WO2017078376A1 - Apparatus and method for generating broadcasting signal frame that includes preamble for signalling injection level information - Google Patents

Abstract

An apparatus and a method for generating a broadcasting signal frame that includes a preamble for signalling injection level information are disclosed. The broadcasting signal frame generating apparatus according to an embodiment of the present invention comprises: an injection level controller for reducing the power of an enhanced layer signal so as to generate a power-reduced enhanced layer signal; a combiner for combining a core layer signal with the power-reduced enhanced layer signal so as to generate a multiplexed signal; a power normaliser for reducing the power of the multiplexed signal to a power corresponding to the core layer signal; a time-interleaver for performing interleaving that is applied to both the core layer signal and the enhanced layer signal so as to generate a time-interleaved signal; and a frame builder for generating a broadcasting signal frame that includes a preamble for signalling injection level information corresponding to the injection level controller.

Description

Broadcast signal frame generating apparatus and preamble signal signaling method for generating the injection level information and broadcast signal frame generation method

The present invention relates to a broadcast signal transmission / reception technique used in a broadcast system, and more particularly, to a broadcast signal transmission / reception system for transmitting / receiving by multiplexing / demultiplexing two or more signals.

Bit-Interleaved Coded Modulation (BICM) is a bandwidth-efficient transmission technology that includes an error-correction coder, a bit-by-bit interleaver, and a high-order modulator. In combined form.

BICM can provide excellent performance with a simple structure by using a low-density parity check (LDPC) encoder or a turbo encoder as an error correction encoder. In addition, BICM provides a high level of flexibility because it can select various modulation orders, error correction codes, lengths, and code rates. Because of these advantages, BICM is not only used in broadcasting standards such as DVB-T2 and DVB-NGH, but also in other next generation broadcasting systems.

In order to simultaneously support multiple services, multiplexing, a process of mixing multiple signals, is required. Among these multiplexing techniques, currently widely used techniques include time division multiplexing (TDM) for dividing time resources and frequency division multiplexing (FDM) for dividing frequency resources. That is, TDM is a method of allocating time divided by services, and FDM is a technique of allocating and using frequency resources divided by services. Recently, there is an urgent need for a new multiplexing technique that provides higher levels of flexibility and better performance than TDM and FDM applicable to next generation broadcasting systems.

An object of the present invention is to provide a broadcast signal frame structure to which a new signal multiplexing technique is applied that can provide higher levels of flexibility and better performance than time division multiplexing (TDM) or frequency division multiplexing (FDM).

In addition, it is an object of the present invention to enable broadcast signal frames for broadcast signals to which layered division multiplexing is applied to efficiently signal injection level information by using different step sizes in consideration of changes in scaling factors.

It is also an object of the present invention to signal injection level information in consideration of various service environments such as local service.

Broadcast signal frame generating apparatus according to the present invention for achieving the above object is an injection level controller for generating a power reduced enhanced layer signal by reducing the power of the enhanced layer signal; A combiner for combining a core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And a frame builder for generating a broadcast signal frame including a preamble for signaling injection level information corresponding to the injection level controller.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

In this case, the power normalizer corresponds to a normalizing factor that increases as the power decrease corresponding to the injection level controller increases, and the injection level controller decreases as the power decrease corresponding to the injection level controller increases. May correspond to

In this case, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change less than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical division.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In addition, the broadcast signal frame generation method according to an embodiment of the present invention comprises the steps of: generating a power reduced enhanced layer signal by reducing the power of the enhanced layer signal; Combining a core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And generating a broadcast signal signal frame including a preamble for signaling injection level information corresponding to the power reduced enhanced layer signal.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

At this time, the step of lowering the power corresponding to the core layer signal corresponds to a normalizing factor that increases as the power reduction corresponding to the power reduced enhanced layer signal increases, and the power reduced enhanced layer Generating the signal may correspond to a scaling factor that decreases as the power reduction corresponding to the power reduced enhanced layer signal increases.

At this time, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change that is smaller than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical division.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

According to the present invention, it is possible to provide a frame structure to which a new signal multiplexing technique is applied that can provide a higher level of flexibility and superior performance than time division multiplexing (TDM) or frequency division multiplexing (FDM).

In addition, according to the present invention, the broadcast signal frame for the broadcast signal to which the layered division multiplexing is applied may efficiently signal the injection level information by using different step sizes in consideration of the change amount of the scaling factor.

In addition, the present invention may signal injection level information in consideration of various service environments such as a local service.

1 is a block diagram illustrating a broadcast signal transmission / reception system according to an embodiment of the present invention.

2 is a flowchart illustrating a broadcast signal transmission / reception method according to an embodiment of the present invention.

3 is a block diagram illustrating an example of an apparatus for generating broadcast signal frames shown in FIG. 1.

4 is a diagram illustrating an example of a broadcast signal frame structure.

FIG. 5 is a diagram illustrating an example of a process of receiving a broadcast signal frame shown in FIG. 4.

6 is a diagram illustrating another example of a process of receiving the broadcast signal frame shown in FIG. 4.

FIG. 7 is a block diagram illustrating another example of the apparatus for generating broadcast signal frames shown in FIG. 1.

FIG. 8 is a block diagram illustrating an example of the signal demultiplexing apparatus shown in FIG. 1.

FIG. 9 is a block diagram illustrating an example of a core layer BICM decoder and an enhanced layer symbol extractor illustrated in FIG. 8.

FIG. 10 is a block diagram illustrating another example of the core layer BICM decoder and the enhanced layer symbol extractor illustrated in FIG. 8.

FIG. 11 is a block diagram illustrating another example of the core layer BICM decoder and the enhanced layer symbol extractor illustrated in FIG. 8.

12 is a block diagram illustrating another example of the signal demultiplexing apparatus illustrated in FIG. 1.

13 is a diagram illustrating a power increase due to a combination of a core layer signal and an enhanced layer signal.

14 is a flowchart illustrating a method of generating a broadcast signal frame according to an embodiment of the present invention.

FIG. 15 is a diagram illustrating a superframe structure including a broadcast signal frame according to an embodiment of the present invention. FIG.

16 is a diagram illustrating an example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe are applied.

FIG. 17 illustrates another example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe are applied.

18 illustrates an example of using an LDM frame using an LDM using two layers and a multiple-physical layer pipe.

FIG. 19 is a diagram illustrating another application example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe are applied.

20 illustrates an example of a case where a convolutional time interleaver is used.

21 is a diagram illustrating another example when a convolutional time interleaver is used.

22 is a diagram illustrating an example of a case where a hybrid time interleaver is used.

FIG. 23 is a diagram illustrating a time interleaver group in the example shown in FIG. 22.

24 to 26 illustrate a process of calculating the size of an incomplete FEC block in the example shown in FIG. 23.

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

28 and 29 are diagrams for describing the number of bits required for L1D_plp_CTI_fec_block_start when L1D_plp_TI_mode = "01".

30 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 4;

FIG. 31 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 5. FIG.

32 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 6. FIG.

33 is a graph illustrating a scaling factor according to a change in an LDM injection level value (dB).

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

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

1 is a block diagram illustrating a broadcast signal transmission / reception system according to an embodiment of the present invention.

Referring to FIG. 1, a broadcast signal transmission / reception system according to an embodiment of the present invention includes a broadcast signal transmission device 110, a wireless channel 120, and a broadcast signal reception device 130.

The broadcast signal transmitting apparatus 110 includes a broadcast signal frame generating apparatus 111 and an OFDM transmitter 113 for generating a broadcast signal frame by multiplexing core layer data and enhanced layer data.

The broadcast signal frame generating apparatus 111 combines the core layer signal corresponding to the core layer data and the enhanced layer signal corresponding to the enhanced layer data into different power levels, and the core layer signal and the enhanced layer signal. Interleaving is applied together to generate a multiplexed signal. In this case, the broadcast signal frame generation device 111 may generate a broadcast signal frame including the bootstrap and the preamble using the time interleaved signal. In this case, the broadcast signal frame may be an ATSC 3.0 frame.

In this case, time interleaving uses one of time interleaver groups, and a boundary between the time interleaver groups is between physical layer pipes (PLPs) of a core layer corresponding to the core layer signal. It may be the boundary of. That is, one of the boundaries between physical layer pipes of the core layer may be a boundary between time interleaver groups.

The OFDM transmitter 113 transmits the multiplexed signal through the antenna 117 by using an OFDM communication scheme so that the transmitted OFDM signal is transmitted through the radio channel 120 through the antenna 137 of the broadcast signal receiving apparatus 130. To be received.

The broadcast signal receiving apparatus 130 includes an OFDM receiver 133 and a signal demultiplexing apparatus 131. When the signal transmitted through the wireless channel 120 is received through the antenna 137, the OFDM receiver 133 receives the OFDM signal through synchronization, channel estimation, and equalization processes. do.

In this case, the OFDM receiver 133 detects and demodulates the bootstrap from the OFDM signal, demodulates the preamble using the information included in the bootstrap, and uses the information included in the preamble to perform the superimposed payload. You can also demodulate.

The signal demultiplexing apparatus 131 first recovers core layer data from a signal (superimposed payload) received through the OFDM receiver 133, and through cancellation corresponding to the recovered core layer data. Restore the enhanced layer data. In this case, the signal demultiplexing apparatus 131 first generates a broadcast signal frame, restores a bootstrap from the broadcast signal frame, restores a preamble using information included in the bootstrap, and then includes signaling information data included in the preamble. It can be used to restore the signal. In this case, the signaling information may be L1 signaling information, and may include injection level information, normalizing factor information, and the like.

In this case, the preamble may include PLP identification information for identifying physical layer pipes (PLPs); And layer identification information for identifying layers corresponding to hierarchical division.

In this case, PLP identification information and layer identification information may be included in the preamble as separate fields.

In this case, the time interleaver information may be included in the preamble based on the core layer.

In this case, the preamble may selectively include injection level information corresponding to the injection level controller according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

In this case, the power normalizer corresponds to a normalizing factor that increases as the power decrease corresponding to the injection level controller increases, and the injection level controller decreases as the power decrease corresponding to the injection level controller increases. May correspond to

In this case, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change less than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical division.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the preamble may include type information, start position information, and size information of physical layer pipes.

In this case, the type information may be for identifying any one of a first type corresponding to a non-dispersed physical layer pipe and a second type corresponding to a distributed physical layer pipe.

In this case, an undistributed physical layer pipe may be allocated for contiguous data cell indices, and the distributed physical layer pipe may be composed of two or more subslices.

In this case, type information may be selectively signaled according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the type information may be signaled only for the core layer.

At this time, the start position information may be set equal to an index corresponding to the first data cell of the physical layer pipe.

In this case, the start position information may indicate a start position of the physical layer pipe by using a cell addressing scheme.

In this case, starting position information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the size information may be set based on the number of data cells allocated to the physical layer pipe.

In this case, size information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the time interleaver information may be signaled based on the core layer.

In this case, the time interleaver may correspond to a hybrid time interleaver. In this case, the physical layer pipes (PLPs) of the core layer and the enhanced layer may include only complete FEC blocks.

In this case, the preamble is information for identifying a part of the FEC block of the enhanced layer corresponding to the boundary of the time interleaver groups when the boundary of the time interleaver groups does not correspond to the boundary of the FEC blocks of the enhanced layer. May be signaled.

In this case, the information for identifying a part of the FEC block includes start position information of the physical layer pipe of the core layer, start position information of the physical layer pipe of the enhanced layer, modulation information corresponding to the enhanced layer, and the enhancement. It may include any one or more of the FEC type information corresponding to the hard layer.

At this time, the start position information of the physical layer pipe may correspond to the index of the first data cell of the physical layer pipe.

In this case, the modulation information may be signaled only when the FEC type information satisfies a preset condition.

In this case, the enhanced layer signal may correspond to enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

At this time, the time interleaver corresponds to a convolutional time interleaver, and the time interleaver groups include a physical layer pipe (PLP) including an incomplete FEC block. The preamble may be for signaling starting position information of a first complete FEC block in the physical layer pipe.

In this case, the time interleaver may perform the interleaving in one of a plurality of operation modes.

In this case, the operation modes may include a first mode that omits time interleaving, a second mode that performs convolutional time interleaving, and a third mode that performs hybrid time interleaving. Can be.

In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to a current physical layer pipe for the first mode and the second mode. The 3 modes may not include a field indicating the start position of the first FEC block. In this case, the field indicating the start position may indicate the start position of the first FEC block started in the current physical layer pipe during the current subframe.

In this case, the field indicating the start position of the first FEC block is any one of the first field used in the first mode and the second field used in the second mode, and the first field and the second field have a length. Can be different.

In this case, the length of the second field may be longer than the length of the first field.

At this time, the length of the first field is determined based on the length of the LDPC codeword and the modulation order, and the length of the second field is the depth of the convolutional time interleaver as well as the length and modulation order of the LDPC codeword. ) May be further considered.

In this case, the length of the first field may be 15 bits, and the length of the second bit may be 22 bits.

In this case, the first field and the second field may be separately signaled for each of the core layer corresponding to the core layer signal and the enhanced layer corresponding to the enhanced layer signal.

As will be described later, the apparatus for generating broadcast signal frame 111 shown in FIG. 1 includes an injection level controller which generates a power reduced enhanced layer signal by reducing the power of the enhanced layer signal; A combiner for combining a core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And a frame builder generating a broadcast signal frame including a preamble for signaling injection level information corresponding to the injection level controller. In this case, the time interleaver may perform the interleaving in one of a plurality of operation modes. In this case, the broadcast signal transmitting apparatus 110 shown in FIG. 1 includes an injection level controller which generates a power reduced enhanced layer signal by reducing the power of the enhanced layer signal; A combiner for combining the core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; A frame builder for generating a broadcast signal frame including a preamble for signaling injection level information corresponding to the injection level controller; And an OFDM transmitter for transmitting the broadcast signal frame through an antenna using an OFDM communication scheme. In this case, the time interleaver may perform the interleaving in one of a plurality of operation modes.

As will be described later, the signal demultiplexing apparatus shown in FIG. 1 includes a time deinterleaver for generating time deinterleaving signals by applying time deinterleaving to a received signal corresponding to a broadcast signal frame; A de-normalizer for raising the power of the received signal or the time deinterleaving signal by a power reduction by the power normalizer of the transmitter; A core layer BICM decoder for recovering core layer data from the signal adjusted by the de-normalizer; An enhancement for extracting an enhanced layer signal by performing a cancellation corresponding to the core layer data with respect to a signal controlled by the de-normalizer using an output signal of a core layer FEC decoder of the core layer BICM decoder. De-layer symbol extractor; A de-injection level controller for raising the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And an enhanced layer BICM decoder for restoring enhanced layer data by using the output signal of the de-injection level controller. In this case, the broadcast signal receiving apparatus 130 shown in FIG. 1 includes an OFDM receiver for 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; A time deinterleaver for generating a time deinterleaving signal by applying time deinterleaving to the received signal; A de-normalizer for raising the power of the received signal or the time deinterleaving signal by a power reduction by the power normalizer of the transmitter; A core layer BICM decoder for recovering core layer data from the signal adjusted by the de-normalizer; An enhancement for extracting an enhanced layer signal by performing a cancellation corresponding to the core layer data with respect to a signal controlled by the de-normalizer using an output signal of a core layer FEC decoder of the core layer BICM decoder. De-layer symbol extractor; A de-injection level controller for raising the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And an enhanced layer BICM decoder for restoring enhanced layer data by using the output signal of the de-injection level controller.

