Apparatus for transmitting broadcast signal by using multiple transmission antennas, and method using same

Abstract

The broadcast signal transmission device according to one embodiment of the present invention comprises: a subframe signal generation unit for outputting a first polorization signal corresponding to a first polorization and a second polorization signal corresponding to a second polorization; and a transmission signal generation unit for generating a first polorization transmission signal corresponding to the first polarization, and generating a second polorization transmission signal corresponding to the second polorization. The first polarization transmission signal and / or the second polarization transmission signal can include a preamble.

Description

Broadcast signal transmission device using multiple transmitting antennas and method using the same

[0001] The present invention relates to a broadcast signal transmission / reception system, and more particularly, to a broadcast signal frame transmission technique including a bootstrap / preamble and a subframe.

[0002] To address the growing demand for ultra-high-definition broadcasting services, efficient use of frequency resources, and the integration of services requiring diverse regions and reception environments, technologies and standards for next-generation terrestrial broadcasting systems have recently been introduced. However, the growing demand for higher resolutions, hyper-realistic media such as AR (Artificial Reality) and VR (Virtual Reality), and additional data for enhanced user experiences, coupled with the lack of idle frequency resources due to the simultaneous provision of existing broadcasting services, necessitates further improvements in the transmission rates of terrestrial broadcasting systems.

[0003] The latest terrestrial digital broadcasting standards, such as ATSC 3.0, have attempted to overcome the transmission capacity limitations of a single broadcast frequency by applying multiple antenna technologies such as MIMO (Multiple Input Multiple Output), and have adopted layered division multiplexing technology in addition to TDM (Time Division Multiplexing) or FDM (Frequency Division Multiplexing) to support multiple services simultaneously.

[0004] MIMO used in ATSC 3.0 is a technology that increases transmission capacity by transmitting two data streams on a single RF (Radio Frequency) channel using orthogonal polarization antennas. At this time, the orthogonal polarization antennas are composed of two antennas whose polarizations are orthogonal to each other, and it takes into account the environment in which both vertical polarization antennas and horizontal polarization antennas are installed at the transmitter and receiver. This type of MIMO is called 2X2 cross-polarized MIMO. At this time, each polarization antenna can be referred to as antenna #1 (ANT 1) and antenna #2 (ANT 2), and in this case, antenna #1 can be a vertical polarization antenna and antenna #2 a horizontal polarization antenna, or conversely, antenna #1 can be a horizontal polarization antenna and antenna #2 a vertical polarization antenna.

[0005] Hierarchical division multiplexing is somewhat more complex than TDM and FDM, but it offers a high level of flexibility and improved system performance.

[0006] Layered division multiplexing (LDM) refers to a system that combines multiple layers into a single transmission layer. In its simplest form, a system with two layers—a core layer and an enhanced layer—is considered. The core layer typically refers to a layer with higher reception robustness than the enhanced layer. In the ATSC 3.0 standard, the transmit power allocated to the core layer is significantly greater than that allocated to the enhanced layer, inducing the receiver to prioritize decoding of the core layer.

[0007] The power ratio of the enhanced layer to the core layer is called the injection level, and the injection level information is transmitted to the receiver through L1 signaling.

[0008] Korean Patent Publication No. 10-2018-0132525 proposes a structure that combines MIMO and layered division multiplexing (LDM) technology for broadcast signal transmission and reception. Specifically, Korean Patent Publication No. 10-2018-0132525 discloses two structures: one in which MIMO is applied to both the core and enhanced layers, and one in which MIMO is applied to only one of the core or enhanced layers.

[0009] When MIMO is applied to a broadcast signal transmission / reception system, the receiver must be equipped with two antennas (a vertically polarized antenna and a horizontally polarized antenna) to fully restore the transmitted MIMO signal, and a conventional single-antenna receiver cannot receive a signal transmitted using the MIMO method. In other words, since MIMO separates a single service into two different streams and then transmits the separated streams to each antenna, a single-antenna receiver cannot restore the original service.

[0010] Therefore, when configuring LDM multiplexing including MIMO transmission signals, compatibility with existing single-antenna receivers must be considered.

[0011] If there is no need to ensure compatibility with existing single-antenna receivers, MIMO can be applied to both the core layer and the enhanced layer when applying LDM and MIMO technologies together.

[0012] However, when LDM and MIMO technologies are used together while ensuring compatibility with existing single-antenna receivers, the core layer can use SISO (Single Input Single Output) and the enhanced layer can use MIMO. In this case, SISO may not separate a single service into multiple streams and transmit them independently. Even when two antennas transmit the same signal, it can still be considered SISO.

[0013] Korean Patent Publication No. 10-2023-0130564 discloses an LDM and MIMO combined structure in which SISO is applied to the core layer and MIMO is applied to the enhanced layer. In the structure disclosed in Korean Patent Publication No. 10-2023-0130564, a SISO transmission signal is generated for the core layer, and a MIMO transmission signal is generated for the enhanced layer. At this time, the SISO receiver does not consider the MIMO signal (considering it as noise) and restores the core layer signal, and the MIMO receiver first restores the SISO signal (core layer signal) and then removes it from the received signal, and then restores the received signal from which the SISO signal has been removed using the MIMO method.

