexer shown in FIG. 6 can correspond to the apparatus for generating a broadcast signal frame shown in FIG. 5. Figure 3

[0321] ​​​​The time deinterleaver 510 receives a received signal from the OFDM receiver for performing operations such as time / frequency synchronization, channel estimation, and equalization, and performs an operation related to distribution of burst errors occurring on a channel. In this case, L1 signaling information is first decoded by the OFDM receiver, and then used for decoding of data. Specifically, injection level information of the L1 signaling information can be transferred to the de-normalizer 1010 and the de-injection level controller 1020. In this case, the OFDM receiver can decode a received signal in the form of a broadcast signal frame (e.g., an ATSC 3.0 frame), can extract a data symbol portion of the frame, and can provide the extracted data symbol portion to the time deinterleaver 510. That is, the time deinterleaver 510 distributes burst errors occurring on a channel by performing deinterleaving while passing the data symbols.

[0322] In this case, the time deinterleaver 510 can perform an operation corresponding to the time interleaver. In this case, the time deinterleaver 510 can perform deinterleaving by using one of a plurality of operation modes, and can perform deinterleaving by using time interleaver information signaled in relation to an operation of the time interleaver.

[0323] The de-normalizer 1010 corresponds to a power normalizer of a transmitter, and increases power by a level at which the power normalizer has decreased the power. That is, the de-normalizer 1010 divides a received signal by a normalization factor of Equation 2.

[0324] Although the de-normalizer 1010 is illustrated as adjusting power of an output signal of the time interleaver 510 in the example shown, Figure 8 In some embodiments, the de-normalizer 1010 can be located before the time interleaver 510 so that power adjustment is performed before interleaving.

[0325] That is, the de-normalizer 1010 can be regarded as being located before or after the time interleaver 510, and amplifies a magnitude of a signal for the purpose of LLR calculation of a core layer symbol demapper.

[0326] An output of the time deinterleaver 510 (or an output of the de-normalizer 1010) is provided to the core layer BICM decoder 520, and the core layer BICM decoder 520 recovers core layer data.

[0327] In this case, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, and a core layer error correction decoder. The core layer symbol demapper calculates an LLR value related to a symbol, the core layer bit deinterleaver de-correlates the calculated LLR value with burst error strong mixing, and the core layer error correction decoder corrects errors occurring on a channel.

[0328] In this case, the core layer symbol demapper can calculate the LLR value for each bit using a predetermined constellation. In this case, the constellation used by the core layer symbol mapper can vary according to a combination of the coding rate and the modulation order used by the transmitter.

[0329] In this case, the core layer bit deinterleaver can perform deinterleaving on the calculated LLR value on a basis of the LDPC codeword.

[0330] Specifically, the core layer error correction decoder can output only information bits, or can output all bits in which the information bits have been mixed with parity bits. In this case, the core layer error correction decoder can output only the information bits as the core layer data, and can output all bits in which the information bits have been mixed with the parity bits to the enhancement layer symbol extractor 530.

[0331] The core layer error correction decoder can be formed by connecting the core layer LDPC decoder and the core layer BCH decoder in series. That is, the input of the core layer error correction decoder can be input to the core layer LDPC decoder, the output of the core layer LDPC decoder can be input to the core layer BCH decoder, and the output of the core layer BCH decoder can become the output of the core layer error correction decoder. In this case, the LDPC decoder performs LDPC decoding, and the BCH decoder performs BCH decoding.

[0332] Further, the enhancement layer error correction decoder can be formed by connecting the enhancement layer LDPC decoder and the enhancement layer BCH decoder in series. That is, the input of the enhancement layer error correction decoder can be input to the enhancement layer LDPC decoder, the output of the enhancement layer LDPC decoder can be input to the enhancement layer BCH decoder, and the output of the enhancement layer BCH decoder can become the output of the enhancement layer error correction decoder.

[0333] The enhancement layer symbol extractor 530 can receive all bits from the core layer error correction decoder of the core layer BICM decoder 520, and can extract the enhancement layer symbol from the output signal of the time deinterleaver 510 or the de-normalizer 1010. In one embodiment, the enhancement layer symbol extractor 530 can not be provided with all bits by the error correction decoder of the core layer BICM decoder 520, but can be provided with LDPC information bits or BCH information bits by the error correction decoder of the core layer BICM decoder 520.

[0334] In this case, the enhancement layer symbol extractor 530 includes a buffer, a subtracter, a core layer symbol mapper, and a core layer bit interleaver. The buffer stores the output signal of the time deinterleaver 510 or the denormalizer 1010. The core layer bit interleaver receives all bits (information bits + parity bits) of the core layer BICM decoder and performs the same core layer bit interleaving as the transmitter. The core layer symbol mapper generates the same core layer symbol as the transmitter from the interleaved signal. The subtracter obtains the enhancement layer symbol by subtracting the output signal of the core layer symbol mapper from the signal stored in the buffer and transfers the enhancement layer symbol to the de- injection level controller 1020. Specifically, when LDPC information bits are provided, the enhancement layer symbol extractor 530 can further include a core layer LDPC encoder. In addition, when BCH information bits are provided, the enhancement layer symbol extractor 530 can further include not only the core layer LDPC encoder but also a core layer BCH encoder.

[0335] In this case, the core layer LDPC encoder, the core layer BCH encoder, the core layer bit interleaver, and the core layer symbol mapper included in the enhancement layer symbol extractor 530 can be the same as those of the reference Figure 3 The described core layer LDPC encoder, BCH encoder, bit interleaver, and symbol mapper are the same.

[0336] The de-injection level controller 1020 receives the enhancement layer symbol and increases the power of the input signal by the level by which the injection level controller of the transmitter has decreased the power. That is, the de-injection level controller 1020 amplifies the input signal and provides the amplified input signal to the enhancement layer BICM decoder 540. For example, if the power used to combine the enhancement layer signal is 3 dB lower than the power used to combine the core layer signal at the transmitter, the de-injection level controller 1020 functions to increase the power of the input signal by 3 dB.

[0337] In this case, the de-injection level controller 1020 can be regarded as receiving the injection level information from the OFDM receiver and multiplying the extracted enhancement layer signal by the enhancement layer gain of Equation 5:

[0338]

[0339] The enhancement layer BICM decoder 540 receives the enhancement layer symbol whose power is increased by the de-injection level controller 1020 and recovers the enhancement layer data.

[0340] In this case, the enhancement layer BICM decoder 540 can include an enhancement layer symbol demapper, an enhancement layer bit deinterleaver, and an enhancement layer error correction decoder. The enhancement layer symbol demapper calculates LLR values related to enhancement layer symbols, the enhancement layer bit deinterleaver strongly mixes the calculated LLR values with burst errors, and the enhancement layer error correction decoder corrects errors occurring on a channel.

[0341] Although the enhancement layer BICM decoder 540 performs tasks similar to those performed by the core layer BICM decoder 520, the enhancement layer LDPC decoder generally performs LDPC decoding related to a coding rate equal to or higher than 6 / 15.

[0342] For example, the core layer can use an LDPC code having a coding rate equal to or higher than 5 / 15, and the enhancement layer can use an LDPC code having a coding rate equal to or higher than 6 / 15. In this case, in a reception environment in which the enhancement layer data can be decoded, the core layer data can be decoded using only a small number of LDPC decoding iterations. With this characteristic, in the hardware of the receiver, the core layer and the enhancement layer share one LDPC decoder, so that the cost required to implement the hardware can be reduced. In this case, the core layer LDPC decoder can use only some time resources (LDPC decoding iterations), and the enhancement layer LDPC decoder can use most of the time resources.

[0343] That is, the signal demultiplexer shown in FIG. 6 first recovers the core layer data by eliminating the core layer symbols from the received signal symbols to leave only the enhancement layer symbols, and then recovers the enhancement layer data by increasing the power of the enhancement layer symbols. Figure 8 Figure 3 and Figure 5 The signals corresponding to each layer are combined at different power levels, so only recovery starting from the signal combined at the strongest power can achieve data recovery with the smallest error.

[0344] Therefore, in the case of the signal demultiplexer shown in FIG. 6, the core layer data is recovered first, and then the enhancement layer data is recovered. Figure 8 ​In the example shown in FIG. 10, the signal demultiplexer can include a time deinterleaver 510 configured to generate a time deinterleaved signal by applying time deinterleaving to the received signal, a denormalizer 1010 configured to increase the power of the received signal or the time deinterleaved signal to a level corresponding to the power reduced by the power normalizer of the transmitter, a core layer BICM decoder 520 configured to recover core layer data from the signal power-adjusted by the denormalizer 1010, an enhancement layer symbol extractor 530 configured to extract an enhancement layer signal by performing cancellation corresponding to the core layer data on the signal power-adjusted by the denormalizer 1010 using the output signal of the core layer FEC decoder of the core layer BICM decoder 520, a de-boosting level controller 1020 configured to increase the power of the enhancement layer signal to a level corresponding to the power reduced by the boosting level controller of the transmitter, and an enhancement layer BICM decoder 540 configured to recover enhancement layer data using the output signal of the de-boosting level controller 1020.

[0345] In this case, the enhancement layer symbol extractor can receive all codewords from the core layer LDPC decoder of the core layer BICM decoder, and can immediately perform bit interleaving on all the codewords.

[0346] In this case, the enhancement layer symbol extractor can receive information bits from the core layer LDPC decoder of the core layer BICM decoder, and can perform core layer LDPC encoding on the information bits and then perform bit interleaving.

[0347] In this case, the enhancement layer symbol extractor can receive information bits from the core layer BCH decoder of the core layer BICM decoder, and can perform core layer BCH encoding and core layer LDPC encoding on the information bits and then perform bit interleaving.

[0348] In this case, the denormalizer and the de-boosting level controller can receive boosting level information IL INFO provided based on the L1 signaling, and can perform power control based on the boosting level information.

[0349] In this case, the core layer BICM decoder can have a lower bit rate than the bit rate of the enhancement layer BICM decoder, and can be more robust than the enhancement layer BICM decoder.

[0350] In this case, the denormalizer can correspond to a reciprocal of a normalization factor.

[0351] In this case, the de-boosting level controller can correspond to a reciprocal of a scaling factor.