In this case, the time deinterleaver may perform deinterleaving in one of a plurality of operation modes. That is, the time deinterleaver may operate to correspond to a time interleaver that performs interleaving in one of a plurality of operation modes.

Although not explicitly illustrated in FIG. 1, the broadcast signal transmission / reception system according to an embodiment of the present invention may multiplex / demultiplex one or more enhancement layer data in addition to core layer data and enhanced layer data. In this case, the enhancement layer data may be multiplexed at a lower power level than the core layer data and the enhanced layer data. Furthermore, when two or more extension layers are included, the injection power level of the second extension layer is lower than the injection power level of the first extension layer, and the injection power level of the third extension layer is lower than the injection power level of the second extension layer. Can be.

2 is a flowchart illustrating a broadcast signal transmission / reception method according to an embodiment of the present invention.

Referring to FIG. 2, in the broadcast signal transmission / reception method according to an embodiment of the present invention, a core layer signal and an enhanced layer signal are combined and multiplexed at different power levels to be shared by the core layer signal and the enhanced layer signal. A broadcast signal frame including time interleaver information and a preamble for signaling the time interleaver information is generated (S210).

In this case, the broadcast signal frame generated by step S210 may include a bootstrap, a preamble, and a super-imposed payload. In this case, any one or more of the bootstrap and the preamble may include L1 signaling information. In this case, the L1 signaling information may include injection level information and normalizing factor information.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

In this case, the step of lowering the power of the combined signal corresponds to a normalizing factor that increases as the power decrease corresponding to the power reduced enhanced layer signal increases, and the step of lowering the power of the core layer signal may include The power reduction corresponding to the power reduced enhanced layer signal may correspond to a scaling factor that decreases.

At this time, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change that is smaller than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical division.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the preamble may include PLP identification information for identifying physical layer pipes (PLPs); And layer identification information for identifying layers corresponding to hierarchical division.

In this case, PLP identification information and layer identification information may be included in the preamble as separate fields.

In this case, the time interleaver information may be included in the preamble based on the core layer.

In this case, the preamble may selectively include injection level information corresponding to the injection level controller according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the preamble may include type information, start position information, and size information of physical layer pipes.

In this case, the type information may be for identifying any one of a first type corresponding to a non-dispersed physical layer pipe and a second type corresponding to a distributed physical layer pipe.

In this case, an undistributed physical layer pipe may be allocated for contiguous data cell indices, and the distributed physical layer pipe may be composed of two or more subslices.

In this case, type information may be selectively signaled according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the type information may be signaled only for the core layer.

At this time, the start position information may be set equal to an index corresponding to the first data cell of the physical layer pipe.

In this case, the start position information may indicate a start position of the physical layer pipe by using a cell addressing scheme.

In this case, starting position information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the size information may be set based on the number of data cells allocated to the physical layer pipe.

In this case, size information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the time interleaver information may be signaled based on the core layer.

At this time, generating the time interleaved signal may perform the interleaving using a hybrid time interleaver. In this case, the physical layer pipes (PLPs) of the core layer and the enhanced layer may include only complete FEC blocks.

In this case, the preamble is information for identifying a part of the FEC block of the enhanced layer corresponding to the boundary of the time interleaver groups when the boundary of the time interleaver groups does not correspond to the boundary of the FEC blocks of the enhanced layer. May be signaled.

In this case, the information for identifying a part of the FEC block includes start position information of the physical layer pipe of the core layer, start position information of the physical layer pipe of the enhanced layer, modulation information corresponding to the enhanced layer, and the enhancement. It may include any one or more of the FEC type information corresponding to the hard layer.

At this time, the start position information of the physical layer pipe may correspond to the index of the first data cell of the physical layer pipe.

In this case, the modulation information may be signaled only when the FEC type information satisfies a preset condition.

In this case, the enhanced layer signal may correspond to enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

In this case, generating the time interleaved signal may perform the interleaving using a convolutional time interleaver, and the time interleaver groups may include an incomplete FEC block. A physical layer pipe (PLP), and the preamble may signal starting position information of the first complete FEC block in the physical layer pipe.

In this case, the interleaving may be performed using one of a plurality of operation modes.

In this case, the operation modes may include a first mode that omits time interleaving, a second mode that performs convolutional time interleaving, and a third mode that performs hybrid time interleaving. have.

In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to a current physical layer pipe for the first mode and the second mode. The 3 modes may not include a field indicating the start position of the first FEC block.

In this case, the field indicating the start position of the first FEC block is any one of the first field used in the first mode and the second field used in the second mode, and the first field and the second field have a length. Can be different.

In this case, the length of the second field may be longer than the length of the first field.

At this time, the length of the first field is determined based on the length of the LDPC codeword and the modulation order, and the length of the second field is the depth of the convolutional time interleaver as well as the length and modulation order of the LDPC codeword. ) May be further considered.

In this case, the length of the first field may be 15 bits, and the length of the second bit may be 22 bits.

In this case, the first field and the second field may be separately signaled for each of the core layer corresponding to the core layer signal and the enhanced layer corresponding to the enhanced layer signal.

In addition, the broadcast signal transmission / reception method according to an embodiment of the present invention performs OFDM transmission of a broadcast signal frame (S220).

In addition, the broadcast signal transmission / reception method according to an embodiment of the present invention receives the transmitted signal by OFDM (S230).

In this case, step S230 may perform synchronization, channel estimation, and equalization processes.

In this case, step S230 may restore the bootstrap, restore the preamble using the signal included in the restored bootstrap, and restore the data signal using the signaling information included in the preamble.

In addition, the broadcast signal transmission / reception method according to an embodiment of the present invention restores core layer data from the received signal (S240).

In addition, the broadcast signal transmission / reception method according to an embodiment of the present invention restores enhanced layer data through core layer signal cancellation (S250).

In particular, steps S240 and S250 illustrated in FIG. 2 may correspond to a demultiplexing operation corresponding to step S210.

As will be described later, step S210 illustrated in FIG. 2 may include combining a core layer signal and an enhanced layer signal at different power levels to generate a multiplexed signal; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And generating a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the interleaving. In this case, the interleaving may be performed using one of a plurality of operation modes. At this time, the broadcast signal transmission method of step S210 and step S220 includes the steps of combining the core layer signal and the enhanced layer signal at different power levels to generate a multiplexed signal; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; Generating a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the interleaving; And transmitting the broadcast signal frame through an antenna using an OFDM communication scheme. In this case, the interleaving may be performed using one of a plurality of operation modes.

As will be described later, steps S240 and S250 illustrated in FIG. 2 may include generating time deinterleaving signals by applying time deinterleaving to a received signal corresponding to a broadcast signal frame; Increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; Restoring core layer data from the power adjusted signal; Extracting an enhanced layer signal by performing cancellation on the core layer data with respect to the power adjusted signal; Increasing the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And restoring enhanced layer data by using the adjusted power enhancement layer signal. At this time, the broadcast signal receiving method according to an embodiment of the present invention, generating a received signal by performing any one or more of the synchronization, channel estimation and equalization for the transmitted signal corresponding to the broadcast signal frame; Generating a time deinterleaving signal by applying time deinterleaving to the received signal; Increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; Restoring core layer data from the power adjusted signal; Extracting an enhanced layer signal by performing cancellation on the core layer data with respect to the power adjusted signal; Increasing the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And restoring enhanced layer data by using the adjusted power enhancement signal.

In this case, time deinterleaving may perform the deinterleaving in one of a plurality of operation modes.

3 is a block diagram illustrating an example of an apparatus for generating broadcast signal frames shown in FIG. 1.

Referring to FIG. 3, the apparatus for generating broadcast signal frame according to an embodiment of the present invention includes a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, and a power source. It may include a normalizer 345, a time interleaver 350, a signaling generator 360, and a frame builder 370.

In general, a bit-interleaved coded modulation (BICM) device includes an error correction encoder, a bit interleaver, and a symbol mapper, and the core layer BICM unit 310 and the enhanced layer BICM unit 320 illustrated in FIG. It may include a correction encoder, a bit interleaver, and a symbol mapper. In particular, the error correction encoder illustrated in FIG. 3 may be a combination of a BCH encoder and an LDPC encoder in series. At this time, the input of the error correction encoder may be input to the BCH encoder, the output of the BCH encoder may be input to the LDPC encoder, and the output of the LDPC encoder may be the output of the error correction encoder.

As shown in FIG. 3, the core layer data and the enhanced layer data pass through different BICM units and then merge through the combiner 340. That is, in the present invention, layered division multiplexing (LDM) may refer to a plurality of layers combined and transmitted using a power difference.

That is, the core layer data passes through the core layer BICM unit 310, and the enhanced layer data passes through the enhanced layer BICM unit 320 and then is combined in the combiner 340 through the injection level controller 330. In this case, the enhanced layer BICM unit 320 may perform different BICM encoding from the core layer BICM unit 310. That is, the enhanced layer BICM unit 320 may perform error correction encoding or symbol mapping corresponding to a higher bit rate than the core layer BICM unit 310. In addition, the enhanced layer BICM unit 320 may perform error correction encoding or symbol mapping that is less robust than the core layer BICM unit 310.

For example, the core layer error correction encoder may have a lower bit rate than the enhanced layer error correction encoder. At this point, the enhanced layer symbol mapper may be less robust than the core layer symbol mapper.

The combiner 340 may be regarded as combining the core layer signal and the enhanced layer signal at different power levels. According to an embodiment, the power level adjustment may be performed on the core layer signal rather than the enhanced layer signal. In this case, the power for the core layer signal may be adjusted to be greater than the power of the enhanced layer signal.

Core layer data uses low code rate forward error correction (FEC) codes for robust reception, while enhanced layer data uses high code rate FEC codes for high data rates. Can be.

That is, the core layer data may have a wider coverage area in the same reception environment as compared with the enhanced layer data.

The enhanced layer data passing through the enhanced layer BICM unit 320 is adjusted through the injection level controller 330 to be combined with the core layer data by the combiner 340.

That is, the injection level controller 330 reduces the power of the enhanced layer signal to generate a power reduced enhanced layer signal. In this case, the magnitude of the signal adjusted by the injection level controller 330 may be determined according to the injection level. In this case, the injection level when the signal B is inserted into the signal A may be defined as in Equation 1 below.

[Equation 1]

For example, assuming that the injection level is 3 dB when inserting the enhanced layer signal into the core layer signal, it means that the enhanced layer signal has a power amount corresponding to half of the core layer signal.

In this case, the injection level controller 330 may adjust the power level of the enhanced layer signal from 0 dB to 25.0 dB in 0.5 dB or 1 dB intervals.

In general, the transmit power allocated to the core layer is larger than the transmit power allocated to the enhanced layer, and thus the receiver can preferentially decode the core layer.

In this case, the combiner 340 may be considered to generate a multiplexed signal by combining the core layer signal and the power reduced enhanced layer signal.

The signal coupled by the combiner 340 is provided to the power normalizer 345 to lower the power by the power increase generated by the combination of the core layer signal and the enhanced layer signal, thereby performing power adjustment. That is, the power normalizer 345 lowers the power of the signal multiplexed by 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 one layer signal, power normalization of the power normalizer 345 is necessary to prevent amplitude clipping or the like in the rest of the broadcast signal transmission / reception system.

At this time, the power normalizer 345 may multiply the normalizing factor of Equation 2 by the magnitude of the combined signal to adjust the appropriate signal size. Injection level information for calculating Equation 2 may be transferred to the power normalizer 345 through a signaling flow.

[Equation 2]

When the enhanced layer signal S _E is injected by the injection level preset to the core layer signal S _C , assuming that the power levels of the core layer signal and the enhanced layer signal are normalized to 1, the combined signal is

It can be expressed as

In this case, α represents a scaling factor corresponding to various injection levels. That is, the injection level controller 330 may correspond to a scaling factor.

For example, if the injection level of the enhanced layer is 3 dB, the combined signal

It can be expressed as

Since the power of the combined signal (multiplexed signal) has increased compared to the core layer signal, the power normalizer 345 must mitigate this power increase.

The output of the power normalizer 345 is

It can be expressed as

In this case, β represents a normalizing factor according to various injection levels of the enhanced layer.

When the injection level of the enhanced layer is 3dB, the combined signal power increase is 50% compared to the core layer signal. Thus, the output of the power normalizer 345 is

It can be expressed as

Table 1 below shows scaling factors α and normalizing factors β according to various injection levels (CL: Core Layer, EL: Enhanced Layer). The relationship between the injection level and the scaling factor α and the normalizing factor β may be defined as follows.

[Equation 3]

EL Injection level relative to CL	Scaling factor α	Normalizing factor β
3.0 dB	0.7079458	0.8161736
3.5 dB	0.6683439	0.8314061
4.0 dB	0.6309573	0.8457262
4.5 dB	0.5956621	0.8591327
5.0 dB	0.5623413	0.8716346
5.5 dB	0.5308844	0.8832495
6.0 dB	0.5011872	0.8940022
6.5 dB	0.4731513	0.9039241
7.0 dB	0.4466836	0.9130512
7.5 dB	0.4216965	0.9214231
8.0 dB	0.3981072	0.9290819
8.5 dB	0.3758374	0.9360712
9.0 dB	0.3548134	0.9424353
9.5 dB	0.3349654	0.9482180
10.0 dB	0.3162278	0.9534626

That is, the power normalizer 345 corresponds to a normalizing factor, and may be viewed as lowering the power of the multiplexed signal by the combiner 340.

In this case, the normalizing factor and the scaling factor may be rational numbers larger than 0 and smaller than 1, respectively.

In this case, the scaling factor may decrease as the power reduction corresponding to the injection level controller 330 increases, and the normalizing factor may increase as the power reduction corresponding to the injection level controller 330 increases.

The power normalized signal passes through a time interleaver 350 to distribute the burst errors occurring in the channel.

In this case, the time interleaver 350 may be regarded as performing interleaving applied to both the core layer signal and the enhanced layer signal. That is, since the core layer and the enhanced layer share the time interleaver, unnecessary memory usage can be prevented and latency at the receiver can be reduced.

As will be described later, the enhanced layer signal may correspond to enhanced layer data reconstructed based on cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal, and the combiner 340 may correspond to the core layer. One or more extension layer signals of a lower power level than the signal and enhanced layer signal may be combined with the core layer signal and the enhanced layer signal.