[0014] However, No. 10-2023-0130564 only presents LDM and its rough combination structure when SISO and MIMO are used together, and is completely silent about the bootstrap / preamble transmission method or cell addressing method in the layered division multiplexing system where SISO and MIMO are used together.

[0015] Therefore, there is an urgent need for a new layered division multiplexing technology that can efficiently transmit bootstrap and preamble when LDM and MIMO technologies are used together.

[0016] An object of the present invention is to efficiently transmit / receive bootstrap / preamble signals when using hierarchical division multiplexing and MIMO technology together.

[0017] In addition, an object of the present invention is to efficiently transmit / receive bootstrap / preamble signals in a situation where SISO subframes and MIMO subframes (including MIMO subframes to which LDM is applied) are mixed.

[0018] In addition, it is an object of the present invention to prevent collision between signaling information for a legacy SISO receiver and signaling information for a MIMO receiver when a transmission signal to which LDM and MIMO are applied together is transmitted.

[0019] In addition, an object of the present invention is to prevent inefficient performance of cell addressing for preamble symbols, thereby reducing the efficiency of a broadcast signal transmission / reception system.

[0020] Additionally, it is an object of the present invention to prevent pilots used in preambles and subframes from being used inefficiently.

[0021] In order to achieve the above object, a broadcast signal transmission device according to the present invention includes a subframe signal generation unit that outputs a first polarization signal corresponding to a first polarization and a second polarization signal corresponding to a second polarization; and a transmission signal generation unit that generates a first polarization transmission signal corresponding to the first polarization and a second polarization transmission signal corresponding to the second polarization. At this time, at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

[0022] At this time, the preamble may include a final preamble symbol including at least one cell position.

[0023] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0024] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0025] At this time, the MIMO processing may not be applied to the preamble.

[0026] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0027] At this time, the power of the last preamble symbol may refer to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

[0028] In addition, a broadcast signal transmission method according to one embodiment of the present invention includes the steps of outputting a first polarization signal corresponding to a first polarization and a second polarization signal corresponding to a second polarization; and the steps of generating a first polarization transmission signal corresponding to the first polarization and generating a second polarization transmission signal corresponding to the second polarization. At this time, at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

[0029] At this time, the preamble may include a final preamble symbol containing at least one cell position.

[0030] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0031] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0032] At this time, the MIMO processing may not be applied to the preamble.

[0033] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0034] At this time, the power of the last preamble symbol may refer to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

[0035] In addition, in one embodiment of the present invention, a method for receiving a broadcast signal includes the steps of: receiving a first polarization transmission signal corresponding to a first polarization and a second polarization transmission signal corresponding to a second polarization; and restoring a data stream through decoding corresponding to at least one of the first polarization and the second polarization. At this time, at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

[0036] At this time, the preamble may include a final preamble symbol containing at least one cell position.

[0037] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0038] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0039] At this time, the MIMO processing may not be applied to the preamble.

[0040] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0041] According to the present invention, when hierarchical division multiplexing and MIMO technology are used together, bootstrap / preamble signals can be efficiently transmitted / received.

[0042] In addition, the present invention can efficiently transmit / receive bootstrap / preamble signals in a situation where SISO subframes and MIMO subframes (including MIMO subframes to which LDM is applied) are mixed.

[0043] In addition, the present invention can prevent collision between signaling information for a legacy SISO receiver and signaling information for a MIMO receiver when a transmission signal to which LDM and MIMO are applied together is transmitted.

[0044] In addition, the present invention can prevent the efficiency of a broadcast signal transmission / reception system from being lowered due to inefficient performance of cell addressing for a preamble symbol.

[0045] Additionally, the present invention can prevent pilots used in preambles and subframes from being used inefficiently.

[0046] Figures 1 and 2 are diagrams showing two transmission examples in which SISO is applied to the core layer and MIMO is applied to the enhanced layer.

[0047] FIG. 3 is a block diagram showing an example of a broadcast signal transmission device according to one embodiment of the present invention.

[0048] Fig. 4 is a block diagram showing an example of the LDM coupling unit illustrated in Fig. 3.

[0049] Figure 5 is a diagram showing an example of a SISO distributed pilot pattern corresponding to SP3_2.

[0050] FIG. 6 is a diagram showing an example of a Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0051] FIG. 7 is a diagram showing an example of a null pilot encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0052] FIG. 8 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted only through one of two MIMO antennas.

[0053] FIG. 9 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted through both MIMO antennas.

[0054] Figure 10 is a diagram comparing a SISO distributed pilot pattern and a MIMO distributed pilot pattern.

[0055] Fig. 11 is a block diagram showing an example of a broadcast signal transmission device using multiple transmission antennas and hierarchical division multiplexing.

[0056] FIG. 12 is a diagram showing a physical layer frame of a broadcast signal according to an embodiment of the present invention.

[0057] FIG. 13 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a MIMO subframe.

[0058] FIG. 14 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a first type layered MIMO subframe.

[0059] FIG. 15 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a second type layered MIMO subframe.

[0060] FIG. 16 is a diagram illustrating an example of data cell addressing when a preamble symbol is associated with a subframe.