[0352] In this case, enhancement layer data can be recovered based on the elimination corresponding to the recovery of core layer data, where the core layer data corresponds to the core layer signal.

[0353] In this configuration, the signal demultiplexer may further include: one or more extended layer symbol extractors, each configured to extract the extended layer signal by performing cancellation corresponding to previous layer data; one or more deinjection level controllers, each configured to increase the power of the extended layer signal to a level corresponding to the power reduced by the transmitter's injection level controller; and one or more extended layer BICM decoders configured to use the output signals of the one or more deinjection level controllers to recover one or more pieces of extended layer data.

[0354] according to Figure 8 As shown in the configuration, the signal demultiplexing method according to an embodiment of the present invention includes: generating a time-deinterleaved signal by applying time deinterleaving to a received signal; increasing the power of the received signal or the time-deinterleaved signal to a level corresponding to the power reduced by the power normalizer of the transmitter; recovering core layer data from the power-adjusted signal; extracting an enhancement layer signal by performing elimination corresponding to the core layer data on the power-adjusted signal; increasing the power of the enhancement layer signal to a level corresponding to the power reduced by the injection level controller of the transmitter; and using the enhancement layer signal to recover the enhancement layer data.

[0355] In this case, extracting the enhancement layer signal may involve receiving all codewords from the core layer LDPC decoder of the core layer BICM decoder and immediately performing bit interleaving on all codewords.

[0356] In this case, extracting the enhancement layer signal may include receiving information bits from the core layer LDPC decoder of the core layer BICM decoder, performing core layer LDPC encoding on the information bits, and then performing bit interleaving.

[0357] In this case, extracting the enhancement layer signal may include receiving information bits from the core layer BCH decoder of the core layer BICM decoder, performing core layer BCH encoding and core layer LDPC encoding on the information bits, and then performing bit interleaving.

[0358] Figure 9 It is shown Figure 8 A block diagram of an example of the core layer BICM decoder 520 and the enhancement layer symbol extractor 530 shown.

[0359] refer to Figure 9The core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder.

[0360] That is, in the example shown in FIG. 5, the core layer error correction decoder includes the core layer LDPC decoder and the core layer BCH decoder. Figure 9 Further, in the example shown in FIG. 5, the core layer LDPC decoder provides the information bits excluding the parity bits to the enhancement layer symbol extractor 530.

[0361] Figure 9 In this case, although the enhancement layer symbol extractor 530 does not need to include the core layer BCH encoder, it must include the core layer LDPC encoder.

[0362] In this case, although the enhancement layer symbol extractor 530 does not need to include the core layer BCH encoder, it must include the core layer LDPC encoder.

[0363] Figure 10 is a block diagram illustrating yet another example of the core layer BICM decoder 520 and the enhancement layer symbol extractor 530 shown in FIG. 6. Figure 8 Referring to FIG. 7,

[0364] the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder. Figure 10 That is, in the example shown in FIG. 7, the core layer error correction decoder includes the core layer LDPC decoder and the core layer BCH decoder.

[0365] Figure 10 Further, in the example shown in FIG. 7, the core layer LDPC decoder provides the information bits excluding the parity bits to the enhancement layer symbol extractor 530.

[0366] In this case, although the enhancement layer symbol extractor 530 does not need to include the core layer BCH encoder, it must include the core layer LDPC encoder. Figure 10 In this case, although the enhancement layer symbol extractor 530 does not need to include the core layer BCH encoder, it must include the core layer LDPC encoder.

[0367]

[0368] The example shown in FIG. 8 can be more desirable to eliminate the residual that can remain in the LDPC code parity part than the example shown in FIG. 7. Figure 10 Figure 9 is a block diagram illustrating yet another example of the core layer BICM decoder 520 and the enhancement layer symbol extractor 530 shown in FIG. 8.

[0369] Figure 11 Figure 8 ​​​​a block diagram of still another example of the core layer BICM decoder 520 and the enhancement layer symbol extractor 530 shown in FIG. 5.

[0370] Referring to Figure 11 , the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder.

[0371] That is, in Figure 11 the example shown, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

[0372] In Figure 11 the example shown, the output of the core layer BCH decoder corresponding to the core layer data is provided to the enhancement layer symbol extractor 530.

[0373] In this case, although the enhancement layer symbol extractor 530 has high complexity since it must include both the core layer LDPC encoder and the core layer BCH encoder, it guarantees higher performance than the examples in Figure 9 and 10 .

[0374] Figure 12 is a block diagram illustrating Figure 1 another example of the signal demultiplexer shown in FIG. 5.

[0375] Referring to Figure 12 , the signal demultiplexer according to an embodiment of the present application includes a time deinterleaver 510, a denormalizer 1010, a core layer BICM decoder 520, an enhancement layer symbol extractor 530, an enhancement layer BICM decoder 540, one or more extension layer symbol extractors 650 and 670, one or more extension layer BICM decoders 660 and 680, and de-implant level controllers 1020, 1150, and 1170.

[0376] In this case, Figure 12 the signal demultiplexer shown in FIG. 5 can correspond to the apparatus for generating a broadcast signal frame shown in FIG. 4. Figure 7

[0377] The time deinterleaver 510 receives a received signal from an OFDM receiver for performing operations such as synchronization, channel estimation, and equalization, and performs operations related to distribution of burst errors occurring on a channel. In this case, Ll signaling information can be first decoded by the OFDM receiver and then can be used for data decoding. Specifically, implant level information of the Ll signaling information can be transferred to the denormalizer 1010 and the de-implant level controllers 1020, 1150, and 1170. ​

[0378] In this case, the denormalizer 1010 can obtain the injection level information of all layers, and the denormalization factor can be obtained using the following Equation 6. The input signal can then be multiplied by the denormalization factor:

[0379]

[0380] In other words, the denormalization factor is the reciprocal of the normalization factor expressed in Equation 4 above.

[0381] In one embodiment, when the N1 signaling includes not only injection level information but also normalization factor information, the denormalizer 1010 can easily obtain the denormalization factor by taking the reciprocal of the normalization factor, without needing to use the injection level to calculate the denormalization factor.

[0382] The denormalizer 1010 corresponds to the transmitter's power normalizer and increases the power level that the power normalizer has reduced.

[0383] Despite Figure 12 In the example shown, denormalizer 1010 is illustrated as adjusting the power of the output signal of time interleaver 510. However, in one embodiment, denormalizer 1010 may be located before time interleaver 510, such that power adjustment can be performed before interleaving.

[0384] In other words, the denormalizer 1010 can be considered to be located before or after the time interleaver 510, and amplifies the amplitude of the signal to achieve the purpose of LLR calculation of the core layer symbol demapper.

[0385] The output of the time deinterleaver 510 (or the output of the denormalizer 1010) is provided to the core layer BICM decoder 520, and the core layer BICM decoder 520 recovers the core layer data.

[0386] In this configuration, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, and a core layer error correction decoder. The core layer symbol demapper calculates the symbol-related LLR value, the core layer bit deinterleaver strongly mixes the calculated LLR value with the burst error, and the core layer error correction decoder corrects errors occurring on the channel.

[0387] Specifically, the core layer error correction decoder can output only the information bits, or it can output all bits that have been combined with the parity bits. In this case, the core layer error correction decoder can output only the information bits as core layer data, and can output all bits that have been combined with the parity bits to the enhancement layer symbol extractor 530.

[0388] The core layer error correction decoder can be formed by connecting the core layer LDPC decoder and the core layer BCH decoder in series. That is, an input of the core layer error correction decoder can be input to the core layer LDPC decoder, an output of the core layer LDPC decoder can be input to the core layer BCH decoder, and an output of the core layer BCH decoder can become an output of the core layer error correction decoder. In this case, the LDPC decoder performs LDPC decoding, and the BCH decoder performs BCH decoding.

[0389] The enhancement layer error correction decoder can also be formed by connecting the enhancement layer LDPC decoder and the enhancement layer BCH decoder in series. That is, an input of the enhancement layer error correction decoder can be input to the enhancement layer LDPC decoder, an output of the enhancement layer LDPC decoder can be input to the enhancement layer BCH decoder, and an output of the enhancement layer BCH decoder can become an output of the enhancement layer error correction decoder.

[0390] In addition, the extension layer error correction decoder can also be formed by connecting the extension layer LDPC decoder and the extension layer BCH decoder in series. That is, an input of the extension layer error correction decoder can be input to the extension layer LDPC decoder, an output of the extension layer LDPC decoder can be input to the extension layer BCH decoder, and an output of the extension layer BCH decoder can become an output of the extension layer error correction decoder.

[0391] In particular, the trade-off between the complexity of implementation and performance regarding which of the outputs of the error correction decoders to use, which has been described with reference to Figure 9 , 10 and 11, applies not only to the core layer BICM decoder 520 and the enhancement layer symbol extractor 530 in Figure 12 but also to the extension layer symbol extractors 650 and 670 and the extension layer BICM decoders 660 and 680.

[0392] The enhancement layer symbol extractor 530 can receive all bits from the core layer BICM decoder 520 of the core layer error correction decoder and can extract the enhancement layer symbol from the output signal of the time deinterleaver 510 or the denormalizer 1010. In one embodiment, the enhancement layer symbol extractor 530 can not receive all bits from the error correction decoder of the core layer BICM decoder 520, but can receive LDPC information bits or BCH information bits.

[0393] In this case, the enhancement layer symbol extractor 530 includes a buffer, a subtracter, a core layer symbol mapper, and a core layer bit interleaver. The buffer stores an output signal of the time deinterleaver 510 or the denormalizer 1010. The core layer bit interleaver receives all bits (information bits + parity bits) of the core layer BICM decoder and performs the same core layer bit interleaving as the transmitter. The core layer symbol mapper generates the same core layer symbol as the transmitter from the interleaved signal. The subtracter obtains the enhancement layer symbol by subtracting the output signal of the core layer symbol mapper from the signal stored in the buffer and transfers the enhancement layer symbol to the de-injection level controller 1020.

[0394] In this case, the core layer bit interleaver and the core layer symbol mapper included in the enhancement layer symbol extractor 530 can be the same as the core layer bit interleaver and the core layer symbol mapper shown in FIG. 10. Figure 7

[0395] The de-injection level controller 1020 receives the enhancement layer symbol and increases the power of the input signal by the level at which the injection level controller of the transmitter has decreased the power. That is, the de-injection level controller 1020 amplifies the input signal and provides the amplified input signal to the enhancement layer BICM decoder 540.