Meanwhile, the L1 signaling information including the injection level information is encoded by the signaling generator 360 including the signaling-only BICM. In this case, the signaling generator 360 may receive the injection level information IL INFO from the injection level controller 330 to generate the L1 signaling signal.

In the L1 signaling, L1 represents Layer-1, which is the lowest layer of the ISO 7 layer model. In this case, the L1 signaling may be included in the preamble.

In general, the L1 signaling may include an FFT size, a guard interval size, which are the main parameters of the OFDM transmitter, a channel code rate, modulation information, etc. which are the main parameters of the BICM. The L1 signaling signal is combined with the data signal to form a broadcast signal frame.

The frame builder 370 combines the L1 signaling signal and the data signal to generate a broadcast signal frame. In this case, the frame builder 370 signals time interleaver information and size information of physical layer pipes (PLPs) shared between the core layer signal and the enhanced layer signal using the time interleaved signal. A broadcast signal frame including a preamble may be generated. In this case, the broadcast signal frame may further include a bootstrap.

In this case, the frame builder 370 may be regarded as generating a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the time interleaver 350.

In this case, the time interleaver 350 uses one of time interleaver groups, and the boundary between the time interleaver groups includes physical layer pipes of physical layer pipes corresponding to the core layer signal; PLPs). That is, one of the boundaries between physical layer pipes of the core layer may be a boundary between time interleaver groups.

In this case, the time interleaver information may be signaled based on the core layer.

According to an embodiment, some of the time interleaver information may be signaled based on the core layer, and other parts of the time interleaver information may be signaled regardless of the layer.

That is, time interleaver information may be signaled based on layer identification information corresponding to the core layer.

In this case, the time interleaver 350 may correspond to a hybrid time interleaver. In this case, the physical layer pipes of the core layer and the enhanced layer may include only complete FEC blocks.

In this case, the preamble is information for identifying a part of the FEC block of the enhanced layer corresponding to the boundary of the time interleaver groups when the boundary of the time interleaver groups does not correspond to the boundary of the FEC blocks of the enhanced layer. May be signaled.

In this case, the information for identifying a part of the FEC block includes start position information of the physical layer pipe of the core layer, start position information of the physical layer pipe of the enhanced layer, modulation information corresponding to the enhanced layer, and the enhancement. It may include any one or more of the FEC type information corresponding to the hard layer.

At this time, the start position information of the physical layer pipe may correspond to the index of the first data cell of the physical layer pipe.

In this case, the modulation information may be signaled only when the FEC type information satisfies a preset condition.

In this case, the enhanced layer signal may correspond to enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

In this case, the time interleaver 350 corresponds to a convolutional time interleaver, and the time interleaver groups include a physical layer pipe (PLP) including an incomplete FEC block. The preamble may signal starting position information of the first complete FEC block in the physical layer pipe.

In this case, the time interleaver 350 may perform the interleaving in one of a plurality of operation modes.

In this case, the operation modes include a first mode (L1D_plp_TI_mode = 00) for omitting time interleaving, a second mode (L1D_plp_TI_mode = 01) for performing convolutional time interleaving, and hybrid time interleaving. ) May include a third mode (L1D_plp_TI_mode = 10).

In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to a current physical layer pipe for the first mode and the second mode. The third mode may not include a field indicating a start position of the first FEC block.

In this case, the field indicating the start position of the first FEC block may include a first field L1D_plp_fec_block_start used in the first mode L1D_plp_TI_mode = 00 and a second field used in the second mode L1D_plp_TI_mode = 01. L1D_plp_CTI_fec_block_start), and the first field and the second field may have different lengths. At this time, the first field (L1D_plp_fec_block_start) indicates the start position of the first FEC block started in the current physical layer pipe during the current subframe, and the second field (L1D_plp_CTI_fec_block_start) indicates the current or subsequent subframe. Field, the start position of the first intact FEC block of the current physical layer pipe leaving the convolutional time interleaver. In this case, both the first field L1D_plp_fec_block_start and the second field L1D_plp_CTI_fec_block_start may be signaled based on interleaving. In particular, when the second field L1D_plp_CTI_fec_block_start is signaled based on interleaving, the number of bits required for signaling may increase.

In this case, the length of the second field may be longer than the length of the first field.

In this case, the length of one field is determined based on the length of the LDPC codeword and the modulation order, and the length of the second field is not only the length and modulation order of the LDPC codeword, but also the depth of the convolutional time interleaver. It may be determined considering further.

In this case, the length of the first field may be 15 bits, and the length of the second field may be 22 bits.

In this case, the first field and the second field may be separately signaled for each of the core layer corresponding to the core layer signal and the enhanced layer corresponding to the enhanced layer signal.

In this case, the frame builder 370 may include a bootstrap generator that generates the bootstrap; A preamble generating unit generating the preamble; And a super-imposed payload generator for generating a super-imposed payload corresponding to the time interleaved signal.

In this case, the bootstrap may be shorter than the preamble and have a fixed length.

In this case, the bootstrap includes a symbol representing the structure of the preamble,

The symbol may correspond to a fixed-length bit string representing a combination of a modulation method / coding rate of the preamble, an FFT size, a guard interval length, and a pilot pattern.

In this case, when the modulation method / code rate is the same, the preamble structure corresponding to the second FFT size smaller than the first FFT size is preferentially allocated to the preamble structure corresponding to the first FFT size, and the modulation is performed. If the method / code rate and the FFT size are the same, a lookup table to which a preamble structure corresponding to a second guard interval length greater than the first guard interval length is preferentially assigned to a lookup table, rather than a preamble structure corresponding to a first guard interval length May be equivalent.

The broadcast signal frame is transmitted through an OFDM transmitter that is robust to multipath and Doppler. In this case, the OFDM transmitter may be regarded as responsible for generating a transmission signal of a next generation broadcasting system.

In this case, the preamble may include PLP identification information for identifying physical layer pipes (PLPs); And layer identification information for identifying layers corresponding to hierarchical division.

In this case, PLP identification information and layer identification information may be included in the preamble as separate fields.

In this case, the time interleaver information may be included in the preamble based on the core layer.

In this case, the preamble may selectively include injection level information corresponding to the injection level controller according to a result of comparing (IF (j> 0)) the layer identification information with a predetermined value for each of the physical layer pipes. Can be.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

In this case, the power normalizer corresponds to a normalizing factor that increases as the power decrease corresponding to the injection level controller increases, and the injection level controller decreases as the power decrease corresponding to the injection level controller increases. May correspond to

In this case, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change less than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical partitioning.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the preamble may include type information, start position information, and size information of physical layer pipes.

In this case, the type information may be for identifying any one of a first type corresponding to a non-dispersed physical layer pipe and a second type corresponding to a distributed physical layer pipe.

In this case, an undistributed physical layer pipe may be allocated for contiguous data cell indices, and the distributed physical layer pipe may be composed of two or more subslices.

In this case, type information may be selectively signaled according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the type information may be signaled only for the core layer.

At this time, the start position information may be set equal to an index corresponding to the first data cell of the physical layer pipe.

In this case, the start position information may indicate a start position of the physical layer pipe by using a cell addressing scheme.

In this case, starting position information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the size information may be set based on the number of data cells allocated to the physical layer pipe.

In this case, size information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

4 is a diagram illustrating an example of a broadcast signal frame structure.

Referring to FIG. 4, the broadcast signal frame includes a bootstrap 410, a preamble 420, and a super-imposed payload 430.

The frame shown in FIG. 4 may be included in a super-frame.

In this case, the broadcast signal frame may be composed of one or more OFDM symbols. The broadcast signal frame may include a reference symbol or a pilot symbol.

The frame structure to which Layered Division Multiplexing (LDM) is applied includes a bootstrap 410, a preamble 420, and a super-imposed payload 430 as shown in FIG. 4.

In this case, the bootstrap 410 and the preamble 420 may be regarded as hierarchical two preambles.

In this case, the bootstrap 410 may have a length shorter than that of the preamble 420 for fast acquisition and detection. In this case, the bootstrap 410 may have a fixed length. In this case, the bootstrap 410 may include a symbol of a fixed length. For example, the bootstrap 410 may consist of four OFDM symbols each 0.5 ms long and may have a fixed time length of 2 ms in total.

In this case, the bootstrap 410 may have a fixed bandwidth, and the preamble 420 and the super-imposed payload 430 may have a wider and variable bandwidth than the bootstrap 410.

The preamble 420 may transmit detailed signaling information using a robust LDPC code. In this case, the length of the preamble 420 may vary according to the signaling information.

In this case, the bootstrap 410 and the payload 430 may both be seen as corresponding to a common signal shared by several layers.

The super-imposed payload 430 may correspond to a signal in which two or more layer signals are multiplexed. In this case, the super-imposed payload 430 may be a combination of the core layer payload and the enhanced layer payload at different power levels. In this case, an in-band signaling section may be included in the core layer payload. In this case, the in-band signaling unit may include signaling information for the enhanced layer service.

In this case, the bootstrap 410 may include a symbol indicating the structure of the preamble.

At this time, a symbol included in the bootstrap to indicate the structure of the preamble may be set as shown in Table 2 below.

preamble_structure	L1-Basic Mode	FFT Size	GI Length (samples)	Pilot Pattern (D X )
0	L1-Basic Mode 1	8192	2048	3
One	L1-Basic Mode 1	8192	1536	4
2	L1-Basic Mode 1	8192	1024	3
3	L1-Basic Mode 1	8192	768	4
4	L1-Basic Mode 1	16384	4096	3
5	L1-Basic Mode 1	16384	3648	4
6	L1-Basic Mode 1	16384	2432	3
7	L1-Basic Mode 1	16384	1536	4
8	L1-Basic Mode 1	16384	1024	6
9	L1-Basic Mode 1	16384	768	8
10	L1-Basic Mode 1	32768	4864	3
11	L1-Basic Mode 1	32768	3648	3
12	L1-Basic Mode 1	32768	3648	8
13	L1-Basic Mode 1	32768	2432	6
14	L1-Basic Mode 1	32768	1536	8
15	L1-Basic Mode 1	32768	1024	12
16	L1-Basic Mode 1	32768	768	16
17	L1-Basic Mode 2	8192	2048	3
18	L1-Basic Mode 2	8192	1536	4
19	L1-Basic Mode 2	8192	1024	3
20	L1-Basic Mode 2	8192	768	4
21	L1-Basic Mode 2	16384	4096	3
22	L1-Basic Mode 2	16384	3648	4
23	L1-Basic Mode 2	16384	2432	3
24	L1-Basic Mode 2	16384	1536	4
25	L1-Basic Mode 2	16384	1024	6
26	L1-Basic Mode 2	16384	768	8
27	L1-Basic Mode 2	32768	4864	3
28	L1-Basic Mode 2	32768	3648	3
29	L1-Basic Mode 2	32768	3648	8
30	L1-Basic Mode 2	32768	2432	6
31	L1-Basic Mode 2	32768	1536	8
32	L1-Basic Mode 2	32768	1024	12
33	L1-Basic Mode 2	32768	768	16
34	L1-Basic Mode 3	8192	2048	3
35	L1-Basic Mode 3	8192	1536	4
36	L1-Basic Mode 3	8192	1024	3
37	L1-Basic Mode 3	8192	768	4
38	L1-Basic Mode 3	16384	4096	3
39	L1-Basic Mode 3	16384	3648	4
40	L1-Basic Mode 3	16384	2432	3
41	L1-Basic Mode 3	16384	1536	4
42	L1-Basic Mode 3	16384	1024	6
43	L1-Basic Mode 3	16384	768	8
44	L1-Basic Mode 3	32768	4864	3
45	L1-Basic Mode 3	32768	3648	3
46	L1-Basic Mode 3	32768	3648	8
47	L1-Basic Mode 3	32768	2432	6
48	L1-Basic Mode 3	32768	1536	8
49	L1-Basic Mode 3	32768	1024	12
50	L1-Basic Mode 3	32768	768	16
51	L1-Basic Mode 4	8192	2048	3
52	L1-Basic Mode 4	8192	1536	4
53	L1-Basic Mode 4	8192	1024	3
54	L1-Basic Mode 4	8192	768	4
55	L1-Basic Mode 4	16384	4096	3
56	L1-Basic Mode 4	16384	3648	4
57	L1-Basic Mode 4	16384	2432	3
58	L1-Basic Mode 4	16384	1536	4
59	L1-Basic Mode 4	16384	1024	6
60	L1-Basic Mode 4	16384	768	8
61	L1-Basic Mode 4	32768	4864	3
62	L1-Basic Mode 4	32768	3648	3
63	L1-Basic Mode 4	32768	3648	8
64	L1-Basic Mode 4	32768	2432	6
65	L1-Basic Mode 4	32768	1536	8
66	L1-Basic Mode 4	32768	1024	12
67	L1-Basic Mode 4	32768	768	16
68	L1-Basic Mode 5	8192	2048	3
69	L1-Basic Mode 5	8192	1536	4
70	L1-Basic Mode 5	8192	1024	3
71	L1-Basic Mode 5	8192	768	4
72	L1-Basic Mode 5	16384	4096	3
73	L1-Basic Mode 5	16384	3648	4
74	L1-Basic Mode 5	16384	2432	3
75	L1-Basic Mode 5	16384	1536	4
76	L1-Basic Mode 5	16384	1024	6
77	L1-Basic Mode 5	16384	768	8
78	L1-Basic Mode 5	32768	4864	3
79	L1-Basic Mode 5	32768	3648	3
80	L1-Basic Mode 5	32768	3648	8
81	L1-Basic Mode 5	32768	2432	6
82	L1-Basic Mode 5	32768	1536	8
83	L1-Basic Mode 5	32768	1024	12
84	L1-Basic Mode 5	32768	768	16
85	L1-Basic Mode 6	8192	2048	3
86	L1-Basic Mode 6	8192	1536	4
87	L1-Basic Mode 6	8192	1024	3
88	L1-Basic Mode 6	8192	768	4
89	L1-Basic Mode 6	16384	4096	3
90	L1-Basic Mode 6	16384	3648	4
91	L1-Basic Mode 6	16384	2432	3
92	L1-Basic Mode 6	16384	1536	4
93	L1-Basic Mode 6	16384	1024	6
94	L1-Basic Mode 6	16384	768	8
95	L1-Basic Mode 6	32768	4864	3
96	L1-Basic Mode 6	32768	3648	3
97	L1-Basic Mode 6	32768	3648	8
98	L1-Basic Mode 6	32768	2432	6
99	L1-Basic Mode 6	32768	1536	8
100	L1-Basic Mode 6	32768	1024	12
101	L1-Basic Mode 6	32768	768	16
102	L1-Basic Mode 7	8192	2048	3
103	L1-Basic Mode 7	8192	1536	4
104	L1-Basic Mode 7	8192	1024	3
105	L1-Basic Mode 7	8192	768	4
106	L1-Basic Mode 7	16384	4096	3
107	L1-Basic Mode 7	16384	3648	4
108	L1-Basic Mode 7	16384	2432	3
109	L1-Basic Mode 7	16384	1536	4
110	L1-Basic Mode 7	16384	1024	6
111	L1-Basic Mode 7	16384	768	8
112	L1-Basic Mode 7	32768	4864	3
113	L1-Basic Mode 7	32768	3648	3
114	L1-Basic Mode 7	32768	3648	8
115	L1-Basic Mode 7	32768	2432	6
116	L1-Basic Mode 7	32768	1536	8
117	L1-Basic Mode 7	32768	1024	12
118	L1-Basic Mode 7	32768	768	16
119	Reserved	Reserved	Reserved	Reserved
120	Reserved	Reserved	Reserved	Reserved
121	Reserved	Reserved	Reserved	Reserved
122	Reserved	Reserved	Reserved	Reserved
123	Reserved	Reserved	Reserved	Reserved
124	Reserved	Reserved	Reserved	Reserved
125	Reserved	Reserved	Reserved	Reserved
126	Reserved	Reserved	Reserved	Reserved
127	Reserved	Reserved	Reserved	Reserved

For example, to represent the preamble structure shown in Table 2 above, a fixed symbol of 7 bits may be allocated.