[0061] FIG. 17 is a diagram showing an example of a broadcast signal frame when the first subframe is a MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0062] FIG. 18 is a diagram showing an example of a broadcast signal frame when the first subframe is a first type layered MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0063] FIG. 19 is a diagram showing an example of a broadcast signal frame when the first subframe is a second type layered MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0064] Figure 20 is a diagram showing a broadcast signal frame and transmission signals when a core layer signal is transmitted in combination with a dummy signal in the preamble section.

[0065] Figure 21 is a flowchart illustrating a broadcast signal transmission method according to one embodiment of the present invention.

[0066] Figure 22 is a flowchart illustrating a broadcast signal receiving method according to one embodiment of the present invention.

[0067] Figure 23 is a block diagram showing a computer system configuration according to one embodiment of the present invention.

[0068] The present invention will be described in detail with reference to the attached drawings. Herein, repetitive descriptions, well-known functions that may unnecessarily obscure the gist of the present invention, and detailed descriptions of configurations will be omitted. The embodiments of the present invention are provided to more fully explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0069] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0070] Figures 1 and 2 are diagrams showing two transmission examples in which SISO is applied to the core layer and MIMO is applied to the enhanced layer.

[0071] When configuring LDM multiplexing including MIMO transmission signals, the SISO method can be applied to the core layer and MIMO can be applied only to the enhanced layer, considering compatibility with existing single-antenna receivers.

[0072] Referring to FIG. 1, it can be seen that the SISO signal (LEGACY SERVICE) of the core layer is transmitted only through one (VERTICAL) of the two MIMO antennas (VERTICAL, HORIZONTAL), and the other MIMO antenna (HORIZONTAL) does not transmit the core layer signal.

[0073] Referring to FIG. 2, it can be seen that two MIMO antennas (VERTICAL, HORIZONTAL) transmit the SISO signal (LEGACY SERVICE) of the same core layer in the core layer, and transmit two MIMO signals (STREAM 1, STREAM 2) in the enhanced layer, respectively.

[0074] That is, in the example illustrated in FIG. 1, the SISO signal transmitted to the core layer is transmitted through only one antenna, and in the example illustrated in FIG. 2, the SISO signal transmitted to the core layer is transmitted through both antennas.

[0075] When LDM and MIMO technologies are used together in this combined form of SISO and MIMO, backward compatibility with existing SISO receivers must be guaranteed, so L1 signaling must be applicable to both SISO and MIMO receivers. Therefore, from the perspective of existing SISO receivers, L1 signaling fields must be transmitted in the same manner as in the existing SISO transmission method to ensure normal operation of the SISO receiver.

[0076] FIG. 3 is a block diagram showing an example of a broadcast signal transmission device according to one embodiment of the present invention.

[0077] Figure 3 shows an example of a transmitter configuration in which a SISO signal is transmitted through a core layer and a MIMO signal is transmitted through an enhanced layer.

[0078] Referring to FIG. 3, a broadcast signal transmission device according to one embodiment of the present invention includes a core layer signal generation unit (310), an enhanced layer MIMO signal generation unit (320), an LDM combining unit (330), and a transmission signal generation unit (340).

[0079] The core layer signal generation unit (310) generates a core layer signal (SISO signal).

[0080] The core layer signal generation unit (310) includes an input formatting unit (311) and a core layer BICM (Bit-Interleaved Coded Modulation) unit (312).

[0081] The input formatting unit (311) generates packetized data (baseband packets) in units of processing blocks of the transmission system. At this time, the transmission system can classify packets to which the same BICM (Bit Interleaved Coded Modulation) and transmission signal generation parameters are applied and define them as the same PLP (Physical Layer Pipe).

[0082] The core layer BICM unit (312) may include an FEC (Forward Error Correction) unit, a BIL (Bit Interleaver) unit, and a symbol mapping unit. At this time, the FEC unit may apply channel coding to baseband packets to generate FEC frames (FEC packets), which are groups of bits. At this time, the channel coding may be a single-structure method, or may be a method composed of multiple stages, such as inner and outer coding. At this time, the BIL unit may perform bit interleaving on the FEC frames output from the FEC unit. At this time, the symbol mapping unit may generate data cells for transmitting the output to be transmitted through the antenna for the output bit string of the BIL unit, and output them as core layer signals.

[0083] The enhanced layer MIMO signal generation unit (320) generates enhanced layer MIMO (Multiple Input Multiple Output) signals.

[0084] The enhanced layer MIMO signal generation unit (320) includes an input formatting unit (321), an enhanced layer BICM unit (322), and a MIMO precoder (323).

[0085] The input formatting unit (321) generates packetized data (baseband packets) in units of processing blocks of the transmission system. At this time, the transmission system can classify packets to which the same BICM (Bit Interleaved Coded Modulation) and transmission signal generation parameters are applied and define them as the same PLP (Physical Layer Pipe).