[0396] The enhancement layer BICM decoder 540 receives the enhancement layer symbol whose power is increased by the de-injection level controller 1020 and recovers the enhancement layer data.

[0397] In this case, the enhancement layer BICM decoder 540 can include an enhancement layer symbol demapper, an enhancement layer bit deinterleaver, and an enhancement layer error correction decoder. The enhancement layer symbol demapper calculates LLR values related to the enhancement layer symbol, the enhancement layer bit deinterleaver turbo-deinterleaves the calculated LLR values, and the enhancement layer error correction decoder corrects errors that occur on the channel.

[0398] Specifically, the enhancement layer error correction decoder can output only information bits and can output all bits in which the information bits have been combined with parity bits. In this case, the enhancement layer error correction decoder can output only the information bits as the enhancement layer data and can output all bits in which the information bits have been mixed with the parity bits to the extension layer symbol extractor 650.

[0399] The extension layer symbol extractor 650 receives all bits from the enhancement layer error correction decoder of the enhancement layer BICM decoder 540 and extracts the extension layer symbol from the output signal of the de-injection level controller 1020.

[0400] ​In this case, the de-injection level controller 1020 can amplify the power of the output signal of the subtracter of the enhancement layer symbol extractor 530.

[0401] In this case, the extension layer symbol extractor 650 includes a buffer, a subtracter, an enhancement layer symbol mapper, and an enhancement layer bit interleaver. The buffer stores the output signal of the de-injection level controller 1020. The enhancement layer bit interleaver receives all bits (information bits + parity bits) of the enhancement layer BICM decoder and performs the same enhancement layer bit interleaving as that of the transmitter. The enhancement layer symbol mapper generates the same enhancement layer symbol as that of the transmitter from the interleaved signal. The subtracter obtains the extension layer symbol by subtracting the output signal of the enhancement layer symbol mapper from the signal stored in the buffer and transmits the extension layer symbol to the extension layer BICM decoder 660.

[0402] In this case, the enhancement layer bit interleaver and the enhancement layer symbol mapper included in the extension layer symbol extractor 650 can be the same as the enhancement layer bit interleaver and the enhancement layer symbol mapper shown in FIG. 6. Figure 7

[0403] The de-injection level controller 1150 increases the power of the corresponding layer at the transmitter which the injection level controller has decreased.

[0404] In this case, the de-injection level controller can be regarded as performing the operation of multiplying the extension layer gain of the following Equation 7. In this case, the 0th injection level can be considered as 0 dB:

[0405]

[0406] The extension layer BICM decoder 660 receives the extension layer symbol whose power is increased by the de-injection level controller 1150 and restores the extension layer data.

[0407] In this case, the extension layer BICM decoder 660 can include an extension layer symbol demapper, an extension layer bit deinterleaver, and an extension layer error correction decoder. The extension layer symbol demapper calculates the LLR value related to the extension layer symbol, the extension layer bit deinterleaver burst error strongly mixes the calculated LLR value, and the extension layer error correction decoder corrects the error occurring on the channel.

[0408] Specifically, if there are two or more extension layers, each of the extension layer symbol extractor and the extension layer BICM decoder can include two or more extractors or decoders.

[0409] That is, in the case of the extension layer symbol extractor 650, the extension layer symbol mapper and the subtracter can be regarded as performing the operation of multiplying the extension layer gain of the following Equation 7. Figure 12 ​In the example shown in FIG. 10, the extension layer error correction decoder of the extension layer BICM decoder 660 can output only information bits, and can output all bits in which the information bits have been combined with parity bits. In this case, the extension layer error correction decoder outputs only the information bits as extension layer data, and can output all bits in which the information bits have been mixed with the parity bits to the subsequent extension layer symbol extractor 670.

[0410] According to the configuration and operation of the extension layer symbol extractor 650, the extension layer BICM decoder 660, and the de-injection level controller 1150 described above, the configuration and operation of the extension layer symbol extractor 670, the extension layer BICM decoder 680, and the de-injection level controller 1170 can be easily understood.

[0411] Figure 12 The lower one among the de-injection level controllers 1020, 1150, and 1170 shown in FIG. 10 can correspond to a greater power increase. That is, the de-injection level controller 1150 can increase more power than the de-injection level controller 1020, and the de-injection level controller 1170 can increase more power than the de-injection level controller 1150.

[0412] As can be seen, Figure 12 The signal demultiplexer shown in FIG. 10 first recovers the core layer data, recovers the enhancement layer data using cancellation of the core layer symbols, and recovers the extension layer data using cancellation of the enhancement layer symbols. Two or more extension layers can be provided, in which case recovery is started from the extension layer combined at the highest power level.

[0413] Figure 13 is a graph showing a power increase due to combination of the core layer signal and the enhancement layer signal.

[0414] Referring to Figure 13 As can be seen, when a multiplexed signal is generated by combining the core layer signal with the enhancement layer signal whose power has been reduced by the injection level, the power level of the multiplexed signal is higher than the power level of the core layer signal or the enhancement layer signal.

[0415] In this case, the injection level adjusted by the injection level controller shown in Figure 3 and Figure 7 The injection level adjusted by the injection level controller shown in FIG. 10 is adjusted from 0 dB to 25.0 dB. When the injection level is 3.0 dB, the power of the enhancement layer signal is 3 dB lower than the power of the core layer signal. When the injection level is 10.0 dB, the power of the enhancement layer signal is 10 dB lower than the power of the core layer signal. This relationship can be applied not only between the core layer signal and the enhancement layer signal, but also between the enhancement layer signal and the extension layer signal or between the extension layer signals.

[0416] Figure 3 and Figure 7 The power normalizer shown in Equation 1 can adjust the power level after the combination, thereby solving a problem such as signal distortion that can be caused by a power increase due to the combination.

[0417] Figure 14 FIG. 1 is a flowchart illustrating operations of a method of generating a broadcast signal frame according to an embodiment of the present application.

[0418] Referring to Figure 14 In the method according to an embodiment of the present application, in step S1210, BICM is applied to the core layer data.

[0419] Further, in the method according to an embodiment of the present application, in step S1220, BICM is applied to the enhancement layer data.

[0420] The BICM applied in step S1220 can be different from the BICM applied in step S1210. In this case, the BICM applied in step S1220 can be less robust than the BICM applied in step S1210. In this case, the bit rate of the BICM applied in step S1220 can be less robust than the bit rate of the BICM applied in step S1210.

[0421] In this case, the enhancement layer signal can correspond to enhancement layer data recovered based on cancellation corresponding to recovery of the core layer data, wherein the core layer data corresponds to the core layer signal.

[0422] Further, in the method according to an embodiment of the present application, in step S1230, a power-reduced enhancement layer signal is generated by reducing the power of the enhancement layer signal.

[0423] In this case, in step S1230, the injection level can be changed from 0.0 dB to 25.0 dB in steps of 0.5 dB or 1 dB.

[0424] Further, in the method according to an embodiment of the present application, in step S1240, a multiplexed signal is generated by combining the core layer signal and the power-reduced enhancement layer signal.

[0425] That is, in step S1240, the core layer signal and the enhancement layer signal are combined at different power levels such that the power level of the enhancement layer signal is lower than the power level of the core layer signal.

[0426] In this case, in step S1240, one or more extension layer signals having a lower power level than the core layer signal and the enhancement layer signal can be combined with the core layer signal and the enhancement layer signal.

[0427] Further, in the method according to the embodiment of the present application, in step S1250, the power of the multiplexed signal is reduced.

[0428] In this case, in step S1250, the power of the multiplexed signal can be reduced to the power of the core layer signal. In this case, in step S1250, the power of the multiplexed signal can be reduced to the level of the power that has been increased in step S1240.

[0429] Further, in the method according to the embodiment of the present application, in step S1260, a time-interleaved signal is generated by performing time interleaving applied to both the core layer signal and the enhancement layer signal.

[0430] In this case, step S1260 can use one of time interleaver groups, and a boundary between the time interleaver groups can be a boundary between physical layer pipes (PLPs) of a core layer corresponding to the core layer signal.

[0431] In this case, step S1260 can use a hybrid time interleaver for performing interleaving. In this case, the physical layer pipes (PLPs) of the core layer and the enhancement layer can include only complete FEC blocks.

[0432] In this case, step S1260 can use a convolution time interleaver for performing interleaving, the time interleaver groups can include physical layer pipes (PLPs) including incomplete FEC blocks, and a preamble can be used to signal start position information of the first complete FEC block in the physical layer pipes (PLPs).

[0433] In this case, step S1260 can be performed by using one of a plurality of operation modes.

[0434] In this case, the operation modes can include a first mode corresponding to no time interleaving, a second mode for performing convolution time interleaving, and a third mode for performing hybrid time interleaving.

[0435] Further, in the method according to the embodiment of the present application, in step S1270, a broadcast signal frame including a preamble for signaling time interleaver information corresponding to interleaving is generated.

[0436] In this case, the time interleaver information can be signaled based on the core layer.

[0437] In this case, the preamble can be used to signal information for identifying a portion of an FEC block of the enhancement layer, where the FEC block corresponds to a boundary between the time interleaver packets, in a case where the boundary between the time interleaver packets does not correspond to a boundary between the FEC blocks of the enhancement layer.

[0438] In this case, the information for identifying a portion of an FEC block can include at least one of start position information of a physical layer pipe (PLP) in the core layer, start position information of a physical layer pipe (PLP) in the enhancement layer, modulation information corresponding to the enhancement layer, and FEC type information corresponding to the enhancement layer.

[0439] In this case, the start position information of the physical layer pipe (PLP) can correspond to an index of a first data unit of the physical layer pipe (PLP).

[0440] In this case, the modulation information can be signaled only in a case where the FEC type information satisfies a predetermined condition.

[0441] In this case, the enhancement layer signal corresponds to enhancement layer data that can be recovered based on cancellation corresponding to recovery of the core layer data, where the core layer data corresponds to the core layer signal.

[0442] In this case, the step S1270 can include generating a bootstrap code, generating a preamble, and generating a superimposed payload corresponding to the time interleaved signal.