L1-Basic Mode 1, L1-Basic Mode 2, and L1-Basic Mode 3 described in Table 2 may correspond to QPSK and 3/15 LDPC.

L1-Basic Mode 4 described in Table 2 may correspond to 16-NUC (Non Uniform Constellation) and 3/15 LDPC.

L1-Basic Mode 5 described in Table 2 may correspond to 64-NUC (Non Uniform Constellation) and 3/15 LDPC.

L1-Basic Mode 6 and L1-Basic Mode 7 described in Table 2 may correspond to 256-NUC (Non Uniform Constellation) and 3/15 LDPC. The modulation method / code rate described below represents a combination of a modulation method and a code rate, such as QPSK and 3/15 LDPC.

The FFT size described in Table 2 may indicate a Fast Fourier Transform size.

The GI length described in Table 2 indicates a guard interval length and may indicate a length of a guard interval rather than data in the time domain. At this time, the longer the guard interval length, the more robust the system is.

The pilot pattern described in Table 2 may indicate the Dx of the pilot pattern. Although not explicitly stated in Table 2, in the examples described in Table 2, all Dy may be 1. For example, Dx = 3 may mean that one of three pilots for channel estimation is included in the x-axis direction. For example, Dy = 1 may mean that a pilot is included every time in the y-axis direction.

As can be seen in the example of Table 2, the preamble structure corresponding to the second modulation method / coding rate, which is stronger than the first modulation method / coding rate, takes precedence over the preamble structure corresponding to the first modulation method / coding rate. Can be assigned to a table.

In this case, the preferential allocation may be stored in the lookup table corresponding to a smaller number of indexes.

In addition, in the same modulation method / code rate, a preamble structure corresponding to a second FFT size smaller than the first FFT size may be allocated to the lookup table in preference to the preamble structure corresponding to the first FFT size.

In addition, in the same modulation method / code rate and FFT size, a preamble structure corresponding to a second guard interval larger than the first guard interval may be allocated to the lookup table in preference to the preamble structure corresponding to the first guard interval.

As shown in Table 2, the preamble structure identification using the bootstrap can be more efficiently performed by setting the order in which the preamble structures are allocated to the lookup table.

FIG. 5 is a diagram illustrating an example of a process of receiving a broadcast signal frame shown in FIG. 4.

Referring to FIG. 5, the bootstrap 510 is detected and demodulated, and the preamble 520 is demodulated using the demodulated information to restore signaling information.

The core layer data 530 is demodulated using the signaling information, and the enhanced 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 more detail later.

6 is a diagram illustrating another example of a process of receiving the broadcast signal frame shown in FIG. 4.

Referring to FIG. 6, the bootstrap 610 is detected and demodulated, and the preamble 620 is demodulated using the demodulated information to restore signaling information.

The core layer data 630 is demodulated using the signaling information. In this case, the in-band signaling unit 650 is included in the core layer data 630. The in-band signaling unit 650 includes signaling information for the enhanced layer service. Through the in-band signaling unit 650, it is possible to use more efficient bandwidth (bandwidth). In this case, the in-band signaling unit 650 may be included in a core layer that is stronger than the enhanced layer.

In the example shown in FIG. 6, basic signaling information and information for core layer service are transmitted through the preamble 620, and signaling information for enhanced layer service is transmitted through the in-band signaling unit 650. Can be.

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

In this case, the signaling information may be L1 (Layer-1) signaling information. The L1 signaling information may include information necessary for configuring physical layer parameters.

Referring to FIG. 4, the broadcast signal frame includes an L1 signaling signal and a data signal. For example, the broadcast signal frame may be an ATSC 3.0 frame.

FIG. 7 is a block diagram illustrating another example of the apparatus for generating broadcast signal frames shown in FIG. 1.

Referring to FIG. 7, it can be seen that the apparatus for generating broadcast signal frames multiplexes data corresponding to N extension layers in addition to the core layer data and the enhanced layer data. .

That is, the apparatus for generating a broadcast signal frame shown in FIG. 7 includes the core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, the power normalizer 345, and the time. In addition to the interleaver 350, the signaling generator 360 and the frame builder 370, the N enhancement layer BICM units 410, ..., 430 and injection level controllers 440, ..., 460 are included. .

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, and the signaling generator illustrated in FIG. 7. 360 and the frame builder 370 have already been described in detail with reference to FIG. 3.

The N enhancement layer BICM units 410, ..., 430 independently perform BICM encoding, and the injection level controllers 440, ..., 460 perform power reducing corresponding to each enhancement layer. The power reduced extended layer signal is combined with other layer signals through the combiner 340.

In this case, the error correction encoder of each of the enhancement layer BICM units 410,..., 430 may be a BCH encoder and an LDPC encoder connected in series.

In particular, the power reduction corresponding to each of the injection level controllers 440,... 460 is preferably greater than the power reduction of the injection level controller 330. That is, the injection level controllers 330, 440,... 460 illustrated in FIG. 7 may correspond to a large power reduction as it descends.

The injection level information provided from the injection level controllers 330, 440, and 460 illustrated in FIG. 7 is included in the broadcast signal frame of the frame builder 370 via the signaling generator 360 and transmitted to the receiver. That is, the injection level of each layer is delivered to the receiver in the L1 signaling information.

In the present invention, the power adjustment may be to increase or decrease the power of the input signal, or may be to increase or decrease the gain of the input signal.

The power normalizer 345 mitigates the power increase caused by combining the plurality of layer signals by the combiner 340.

In the example shown in FIG. 7, the power normalizer 345 may adjust the signal power to an appropriate signal size by multiplying the normalizing factor by the magnitude of the signal combined with the signals of each layer using Equation 4 below. .

[Equation 4]

Normalizing Factor =

The time interleaver 350 performs interleaving on signals combined by the combiner 340, thereby interleaving the signals of the layers.

FIG. 8 is a block diagram illustrating an example of the signal demultiplexing apparatus shown in FIG. 1.

8, a signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, and an enhanced layer symbol extractor 530. A de-injection level controller 1020 and an enhanced layer BICM decoder 540.

In this case, the signal demultiplexing apparatus illustrated in FIG. 8 may correspond to the broadcast signal frame generating apparatus illustrated in FIG. 3.

The time deinterleaver 510 receives a received signal from an OFDM receiver that performs operations such as time / frequency synchronization, channel estimation, and equalization, and a burst error occurred in a channel. Performs operations on distribution In this case, the L1 signaling information may be preferentially decoded in the OFDM receiver and used for data decoding. In particular, the injection level information among the L1 signaling information may be delivered to the de-normalizer 1010 and the de-injection level controller 1020. In this case, the OFDM receiver may decode the received signal in the form of a broadcast signal frame (eg, an ATSC 3.0 frame), extract a data symbol portion of the frame, and provide the same to the time deinterleaver 510. That is, the time deinterleaver 510 performs a deinterleaving process while passing a data symbol to distribute clustering errors occurring in a channel.

At this time, the time deinterleaver 510 may perform an operation corresponding to the time interleaver. In this case, the time deinterleaver 510 may perform deinterleaving in one of a plurality of operation modes, and may perform deinterleaving using time interleaver information signaled in association with an operation of the time interleaver.

The de-normalizer 1010 corresponds to the power normalizer of the transmitter, increasing power by a decrease in the power normalizer. That is, the de-normalizer 1010 divides the received signal by the normalizing factor of Equation 2 above.

In the example shown in FIG. 8, the de-normalizer 1010 is shown to adjust the power of the output signal of the time interleaver 510, but according to an embodiment the de-normalizer 1010 may be a time interleaver 510. It can also be placed in front of to allow power adjustment to be performed before interleaving.

That is, the de-normalizer 1010 may be located in front of or behind the time interleaver 510 to amplify the signal size for LLR calculation of the core layer symbol demapper.

The output of the time deinterleaver 510 (or the output of the de-normalizer 1010) is provided to the core layer BICM decoder 520, and the core layer BICM decoder 520 restores the core layer data.

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 the Log-Likelihood Ratio (LLR) values associated with the symbol, the core layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error, and the core layer error correction decoder Correct.

In this case, the core layer symbol demapper may calculate the LLR value for each bit using a predetermined constellation. In this case, the constellation used in the core layer symbol mapper may be different according to a combination of a code rate and a modulation order used in the transmitter.

At this time, the core layer bit deinterleaver may perform deinterleaving on the calculated LLR values in LDPC codeword units.

In particular, the core layer error correction decoder may output only information bits, or may output all bits in which information bits and parity bits are combined. In this case, the core layer error correction decoder may output only information bits as core layer data, and output all bits in which parity bits are combined to the enhanced layer symbol extractor 530.

The core layer error correction decoder may have a form in which a core layer LDPC decoder and a core layer BCH decoder are connected in series. That is, the input of the core layer error correction decoder is input to the core layer LDPC decoder, the output of the core layer LDPC decoder is input to the core layer BCH decoder, and the output of the core layer BCH decoder is It can be an output. At this time, the LDPC decoder performs LDPC decoding, and the BCH decoder performs BCH decoding.

Further, the enhanced layer error correction decoder may also be in the form of an enhanced layer LDPC decoder and an enhanced layer BCH decoder connected in series. That is, the input of the enhanced layer error correction decoder is input to the enhanced layer LDPC decoder, the output of the enhanced layer LDPC decoder is input to the enhanced layer BCH decoder, and the output of the enhanced layer BCH decoder is enhanced. It can be the output of the layer error correction decoder.

The enhanced layer symbol extractor 530 receives the entire bits from the core layer error correction decoder of the core layer BICM decoder 520 and receives an enhanced layer from the output signal of the time deinterleaver 510 or the de-normalizer 1010. Symbols can be extracted. According to an embodiment, the enhanced layer symbol extractor 530 does not receive the entire bits from the error correction decoder of the core layer BICM decoder 520, receives information bits of the LDPC, or receives BCH information bits. You can be provided.

In this case, the enhanced 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 de-normalizer 1010. The core layer bit interleaver receives the entire 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 subtractor subtracts the output signal of the core layer symbol mapper from the signal stored in the buffer, thereby obtaining the enhanced layer symbol and passing it to the de-injection level controller 1020. In particular, when the LDPC information bits are provided, the enhanced layer symbol extractor 530 may further include a core layer LDPC encoder. In addition, when the BCH information bits are provided, the enhanced layer symbol extractor 530 may further include a core layer BCH encoder as well as a core layer LDPC encoder.

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 enhanced layer symbol extractor 530 may be LDPC encoder, BCH encoder, or bit interleaver of the core layer described with reference to FIG. 3. And symbol mapper.

The de-injection level controller 1020 receives the enhanced layer symbol and increases the power by the power dropped by the injection level controller of the transmitter. That is, the de-injection level controller 1020 amplifies the input signal and provides the amplified signal to the enhanced layer BICM decoder 540. For example, if the transmitter combines the power of the enhanced layer signal by 3 dB less than the power of the core layer signal, the de-injection level controller 1020 serves to increase the power of the input signal by 3 dB.

At this time, the de-injection level controller 1020 may be regarded as multiplying the enhanced layer signal obtained by receiving the injection level information from the OFDM receiver and the enhanced layer gain of Equation 5 below.

[Equation 5]

Enhanced Layer Gain =

The enhanced layer BICM decoder 540 receives the enhanced layer symbol whose power is increased by the de-injection level controller 1020 and restores the enhanced layer data.

In this case, the enhanced layer BICM decoder 540 may include an enhanced layer symbol demapper, an enhanced layer bit deinterleaver, and an enhanced layer error correction decoder. The enhanced layer symbol demapper calculates the Log-Likelihood Ratio (LLR) values associated with the enhanced layer symbol, and the enhanced layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error and decrypts the enhanced layer error correction. The device corrects errors that occur in the channel.

The enhanced layer BICM decoder 540 performs operations similar to the core layer BICM decoder 520, but in general, the enhanced layer LDPC decoder performs LDPC decoding for a code rate of 6/15 or more.

For example, the core layer may use an LDPC code having a code rate of 5/15 or less, and the enhanced layer may use an LDPC code having a code rate of 6/15 or more. At this time, in a reception environment in which enhanced layer data can be decoded, core layer data can be decoded by only a small number of LDPC decoding iterations. Using this property, the receiver hardware can share a single LDPC decoder between the core layer and the enhanced layer to reduce the cost of implementing the hardware. At this time, the core layer LDPC decoder uses only a small amount of time resources (LDPC decoding iterations), and most of the time resources can be used by the enhanced layer LDPC decoder.

The signal demultiplexing apparatus shown in FIG. 8 first restores core layer data, cancels core layer symbols from a received signal symbol to leave only enhanced layer symbols, and then increases power of an enhanced layer symbol to enhance it. Restores the layer data. As described above with reference to FIGS. 3 and 5, since signals corresponding to the respective layers are combined at different power levels, the data having the lowest error may be recovered only from the signal having the strongest power.

As a result, in the example shown in FIG. 8, the signal demultiplexing apparatus includes: a time deinterleaver 510 for generating a time deinterleaving signal by applying time deinterleaving to a received signal; A de-normalizer (1010) for increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; A core layer BICM decoder (520) for recovering core layer data from the signal adjusted by the de-normalizer (1010); Enhanced using the output signal of the core layer FEC decoder of the core layer BICM decoder 520 to perform cancellation corresponding to the core layer data with respect to the signal adjusted by the de-normalizer 1010. An enhanced layer symbol extractor 530 for extracting a layer signal; A de-injection level controller 1020 for raising the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And an enhanced layer BICM decoder 540 for restoring enhanced layer data by using the output signal of the de-injection level controller 1020.

In this case, the enhanced layer symbol extractor may receive the entire codeword from the core layer LDPC decoder of the core layer BICM decoder and may directly bit interleave the entire codeword.

In this case, the enhanced layer symbol extractor may receive information bits from a core layer LDPC decoder of the core layer BICM decoder, perform bit interleaving after performing core layer LDPC encoding on the information bits.