[0086] The enhanced layer BICM unit (322) may include an FEC (Forward Error Correction) unit, a BIL (Bit Interleaver) unit, and a MIMO (Multi-Input Multi-Output) MAP (mapping) unit. At this time, the FEC unit may apply channel coding to baseband packets to generate FEC frames, which are groups of bits. At this time, the channel coding may be a single-structure method, or may be a method composed of multiple stages, such as inner and outer coding. At this time, the BIL unit may perform bit interleaving on the FEC frames output from the FEC unit. At this time, the MIMO MAP unit may generate data cells for transmitting the output to each of the multiple antennas for the output bit string of the BIL unit. For this purpose, the MIMO MAP unit may be composed of two detailed blocks: a demultiplexer unit and a bit to IQ mapping unit. At this time, the demultiplexer unit can group the input bit stream according to the modulation order and the number of multiple antennas in order to convert the input bit stream into data cells. At this time, the bit stream corresponding to each group may be different depending on the modulation order and the number of multiple antennas. The bit-to-IQ mapping unit maps the output of the demultiplexer unit to constellations corresponding to groups of bits corresponding to each antenna output, and generates data cells corresponding to each antenna output. In one embodiment, even-numbered bits in a bit group can be mapped to data cells for the first antenna (first polarization), and odd-numbered bits can be mapped to data cells for the second antenna (second polarization). At this time, the grouping of each bit in the MIMO MAP unit or the constellation mapping of the bits using the same can be performed using various methods not illustrated. At this time, the first polarization can be vertical polarization, and the second polarization can be horizontal polarization.

[0087] Here, polarization can be the orientation of the electric field vector of a radiated electromagnetic wave with respect to the horizon as seen from the antenna. In other words, polarization can describe the orientation of the wave emitted from. This orientation can be planar or circular.

[0088] Hereinafter, the first antenna may be replaced with the first polarization, and the second antenna may be replaced with the second polarization.

[0089] Two groups of data cells are input to the MIMO precoder (323).

[0090] At this time, the MIMO precoder (323) may include a streaming combiner, an IQ polarization interleaving unit, and a phase hopping unit. At this time, the stream combiner may combine two data cells inputted and output them. At this time, the IQ polarization interleaving unit may exchange the quadrature components of the two data cells inputted and output them. At this time, the phase hopping unit may change the phase of the data cells inputted and output them. At this time, all three sub-blocks may operate while being activated, all may operate while being deactivated, or only some of the blocks may operate while being activated. In addition, each sub-block may output a different signal or the same signal depending on the channel coding rate and modulation order applied to the data cells inputted to each sub-block. The MIMO precoder (323) illustrated in FIG. 3 can output two data cells to be output through the first antenna (first polarization) and the second antenna (second polarization).

[0091] The LDM combiner (330) hierarchically multiplexes one of the core layer signal and the enhanced layer MIMO signals to output a first polarization signal corresponding to the first polarization (first antenna), and outputs the other one of the enhanced layer MIMO signals as a second polarization signal corresponding to the second polarization (second antenna).

[0092] At this time, the LDM coupling unit (330) can output the second polarization signal with unity power.

[0093] The transmission signal generation unit (340) generates a first polarization transmission signal using the first polarization signal, and generates a second polarization transmission signal using the second polarization signal.

[0094] The transmission signal generation unit (340) includes framing & interleaving units (341, 342) and waveform generators (345, 346).

[0095] Time interleaving, frame generation (including preamble), and frequency interleaving can be performed in the framing & interleaving unit (341) on the first polarization signal output through the LDM combining unit (330). The output of the framing & interleaving unit (341) is input to the waveform generator (345) and output to the first antenna as the first polarization transmission signal.

[0096] Time interleaving, frame generation (including preamble), and frequency interleaving can be performed in the framing & interleaving unit (342) on the second polarization signal output through the LDM coupling unit (330). The output of the framing & interleaving unit (342) is input to the waveform generator (346) and output to the second antenna as the second polarization transmission signal.

[0097] The framing & interleaving units (341, 342) illustrated in FIG. 3 can each generate a signal corresponding to a frame to be transmitted via an antenna using data cells input as input. At this time, the framing & interleaving units (341, 342) may or may not activate and perform time interleaving for each input data cell. At this time, the framing & interleaving units (341, 342) may each perform framing for configuring preamble symbols and subframes for each data cell. At this time, the preamble symbol may not include a data cell. At this time, frequency interleaving may or may not be activated and applied.

[0098] Depending on the embodiment, the first polarization transmission signal and the second polarization transmission signal may each include a preamble, but only one of them may include a preamble.

[0099] If the first polarization transmission signal includes a first preamble and the second polarization transmission signal includes a second preamble, the first preamble and the second preamble may each include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0. Furthermore, the first preamble and the second preamble may include the same L1 signaling information.

[0100] If only one of the first polarization transmission signal and the second polarization transmission signal includes a preamble, this preamble can be applied not only to the polarization (antenna) transmitting the preamble but also to the other polarization (antenna). For example, if only the first polarization transmission signal includes a preamble, the signaling fields included in this preamble can be used by both the first polarization and the second polarization.

[0101] The grouped data cells, which are outputs of the framing & interleaving units (341, 342), are input to the waveform generators (345, 346). At this time, the waveform generators (345, 346) may each perform an inverse fast Fourier transform (IFFT) after pilot insertion and insert a guard interval symbol. In addition, the waveform generators (345, 346) may each generate a bootstrap symbol and output it by positioning it at the very beginning of the transmission frame.