[0443] In this case, the preamble can include PLP identification information for identifying a physical layer pipe (PLP), and layer identification information for identifying a layer corresponding to a hierarchy.

[0444] In this case, the PLP identification information and the layer identification information can be included in the preamble as fields different from each other.

[0445] In this case, the time interleaver information can be selectively included in the preamble for each physical layer pipe (PLP) based on a result of comparing the layer identification information with a predetermined value (IF(j>0)).

[0446] In this case, the preamble can selectively include injection level information corresponding to an injection level controller for each physical layer pipe (PLP) based on a result of comparing the layer identification information with a predetermined value (IF(j>0)).

[0447] In this case, the bootstrap code can be shorter than the preamble and have a fixed length.

[0448] In this case, the bootstrap code can include a symbol representing a structure of the preamble, wherein the symbol corresponds to a fixed length bit string representing a combination of a modulation scheme / coding rate, an FFT size, a guard interval length, and a pilot pattern of the preamble.

[0449] In this case, the symbol can correspond to a look-up table in which a preamble structure corresponding to a second FFT size is allocated before a preamble structure corresponding to a first FFT size when a modulation scheme / coding rate is the same and the second FFT size is smaller than the first FFT size, and a preamble structure corresponding to a second guard interval length is allocated before a preamble structure corresponding to a first guard interval length when a modulation scheme / coding rate is the same and an FFT size is the same and the second guard interval length is longer than the first guard interval length.

[0450] In this case, the broadcast signal frame can be an ATSC 3.0 frame.

[0451] In this case, the L1 signaling information can include injection level information and / or normalization factor information.

[0452] In this case, the preamble can include type information of a physical layer pipe, start position information, and size information.

[0453] In this case, the type information can be used to identify one of a first type corresponding to a non-scattered physical layer pipe and a second type corresponding to a scattered physical layer pipe.

[0454] In this case, a non-scattered physical layer pipe can be allocated for a continuous data unit index, and a scattered physical layer pipe can include two or more sub-slices.

[0455] In this case, type information can be selectively signaled according to a comparison result of layer identification information and a predetermined value for each physical layer pipe (PLP).

[0456] In this case, the type information can be signaled only for a core layer.

[0457] In this case, the start position information can be the same as an index of a first data unit corresponding to the physical layer pipe.

[0458] In this case, the start position information can indicate a start position of the physical layer pipe using a unit addressing scheme.

[0459] In this case, the start position information can be included in a preamble for each physical layer pipe (PLP) without verifying a condition of a conditional statement corresponding to layer identification information.

[0460] In this case, the size information can be generated based on the number of data units allocated to the physical layer channel.

[0461] In this case, the size information can be included in a preamble for each physical layer channel (PLP) without verifying a condition of a conditional statement corresponding to the layer identification information.

[0462] In this case, the preamble can include a field indicating a start position of a first complete FEC block for the first mode and the second mode corresponding to the current physical layer channel, and can not include a field indicating a start position of a first FEC block for the third mode.

[0463] In this case, the field indicating the start position of the first FEC block can be one of a first field used in the first mode and a second field used in the second mode, and the first field and the second field can have different lengths.

[0464] In this case, the length of the second field can be longer than the length of the first field.

[0465] In this case, the length of the first field can be determined based on a length of an LDPC codeword and a modulation order, and the length of the second field can be determined further considering a depth of a convolutional time interleaver in addition to the length of the LDPC codeword and the modulation order.

[0466] In this case, the length of the first field can be 15 bits, and the length of the second field can be 22 bits.

[0467] In this case, the first field and the second field can be respectively signaled for each of a core layer corresponding to a core layer signal and an enhancement layer corresponding to an enhancement layer signal.

[0468] In this case, the preamble can include a field indicating a start position of a first complete FEC block corresponding to each of the physical layer channels.

[0469] In this case, the start position of the first complete FEC block can be specified with respect to a first unit of each of the physical layer channels.

[0470] In this case, when interleaving corresponds to convolutional time interleaving, the start position of the first complete FEC block can indicate a first unit of the first complete FEC block before the convolutional time interleaving, and a position of the first unit of the first complete FEC block can be signaled after the convolutional time interleaving.

[0471] In this case, the field indicating the start position of the first complete FEC block can correspond to a position after convolutional time interleaving, which is calculated by adding the position (C) before convolutional time interleaving and a delay caused by convolutional time interleaving.

[0472] In this case, the delay caused by convolutional time interleaving can be calculated by using the position (L1D_plp_CTI_start_row) of the interleaver selector corresponding to convolutional time interleaving.

[0473] In this case, the delay caused by convolutional time interleaving can be calculated by using a sum of the position of the interleaver selector corresponding to convolutional time interleaving and the position before convolutional time interleaving (L1D_plp_CTI_start_row+C) and a modulo operation of the number of delay lines (N_row) corresponding to convolutional time interleaving.

[0474] In this case, the position of the interleaver selector can be signaled only for the core layer physical layer pipe corresponding to the core layer, and the position of the interleaver selector can not be signaled for the enhancement layer physical layer pipe corresponding to the enhancement layer.

[0475] In this case, the position of the interleaver selector for the enhancement layer physical layer pipe can be calculated by using the position of the interleaver selector signaled for the core layer physical layer pipe corresponding to the enhancement layer physical layer pipe.

[0476] In this case, the field indicating the start position of the first complete FEC block can have a length of 22 bits.

[0477] In this case, the field indicating the start position of the first complete FEC block can be signaled for each of the core layer physical layer pipe and the enhancement layer physical layer pipe.

[0478] Although not explicitly shown in Figure 14 , the method can further include a step of generating signaling information including the injection level information corresponding to step S1230. In this case, the signaling information can be L1 signaling information.

[0479] Figure 14 The method of generating a broadcast signal frame shown in Figure 2 may correspond to step S210 shown in

[0480] Figure 15 is a diagram illustrating a structure of a superframe including a broadcast signal frame according to an embodiment of the present application.

[0481] Referring to Figure 15, a superframe based on layer division multiplexing (LDM) configures at least one frame, and each frame configures at least one OFDM symbol.

[0482] In this case, each OFDM symbol can start with at least one preamble symbol. Also, the frame can include a reference symbol or a pilot symbol.

[0483] Figure 15 The superframe 1510 illustrated in FIG. 15A can include an LDM frame 1520, a single layer frame 1530 without LDM, and a future extension frame (FEF) 1540 for future scalability, and can be configured using time division multiplexing (TDM).

[0484] When two layers are applied, the LDM frame 1520 can include an upper layer (UL) 1553 and a lower layer (LL) 1555.

[0485] In this case, the upper layer 1553 can correspond to a core layer, and the lower layer 1555 can correspond to an enhancement layer.

[0486] In this case, the LDM frame 1520 including the upper layer 1553 and the lower layer 1555 can be a bootstrap 1552 and a preamble 1551.

[0487] In this case, the upper layer data and the lower layer data can share a time interleaver to reduce complexity and memory size, and can use the same frame length and FFT size.

[0488] Also, the single layer frame 1530 can include a bootstrap 1562 and a preamble 1561.

[0489] In this case, the single layer frame 1530 can use a different FFT size, time interleaver, and frame length from the LDM frame 1520. In this case, the single layer frame 1530 can be multiplexed with the LDM frame 1520 in the superframe 1510 based on a TDM scheme.

[0490] Figure 16 FIG. 16 is a diagram illustrating an example of an LDM frame using multiple physical layer pipes and two layers.

[0491] Referring to FIG. 16, Figure 16 The LDM frame starts with a bootstrap signal including version information of a system or general signaling information. An L1 signaling signal including coding rate, modulation information, number of physical layer pipe information can follow the bootstrap as a preamble.

[0492] A common physical layer pipe (PLP) in burst form can be transmitted following the preamble (L1 signal). In this case, the common physical layer pipe can transmit data that can be shared with other physical layer pipes in the frame.

[0493] A two-layer LDM scheme can be used to transmit a plurality of physical layer pipes for broadcast signals that serve different services from each other. In this case, a service requiring robust reception performance such as indoor / mobility (720p or 1080p HD, etc.) can use a core layer (upper layer) data physical layer pipe. In this case, a fixed reception service requiring a high transmission rate (4K-UHD or multi-HD, etc.) can use an enhancement layer (lower layer) data physical layer pipe.

[0494] If a plurality of physical layer pipes are layer division multiplexed, it can be seen that the total number of physical layer pipes increases.

[0495] In this case, the core layer data physical layer pipe and the enhancement layer data physical layer pipe can share a time interleaver to reduce complexity and memory size. In this case, the core layer data physical layer pipe and the enhancement layer data physical layer pipe can have the same physical layer pipe size (PLP size), and can have different physical layer pipe sizes from each other.

[0496] According to an embodiment, the layer division PLPs can have different PLP sizes from each other, and information for identifying a start position of a PLP or information for identifying a size of a PLP can be signaled.

[0497] Figure 17 is a diagram illustrating yet another example of an LDM frame using a plurality of physical layer pipes and a two-layer LDM.

[0498] Referring to Figure 17 , the LDM frame can include a common physical layer pipe after a bootstrap and a preamble (L1 signal). A core layer data physical layer pipe and an enhancement layer data physical layer pipe can be transmitted using a dual-layer LDM scheme after the common physical layer pipe.

[0499] In detail, Figure 17 The core layer data physical layer pipe and the enhancement layer data physical layer pipe of the LDM frame of

[0500] - Type 1 PLP

[0501] If a common PLP exists, it is transmitted after the common PLP

[0502] It is transmitted in the form of a burst (one slice) in a frame

[0503] - Type 2 PLP

[0504] If a Type 1 PLP exists, it is transmitted after the Type 1 PLP

[0505] It is transmitted in the form of two or more sub-slices in a frame

[0506] Time diversity and power consumption increase with the number of sub-slices

[0507] In this case, Type 1 PLP can correspond to a non-scattered PLP, and Type 2 PLP can correspond to a scattered PLP. In this case, the non-scattered PLP can be allocated for a continuous data unit index. In this case, the scattered PLP can be allocated to two or more sub-slices.

[0508] Figure 18 is a diagram illustrating another application example of an LDM frame using multiple physical layer channels and two layers.