In this case, the enhanced layer symbol extractor may receive information bits from a core layer BCH decoder of the core layer BICM decoder, perform bit interleaving after performing core layer BCH encoding and core layer LDPC encoding.

At this time, the de-normalizer and the de-injection level controller may receive the injection level information IL INFO provided based on the L1 signaling and perform power control based on the injection level information.

In this case, the core layer BICM decoder may have a lower bit rate than the enhanced layer BICM decoder and may be more robust than the enhanced layer BICM decoder.

At this time, the de-normalizer may correspond to the inverse of the normalizing factor.

At this time, the de-injection level controller may correspond to the inverse of the scaling factor.

In this case, the enhanced layer data may be reconstructed based on a cancellation corresponding to reconstruction of the core layer data corresponding to the core layer signal.

In this case, the signal demultiplexing apparatus may include one or more enhancement layer symbol extractors configured to extract an enhancement layer signal by performing cancellation corresponding to previous layer data; One or more extensions that restore one or more enhancement layer data using one or more de-injection level controllers that increase the power of the enhancement layer signal by a power reduction of the injection level controller of the transmitter and the output signals of the one or more de-injection level controllers. It may further include a layer BICM decoder.

The signal demultiplexing method according to an embodiment of the present invention through the configuration shown in FIG. 8 includes: generating a time deinterleaving signal by applying time deinterleaving to a received signal; Increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; Restoring core layer data from the power adjusted signal; Extracting an enhanced layer signal by performing cancellation on the core layer data with respect to the power adjusted signal; Increasing the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And restoring enhanced layer data by using the power-adjusted enhanced layer signal.

In this case, the extracting of the enhanced layer signal may receive the entire codeword from the core layer LDPC decoder of the core layer BICM decoder and directly interleave the entire codeword.

In this case, the extracting of the enhanced layer signal may receive information bits from the core layer LDPC decoder of the core layer BICM decoder, perform bit interleaving after performing core layer LDPC encoding on the information bits.

In this case, the extracting of the enhanced layer signal may receive information bits from the core layer BCH decoder of the core layer BICM decoder, perform bit interleaving after performing the core layer BCH encoding and core layer LDPC encoding. .

FIG. 9 is a block diagram illustrating an example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 8.

Referring to FIG. 9, 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.

That is, in the example shown in FIG. 9, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

In addition, in the example illustrated in FIG. 9, the core layer LDPC decoder provides a whole codeword including parity bits to the enhanced layer symbol extractor 530. That is, in general, the LDPC decoder outputs only information bits of the entire LDPC codeword, but may output the entire codeword.

In this case, since the enhanced layer symbol extractor 530 does not need to include a core layer LDPC encoder or a core layer BCH encoder, the implementation is simple, but there is a possibility that residual errors remain in the LDPC code parity part.

FIG. 10 is a block diagram illustrating another example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 8.

Referring to FIG. 10, 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.

That is, in the example shown in FIG. 10, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

In addition, in the example illustrated in FIG. 10, the core layer LDPC decoder provides information bits that do not include parity bits to the enhanced layer symbol extractor 530.

In this case, the enhanced layer symbol extractor 530 does not need to include a core layer BCH encoder separately, but must include a core layer LDPC encoder.

The example illustrated in FIG. 10 may eliminate residual errors that may remain in the LDPC code parity portion as compared to the example illustrated in FIG. 9.

FIG. 11 is a block diagram illustrating another example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 8.

Referring to FIG. 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.

That is, in the example shown in FIG. 11, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

In the example shown in FIG. 11, the output of the core layer BCH decoder corresponding to the core layer data is provided to the enhanced layer symbol extractor 530.

In this case, since the enhanced layer symbol extractor 530 must include both the core layer LDPC encoder and the core layer BCH encoder, the complexity is high, but the highest performance is guaranteed compared to the examples of FIGS. 9 and 10.

12 is a block diagram illustrating another example of the signal demultiplexing apparatus illustrated in FIG. 1.

Referring to FIG. 12, a signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, and an enhanced layer symbol extractor 530. Enhanced layer BICM decoder 540, one or more enhancement layer symbol extractors 650, 670, one or more enhancement layer BICM decoders 660, 680 and de-injection level controllers 1020, 1150, 1170. Include.

In this case, the signal demultiplexing apparatus illustrated in FIG. 12 may correspond to the broadcast signal frame generating apparatus illustrated in FIG. 7.

The time deinterleaver 510 receives a received signal from an OFDM receiver that performs operations such as synchronization, channel estimation, and equalization, and relates to distribution of burst errors occurring in a channel. Perform the action. In this case, the L1 signaling information may be preferentially decoded in the OFDM receiver and used for data decoding. In particular, the injection level information among the L1 signaling information may be delivered to the de-normalizer 1010 and the de-injection level controllers 1020, 1150, and 1170.

At this time, the de-normalizer 1010 may obtain injection level information of all layers, obtain a de-normalizing factor using Equation 6, and then multiply the input signal.

[Equation 6]

De-Normalizing factor = (Normalizing factor) ^-1 =

That is, the de-normalizing factor is an inverse of the normalizing factor expressed by Equation 4 above.

According to an embodiment, when the N1 signaling includes not only the injection level information but also the normalizing factor information, the de-normalizer 1010 simply takes a reciprocal of the normalizing factor without using the injection level and calculates the inverse of the normalizing factor. Normalizing factor can be obtained.

The de-normalizer 1010 corresponds to the power normalizer of the transmitter, increasing power by a decrease in the power normalizer.

In the example shown in FIG. 12, the de-normalizer 1010 is shown to adjust the power of the output signal of the time interleaver 510, but according to an embodiment the de-normalizer 1010 may be a time interleaver 510. It can also be placed in front of to allow power adjustment to be performed before interleaving.

That is, the de-normalizer 1010 may be located in front of or behind the time interleaver 510 to amplify the signal size for LLR calculation of the core layer symbol demapper.

The output of the time deinterleaver 510 (or the output of the de-normalizer 1010) is provided to the core layer BICM decoder 520, and the core layer BICM decoder 520 restores the core layer data.

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 the Log-Likelihood Ratio (LLR) values associated with the symbol, the core layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error, and the core layer error correction decoder Correct.

In particular, the core layer error correction decoder may output only information bits, or may output all bits in which information bits and parity bits are combined. In this case, the core layer error correction decoder may output only information bits as core layer data, and output all bits in which parity bits are combined to the enhanced layer symbol extractor 530.

The core layer error correction decoder may have a form in which a core layer LDPC decoder and a core layer BCH decoder are connected in series. That is, the input of the core layer error correction decoder is input to the core layer LDPC decoder, the output of the core layer LDPC decoder is input to the core layer BCH decoder, and the output of the core layer BCH decoder is It can be an output. At this time, the LDPC decoder performs LDPC decoding, and the BCH decoder performs BCH decoding.

The enhanced layer error correction decoder may also have a form in which the enhanced layer LDPC decoder and the enhanced layer BCH decoder are connected in series. That is, the input of the enhanced layer error correction decoder is input to the enhanced layer LDPC decoder, the output of the enhanced layer LDPC decoder is input to the enhanced layer BCH decoder, and the output of the enhanced layer BCH decoder is enhanced. It can be the output of the layer error correction decoder.

In addition, the enhancement layer error correction decoder may also have a form in which the enhancement layer LDPC decoder and the enhancement layer BCH decoder are connected in series. That is, the input of the enhancement layer error correction decoder is input to the enhancement layer LDPC decoder, the output of the enhancement layer LDPC decoder is input to the enhancement layer BCH decoder, and the output of the enhancement layer BCH decoder is It can be an output.

In particular, the trade off between implementation complexity and performance depending on which of the outputs of the error correction decoder described with reference to FIGS. 9, 10 and 11 is to be used is the core layer BICM decoder 520 of FIG. In addition to the enhanced layer symbol extractor 530, the enhancement layer symbol extractors 650 and 670 and the enhancement layer BICM decoders 660 and 680 are applied.

The enhanced layer symbol extractor 530 receives the entire bits from the core layer error correction decoder of the core layer BICM decoder 520 and receives an enhanced layer from the output signal of the time deinterleaver 510 or the de-normalizer 1010. Symbols can be extracted. According to an embodiment, the enhanced layer symbol extractor 530 does not receive the entire bits from the error correction decoder of the core layer BICM decoder 520, receives information bits of the LDPC, or receives BCH information bits. You can be provided.

In this case, the enhanced 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 de-normalizer 1010. The core layer bit interleaver receives the entire 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 subtractor subtracts the output signal of the core layer symbol mapper from the signal stored in the buffer, thereby obtaining the enhanced layer symbol and passing it to the de-injection level controller 1020.

In this case, the core layer bit interleaver and the core layer symbol mapper included in the enhanced layer symbol extractor 530 may be the same as the bit interleaver and symbol mapper of the core layer illustrated in FIG. 7.

The de-injection level controller 1020 receives the enhanced layer symbol and increases the power by the power dropped by the injection level controller of the transmitter. That is, the de-injection level controller 1020 amplifies the input signal and provides the amplified signal to the enhanced layer BICM decoder 540.

The enhanced layer BICM decoder 540 receives the enhanced layer symbol whose power is increased by the de-injection level controller 1020 and restores the enhanced layer data.

In this case, the enhanced layer BICM decoder 540 may include an enhanced layer symbol demapper, an enhanced layer bit deinterleaver, and an enhanced layer error correction decoder. The enhanced layer symbol demapper calculates the Log-Likelihood Ratio (LLR) values associated with the enhanced layer symbol, and the enhanced layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error and decrypts the enhanced layer error correction. The device corrects errors that occur in the channel.

In particular, the enhanced layer error correction decoder may output only information bits, or may output all bits in which information bits and parity bits are combined. In this case, the enhanced layer error correction decoder may output only information bits as enhanced layer data, and output all bits in which the parity bits are combined with the information bits to the enhancement layer symbol extractor 650.

The enhancement layer symbol extractor 650 receives the entire bits from the enhanced layer error correction decoder of the enhanced layer BICM decoder 540 and extracts extension layer symbols from the output signal of the de-injection level controller 1020. do.

In this case, the de-injection level controller 1020 may amplify the power of the output signal of the subtractor of the enhanced layer symbol extractor 530.

In this case, the enhancement layer symbol extractor 650 includes a buffer, a subtracter, an enhanced layer symbol mapper, and an enhanced layer bit interleaver. The buffer stores the output signal of the de-injection level controller 1020. The enhanced layer bit interleaver receives the entire bits (information bits + parity bits) of the enhanced layer BICM decoder and performs the same enhanced layer bit interleaving as the transmitter. The enhanced layer symbol mapper generates the same enhanced layer symbol as the transmitter from the interleaved signal. The subtractor subtracts the output signal of the enhanced layer symbol mapper from the signal stored in the buffer, thereby obtaining the enhancement layer symbol and delivering it to the de-injection level controller 1150.

In this case, the enhanced layer bit interleaver and the enhanced layer symbol mapper included in the enhancement layer symbol extractor 650 may be the same as the bit interleaver and the symbol mapper of the enhanced layer shown in FIG. 7.

The de-injection level controller 1150 increases the power by the injection level controller of the layer at the transmitter.

In this case, the de-injection level controller may be regarded as performing an operation of multiplying the enhancement layer gain of Equation 7 below. At this time, the 0 th injection level may be regarded as 0 dB.

[Equation 7]

n-th Extension Layer Gain =

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

In this case, the enhancement layer BICM decoder 660 may include an enhancement layer symbol demapper, an enhancement layer bit deinterleaver, and an enhancement layer error correction decoder. The enhancement layer symbol demapper calculates the Log-Likelihood Ratio (LLR) values associated with the enhancement layer symbol, the enhancement layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error, and the enhancement layer error correction decoder Correct the error.

In particular, two or more enhancement layer symbol extractors and enhancement layer BICM decoders may be provided when there are two or more enhancement layers.

That is, in the example shown in FIG. 12, the enhancement layer error correction decoder of the enhancement layer BICM decoder 660 may output only information bits and output all bits in which the information bits and the parity bits are combined. It may be. In this case, the enhancement layer error correction decoder may output only information bits as enhancement layer data, and output all bits in which parity bits are combined with the information bits to the next enhancement layer symbol extractor 670.

The structure and operation of the enhancement layer symbol extractor 670, the enhancement layer BICM decoder 680, and the de-injection level controller 1170 are described in detail above with the enhancement layer symbol extractor 650, the enhancement layer BICM decoder 660 and de-injection. It can be easily seen from the structure and operation of the level controller 1150.

The de-injection level controllers 1020, 1150, and 1170 shown in FIG. 12 may correspond to a greater power rise as it goes down. That is, the de-injection level controller 1150 increases power more than the de-injection level controller 1020, and the de-injection level controller 1170 increases the power more significantly than the de-injection level controller 1150. You can.

The signal demultiplexing apparatus shown in FIG. 12 first restores core layer data, restores enhanced layer data using cancellation of the core layer symbols, and extends the extended layer data using cancellation of the enhanced layer symbols. It can be seen that the restoration. Two or more enhancement layers may be provided, in which case they are restored from the combined enhancement layers at higher power levels.

13 is a diagram illustrating a power increase due to a combination of a core layer signal and an enhanced layer signal.

Referring to FIG. 13, when a multiplexed signal is generated by combining an enhanced layer signal whose power is reduced by an injection level with a core layer signal, the power level of the multiplexed signal is determined by the core layer signal or the enhanced layer signal. It can be seen that the power level is higher.

In this case, the injection level controlled by the injection level controller shown in FIGS. 3 and 7 may be adjusted in 0.5dB or 1dB intervals from 0dB to 25.0dB. At an injection level of 3.0dB, the power of the enhanced layer signal is 3dB lower than the power of the core layer signal. At an injection level of 10.0 dB, the power of the enhanced layer signal is 10 dB lower than the power of the core layer signal. This relationship may be applied not only between the core layer signal and the enhanced layer signal but also between the enhanced layer signal and the enhancement layer signal or the enhancement layer signals.

The power normalizers shown in FIGS. 3 and 7 may adjust power levels after coupling to solve problems such as distortion of signals that may be caused by power increase due to coupling.

14 is a flowchart illustrating a method of generating a broadcast signal frame according to an embodiment of the present invention.

Referring to FIG. 14, in the broadcast signal frame generation method according to an embodiment of the present invention, BICM is applied to core layer data (S1210).

In addition, the method for generating broadcast signal frame according to an embodiment of the present invention applies BICM to enhanced layer data (S1220).

The BICM applied at step S1220 and the BICM applied at step S1210 may be different. At this time, the BICM applied in step S1220 may be less robust than the BICM applied in step S1210. At this time, the bit rate of the BICM applied in step S1220 may be greater than the bit rate applied in step S1210.

In this case, the enhanced layer signal may correspond to enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

In addition, the broadcast signal frame generation method according to an embodiment of the present invention generates a power reduced enhanced layer signal by reducing the power of the enhanced layer signal (S1230).