[0102] In particular, the waveform generator (346) may apply power scaling for the second polarization in the IFFT stage according to an injection level corresponding to the second polarization (which may be the same as the injection level corresponding to the first polarization). At this time, the power of the second polarization transmission signal may be lower than the power of the first polarization transmission signal.

[0103] Information about the scattered pilots inserted through the waveform generators (345, 346) may be included in the preamble generated by the framing & interleaving units (341, 342).

[0104] FIG. 4 is a block diagram showing an example of the LDM coupling unit (330) illustrated in FIG. 3.

[0105] Referring to FIG. 4, the LDM coupling unit (330) includes an injection level controller (410), a coupler (420), and a power normalizer (430).

[0106] The LDM coupling unit (330) is a core layer signal (S C ) and enhanced layer MIMO signals (S E,1 , S E,2 ) one of (S E,1 ) is hierarchically divided into multiplexes to generate the first polarization signal (β(S) corresponding to the first polarization (POLARIZATION #1). C + αS E,1 )) and output enhanced layer MIMO signals (S E,1 , S E,2 ) another one (S) E,2 ) is output as a second polarization signal corresponding to the second polarization.

[0107] The injection level controller (410) provides enhanced layer MIMO signals (S) for hierarchical division multiplexing. E,1 , S E,2 ) one of (S E,1 ) to control the power.

[0108] The coupler (420) is a core layer signal (S C ) and one of the enhanced layer signals (αS) whose power is controlled by the injection level controller (410). E,1 ) are combined.

[0109] The power normalizer (430) performs transmission power normalization and outputs a first polarization signal.

[0110] In this way, the LDM combining unit illustrated in FIG. 4 combines the core layer signal and the enhanced layer signal through hierarchical division multiplexing for the first polarization, but for the second polarization, the combination of the two layer signals through hierarchical division multiplexing is not performed and the input MIMO signal (S E,2 ) is output as is. That is, in the structure illustrated in FIG. 4, constellation-superposed signals are transmitted only in the first polarization (POLARIZATION #1), and the second polarization (POLARIZATION #2) can transmit a dedicated MIMO stream composed solely of enhanced layer cells.

[0111] At this time, in the first polarization, at least one SISO (Single Input Single Output) PLP (Physical Layer Pipe) and at least one MIMO PLP superposed with the at least one SISO PLP can share pilot cells. That is, the SISO PLP(s) and MIMO PLP(s) superposed by the broadcast signal transmission apparatus illustrated in FIGS. 3 and 4 can share pilot cells transmitted through the first polarization (first antenna). This can be viewed as the pilot cells transmitted through the first polarization (first antenna) of the broadcast signal transmission apparatus illustrated in FIGS. 3 and 4 being shared by the core layer used for SISO transmission and the enhanced layer used for MIMO transmission.

[0112] At this time, the first polarization transmission signal and the second polarization transmission signal may be generated using only the first MIMO distributed pilot encoding among the first MIMO distributed pilot encoding that transmits pilots to the same OFDM cell positions for the first polarization and the second polarization, and the second MIMO distributed pilot encoding that transmits pilots to different OFDM cell positions for the first polarization and the second polarization.

[0113] At this time, the first MIMO distributed pilot encoding may correspond to a first group in which identical pilots are transmitted for the first polarization and the second polarization, and a second group in which pilots with opposite phases are transmitted for the first polarization and the second polarization.

[0114] At this time, the second MIMO distributed pilot encoding may correspond to a first group in which only pilots for the first polarization are transmitted with valid power and pilots for the second polarization are transmitted with null power, and a second group in which only pilots for the second polarization are transmitted with valid power and pilots for the first polarization are transmitted with null power.

[0115] At this time, the first MIMO distributed pilot encoding may be Walsh-Hadamard encoding, and the second MIMO distributed pilot encoding may be null pilot encoding.

[0116] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble. At this time, the preamble may include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

[0117] At this time, the 1-bit L1B_mimo_scattered_pilot_encoding field set to 0 can indicate both a MIMO pilot pattern with Walsh-Hadamard encoding and the SISO pilot pattern simultaneously.

[0118] In this way, when considering a conventional single-antenna receiver in a broadcast signal transmitter that uses LDM and MIMO together, a collision may occur between the pilot pattern for the MIMO terminal and the pilot pattern for the SISO terminal (between the signaling information of the pilot pattern for the MIMO terminal and the signaling information of the pilot pattern for the SISO terminal).

[0119] In the ATSC 3.0 broadcast system, L1B_first_sub_scattered_pilot_pattern (for the first subframe) and L1D_scattered_pilot_pattern (for other subframes) are used as scattered pilot pattern identification fields, and the scattered pilot pattern is signaled through these fields.

[0120] These fields are signaling fields commonly used for SISO transmission and MIMO transmission, and the receiver can distinguish whether it is a SISO distributed pilot pattern or a MIMO distributed pilot pattern by combining these fields with other MIMO-related fields (e.g., L1B_first_sub_mimo (for the first subframe) and L1D_mimo (for other subframes)) and then find out the exact distributed pilot pattern.