[0509] Referring to Figure 18 , in the LDM frame, a common physical layer channel (PLP(1,1)) can be included after the bootstrap and the preamble. A data physical layer channel (PLP(2,1)) for a robust audio service can be included in the LDM frame using a time division scheme.

[0510] Also, a core layer data physical layer channel (PLP(3,1)) for a mobile / indoor service (720p or 1080p HD) and an enhancement layer data physical layer channel (PLP(3,2)) for a high data rate service (4K-UHD or multiple HD) can be transmitted using a 2-layer LDM scheme.

[0511] Figure 19 is a diagram illustrating another application example of an LDM frame using multiple physical layer channels and two layers.

[0512] Referring to Figure 19 , the LDM frame can include a bootstrap, a preamble, a common physical layer channel (PLP(1,1)). In this case, a robust audio service and a mobile / indoor service (720p or 1080p HD) can be transmitted using a core layer data physical layer channel (PLP(2,1), PLP(3,1)), and a high data rate service (4K-UHD or multiple HD) can be transmitted using an enhancement layer data physical layer channel (PLP(2,2), PLP(3,2)).

[0513] In this case, the core layer data physical layer channel and the enhancement layer data physical layer channel can use the same time interleaver.

[0514] In this case, the physical layer channels (PLP(2,2), PLP(3,2)) providing the same service can be identified using PLP_GROUP_ID indicating the same PLP grouping.

[0515] According to an embodiment, when physical layer pipes having different sizes from each other are used for different LDM layers, a service can be identified using a start position and a size of each physical layer pipe instead of using PLP_GROUP_ID.

[0516] Although in Figure 18 and Figure 19 a plurality of physical layer pipes and layers corresponding to layer division multiplexing are identified by PLP(i,j), PLP identification information and layer identification information can be signaled as different fields from each other.

[0517] According to an embodiment, different layers can use PLPs having different sizes. In this case, each service can be identified using a PLP identifier.

[0518] When PLPs having different sizes are used for different layers, a PLP start position and a PLP size can be signaled for each PLP.

[0519] The following pseudo code is used to show an example of fields included in a preamble according to an embodiment of the present application. The following pseudo code can be included in L1 signaling information of the preamble.

[0520] [ Pseudo code ]

[0521] SUB_SLICES_PER_FRAME (15 bits)

[0522] NUM_PLP (8 bits)

[0523] NUM_AUX (4 bits)

[0524] AUX_CONFIG_RFU (8 bits)

[0525] for i = 0..NUM_RF-1{

[0526] RF IDX (3 bits)

[0527] FREQUENCY (32 bits)

[0528] }

[0529] IF S2 == 'xxx1'{

[0530] FEF TYPE (4 bits)

[0531] FEF LENGTH (22 bits)

[0532] FEF INTERVAL (8 bits)

[0533] }

[0534] ​for i = 0..NUM_PLP - 1 {

[0535] NUM_LAYER (2~3 bits)

[0536] for j = 0..NUM_LAYER - 1 {

[0537] / * Signaling for each layer * /

[0538] PLP_ID(i,j) (8 bits) PLP_GROUP_ID (8 bits) PLP_TYPE (3 bits) PLP_PAYLOAD_TYPE (5 bits) PLP_COD (4 bits) PLP_MOD (3 bits) PLP_SSD (1 bit) PLP_FEC_TYPE (2 bits) PLP_NUM_BLOCKS_MAX (10 bits) IN_BAND_A_FLAG (1 bit) IN_BAND_B_FLAG (1 bit) PLP_MODE (2 bits)

[0539] STATIC_PADDING_FLAG (1 bit) IF(j>0)

[0540] LL_INJECTION_LEVEL (3~8 bits)

[0541] } / * End of NUM_LAYER loop * /

[0542] / * Common signaling for all layers * /

[0543] FF_FLAG (1 bit) FIRST_RF_IDX (3 bits) FIRST_FRAME_IDX (8 bits) FRAME_INTERVAL (8 bits) TIME_IL_LENGTH (8 bits) TIME_IL_TYPE (1 bit) RESERVED_1 (11 bits) STATIC_FLAG (1 bit)

[0544] PLP_START (24 bits)

[0545] PLP_SIZE (24 bits)

[0546] } / * End of NUM_PLP loop * /

[0547] FEF_LENGTH_MSB (2 bits)

[0548] RESERVED_2 (30 bits)

[0549] for i = 0..NUM_AUX-1 {

[0550] AUX_STREAM_TYPE (4 bits)

[0551] AUX_PRIVATE_CONF (28 bits)

[0552] }

[0553] NUM_LAYER can correspond to two or three bits in the pseudo code described above. In this case, NUM_LAYER can be a field for identifying the number of layers in each PLP divided by time. In this case, NUM_LAYER can be defined in the NUM_PLP loop so that the number of layers can be different for each PLP divided by time.

[0554] LL_INJECTION_LEVEL can correspond to 3 to 8 bits. In this case, LL_INJECTION_LEVEL can be a field for identifying the injection level of the lower layer (enhancement layer). In this case, LL_INJECTION_LEVEL can correspond to injection level information.

[0555] In this case, when the number of layers is 2 or more, LL_INJECTION_LEVEL can be defined from the second layer (j > 0).

[0556] Fields such as PLP_ID(i,j), PLP_GROUP_ID, PLP_TYPE, PLP_PAYLOAD_TYPE, PLP_CDO, PLP_MOD, PLP_SSD, PLP_FEC_TYPE, PLP_NUM_BLOCKS_MAX, IN_BAND_A_FLAG, IN_BAND_B_FLAG, PLP_MODE, STATIC_PADDING_FLAG, etc. can correspond to parameters defined for each layer, and can be defined inside the NUM_LAYER loop.

[0557] In this case, PLP_ID(i,j) can correspond to PLP identification information and layer identification information. For example, "i" of PLP_ID(i,j) can correspond to PLP identification information, and "j" of PLP_ID(i,j) can correspond to layer identification information.

[0558] According to an embodiment, the PLP identification information and the layer identification information can be included in the preamble as fields different from each other.

[0559] In addition, time interleaver information such as TIME_IL_LENGTH and TIME_IL_TYPE, FRAME_INTERVAL related to a PLP size, and fields such as FF_FLAG, FIRST_RF_IDX, FIRST_FRAME_IDX, RESERVED_1, STATIC_FLAG, etc. can be defined outside the NUM_LAYER loop and inside the NUM_PLP loop.

[0560] Specifically, PLP_TYPE corresponds to type information of a physical layer channel, and can correspond to 1 bit for identifying one of two types of Type 1 and Type 2. Although PLP_TYPE is included in the preamble without verifying the condition of the conditional statement corresponding to the layer identification information (j) in the above pseudo code, PLP_TYPE can be selectively signaled based on the result of comparison of the layer identification information (j) with a predetermined value (0) (if (j=0)) (transmitted only for a core layer).

[0561] Although PLP_TYPE is defined in the NUM_LAYER loop in the above pseudo code, PLP_TYPE can also be defined outside the NUM_LAYER loop and inside the NUM_PLP loop.

[0562] In the pseudocode above, PLP_START corresponds to the start position of the corresponding physical layer channel. In this case, PLP_START can use a cell addressing scheme to identify the start position. In this case, PLP_START can be the index of the first data unit corresponding to the corresponding PLP.

[0563] Specifically, PLP_START can be sent as a signal for each physical layer channel, and the PLP_START can be used to identify the service by using multiple physical layer channels and a field for the size of the PLP sent as a signal.

[0564] In the pseudocode above, PLP_SIZE corresponds to the size information of the physical layer channel. In this case, PLP_SIZE can be the same as the number of data units allocated to the corresponding physical layer channel.

[0565] In other words, PLP_TYPE can be sent using signals based on layer identification information, and PLP_START and PLP_SIZE can be sent using signals for each physical layer channel without considering layer identification information.

[0566] Figure 3 and Figure 7 The combinedr 340 shown functions to combine core layer signals and enhancement layer signals, and can perform the combination on the basis of a time-interleaved group shared by the core layer signals and enhancement layer signals, because the core layer signals and enhancement layer signals share a time-interleaved group.

[0567] In this case, time interleaver groups can be configured based on memory efficiency and system efficiency, using the core layer as the basis.

[0568] However, when setting up time-interleaver groups based on the core layer, there may be FEC blocks that are divided by time-interleaver group boundaries in the enhancement layer. If such divided FEC blocks exist, it may be necessary to signal a field to identify a portion of the FEC block corresponding to the time-interleaver group boundary.

[0569] The temporal interleaver used for layer demultiplexing can be a convolutional temporal interleaver (CTI) or a hybrid temporal interleaver (HTI). In this case, a convolutional temporal interleaver or a hybrid temporal interleaver can be used when there is one physical layer channel in the core layer, and a hybrid temporal interleaver can be used when there are two or more physical layer channels in the core layer. When using a hybrid temporal interleaver, the physical layer channel can consist only of a complete FEC block.

[0570] Figure 20 This is a diagram illustrating an example of using a convolutional temporal interleaver.

[0571] Reference Figure 20 The subframe includes two layers: a core layer and an enhancement layer.

[0572] Since the subframe includes only one physical layer pipe (PLP #0) in the core layer in the example shown in FIG. 13A, a time interleaver corresponding to the subframe can be a convolutional time interleaver or a hybrid time interleaver, and the example shown corresponds to an example using a convolutional time interleaver. When a convolutional time interleaver is used, the physical layer pipe in each layer can include an incomplete FEC block. Figure 20

[0573] Such an incomplete FEC block is located at the edge of the PLP, and can be identified using a field such as "L1D_plp_CTI_fec_block_start" indicating the position of the first complete FEC block in each PLP.

[0574] In the example shown in FIG. 13B, the physical layer pipe of the core layer (PLP #0) and the physical layer pipe of the enhancement layer (PLP #1) have the same start position and size. Figure 20 In the example shown in FIG. 13C, it can be seen that the time interleaver grouping (TI grouping) corresponds to the physical layer pipe of the core layer (PLP #0). The time interleaver grouping is commonly applied to the core layer and the enhancement layer, and is advantageous in terms of memory and system efficiency to be set to correspond to the core layer.

[0575] Figure 20 is a diagram illustrating yet another example using a convolutional time interleaver.