At this time, step S1230 may change the injection level in 0.5dB or 1dB interval between 0dB and 25.0dB.

In addition, the broadcast signal frame generation method according to an embodiment of the present invention generates a multiplexed signal by combining the core layer signal and the power reduced enhanced layer signal (S1240).

That is, in step S1240, the core layer signal and the enhanced layer signal are combined at different power levels, but the power layer of the enhanced layer signal is combined to be lower than the power level of the core layer signal.

In this case, in operation S1240, one or more extension layer signals having a lower power level than the core layer signal and the enhanced layer signal may be combined with the core layer signal and the enhanced layer signal.

In addition, the method for generating a broadcast signal frame according to an embodiment of the present invention lowers the power of the signal multiplexed by step S1250 (S1250).

In this case, step S1250 may lower the power of the multiplexed signal by the power of the core layer signal. In this case, step S1250 may lower the power of the multiplexed signal as much as it is increased by step S1240.

In addition, the method for generating a broadcast signal frame according to an embodiment of the present invention generates a time interleaved signal by performing time interleaving applied to both the core layer signal and the enhanced layer signal (S1260).

In this case, step S1260 uses one of the time interleaver groups, and the boundary between the time interleaver groups includes physical layer pipes (PLPs) of the core layer corresponding to the core layer signal. ) May be a boundary between

At this time, step S1260 may perform the interleaving using a hybrid time interleaver. In this case, the physical layer pipes of the core layer and the enhanced layer may include only complete FEC blocks.

In this case, step S1260 performs the interleaving using a convolutional time interleaver, and the time interleaver groups include a physical layer pipe including an incomplete FEC block. Layer Pipe (PLP), and the preamble may signal starting position information of a first complete FEC block in the physical layer pipe.

In this case, step S1260 may be performed using one of a plurality of operation modes.

In this case, the operation modes may include a first mode that omits time interleaving, a second mode that performs convolutional time interleaving, and a third mode that performs hybrid time interleaving. Can be.

In addition, the broadcast signal frame generation method according to an embodiment of the present invention generates a broadcast signal frame including a preamble for signaling time interleaver information corresponding to the interleaving (S1270).

In this case, the time interleaver information may be signaled based on the core layer.

In this case, the preamble is information for identifying a part of the FEC block of the enhanced layer corresponding to the boundary of the time interleaver groups when the boundary of the time interleaver groups does not correspond to the boundary of the FEC blocks of the enhanced layer. May be signaled.

In this case, the information for identifying a part of the FEC block includes start position information of the physical layer pipe of the core layer, start position information of the physical layer pipe of the enhanced layer, modulation information corresponding to the enhanced layer, and the enhancement. It may include any one or more of the FEC type information corresponding to the hard layer.

At this time, the start position information of the physical layer pipe may correspond to the index of the first data cell of the physical layer pipe.

In this case, the modulation information may be signaled only when the FEC type information satisfies a preset condition.

In this case, the enhanced layer signal may correspond to enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

In this case, step S1270 may include generating the bootstrap; Generating the preamble; And generating a super-imposed payload corresponding to the time interleaved signal.

In this case, the preamble may include PLP identification information for identifying physical layer pipes (PLPs); And layer identification information for identifying layers corresponding to hierarchical division.

In this case, PLP identification information and layer identification information may be included in the preamble as separate fields.

In this case, time interleaver information may be selectively included in the preamble according to a result of comparing (IF (j> 0)) the layer identification information with a predetermined value for each of the physical layer pipes.

In this case, the preamble may selectively include injection level information corresponding to the injection level controller according to a result of comparing (IF (j> 0)) the layer identification information with a predetermined value for each of the physical layer pipes. Can be.

In this case, the bootstrap may be shorter than the preamble and have a fixed length.

In this case, the bootstrap may include a symbol indicating a structure of the preamble, and the symbol may correspond to a fixed bit string indicating a combination of a modulation method / coding rate, an FFT size, a guard interval length, and a pilot pattern of the preamble. .

In this case, when the modulation method / code rate is the same, the preamble structure corresponding to the second FFT size smaller than the first FFT size is preferentially allocated to the preamble structure corresponding to the first FFT size, and the modulation is performed. If the method / code rate and the FFT size are the same, the preamble structure corresponding to the second guard interval length greater than the first guard interval length than the preamble structure corresponding to the first guard interval length corresponds to the lookup table to which the priority is assigned. It may be.

In this case, the broadcast signal frame may be an ATSC 3.0 frame.

In this case, the L1 signaling information may include injection level information and / or normalizing factor information.

In this case, the preamble may include type information, start position information, and size information of physical layer pipes.

In this case, the type information may be for identifying any one of a first type corresponding to a non-dispersed physical layer pipe and a second type corresponding to a distributed physical layer pipe.

In this case, an undistributed physical layer pipe may be allocated for contiguous data cell indices, and the distributed physical layer pipe may be composed of two or more subslices.

In this case, type information may be selectively signaled according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

In this case, the type information may be signaled only for the core layer.

At this time, the start position information may be set equal to an index corresponding to the first data cell of the physical layer pipe.

In this case, the start position information may indicate a start position of the physical layer pipe by using a cell addressing scheme.

In this case, starting position information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the size information may be set based on the number of data cells allocated to the physical layer pipe.

In this case, size information may be included in the preamble for each of the physical layer pipes without determining a condition of a conditional statement corresponding to the layer identification information.

In this case, the preamble includes a field indicating a start position of a first complete FEC block corresponding to a current physical layer pipe for the first mode and the second mode. The 3 modes may not include a field indicating the start position of the first FEC block.

In this case, the field indicating the start position of the first FEC block is any one of the first field used in the first mode and the second field used in the second mode, and the first field and the second field have a length. Can be different.

In this case, the length of the second field may be longer than the length of the first field.

In this case, the length of the first field is determined based on the length of the LDPC codeword and the modulation order, and the length of the second field is not only the length and modulation order of the LDPC codeword, but also the depth of the convolutional time interleaver ( depth may be further considered.

In this case, the length of the first field may be 15 bits, and the length of the second field may be 22 bits.

In this case, the first field and the second field may be separately signaled for each of the core layer corresponding to the core layer signal and the enhanced layer corresponding to the enhanced layer signal.

Although not explicitly shown in FIG. 14, the method for generating a broadcast signal frame may further include generating signaling information including injection level information corresponding to step S1230. In this case, the signaling information may be L1 signaling information.

In this case, the injection level information may be signaled using 31 values identified using the 5-bit-field.

In this case, step S1250 corresponds to a normalizing factor that increases as the power decrease corresponding to the power reduced enhanced layer signal increases, and step S1230 corresponds to the power reduced enhanced layer signal. The larger power reduction corresponding to may correspond to a scaling factor that decreases.

At this time, the 31 values may be matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval.

In this case, the first section may correspond to a first rate of change of the scaling factor, and the second section may correspond to a second rate of change that is smaller than the first rate of change of the scaling factor.

In this case, the first section may correspond to a section of 0 dB or more and 5 dB or less, and the second section may correspond to a section of 6 dB or more and 25 dB or less.

In this case, the first step size may be 0.5 dB, and the second step size may be 1 dB.

In this case, the first section may include 5 bit-field values belonging to a section of 0 dB or more and less than 3 dB, and the second section may include 5 bit-field values belonging to a section of more than 10 dB and 25 dB or less.

In this case, the preamble may include layer identification information for identifying layers corresponding to hierarchical division.

In this case, the preamble may selectively include the injection level information according to a result of comparing the layer identification information and a predetermined value with respect to each of the physical layer pipes.

The broadcast signal frame generation method illustrated in FIG. 14 may correspond to step S210 illustrated in FIG. 2.

FIG. 15 is a diagram illustrating a super-frame structure including a broadcast signal frame according to an embodiment of the present invention. FIG.

Referring to FIG. 15, it can be seen that a layered division multiplexing (LDM) based superframe consists of one or more frames, and one frame consists of one or more OFDM symbols.

In this case, each OFDM symbol may start with one or more preamble symbols. In addition, the frame may include a reference symbol or a pilot symbol.

The superframe 1510 illustrated in FIG. 15 includes an LDM frame 1520, a single-layer frame 1530 without LDM, and a future extension frame for future extensibility. It may be configured in a time division multiplexing (TDM) scheme, including a Future Extension Frame (FEF) 1540.

The LDM frame 1520 may include an upper layer (UL) 1553 and a lower layer (LL) 1555 when two layers are applied.

In this case, the upper layer 1553 may correspond to the core layer, and the lower layer 1555 may correspond to the enhanced layer.

In this case, the LDM frame 1520 including the upper layer 1553 and the lower layer 1555 may include a bootstrap 1552 and a preamble 1551.

In this case, the upper layer 1553 data and the lower layer 1555 data may share a time interleaver and use the same frame length and FFT size in order to reduce complexity and memory size.

In addition, the single-layer frame 1530 may also include a bootstrap 1562 and a preamble 1561.

In this case, the single-layer frame 1530 may use a different FFT size, time interleaver, and frame length than the LDM frame 1520. In this case, the single-layer frame 1530 may be considered to be multiplexed with the LDM frame 1520 in a TDM manner within the superframe 1510.

FIG. 16 is a diagram illustrating an example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe (PLP) are applied.

Referring to FIG. 16, it can be seen that the LDM frame starts with a bootstrap signal including version information or general signaling information of the system. After the bootstrap, an L1 signaling signal including a code rate, modulation information, and physical layer pipe number information may be followed as a preamble.

Following the preamble (L1 SIGNAL), a burst of a common physical layer pipe (PLP) may be transmitted. In this case, the common physical layer pipe may transmit data that may be shared with other physical layer pipes in the frame.

After the common physical layer pipe, a multiple-physical layer pipe for servicing different broadcast signals is transmitted in an LDM scheme of two layers. At this time, services that require robust reception such as Indo / Mobile (720p or 1080p HD) are fixed reception services (4K-UHD) requiring high data rates through core layer (upper layer) data physical layer pipes. Or multiple HD, etc.) may be transmitted through enhanced layer (lower layer) data physical layer pipes.

When multiple-physical layer pipes are layer division multiplexed, it can be seen that the total number of multiple-physical layer pipes increases as a result.

In this case, the core layer data physical layer pipe and the enhanced layer data physical layer pipe may share a time interleaver in order to reduce complexity and memory size. At this time, the core layer data physical layer pipe and the enhanced layer data physical layer pipe may have the same physical layer pipe size (PLP size) or may have different physical layer pipe sizes.

According to an embodiment, the physical layer pipes divided into layers may have different PLP sizes, and in this case, signal for identifying a start position of the PLP or a size of the PLP may be signaled.

FIG. 17 illustrates another example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe (PLP) are applied.

Referring to FIG. 17, it can be seen that the LDM frame may include a common physical layer pipe after the bootstrap and preamble (L1 SIGNAL). After the common physical layer pipe, core layer data physical layer pipes and enhanced layer data physical layer pipes may be transmitted in a two-layer LDM manner.

In particular, the core layer data physical layer pipes and the enhanced layer data physical layer pipes illustrated in FIG. 17 may have any one of type 1 and type 2, and type 1 and type 2 may be defined as follows. have.

*-Type 1 PLP

If a common PLP exists, it is sent after the common PLP

Transmitted as a burst in one frame (one slice)

Type 2 PLP

If Type1 PLP is present, it is sent after Type1 PLP

Transmitted in two or more sub-slices within a frame

As the number of sub-slices increases, time diversity increases and has the effect of power consumption.

At this time, the type 1 PLP may correspond to a nun-dispersed PLP, and the type 2 PLP may correspond to a dispersed PLP. In this case, the non-distributed PLP may be assigned to contiguous data cell indices. In this case, the distributed PLPs may be allocated to two or more subslices.

FIG. 18 is a diagram illustrating an example of using an LDM frame to which an LDM using two layers and a multiple-physical layer pipe (PLP) are applied.

Referring to FIG. 18, the LDM frame may include a common physical layer pipe (PLP (1,1)) after bootstrap and preamble, and a data physical layer pipe (PLP (2,1)) for robust audio service. ) May be included in a time-division manner.

In addition, core layer data physical layer pipes (PLP (3,1)) for mobile / indoor services (720p or 1080p HD) and enhanced layer data physical layers for high data rate services (4K-UHD or multiple HD) The pipe PPL (3,2) may be transmitted in a two-layer LDM scheme.

FIG. 19 is a diagram illustrating another application example of an LDM frame to which an LDM using two layers and a multiple-physical layer pipe are applied.

Referring to FIG. 19, an LDM frame may include a bootstrap, a preamble, and a common physical layer pipe (PLP (1,1)). At this time, the robust audio service and the mobile / indoor service (720p or 1080p HD) are divided and transmitted to the core layer data physical layer pipes (PLP (2,1) and PLP (3,1)) and have a high data rate. The service (4K-UHD or multiple HD) may be transmitted by enhanced layer data physical layer pipes (PLP (2,2), PLP (3,2)).

At this time, the core layer data physical layer pipe and the enhanced layer data physical layer pipe may use the same time interleaver.

In this case, the physical layer pipes PPL (2,2) and PLP (3,2) providing the same service may signal that the same service is provided using PLP_GROUP_ID representing the same PLP group.

According to an embodiment, when physical layer pipes of different sizes are used for each LDM layer, a service may be identified according to the start position and size of each of the physical layer pipes without PLP_GROUP_ID.

In FIG. 18 and FIG. 19, a case in which layers corresponding to multiple physical layer pipes and layer division multiplexing are identified by PLP (i, j) is illustrated as an example. However, PLP identification information and layer identification information are signaled in separate fields. May be

According to an embodiment, different sizes of PLPs may be used for each layer. In this case, each service may be identified through a PLP identifier.

When PLPs having different sizes are used for each layer, the PLP start position and the PLP length may be signaled for each PLP.

The following code illustrates an example of fields included in a preamble according to an embodiment of the present invention. In this case, the following pseudo code may be included in the L1 signaling information of the preamble.

[Capital Code]

SUB_SLICES_PER_FRAME (15 bits)

NUM_PLP (8 bits)

NUM_AUX (4 bits)

AUX_CONFIG_RFU (8 bits)

for i = 0 .. NUM_RF-1 {

RF_IDX (3 bits)

FREQUENCY (32 bits)

}

IF S2 == 'xxx1' {

FEF_TYPE (4 bits)

FEF_LENGTH (22 bits)

FEF_INTERVAL (8 bits)

}

for i = 0 .. NUM_PLP-1 {

NUM_LAYER (2 ~ 3 bits)

  for j = 0 .. NUM_LAYER-1 {

  / * Signaling for each layer * /

  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)

  STATIC_PADDING_FLAG (1 bit)

  IF (j> 0)

    LL_INJECTION_LEVEL (3 ~ 8 bits)

  } / * End of NUM_LAYER loop * /

/ * Common signaling for all layers * /

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)

PLP_START (24 bits)

PLP_SIZE (24 bits)

} / * End of NUM_PLP loop * /

FEF_LENGTH_MSB (2 bits)

RESERVED_2 (30 bits)

for i = 0 .. NUM_AUX-1 {

AUX_STREAM_TYPE (4 bits)

AUX_PRIVATE_CONF (28 bits)

}

In the pseudo code, NUM_LAYER may consist of 2 bits or 3 bits. In this case, NUM_LAYER may be a field used to indicate the number of layers in each PLP divided in time. In this case, NUM_LAYER may have a different number of layers for each PLP defined in the NUM_PLP loop and partitioned in time.