[0121] At this time, L1B_first_sub_mimo and L1D_mimo can indicate whether MIMO transmission is applied to the corresponding subframe.

[0122] That is, even if L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern has the same value, depending on whether it is SISO transmission or MIMO transmission, the scattered pilot pattern may be interpreted as a SISO pattern as shown in Table 1 below, or as a MIMO pattern as shown in Table 2 below.

[0123] ValueSP patternValueSP patternValueSP pattern00000SP3_201000SP12_210000Reserved00001SP3_401001SP12_4......00010SP4_201010SP16_2......00011SP4_401011SP16_4.. ....00100SP6_201100SP24_2......00101SP6_401101SP24_4......00110SP8_201110SP32_2......00111SP8_401111SP32_411111Reserved

[0124] Table 1 shows the signaling formats of L1D_scattered_pilot_pattern and L1B_first_sub_scattered_pilot_pattern for SISO.

[0125] ValueSP patternValueSP patternValueSP pattern00000MP3_201000MP12_210000Reserved00001MP3_401001MP12_4......00010MP4_201010MP16_2......00011MP4_401011MP16_4.. ....00100MP6_201100MP24_2......00101MP6_401101MP24_4......00110MP8_201110MP32_2......00111MP8_401111MP32_411111Reserved

[0126] Table 2 shows the signaling formats of L1D_scattered_pilot_pattern and L1B_first_sub_scattered_pilot_pattern for MIMO.

[0127] In Tables 1 and 2, SP represents SISO Pilot and MP represents MIMO Pilot.

[0128] Ultimately, when considering the existing SISO receiver and combining LDM and MIMO technologies to transmit SISO and MIMO signals in the same subframe, both the SISO receiver and the MIMO receiver must be able to simultaneously receive accurate scattered pilot pattern information through a common signaling field, L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern. This means that L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern must be compatible with both SISO and MIMO.

[0129] For example, if L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern is 00000, the SISO receiver must perform channel estimation through SP3_2 in Table 1, and the MIMO receiver must perform channel estimation through MP3_2 in Table 2.

[0130] In order to receive a MIMO transmission signal, it is necessary to estimate the first polarization channel and the second polarization channel separately, and therefore, distinguishable pilot signals are transmitted to both the first polarization (first antenna) and the second polarization (second antenna).

[0131] The MIMO distributed pilot pattern used in ATSC 3.0 systems is defined using either Walsh-Hadamard encoding or null-pilot encoding.

[0132] The pilot pattern corresponding to Walsh-Hadamard encoding is such that both the first polarization and the second polarization transmit their respective pilots at the same OFDM cell locations. That is, Walsh-Hadamard encoding designs the sequences corresponding to the pilots for the first polarization and the sequences corresponding to the pilots for the second polarization to be orthogonal, so that only the corresponding pilots can be extracted from each transmission channel.

[0133] The pilot pattern corresponding to the null pilot encoding is such that the second polarization is muted at the position where the first polarization transmits the pilot, and the first polarization is muted at the position where the second polarization transmits the pilot.

[0134] Comparing the SISO distributed pilot pattern, the MIMO Walsh-Hadamard distributed pilot pattern, and the MIMO null-pilot distributed pilot pattern signaled with the same 5-bit value in Tables 1 and 2 above, the following relationship can be confirmed.

[0135] The first polarization (first antenna) portion of the MIMO Walsh-Hadamard distributed pilot pattern transmits pilot signals identical to the SISO distributed pilot pattern to the same OFDM cell location.

[0136] The first polarization (first antenna) portion of the MIMO null-pilot distributed pilot pattern transmits pilot signals at only half of the pilot positions of the SISO distributed pilot pattern.

[0137] This relationship can be summarized as shown in Table 3 below.

[0138] Pilot EncodingAlgorithmAntennaScatteredPilotSubframeBoundaryPilotCommonContinualPilotAdditionalContinualPilotEdgePilotWalsh-Hadamard#1SISOSISOSISOSISOSISO#2WHWHSISOSISO / WHWHNull Pilot#1NPSISOSISOSISO / NPSISO#2NPWHSISOSISO / NPWH

[0139] In Table 3, WH represents Walsh-Hadamard and NP represents Null Pilot.

[0140] Figures 5, 6 and 7 illustrate SISO scattered pilot patterns, MIMO Walsh-Hadamard scattered pilot patterns and MIMO null-pilot scattered pilot patterns when 5-bit L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern is 00000.

[0141] Figure 5 is a diagram showing an example of a SISO distributed pilot pattern corresponding to SP3_2.

[0142] Referring to Figure 5, D for SISO X = 3 and D Y = You can find out the pilot positions in case 2.

[0143] FIG. 6 is a diagram showing an example of a Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0144] Referring to FIG. 6, it can be seen that the OFDM cell locations of the SISO distributed pilot pattern corresponding to SP3_2 and the OFDM cell locations of the Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2 are basically the same.