[0576] Figure 21 Reference It can be seen that the start position and size of the core layer physical layer pipe (PLP #0) and the enhancement layer physical layer pipe (PLP #1) are different.

[0577] Figure 21 If the start position and size of the core layer physical layer pipe (PLP #0) and the start position and size of the enhancement layer physical layer pipe (PLP #1) are different from each other, an empty area can be included in the enhancement layer.

[0578] As shown in FIG. 14B, when an empty area is included at the rear end of the enhancement layer physical layer pipe (PLP #1), the enhancement layer physical layer pipe (PLP #1) ends with a complete FEC block.

[0579] As shown in FIG. 14C, when an empty area is included at the rear end of the enhancement layer physical layer pipe (PLP #1), the enhancement layer physical layer pipe (PLP #1) ends with a complete FEC block. Figure 21

[0580] is a diagram illustrating an example using a hybrid time interleaver. Figure 22 Reference

[0581] It can be seen that the start position and size of the core layer physical layer pipe (PLP #0) and the enhancement layer physical layer pipe (PLP #1) are different. Figure 22 ​​, two physical layer pipes (PLP#0, PLP#1) are included in the core layer.

[0582] Therefore, when the core layer is composed of a plurality of physical layer pipes, a hybrid time interleaver is used.

[0583] When the hybrid time interleaver is used, all of the physical layer pipes of the core layer and the enhancement layer include only complete FEC blocks.

[0584] In this case, some portions of the enhancement layer can be emptied to align with the core layer boundary.

[0585] Figure 23 is a diagram illustrating a time interleaver packet in an example of Figure 22 .

[0586] Referring to Figure 23 , it can be seen that the time interleaver packet boundary is set corresponding to the boundary of the physical layer pipe of the core layer.

[0587] Although the time interleaver packet includes one core layer physical layer pipe in Figure 23 , according to an embodiment, the time interleaver packet can include two or more core layer physical pipes.

[0588] In the example illustrated in Figure 23 , one FEC block of the enhancement layer can be divided by the time interleaver packet boundary.

[0589] This is because the time interleaver packet division is performed on the basis of the core layer, and in this case, it is possible to signal information for identifying an incomplete FEC block of the enhancement layer, which corresponds to the time interleaver packet boundary.

[0590] Figure 24 to Figure 26 is a diagram illustrating a process of calculating the size of the incomplete FEC block in an example of Figure 23 .

[0591] Referring to Figure 24 , the distance (A) between the start position of the enhancement layer physical layer pipe (L1D_plp_start(PLP#2)) and the time interleaver packet boundary is calculated using the start position of the core layer physical layer pipe (L1D_plp_start(PLP#0)), the size of the core layer physical layer pipe (L1D_plp_size(PLP#0)), and the start position of the enhancement layer physical layer pipe (L1D_plp_start(PLP#2)).

[0592] Referring to Figure 25The distance (B) between the start position of the divided FEC block and the time interleaver packet boundary is calculated using the FEC block size of the enhancement layer.

[0593] In this case, the FEC block size can be decided by using modulation information (L1D_plp_mod) corresponding to the enhancement layer and FEC type information (L1D_plp_fec_type) corresponding to the enhancement layer.

[0594] Referring to Figure 26 The portion (C) of the FEC block of the enhancement layer corresponding to the boundary between the time interleaver packets is identified.

[0595] Table 3 below shows an example of an Ll-detail field of a preamble according to an embodiment of the present application.

[0596] The preamble according to an embodiment of the present application can include an Ll-basic and an Ll-detail.

[0597] Table 3

[0598]

[0599]

[0600]

[0601]

[0602]

[0603] All fields corresponding to the allocation bits in Table 3 can correspond to an unsigned integer most significant bit first (uimsbf) format.

[0604] Among the fields in Table 3, L1D_plp_layer can be a field for representing a layer corresponding to each physical layer channel. L1D_plp_start can correspond to start position information of a current PLP and can indicate an index of a first data unit of the current PLP. L1D_plp_size can correspond to size information of the current PLP and can indicate the number of data units allocated to the current PLP.

[0605] L1D_plp_fec_type can correspond to FEC type information of the current PLP and can indicate a forward error correction (FEC) method used to encode the current PLP.

[0606] For example, L1D_plp_fec_type="0000" can correspond to BCH and 16200 LDPC, L1D_plp_fec_type="0001" can correspond to BCH and 64800 LDPC, L1D_plp_fec_type="0010" can correspond to CRC and 16200 LDPC, L1D_plp_fec_type="0011" can correspond to CRC and 64800 LDPC, L1D_plp_fec_type="0100" can correspond to 16200 LDPC, and L1D_plp_fec_type="0101" can correspond to 64800 LDPC.

[0607] L1D_plp_mod can indicate modulation information of the current PLP. In this case, L1D_plp_mod can be signaled only when L1D_plp_fec_type satisfies a predetermined condition shown in Table 3.

[0608] For example, L1D_plp_mod="0000" can correspond to QPSK, L1D_plp_mod="0001" can correspond to 16QAM-NUC, L1D_plp_mod="0010" can correspond to 64QAM-NUC, L1D_plp_mod="0011" can correspond to 256QAM-NUC, L1D_plp_mod="0100" can correspond to 1024QAM-NUC, and L1D_plp_mod="0101" can correspond to 4096QAM-NUC. In this case, L1D_plp_mod can be set to "0100" or "0101" only when L1D_plp_fec_type corresponds to 64800 LDPC.

[0609] L1D_plp_TI_mode indicates a time interleaving mode of the PLP.

[0610] For example, L1D_plp_TI_mode="00" can represent a no time interleaving mode, L1D_plp_TI_mode="01" can represent a convolutional time interleaving mode, and L1D_plp_TI_mode="10" can represent a hybrid time interleaving mode.

[0611] L1D_plp_fec_block_start can correspond to start position information of the first complete FEC block in the physical layer channel. L1D_plp_fec_block_start can be signaled only in the case of L1D_plp_TI_mode="00".

[0612] When layer division multiplexing is used, since the start position of the first FEC block in each layer can be different, L1D_plp_fec_block_start can be signaled individually for each layer.

[0613] L1D_plp_CTI_fec_block_start can correspond to start position information of the first complete block in the physical layer channel. L1D_plp_CTI_fec_block_start can be signaled only in the case of L1D_plp_TI_mode = "01".

[0614] In this case, the number of bits allocated to L1D_plp_CTI_fec_block_start can be more than the number of bits allocated to L1D_plp_fec_block_start.

[0615] As described above, when L1D_plp_TI_mode = "10", all PLPs include only complete FEC blocks, and thus, the start position of the first FEC block does not need to be signaled separately.

[0616] L1D_plp_HTI_num_fec_blocks can correspond to the number of FEC blocks contained in the current interlaced frame of the physical layer channel for the core layer.

[0617] In this case, it can be seen that, when L1D_plp_layer is 0 (core layer), each of the fields corresponding to convolution time interleaving (L1D_plp_CTI_depth, L1D_plp_CTI_start_row) and the fields corresponding to hybrid time interleaving (L1D_plp_HTI_inter_subframe, L1D_plp_HTI_num_ti_blocks, L1D_plp_HTI_num_fec_blocks_max, L1D_plp_HTI_num_fec_blocks, L1D_plp_HTI_cell_interleaver, etc.) according to whether L1D_plp_TI_mode is 01 or 10 can be signaled as time interleaver information.

[0618] In this case, L1D_plp_CTI_depth can indicate the number of rows used in the convolution time interleaver, and L1D_plp_CTI_start_row can indicate the position of the interleaver selector at the beginning of the subframe.

[0619] In this case, L1D_plp_HTI_inter_subframe can indicate a hybrid time interleaving mode, and L1D_plp_HTI_num_ti_blocks can indicate the number of TI blocks per interleaving frame or the number of subframes carrying a cell from one TI block, and L1D_plp_HTI_num_fec_blocks_max can indicate a number less than the maximum number of FEC blocks per interleaving frame for the current physical layer channel by 1, and L1D_plp_HTI_num_fec_blocks can indicate a number less than the number of FEC blocks included in the current interleaving frame for the current physical layer channel by 1, and L1D_plp_HTI_cell_interleaver can indicate whether a cell interleaver is used.

[0620] In this case, time interleaver information signaled based on a core layer can be signaled separately from a field such as L1D_plp_TI_mode.

[0621] Figure 27 is a diagram for explaining the number of bits required for L1D_plp_fec_block_start when L1D_plp_TI_mode = "00".

[0622] Referring to Figure 27 , it can be seen that, when L1D_plp_TI_mode = "00" (no time interleaving), the cell address of the FEC block start position before time interleaving (C_in) and the cell address of the FEC block start position after time interleaving (C_out) are the same.

[0623] In the case of no time interleaving, as shown in Figure 27 , it can be seen that convolution interleaving is performed with a depth of 0.

[0624] In this case, L1D_plp_fec_block_start is defined after time interleaving so that C_out can be signaled as L1D_plp_fec_block_start for each physical layer channel in a subframe.

[0625] When the LDPC code word is 16200 or 64800 and the modulation order is 2, 4, 6, 8, 10, and 12, the longest FEC block can have a length of 64800 / 2 = 32400.

[0626] Since 32400 can be represented by 15 bits, allocating 15 bits to L1D_plp_fec_block_start can cover the case of L1D_plp_TI_mode = "00".

[0627] Figure 28 and 29 is a diagram for explaining the number of bits required for L1D_plp_CTI_fec_block_start when L1D_plp_TI_mode = "01".

[0628] Referring to Figure 28 , it can be seen that when L1D_plp_TI_mode = "01" (convolutional time interleaving), the cell address of the FEC block start position before time interleaving (C_in) and the cell address of the FEC block start position after time interleaving (C_out) are not identical due to interleaving.

[0629] In this case, L1D_plp_CTI_fec_block_start is defined after time interleaving so that C_out can be signaled as L1D_plp_CTI_fec_block_start for each physical layer pipe in a subframe.

[0630] Referring to Figure 29 , it can be seen that a convolutional time interleaver with a depth of 4 operates with C_in as input and C_out as output.