In the pseudo code, LL_INJECTION_LEVEL may be configured with 3 to 8 bits. In this case, LL_INJECTION_LEVEL may be a field for defining an injection level of a lower layer (enhanced layer). In this case, LL_INJECTION_LEVEL may correspond to the injection level information.

In this case, LL_INJECTION_LEVEL may be defined from the second layer (j> 0) when there are two or more layers.

Each of PLP_ID (i, j), PLP_GROUP_ID, PLP_TYPE, PLP_PAYLOAD_TYPE, PLP_COD, PLP_MOD, PLP_SSD, PLP_FEC_TYPE, PLP_NUM_BLOCKS_MAX, IN_BAND_A_FLAG, IN_BAND_B_FLAG, PLP_MODE, and _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ s Can be.

In this case, PLP_ID (i, j) may correspond to PLP identification information and layer identification information. For example, i of PLP_ID (i, j) may correspond to PLP identification information and j may correspond to layer identification information.

According to an embodiment, the PLP identification information and the layer identification information may be included in the preamble as separate fields.

In addition, fields such as time interleaver information such as TIME_IL_LENGTH or TIME_IL_TYPE or FRAME_INTERVAL related to PLP size, FF_FLAG, FIRST_RF_IDX, FIRST_FRAME_IDX, RESERVED_1, STATIC_FLAG, etc. may be defined in the NUM_PLP loop.

In particular, PLP_TYPE indicates the type information of the above-described physical layer pipes, and may be configured as 1 bit because both of the first type and the second type need to be identified. In the pseudo code, the example in which the PLP_TYPE is included in the preamble without judging a conditional statement corresponding to the layer identification information j has been described. However, the PLP_TYPE is a result of comparing the layer identification information j with a preset value (if) (if). (j = 0)) may optionally be signaled (transmitted only for core layer).

In the pseudo code, the PLP_TYPE is defined in the NUM_LAYER loop as an example. However, in some embodiments, the PLP_TYPE may be defined outside the NUM_LAYER loop and in the NUM_PLP loop.

In the pseudo code, PLP_START indicates a start position of a corresponding physical layer pipe. In this case, PLP_START may indicate a start position using a cell addressing scheme. In this case, PLP_START may be an index corresponding to the first data cell of the corresponding PLP.

In particular, PLP_START may be signaled for each of all physical layer pipes and may be used for service identification using multiple-physical layer pipes along with a field signaling the size of a PLP according to an embodiment.

In the pseudo code, PLP_SIZE is size information of physical layer pipes. At this time, PLP_SIZE may be set equal to the number of data cells allocated to the corresponding physical layer pipe.

That is, in the pseudo code, PLP_TYPE may be signaled in consideration of layer identification information, and PLP_SIZE and PLP_START may be signaled for all physical layer pipes regardless of layer identification information.

The combiner 340 shown in FIGS. 3 and 7 functions to combine the core layer signal and the enhanced layer signal, and since the core layer signal and the enhanced layer signal share one time interleaver, the core layer signal And combining may be performed in units of a time interleaver group shared with the enhanced layer signal.

At this time, it is advantageous in terms of memory efficiency or system efficiency that the time interleaver group is set based on the core layer.

However, when the time interleaver group is set based on the core layer, there may be an FEC block divided into the time interleaver group boundary in the enhanced layer. Signaling of the fields needed to identify the portion of the corresponding FEC block may be needed.

The time interleaver used for layer division multiplexing may be a convolutional time interleaver (CTI) or a hybrid time interleaver (HTI). In this case, the convolutional time interleaver may be used when there is only one physical layer pipe of the core layer, and when there is more than one physical layer pipe of the core layer, the hybrid time interleaver may be used. If a hybrid time interleaver is used, the physical layer pipe may contain only complete FEC blocks.

20 illustrates an example of a case where a convolutional time interleaver is used.

Referring to FIG. 20, it can be seen that a subframe includes two layers of a core layer and an enhanced layer.

In the example shown in FIG. 20, since the subframe includes only one physical layer pipe (PLP # 0) in the core layer, the time interleaver corresponding to the subframe is a convolutional time interleaver. When the convolutional time interleaver is used, the physical layer pipe of each layer may include an incomplete FEC block.

Such an incomplete FEC block may be identified using a field such as "L1D_plp_CTI_fec_block_start" which is located at the edge of the PLP and indicates the position of the first complete FEC block in each PLP.

The example shown in FIG. 20 is a case where the start positions and sizes of the physical layer pipe PPL # 0 of the core layer and the physical layer pipe PLP # 1 of the enhanced layer are the same.

In the example shown in FIG. 20, it can be seen that the time interleaver group TI group corresponds to the physical layer pipe PPL # 0 of the core layer. The time interleaver group is commonly applied to the core layer and the enhanced layer. The time interleaver group is set to correspond to the core layer in terms of memory and system efficiency.

21 is a diagram illustrating another example when a convolutional time interleaver is used.

Referring to FIG. 21, it can be seen that starting positions and sizes of the core layer physical layer pipe PPL # 0 and the enhanced layer physical layer pipe PLP # 1 are different.

As such, when the start positions and sizes of the core layer physical layer pipe PPL # 0 and the enhanced layer physical layer pipe PLP # 1 are different from each other, an empty area may be included in the enhanced layer.

As shown in FIG. 21, when a blank area is included at the rear end of the enhanced layer physical layer pipe PPL # 1, the enhanced layer physical layer pipe PPL # 1 ends with a complete FEC block.

22 is a diagram illustrating an example of a case where a hybrid time interleaver is used.

Referring to FIG. 22, it can be seen that two physical layer pipes PLP # 0 and PLP # 1 are included in the core layer.

As such, when the core layer consists of multiple physical layer pipes, a hybrid time interleaver is used.

When a hybrid time interleaver is used, all physical layer pipes of the core layer and the enhanced layer contain only complete FEC blocks.

At this time, some parts of the enhanced layer may be empty for alignment with the core layer boundary.

FIG. 23 is a diagram illustrating a time interleaver group in the example shown in FIG. 22.

Referring to FIG. 23, it can be seen that a time interleaver group boundary is set corresponding to a boundary of physical layer pipes of a core layer.

In FIG. 23, the time interleaver group includes only one core layer physical layer pipe. However, according to an embodiment, the time interleaver group may include two or more core layer physical pipes.

In the example shown in FIG. 23, in the case of an enhanced layer, one FEC block may be divided by a time interleaver group boundary.

This is because time interleaver group splitting is performed on a core layer basis. In this case, information for identifying an incomplete FEC block of an enhanced layer corresponding to a time interleaver group boundary may be signaled.

24 to 26 illustrate a process of calculating the size of an incomplete FEC block in the example shown in FIG. 23.

Referring to FIG. 24, the start position of the physical layer pipe of the core layer (L1D_plp_start (PLP # 0)), the size of the physical layer pipe of the core layer (L1D_plp_size (PLP # 0)), and the start of the physical layer pipe of the enhanced layer The distance A between the start position L1D_plp_start (PLP # 2) of the enhanced layer physical layer pipe and the time interleaver group boundary may be calculated using the position L1D_plp_start (PLP # 2).

Referring to FIG. 25, it can be seen that the distance B between the start position of the divided FEC block and the time interleaver group boundary is calculated using the FEC block size of the enhanced layer.

In this case, the FEC block size may be determined using modulation information L1D_plp_mod corresponding to the enhanced layer and FEC type information L1D_plp_fec_type corresponding to the enhanced layer.

Referring to FIG. 26, it can be seen that a portion C of the FEC block of the enhanced layer corresponding to the boundary of the time interleaver groups is identified.

Table 3 below shows an example of L1-Detail fields of a preamble according to an embodiment of the present invention.

The preamble according to an embodiment of the present invention may include L1-Basic and L1-Detail.

Syntax	# of bits
L1_Detail_signaling () {
L1D_version	4
L1D_num_rf	3
for L1D_rf_id = 1 .. L1D_num_rf {
L1D_rf_frequency	19
}
if (L1B_time_info_flag! = 00) {
L1D_time_sec	32
L1D_time_msec	10
if (L1B_time_info_flag! = 01) {
L1D_time_usec	10
if (L1B_time_info_flag! = 10) {
L1D_time_nsec	10
}
}
}
for i = 0 .. L1B_num_subframes {
if (i> 0) {
L1D_mimo	One
L1D_miso	2
L1D_fft_size	2
L1D_reduced_carriers	3
L1D_guard_interval	4
L1D_num_ofdm_symbols	11
L1D_scattered_pilot_pattern	5
L1D_scattered_pilot_boost	3
L1D_sbs_first	One
L1D_sbs_last	One
}
if (L1B_num_subframes> 0) {
L1D_subframe_multiplex	One
}
L1D_frequency_interleaver	One
L1D_num_plp	6
for j = 0 .. L1D_num_plp {
L1D_plp_id	6
L1D_plp_lls_flag	One
L1D_plp_layer	2
L1D_plp_start	24
L1D_plp_size	24
L1D_plp_scrambler_type	2
L1D_plp_fec_type	4
if (L1D_plp_fec_type ∈ {0,1,2,3,4,5}) {
L1D_plp_mod	4
L1D_plp_cod	4
}
L1D_plp_TI_mode	2
if (L1D_plp_TI_mode = 00) {
L1D_plp_fec_block_start	15
}
if (L1D_plp_TI_mode = 01) {
L1D_plp_CTI_fec_block_start	22
}
if (L1D_num_rf> 0) {
L1D_plp_num_channel_bonded	3
if (L1D_plp_num_channel_bonded> 0) {
L1D_plp_channel_bonding_format	2
for k = 0 .. L1D_plp_num_channel_bonded {
L1D_plp_bonded_rf_id	3
}
}
}
if (i = 0 && L1B_first_sub_mimo = 1) || (i> 1 && L1D_mimo = 1) {
L1D_plp_stream_combining	One
L1D_plp_IQ_interleaving	One
L1D_plp_PH	One
}
if (L1D_plp_layer = 0) {
L1D_plp_type	One
if L1D_plp_type = 1 {
L1D_plp_num_subslices	14
L1D_plp_subslice_interval	24
}
L1D_plp_TI_extended_interleaving	One
if (L1D_plp_TI_mode = 01) {
L1D_plp_CTI_depth	3
L1D_plp_CTI_start_row	11
} else if (L1D_plp_TI_mode = 10) {
L1D_plp_HTI_inter_subframe	One
L1D_plp_HTI_num_ti_blocks	4
L1D_plp_HTI_num_fec_blocks_max	12
if (L1D_plp_HTI_inter_subframe = 0) {
L1D_plp_HTI_num_fec_blocks	12
} else {
for (k = 0 .. L1D_plp_HTI_num_ti_blocks) {
L1D_plp_HTI_num_fec_blocks	12
}
}
L1D_plp_HTI_cell_interleaver	One
}
} else {
L1D_plp_ldm_injection_level	5
}
}
}
L1D_reserved	as needed
L1D_crc	32
}

In Table 3, all bits to which a bit is allocated may correspond to an Unsigned integer most significant bit first (uimsbf) format.

Among the fields described in Table 3, L1D_plp_layer may indicate a layer corresponding to each physical layer pipe. L1D_plp_start corresponds to starting position information of the current physical layer pipe (current PLP) and may indicate an index of the first data cell of the current physical layer pipe. L1D_plp_size corresponds to size information of the current physical layer pipe and may indicate the number of data cells allocated to the current physical layer pipe.

L1D_plp_fec_type corresponds to FEC type information of the current physical layer pipe and may indicate a Forward Error Correction (FEC) method used to encode the current physical layer pipe.

For example, L1D_plp_fec_type = "0000" corresponds to BCH and 16200 LDPC, L1D_plp_fec_type = "0001" corresponds to BCH and 64800 LDPC, L1D_plp_fec_type = "0010" corresponds to CRC and 16200 LDPC, and L1D_plp_fec_type = "0011 "Corresponds to CRC and 64800 LDPC, L1D_plp_fec_type =" 0100 "corresponds to 16200 LDPC, and L1D_plp_fec_type =" 0101 "may correspond to 64800 LDPC.

L1D_plp_mod may indicate modulation information of the current physical layer pipe. At this time, L1D_plp_mod may be signaled only when L1D_plp_fec_type satisfies a predetermined condition as shown in Table 3 above.

For example, L1D_plp_mod = "0000" corresponds to QPSK, L1D_plp_mod = "0001" corresponds to 16QAM-NUC, L1D_plp_mod = "0010" corresponds to 64QAM-NUC, and L1D_plp_mod = "0011" is 256QAM-NUC And L1D_plp_mod = "0100" may correspond to 1024QAM-NUC, and L1D_plp_mod = "0101" may correspond to 4096QAM-NUM. At this time, L1D_plp_mod may be set to "0100" or "0101" only when L1D_plp_fec_type corresponds to 64800 LDPC.

L1D_plp_TI_mode indicates a time interleaving mode of the PLP.

For example, L1D_plp_TI_mode = "00" may indicate a mode that does not use time interleaver, L1D_plp_TI_mode = "01" may indicate a convolutional time interleaving mode, and L1D_plp_TI_mode = "10" may indicate a hybrid time interleaving mode.

L1D_plp_fec_block_start may correspond to start position information of the first complete FEC block in the physical layer pipe. L1D_plp_fec_block_start may be signaled only when L1D_plp_TI_mode = "00".

When layered division multiplexing is used, L1D_plp_fec_block_start may be signaled for each layer since the start position of the first FEC block in each layer may be different.

L1D_plp_CTI_fec_block_start may correspond to start position information of the first complete block in the physical layer pipe. L1D_plp_CTI_fec_block_start may be signaled only when L1D_plp_TI_mode = "01".

At this time, more bits may be allocated to L1D_plp_CTI_fec_block_start than to L1D_plp_fec_block_start.

As described above, when L1D_plp_TI_mode = "10", since all PLPs include only complete FEC blocks, there is no need to separately signal the start position of the first FEC block.

L1D_plp_HTI_num_fec_blocks may correspond to the number of FEC blocks included in the current interleaving frame for the physical layer pipe of the core layer.

In this case, when the L1D_plp_layer is 0 (core layer), the time interleaver information corresponds to fields L1D_plp_CTI_depth, L1D_plp_CTI_start_row, and hybrid time interleaving according to whether L1D_plp_TI_mode is 01 or 10, respectively. (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.) may be signaled as time interleaver information.