[0145] The Walsh-Hadamard encoded MIMO distributed pilot pattern illustrated in FIG. 6 transmits the same pilots as illustrated in FIG. 5 in both group 1 positions and group 2 positions for the first polarization. At this time, for the second polarization, the same pilots as those for the first polarization are transmitted in group 1 positions, and pilots that are opposite in phase to the pilots for the first polarization are transmitted in group 2 positions.

[0146] That is, in the Walsh-Hadamard encoded MIMO distributed pilot pattern illustrated in FIG. 6, the same pilots as the SISO distributed pilot pattern illustrated in FIG. 5 are transmitted in the first polarization, and in the second polarization, only some pilots are transmitted with their phases reversed at the same positions as the SISO distributed pilot pattern illustrated in FIG. 5.

[0147] FIG. 7 is a diagram showing an example of a null pilot encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0148] Referring to FIG. 7, it can be seen that the OFDM cell locations of the Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2 are basically the same as the OFDM cell locations of the null-pilot encoded MIMO distributed pilot pattern corresponding to MP3_2, except that the grouping is different.

[0149] However, the null-pilot encoded MIMO distributed pilot pattern illustrated in FIG. 7 transmits pilots only at group 1 positions for the first polarization, and transmits pilots only at group 2 positions for the second polarization.

[0150] That is, the null-pilot encoded MIMO distributed pilot pattern illustrated in FIG. 7 transmits pilot signals only at half of the pilot positions (group 1 positions) of the SISO distributed pilot pattern distributed pilot pattern illustrated in FIG. 5 in the first polarization. Similarly, the null-pilot encoded MIMO distributed pilot pattern transmits pilot signals only at the other half of the pilot positions (group 2 positions) of the SISO distributed pilot pattern distributed pilot pattern illustrated in FIG. 5 in the second polarization.

[0151] In a broadcast signal transmission / reception system combining LDM and MIMO, the core layer and the enhanced layer may need to use the same pilot signal to prevent increased receiver complexity and reduce the burden of receiver memory usage.

[0152] The broadcast signal transmitter having the structure described through FIGS. 3 and 4 transmits a broadcast signal combining SISO and MIMO, taking into account a conventional single-antenna receiver, and the single-antenna receiver can only receive the first polarization signal. In such an environment, if a null pilot pattern is applied as a distributed pilot pattern, the SISO receiver will use the interference signal transmitted in the second polarization for pilot-based channel estimation using the corresponding PLP (Physical Layer Pipe), which may result in misestimation.

[0153] Meanwhile, when transmitting a broadcast signal combining SISO and MIMO by combining LDM and MIMO technologies, if a null-pilot pattern is applied, a conflict may occur with the L1-basic and L1-detail signaling for the existing SISO service.

[0154] The existing ATSC 3.0 broadcast system sets the L1B_mimo_scattered_pilot_encoding field (L1-Basic signaling field) to 0 in the following two cases.

[0155] - When the Walsh-Hadamard pilot pattern is used

[0156] - If there is no subframe with MIMO applied within the transmission frame

[0157] When receiving a subframe that combines SISO and MIMO by combining LDM and MIMO technologies, it may be desirable for the SISO receiver to be unaware of the presence of the enhanced layer transmitted in the form of MIMO. Therefore, in this case, L1B_first_sub_mimo (for the first subframe) or L1D_mimo (for other subframes) should be set to 0. In this case, L1B_first_sub_mimo and L1D_mimo may be fields indicating whether MIMO is applied to the corresponding subframe (in principle, they are set to 1 if MIMO is applied). In this way, even though MIMO is applied to the enhanced layer, if L1B_first_sub_mimo (for the first subframe) or L1D_mimo (for other subframes) is set to 0, the MIMO receiver may operate based on other MIMO-related fields other than these fields to identify the MIMO pilot pattern.

[0158] When the core layer transmits a SISO signal and only the enhanced layer applies MIMO, there may be no MIMO subframes in the transmission frame other than the subframes in which SISO and MIMO are combined with LDM, and there may be MIMO subframes in the transmission frame other than the subframes in which SISO and MIMO are combined with LDM.

[0159] If there are no MIMO subframes in a transmission frame other than the subframes in which SISO and MIMO are combined with LDM, and the null-pilot pattern is applied to the subframes in which SISO and MIMO are combined with LDM, and L1B_mimo_scattered_pilot_encoding must be set to 1, then this is not desirable because it causes a conflict with L1B_first_sub_mimo or L1D_mimo set to 0 in the received preamble from the perspective of the existing SISO receiver.

[0160] In the case where a MIMO subframe exists in a transmission frame other than the subframes in which SISO and MIMO are LDM-combined, a signaling collision may not occur if other MIMO subframes in the transmission frame apply the null pilot pattern. However, even in this case, considering the situation where a single scattered pilot pattern identification field (L1B_first_sub_scattered_pilot_pattern or L1D_scattered_pilot_pattern) is shared by the SISO receiver and the MIMO receiver, it is desirable to prohibit the use of the null pilot pattern and use only the Walsh-Hadamard pilot pattern. In this case, the Walsh-Hadamard pilot pattern may be applied to the enhanced layer of the broadcast signal transmission device of FIGS. 3 and 4 regardless of the value signaled in L1B_mimo_scattered_pilot_encoding.