[0631] In this case, 0 corresponds to the 0th row, 1 to the 1st row, 2 to the 2nd row, 3 to the 3rd row, 4 to the 0th row, 5 to the 1st row, 6 to the 2nd row, 7 to the 3rd row, 8 to the 0th row, 9 to the 1st row, and 10 to the 2nd row in the case of input.

[0632] First, 0, 4, 8, etc. corresponding to the 0th row are output without delay.

[0633] 1, 5, 9, etc. corresponding to the 1st row are output with 4 delays.

[0634] 2, 6, 10, etc. corresponding to the 2nd row are output with 8 delays.

[0635] 3, 7, etc. corresponding to the 3rd row are output with 12 delays.

[0636] That is, it can be seen that for the nth row, (n x 4) delays occur.

[0637] Although an example of a depth of 4 (the number of rows of the time interleaver is 4) is explained in Figure 29 , when the number of rows (the number of delay lines) corresponding to the time interleaver is N_row, input corresponding to the nth row is delayed (n x N_row).

[0638] In this case, the unit address of the FEC block start position (L1D_plp_CTI_fec_block_start) after time interleaving can be calculated as (C_in + (n x N_row)). In this case, n is a row corresponding to C_in and can be determined by L1D_CTI_start_row in the time interleaver information signaled by the L1-detail. In this case, n can be ((L1D_CTI_start_row + C_in) % N_row). In this case, L1D_CTI_start_row can indicate the position of the interleaver selector at the start of a subframe.

[0639] That is, L1D_plp_CTI_fec_block_start can be calculated by adding the delay caused by time interleaving to C_in.

[0640] In order to calculate the number of bits required to signal L1D_plp_CTI_fec_block_start, the maximum value of L1D_plp_CTI_fec_block_start is required. As shown above, in the case of non-extended interleaving, the maximum value of C_in is (32400-1), the maximum value of n is N_row-1, and N_row can be at most 1024. In this case, the maximum value of L1D_plp_CTI_fec_block_start is ((32400-1) + (1024-1) x 1024) = 1079951. At least 21 bits can be used to signal 1079951.

[0641] In the case of extended interleaving, N_row can be at most 1448. In this case, the maximum value of L1D_plp_CTI_fec_block_start is ((32400-1) + (1448-1) x 1448) = 2127655. At least 22 bits can be used to signal 2127655.

[0642] Therefore, since the maximum value of L1D_plp_fec_block_start is the same as the maximum value of C_in when L1D_plp_TI_mode = "00", and the maximum value of L1D_plp CTI_fec_block_start is the sum of the maximum value of C_in and the delay due to interleaving when L1D_plp_TI_mode = "01", an efficient signaling operation is possible when the number of bits for signaling L1D_plp CTI_fec_block_start is greater than the number of bits for signaling L1D_plp_fec_block_start.

[0643] Since all physical layer pipes of the core layer and the enhancement layer include only a complete FEC block when L1D_plp_TI_mode = "10", the start position of all physical layer pipes becomes the start position of the first complete FEC block, thereby making it unnecessary to signal a field such as L1D_plp_fec_block_start or L1D_plp CTI_fec_block_start.

[0644] Figure 30 is a diagram showing an example of L1D_plp_fec_block_start for the enhancement layer.

[0645] Referring to Figure 30 , the start position of the first complete FEC block for the enhancement layer physical layer pipe (enhancement PLP #2) exceeds the length of the enhancement layer physical layer pipe (enhancement PLP #1).

[0646] As shown in the example of Figure 30 , if the start position of the first complete FEC block for the enhancement layer physical layer pipe is designated with respect to the first cell of the core layer physical layer pipe, it can not be possible to signal the start position of the first complete FEC block (L1D_plp_CTI_fec_block_start) with 22 bits.

[0647] That is, in Figure 30In the example of FIG. 6, because the L1D_plp_CTI_fec_block_start of the enhancement layer physical layer channel (enhancement PLP #2) is the distance from the start position of the core layer physical layer channel (core PLP #0), the L1D_plp_CTI_fec_block_start of the enhancement layer physical layer channel (enhancement PLP #2) is greater than the plp_size of the enhancement layer physical layer channel (enhancement PLP #1). In this case, because the plp_size is a field represented by 24 bits, the L1D_plp_CTI_fec_block_start of the enhancement layer physical layer channel (enhancement PLP #2) cannot be represented by 22 bits.

[0648] Therefore, it is preferable that the L1D_plp_CTI_fec_block_start or the L1D_plp_fec_block_start is determined as the distance from the first cell of the corresponding PLP. In particular, it is preferable that the L1D_plp_CTI_fec_block_start or the L1D_plp_fec_block_start for the enhancement layer physical layer channel is not the distance from the first cell of the corresponding core layer physical layer channel, but is the distance from the first cell of the corresponding (current) physical layer channel (enhancement layer physical layer channel).

[0649] The L1D_plp_CTI_fec_block_start can indicate the position after convolutional time interleaving (CTI) of the first cell of the first complete FEC block before convolutional time interleaving (CTI) for the current physical layer channel in the current subframe or a subsequent subframe. The position can be specified in the current subframe with respect to the first cell of the current physical layer channel leaving the convolutional time interleaver, where the CTI selector is located at the position L1D_plp_CTI_start_row. The L1D_plp_CTI_fec_block_start can exceed the subframe boundary, and thus can indicate the position in the physical layer channel data belonging to the subsequent subframe. The L1D_plp_CTI_fec_block_start can be determined before cell multiplexing.

[0650] The L1D_plp_CTI_fec_block_start can be determined as follows.

[0651] Let C be the position of the first cell of the first complete FEC block before the CTI of the current PLP in the current subframe or the subsequent subframe, where the index of C starts from 0, where 0 corresponds to the first cell of the current physical layer channel before the CTI. In this case, C can be equal to the number of cells belonging to the immediately preceding FEC block of the physical layer channel and not yet input to the convolutional time interleaver. In this case, L1D_plp_CTI_fec_block_start can be C + N_row x ((L1D_plp_CTI_start_row + C) mod N_row).

[0652] When LDM is used, L1D_plp_CTI_fec_block_start can be signaled separately for the core layer physical layer channel and the enhancement layer physical layer channel. This is because the start position of the first complete FEC block of the core layer physical layer channel and the enhancement layer physical layer channel, which have been layer multiplexed together, is usually different.

[0653] Figure 31 is a diagram showing the relationship between before convolutional time interleaving and after convolutional time interleaving.

[0654] Referring to Figure 31 After convolutional time interleaving by convolutional time interleaving, the position of the first cell of the first complete FEC block before convolutional time interleaving in the current subframe (C, 3110) is changed to the position (3120). In this case, L1D_plp_CTI_fec_block_start can indicate the position (3120) after convolutional time interleaving. In this case, L1D_plp_CTI_fec_block_start can be calculated after convolutional time interleaving, and L1D_plp_CTI_fec_block_start can be with respect to the position before convolutional time interleaving. In this case, L1D_plp_CTI_fec_block_start can be C + N_row x ((L1D_plp_CTI_start_row + C) mod N_row).

[0655] The position of the first cell of the second complete FEC block before convolutional time interleaving in the current subframe (3130) can be changed to a position before (in front of) the start position (3120) of the first complete FEC block by convolutional time interleaving. Even in this case, the start position (3120) of the first complete FEC block before time interleaving can be signaled as L1D_plp_CTI_fec_block_start.

[0656] In Figure 31In an example of the case of FIG. 10, L1D_plp_CTI_start_row can be signaled only for the core layer physical layer pipe, and L1D_plp_CTI_start_row can not be signaled for the enhancement layer physical layer pipe. In this case, the position of the interleaver selector for the enhancement layer physical layer pipe can be calculated from L1D_plp_CTI_start_row of the core layer physical layer pipe corresponding to the current enhancement layer physical layer pipe.

[0657] Figure 32 FIG. 11 is a diagram illustrating a single physical layer pipe case to which convolutional time interleaving of depth 0 (no time interleaving mode) is applied.

[0658] Referring to FIG. 11, Figure 32 , one FEC block (#0, n0) is divided by a boundary between subframes.

[0659] In this case, fec_block_start, C_in (#1) of the first subframe can be {FEC_Block_size (#0) - {(L1D_plp_size (#0) - C_in (#0)) % FEC_Block_size (#0)}} % FEC_Block_size (#0).

[0660] In an example of the case of FIG. 11, Figure 32 , because time interleaving is not applied, C_in can be signaled as L1D_plp_fec_block_start.

[0661] Figure 33 FIG. 12 is a diagram illustrating an operation of a receiver side in a single physical layer pipe case.

[0662] Referring to FIG. 12, Figure 33 , the receiver performs time de-interleaving and calculates a position before time interleaving (C_in) using received L1D_plp_CTI_fec_block_start.

[0663] In this case, the position before time interleaving (C_in) can be L1D_plp_CTI_fec_block_start - (k x N_row). In this case, k can be a row corresponding to L1D_plp_CTI_fec_block_start, and can be (L1D_CTI_start_row + L1D_plp_CTI_fec_block_start) % N_row.

[0664] The parameters of the convolution time interleaving for the case of a single physical layer pipe can be calculated from the signaling parameters as follows. In this case, the parameters can correspond to the i-th subframe and the 0-th physical layer pipe.

[0665] - L1D_plp_CTI_depth(i-1) -> N_row(i-1)

[0666] - L1D_plp_CTI_depth(i) -> N_row(i)

[0667] - L1D_plp_size(i-1,0)

[0668] - L1D_plp_fec_type(i-1,0) & L1D_plp_mod(i-1,0) -> FEC_Block_size(i-1,0)

[0669] - L1D_CTI_start_row(i,0) = (L1D_CTI_start_row(i-1,0) + L1D_plp_size(i-1,0)) % N_row(i-1)

[0670] - L1D_CTI_fec_block_start(i) = C_in(i) + (n * N_row),

[0671] where C_in(i) = {FEC_Block_size(i-1,0) - {(L1D_plp_size(i-1,0) - C_in(i-1)) % FEC_Block_size(i-1,0))}} % FEC_Block_size(i-1,0)

[0672] n = (L1D_CTI_start_row(i,0) + C_in(i)) % N_row(i)

[0673] In this case, N_row(i-1) can be the same as N_row(i). If N_row(i-1) is different from N_row(i), the operation of the convolution time interleaver can be reset.