In this case, L1D_plp_CTI_depth may indicate the number of rows used in the convolutional time interleaver, and L1D_plp_CTI_start_row may indicate the position of the interleaver selector at the start of the subframe.

At this time, L1D_plp_HTI_inter_subframe represents a hybrid time interleaving mode, L1D_plp_HTI_num_ti_blocks represents the number of TI blocks per interleaving frame or the number of subframes in which cells from one TI block are transmitted, and L1D_plp_HTI_num_fec_blocks_max of the current physical layer pipe EC of the current physical layer pipe per frame L1D_plp_HTI_num_fec_blocks represents the maximum number of subtracted from 1, L1D_plp_HTI_num_fec_blocks represents subtracting 1 from the number of FEC blocks included in the current interleaving frame of the current physical layer pipe, and L1D_plp_HTI_cell_interleaver may represent whether a cell interleaver is used.

In this case, a field such as L1D_plp_TI_mode may be signaled separately from time interleaver information signaled based on the core layer.

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

Referring to FIG. 27, when L1D_plp_TI_mode = "00" (time interleaving is omitted), the cell address of the FEC block start position before time interleaving (C_in) and the time before the time interleaving are performed. It can be seen that the cell address of the FEC block start position after interleaving (C_out) is the same.

As shown in FIG. 27, when time interleaving is omitted, convolutional interleaving may be performed with a depth of 0.

At this time, since L1D_plp_fec_block_start is defined after time interleaving, C_out may be signaled for each physical layer pipe in the subframe as L1D_plp_fec_block_start.

If the LDPC codeword is 16200 or 64800 and the modulation order is 2, 4, 6, 8, 10 and 12, the longest FEC block may have a length of 64800/2 = 32400.

Since 32400 can be represented by 15 bits, when 15 bits are allocated to L1D_plp_fec_block_start, the case of L1D_plp_TI_mode = "00" can be covered.

28 and 29 are diagrams for describing the number of bits required for L1D_plp_CTI_fec_block_start when L1D_plp_TI_mode = "01".

Referring to FIG. 28, when L1D_plp_TI_mode = "01" (convolutional time interleaving), a cell address of FEC block start position before time interleaving (C_in) and time interleaving before time interleaving It can be seen that the cell address of the FEC block start position after time interleaving (C_out) is changed by interleaving.

At this time, since L1D_plp_CTI_fec_block_start is defined after time interleaving, C_out may be signaled for each physical layer pipe in the subframe as L1D_plp_CTI_fec_block_start.

Referring to FIG. 29, it can be seen that a convolutional time interleaver having a depth of 4 operates C_in as an input and C_out as an output.

In this case, for input, 0 corresponds to the 0th row, 1 corresponds to the 1st row, 2 corresponds to the 2nd row, 3 corresponds to the 3rd row, 4 corresponds to the 0th row, , 5 corresponds to the 1st row, 6 corresponds to the 2nd row, 7 corresponds to the 3rd row, 8 corresponds to the 0th row, 9 corresponds to the 1st row, 10 corresponds to the 2nd row Corresponds to the row.

First, in the case of 0, 4, 8, etc. corresponding to the 0th row, the output is immediately performed without delay.

In the case of 1, 5, 9, etc. corresponding to the first row, the output is delayed by 4.

In the case of 2, 6, 10, etc. corresponding to the second row, the output is delayed by 8.

In the case of 3, 7, etc. corresponding to the third row, the output is delayed by 12.

That is, it can be seen that delays of (n × 4) occur for the nth row.

In FIG. 29, the case where the depth is 4 (the row of the time interleaver is 4) is taken as an example. However, if the row of the time interleaver is N_row, the input corresponding to the n th row is delayed by (n x N_row).

At this time, the cell address L1D_plp_CTI_fec_block_start of the FEC block start position after time interleaving may be calculated as (C_in + (n x N_row)). In this case, n is a row corresponding to C_in and may be determined by L1D_CTI_start_row among time interleaving information signaled by L1-Detail. In this case, n may be ((L1D_CTI_start_row + C_in)% N_row). In this case, L1D_CTI_start_row may indicate the position of the interleaver selector at the start of the subframe.

That is, L1D_plp_CTI_fec_block_start may be calculated by adding delay caused by time interleaving to C_in.

To calculate the number of bits necessary to signal L1D_plp_CTI_fec_block_start, the maximum value of L1D_plp_CTI_fec_block_start is required. As described above, the maximum value of C_in may be 32400, the maximum value of n may be N_row-1, and N_row may be up to 1024 in the case of non-extended interleaving. At this time, the maximum value of L1D_plp_CTI_fec_block_start is (32400 + (1024-1) x1024) = 1079952. 1079952 requires at least 21 bits to be signaled.

N_row may be up to 1448 in the case of extended interleaving. At this time, the maximum value of L1D_plp_CTI_fec_block_start is (32400 + (1448-1) x1448) = 2127656. 2127656 requires at least 22 bits to signal.

After all, when L1D_plp_TI_mode = "00", the maximum value of L1D_plp_fec_block_start is equal to the maximum value of C_in, and when L1D_plp_TI_mode = "01", the maximum value of L1D_plp CTI_fec_block_start is delayed due to interleaving to the maximum value of C_in. The number of bits used for signaling L1D_plp CTI_fec_block_start is larger than the number of bits used for signaling the C-subframe.

If L1D_plp_TI_mode = "10", all physical layer pipes of the core layer and the enhanced layer can contain only intact FEC blocks, so the starting position of all physical layer pipes is the starting position of the first intact FEC block. It is not necessary to signal a field such as L1D_plp_fec_block_start or L1D_plp CTI_fec_block_start.

	Data rate	Modcod	SNR before LDM	SNR after LDM (injection level = 4 dB)
Core layer	2.7 Mbps	QPSK & 4/15	-2.9 dB	-0.5 dB
Enhanced Layer	20.5 Mbps	64QAM & 10/15	12.9 dB	18.4 dB

Table 4 shows an example of a case where a more robust mobile / indoor service is used for the core layer and a less robust fixed service is used for the enhanced layer. .

30 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 4;

In the example shown in Table 4 and FIG. 30, the core layer signal is more robust than the enhanced layer signal, and the injection level may be determined in a range of about 3 dB to 10 dB.

	Data rate	Modcod	SNR before LDM	SNR after LDM (injection level = 19 dB)
Core layer	22.0 Mbps	256QAM & 8/15	13.9 dB	15.5 dB
Enhanced Layer	2.7 Mbps	QPSK & 4/15	-2.7 dB	16.3 dB

Table 5 shows that for LDM-based local services, a less robust fixed service is used at the core layer and a more robust local service at the enhanced layer. The table which shows the example in the case of being used.

FIG. 31 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 5. FIG.

In the example shown in Table 5 and FIG. 31, the core layer is used for digital TV broadcasting, and the enhanced layer is a local service (eg, local advertising, non-real) capable of transmitting different content from each region's transmitter. time service, etc.).

Since the enhanced layer operates in a negative SNR, seamless switching between local services may be possible in an area where signals of different local services overlap, such as cloud transmission.

In this case, an injection level larger than the operating SNR of the core layer may be required for decoding of the core layer.

In this case, an injection level of about 10 dB to 25 dB may be required for the enhanced layer and the core layer to have the same coverage.

	Data rate	Modcod	SNR before LDM	SNR after LDM (injection level = 19 dB)
Core Layer # 1	16.4 Mbps 1.9 Mbps	256QAM & 8 / 15QPSK & 11/15	13.9 dB3.4 dB	15.5 dB3.5 dB
Enhanced Layer	2.7 Mbps	QPSK & 4/15	-2.7 dB	16.3 dB

Table 6 shows less robust fixed and mobile services at the core layer and more robust local services at the enhanced layer for LDM-based local services. table shows an example of using service).

32 is a diagram illustrating a core layer signal and an enhanced layer signal in the example of Table 6. FIG.

In the example shown in Table 6 and FIG. 32, the fixed service and the mobile service may be multiplexed by the TDM scheme and transmitted to the core layer.

In this case, an injection level larger than the operating SNR of the core layer may be required for decoding the core layer, and an injection level of about 10 dB to 25 dB may be required to have the same coverage of the enhanced layer and the core layer.

	Data rate	Modcod	SNR after LDM (injection level = 4 dB)	SNR after LDM (injection level = 1 dB)
Core layer	2.7 Mbps	QPSK & 4/15	-0.5 dB	1.9 dB
Enhanced Layer	24.4 Mbps	256QAM & 9/15	21.0 dB	19.1 dB

Table 7 is a table showing an example of serving a high data rate 4K-UHD to the enhanced layer in the LDM-based service.

If a data rate of about 25 Mbps is required in the enhanced layer, an SNR of 20 dB or more is required for the enhanced layer if an injection level of 4 dB is applied.

Therefore, if the LDM injection level can be 0 to 3dB, even when such a high data rate service is applied, the SNR required for the enhanced layer can be lowered to 20 dB or less.

33 is a graph illustrating a scaling factor according to a change in an LDM injection level value (dB).

Referring to FIG. 33, it can be seen that the scaling factor changes abruptly in a 0 to 5 dB range, and changes relatively slowly in a 5 dB to 25 dB range. In this case, the scaling factor may indicate a linear scale value of the enhanced layer signal to be inserted.

Therefore, a more detailed step size (0.5 dB) may be required in the 0 to 5 dB range, and a less detailed step size (1 dB) may be necessary in the 5 dB to 25 dB range.

Value	Injection level [dB]
00000	0.0
00001	0.5
00010	1.0
00011	1.5
00100	2.0
00101	2.5
00110	3.0
00111	3.5
01000	4.0
01001	4.5
01010	5.0
01011	6.0
01100	7.0
01101	8.0
01110	9.0
01111	10.0
10000	11.0
10001	12.0
10010	13.0
10011	14.0
10100	15.0
10101	16.0
10110	17.0
10111	18.0
11000	19.0
11001	20.0
11010	21.0
11011	22.0
11100	23.0
11101	24.0
11110	25.0
11111	Reserved

Table 8 shows an example of the correspondence relationship between the 5-bit field values and the injection level information.

The example in Table 8 contains 5 bit-field values corresponding to injection level information (0.0 dB, 0.5 dB, 1.0 dB, 1.5 dB, 2.0 dB, 2.5 dB) of less than 3.0 dB, and injection levels greater than 10 dB. Information (11 dB, 12 dB, 13 dB, 14 dB, 15 dB, 16 dB, 17 dB, 18 dB, 19 dB, 20 dB, 21 dB, 22 dB, 23 dB, 24 dB, 25 dB). In this case, the injection level information of less than 3.0dB may be for extending coverage of the enhanced layer service as described through Table 7 above. In this case, injection level information exceeding 10dB may be for implementing an LDM based local service as described with reference to Tables 5 and 6 and FIGS. 31 and 32.

Furthermore, Table 8 shows the change in units of 0.5 dB step size in the range of 0.0 dB to 5 dB (first section), and in the unit of 1.0 dB step size in the range of 6 dB (or 5 dB) to 25 dB (second section). Able to know. As such, by including two sections having different step sizes, the corresponding relationship as shown in Table 8 may properly reflect the change in the scaling factor.

As described above, the apparatus and method for generating a broadcast signal frame according to the present invention is not limited to the configuration and method of the embodiments described as described above, but the embodiments may be modified in various ways. All or some of these may optionally be combined.

Claims (20)

1. An injection level controller for reducing the power of the enhanced layer signal to generate a power reduced enhanced layer signal;

   A combiner for combining a core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal;

   A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal;

   A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And

   And a frame builder for generating a broadcast signal frame including a preamble for signaling injection level information corresponding to the injection level controller.
2. The method according to claim 1,

   The injection level information

   And signaling using 31 values identified using a 5-bit-field.
3. The method according to claim 2,

   The power normalizer corresponds to a normalizing factor that increases as the power reduction corresponding to the injection level controller increases, and the injection level controller corresponds to a scaling factor that decreases as the power reduction corresponding to the injection level controller increases. Broadcast signal frame generating apparatus, characterized in that.
4. The method according to claim 3,

   The 31 values are matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval. Frame generation device.
5. The method according to claim 4,

   And the first section corresponds to a first rate of change of the scaling factor, and the second section corresponds to a second rate of change less than the first rate of change of the scaling factor.
6. The method according to claim 4,

   The first section corresponds to a section of 0dB or more and 5dB or less, and the second section corresponds to a section of 6dB or more and 25dB or less.
7. The method according to claim 6,

   And the first step size is 0.5 dB and the second step size is 1 dB.
8. The method according to claim 7,

   And the first section includes five bit-field values belonging to a section that is greater than or equal to 0 dB and less than 3 dB, and the second section comprises five bit field values belonging to a section that is greater than 10 dB and less than or equal to 25 dB. .
9. The method according to claim 8,

   And the preamble includes layer identification information for identifying layers corresponding to hierarchical division.
10. The method according to claim 9,

    The preamble is

    And the injection level information is selectively included in the physical layer pipes according to a result of comparing the layer identification information with a preset value.
11. Reducing the power of the enhanced layer signal to generate a power reduced enhanced layer signal;

    Combining a core layer signal and the power reduced enhanced layer signal to produce a multiplexed signal;

    Lowering the power of the multiplexed signal to a power corresponding to the core layer signal;

    Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And

    Generating a broadcast signal signal frame including a preamble for signaling injection level information corresponding to the power reduced enhanced layer signal.
12. The method according to claim 11,

    The injection level information

    And signaling using 31 values identified using a 5-bit-field.
13. The method according to claim 12,

    The step of lowering the power corresponding to the core layer signal corresponds to a normalizing factor that increases as the power decrease corresponding to the power reduced enhanced layer signal increases, and decreases the power reduced enhanced layer signal. The generating step corresponds to a scaling factor that decreases as the power reduction corresponding to the power reduced enhanced layer signal increases.
14. The method according to claim 13,

    The 31 values are matched with 5-bit field values in any one of a first section corresponding to a first step size and a second section corresponding to a second step size different from the first interval. How to create a frame.
15. The method according to claim 14,

    And wherein the first period corresponds to a first rate of change of the scaling factor, and the second period corresponds to a second rate of change that is less than the first rate of change of the scaling factor.
16. The method according to claim 14,

    The first section corresponds to a section of 0dB or more and 5dB or less, and the second section corresponds to a section of 6dB or more and 25dB or less.
17. The method according to claim 16,

    And the first step size is 0.5 dB and the second step size is 1 dB.
18. The method according to claim 17,

    Wherein the first section includes five bit-field values belonging to a section that is greater than or equal to 0 dB and less than 3 dB, and the second section comprises five bit-field values belonging to a section that is greater than 10 dB and less than or equal to 25 dB. .
19. The method according to claim 18,

    The preamble includes a layer identification information for identifying layers corresponding to hierarchical division.
20. The method according to claim 19,

    The preamble is

    And the injection level information is selectively included in each physical layer pipe according to a result of comparing the layer identification information with a predetermined value.

Images