[0674] The amount of delay caused by the CTI is calculated based on the i-th subframe.

[0675] Since the current C_in(i) is calculated from the previous subframe conditions, the other parameters are calculated based on the (i-1)-th subframe.

[0676] In the following, the case of multiple enhanced physical layer pipes is explained.

[0677] In this case, the L1D_plp_CTI_fec_block_start can be signaled separately per enhanced layer physical layer channel.

[0678] In this case, the L1D_CTI_start_row for the enhanced layer physical layer channel can not be signaled and can be calculated at the receiver side for use. In this case, the L1D_CTI_start_row for the core layer physical layer channel only can be explicitly signaled.

[0679] When at least two enhanced layer physical layer channels are layer multiplexed with one core layer physical layer channel, the L1D_CTI_start_row for the first enhanced layer physical layer channel can be the same as the L1D_CTI_start_row for the core layer physical layer channel. In this case, the L1D_CTI_start_row for the other enhanced layer physical layer channels can be calculated by using some parameters.

[0680] Figure 34 and 35 is a diagram showing the case of multiple enhanced physical layer channels.

[0681] Referring to Figure 34 , one FEC block (#0, 1, n0) of the enhanced layer physical layer channel (enhanced PLP #1) is divided by the boundary between subframes.

[0682] In this case, the fec_block_start, C_in (#1, 1) of the first physical layer channel in the first subframe can be {FEC_Block_size (#0, 1) - {(L1D_plp_size (#0, 1) - C_in (#0, 1)) % FEC_Block_size (#0, 1))}} % FEC_Block_size (#0, 1).

[0683] In general, C_in (i, j) corresponding to the jth enhanced layer physical layer channel in the ith subframe can be {FEC_Block_size (i-1, j) - {(L1D_plp_size (i-1, j) - C_in (i-1, j)) % FEC_Block_size (i-1, j))}} % FEC_Block_size (i-1, j).

[0684] Referring to Figure 35 , one FEC block (#0, 2, p0) of the enhanced layer physical layer channel (enhanced PLP #2) is divided by the boundary between subframes.

[0685] In this case, fec_block_start of the second physical layer channel in the first sub-frame, C_in(#1,2) can be {FEC_Block_size(#0,2)-{(L1D_plp_size(#0,2)-C_in(#0,2))%FEC_Block_size(#0,2))}}%FEC_Block_size(#0,2).

[0686] The parameters for the convolution time interleaving for the case of multiple enhancement layer physical layer channels can be calculated from the signaling parameters as follows. In this case, the parameters can correspond to the ith sub-frame and the jth enhancement layer physical layer channel.

[0687] -L1D_plp_CTI_depth(i-1) -> N_row(i-1)

[0688] -L1D_plp_CTI_depth(i) -> N_row(i)

[0689] -L1D_plp_size(i-1,j)

[0690] -L1D_plp_fec_type(i-1,j) & L1D_plp_mod(i-1,j) -> FEC_Block_size(i-1,j)

[0691] -L1D_CTI_start_row(i,0) = (L1D_CTI_start_row(i-1,0) + L1D_plp_size(i-1,0))%N_row(i-1)

[0692] -L1D_CTI_fecframe_start(i) = C_in(i) + (n*N_row),

[0693] where C_in(i) = {FEC_Block_size(i-1,j)-{(L1D_plp_size(i-1,j)-C_in(i-1))%FEC_Block_size(i-1,j))}}%FEC_Block_size(i-1,j)

[0694] n = (L1D_CTI_start_row(i,j) + C_in(i))%N_row(i)

[0695] In this case, N_row(i-1) can be the same as N_row(i). If N_row(i-1) is not the same as N_row(i), the operation of the convolution time interleaver can be reset.

[0696] In this case, the L1D_CTI_start_row can be signaled only for the core layer physical layer channel or the physical layer channel not being layer division multiplexed. In this case, the L1D_CTI_start_row for the first enhancement layer physical layer channel can be the same as the L1D_CTI_start_row for the core layer physical layer channel of the current CTI packet (L1D_CTI_start_row(i,0) in the above example). In this case, the L1D_CTI_start_row for the other enhancement layer physical layer channels can be calculated as follows.

[0697] When the PLP #0 is the core layer physical layer channel and the PLP #1 ~ #j are the enhancement layer physical layer channels, the L1D_CTI_start_row for the enhancement layer physical layer channels can be calculated in a recursive form as follows.

[0698] Core PLP #0: L1D_CTI_start_row(i,0) = (L1D_CTI_start_row(i-1,0) + L1D_plp_size(i-1,0)) % N_row(i-1)

[0699] Enhancement PLP #1: L1D_CTI_start_row(i,1) = L1D_CTI_start_row(i,0)

[0700] Enhancement PLP #2: L1D_CTI_start_row(i,2) = (L1D_CTI_start_row(i,1) + L1D_plp_size(i,1)) % N_row(i) ...

[0702] Enhancement PLP #j: L1D_CTI_start_row(i,j) = (L1D_CTI_start_row(i,j-1) + L1D_plp_size(i,j-1)) % N_row(i)

[0703] When the PLP #0 is the core layer physical layer channel and the PLP #1 ~ #j are the enhancement layer physical layer channels, the L1D_CTI_start_row for the enhancement layer physical layer channels can be calculated in a closed form as follows.

[0704] Core PLP #0: L1D_CTI_start_row(i,0) = (L1D_CTI_start_row(i-1,0) + L1D_plp_size(i-1,0)) % N_row(i-1)

[0705] Enhanced PLP #1 : L1D_CTI_start_row(i, 1) = L1D_CTI_start_row(i, 0)

[0706] Enhanced PLP #2: L1D_CTI_start_row(i, 2) = (L1D_CTI_start_row(i, 0) + L1D_plp_size(i, 1)) % N_row(i)

[0707] Enhanced PLP #3: L1D_CTI_start_row(i, 3) = (L1D_CTI_start_row(i, 0) + L1D_plp_size(i, 1) + L1D_plp_size(i, 2)) % N_row(i) ...

[0709] Enhanced PLP #j:

[0710] As described above, the apparatus for generating broadcast signal frames and methods according to the present application are not limited to the configurations and methods of the above-described embodiments, but some or all of the embodiments can be selectively combined so that the embodiments are modified in various ways.

Claims

1. A broadcast signal receiving device, comprising: A time deinterleaver is configured to perform time deinterleaver on a received signal corresponding to a broadcast signal frame, wherein the broadcast signal frame includes a preamble for signaling time interleaver information corresponding to the time interleaver; The core layer BICM decoder is configured to recover the core layer data corresponding to the broadcast signal frame; The enhancement layer symbol extractor is configured to extract enhancement layer symbols by performing elimination corresponding to the recovered core layer data; and The enhancement layer BICM decoder is configured to recover the enhancement layer data corresponding to the enhancement layer symbols. The time interleaver performs time interleaving by using one of several operating modes. The plurality of operating modes include a first mode corresponding to no temporal interleaving, a second mode for performing convolutional temporal interleaving, and a third mode for performing mixed temporal interleaving. The preamble includes a first field indicating the start position of the first complete FEC block for the first mode corresponding to each physical layer channel, or a second field indicating the start position of the first complete FEC block for the second mode corresponding to each physical layer channel, but does not include any field indicating the start position of the first complete FEC block for the third mode.

2. The broadcast signal receiving device as described in claim 1, wherein, The second field has a longer length than the first field.

3. The broadcast signal receiving device as described in claim 1, wherein, The length of the first field is 15 bits, and The length of the second field is 22 bits.

4. The broadcast signal receiving device as described in claim 3, wherein, When the time interleaver corresponds to the second mode The start position of the first complete FEC block indicates the first unit of the first complete FEC block prior to convolutional temporal interleaving, and After convolutional temporal interleaving, the position of the first cell of the first complete FEC block is sent using a signal.

5. The broadcast signal receiving device as described in claim 4, wherein, The second field corresponds to the position after convolution time interleaving, which is calculated by adding the position before convolution time interleaving and the delay caused by convolution time interleaving.

6. The broadcast signal receiving device as described in claim 5, wherein, The latency caused by convolutional temporal interleaving is calculated by using the position of the interleaver selector corresponding to the convolutional temporal interleaving.

7. The broadcast signal receiving device as described in claim 6, wherein, The latency caused by convolutional temporal interleaving is calculated using modulo operations on the following terms: The sum of the positions of the interleaver selectors corresponding to convolutional temporal interleaving and their positions before convolutional temporal interleaving, and The number of delay lines corresponding to the convolution time interleaving.

8. The broadcast signal receiving device as described in claim 7, wherein, The position of the interleaver selector is only signaled for the core layer physical layer channel corresponding to the core layer, and the position of the interleaver selector is not signaled for the enhancement layer physical layer channel corresponding to the enhancement layer.

9. The broadcast signal receiving device as described in claim 8, wherein, The position of the interleaver selector for the enhancement layer physical layer channel is calculated by using the position of the interleaver selector that is signaled for the core layer physical layer channel corresponding to the enhancement layer physical layer channel.

10. The broadcast signal receiving device as described in claim 3, wherein, The first field or the second field is used to send signals for the core layer physical layer channel and the enhancement layer physical layer channel, respectively.

11. A method for receiving broadcast signals, comprising: Time deinterleaving is performed on the received signal corresponding to the broadcast signal frame, wherein the broadcast signal frame includes a preamble for transmitting time interleaver information corresponding to the time interleaver using a signal; The core layer data corresponding to the broadcast signal frame is recovered by the core layer BICM decoder; Enhancement layer symbols are extracted by performing elimination corresponding to the recovered core layer data using the output from the core layer BICM decoder; and The enhancement layer data corresponding to the enhancement layer symbols is recovered by the enhancement layer BICM decoder. The time interleaver performs time interleaving by using one of several operating modes. The operation modes include a first mode corresponding to no temporal interleaving, a second mode for performing convolutional temporal interleaving, and a third mode for performing mixed temporal interleaving. The preamble includes a first field indicating the start position of the first complete FEC block for the first mode corresponding to each physical layer channel, or a second field indicating the start position of the first complete FEC block for the second mode corresponding to each physical layer channel, but does not include any field indicating the start position of the first complete FEC block for the third mode.

Images