[0161] Ultimately, when transmitting a broadcast signal combining SISO and MIMO by combining LDM and MIMO technologies, only Walsh-Hadamard encoding among null-pilot encoding and Walsh-Hadamard encoding can be allowed as pilot encoding.

[0162] At this time, the 1-bit signaling field L1B_mimo_scattered_pilot_encoding can be set to 0, which can indicate both a MIMO pilot pattern with Walsh-Hadamard encoding and the SISO pilot pattern simultaneously.

[0163] The core layer and the enhanced layer can share pilots not only when MIMO is applied to both the core layer and the enhanced layer, but also when SISO is applied to the core layer and MIMO is applied only to the enhanced layer.

[0164] FIG. 8 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted only through one of two MIMO antennas.

[0165] Referring to FIG. 8, it can be seen that in the first polarization (V-POL), the core layer signal and the enhanced layer signal are transmitted together, and in the second polarization (H-POL), only the enhanced layer signal is transmitted.

[0166] The example illustrated in Fig. 8 is an example in which the Walsh-Hadamard pilot pattern is applied, and it can be seen that the distributed pilot pattern is applied equally to the core layer and the enhanced layer in the first polarization (V-POL). In the example illustrated in Fig. 8, the phases of the pilots of some cell positions in the second polarization (H-POL) are opposite to those of the pilots in the first polarization.

[0167] FIG. 9 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted through both MIMO antennas.

[0168] Referring to FIG. 9, it can be seen that the core layer signal and the enhanced layer signal are transmitted together in the first polarization (V-POL) and the second polarization (H-POL).

[0169] The example illustrated in Fig. 9 is an example in which the Walsh-Hadamard pilot pattern is applied. It can be seen that the distributed pilot pattern is applied equally to the core layer and the enhanced layer in the first polarization (V-POL) and the second polarization (H-POL). In the example illustrated in Fig. 9, the phases of the pilots of some cell positions in the second polarization (H-POL) are opposite to those of the pilots in the first polarization.

[0170] Figure 10 is a diagram comparing a SISO distributed pilot pattern and a MIMO distributed pilot pattern.

[0171] Referring to Fig. 10, it can be seen that in the first polarization (V-POL), the Walsh-Hadamard encoded MP3_2 MIMO distributed pilot pattern is completely identical to the SISO SP3_2 distributed pilot pattern. In the second polarization (H-POL), the phases of the pilots at the pilot positions corresponding to the second group are inverted.

[0172] Fig. 11 is a block diagram showing an example of a broadcast signal transmission device using multiple transmission antennas and hierarchical division multiplexing.

[0173] Referring to FIG. 11, a broadcast signal transmission device using multiple transmission antennas and layered division multiplexing according to one embodiment of the present invention includes a core layer MIMO signal generation unit (1110), an enhanced layer MIMO signal generation unit (1120), an LDM combining unit (1130), an L1 signaling generation unit (1140), and a transmission signal generation unit (1150).

[0174] The core layer MIMO signal generation unit (1110) generates core layer MIMO signals.

[0175] At this time, the core layer MIMO signal generation unit (1110) may include a core layer FEC (Forward Error Correction) encoder (1111), a core layer bit-interleaver (1112), a core layer MIMO demux (DEMUX; Demultiplexer) (1113), core layer symbol mappers (1114, 1115), and a core layer MIMO precoder (1116).

[0176] The core layer FEC encoder (1111) can apply channel coding to baseband packets corresponding to the core layer to generate FEC frames (FEC packets), which are groups of bits. At this time, the channel coding may be a single-structure method or a method composed of multiple stages, such as inner and outer coding.

[0177] The core layer bit interleaver (1112) can perform bit interleaving on FEC frames output from the core layer FEC encoder (1111).

[0178] The core layer MIMO demux (1113) and core layer symbol mappers (1114, 1115) can generate data cells for transmitting output to each of the multiple antennas for the output bit stream of the core layer bit-interleaver (1112). That is, the core layer MIMO demux (1113) can group the input bit stream according to the modulation order and the number of multiple antennas in order to convert it into data cells. At this time, the core layer MIMO demux (1113) can map even index bits in the FEC-encoded bit stream that has undergone bit interleaving to the first antenna (polarization) and odd index bits to the second antenna (polarization). At this time, the bit stream corresponding to each group can be different depending on the modulation order and the number of multiple antennas. The core layer symbol mappers (1114, 1115) map the output of the core layer MIMO demux (1113) to constellations corresponding to groups of bits corresponding to each antenna (polarization) output, and generate data cells corresponding to each antenna output. In one embodiment, even-numbered bits in a bit group may be mapped to data cells for a first antenna (ANTENNA 1), and odd-numbered bits may be mapped to data cells for a second antenna (ANTENNA 2). At this time, the grouping of each bit or the constellation mapping of the bits using the same in the core layer symbol mappers (1114, 1115) may be performed using various methods not illustrated.

[0179] Groups of two different data cells are input to a core layer MIMO precoder (1116). At this time, the core layer MIMO precoder (1116) can perform signal processing for spatial multiplexing and can adjust the first antenna (polarization) signal and the second antenna (polarization) signal in units of OFDM cells (constellation symbols).

[0180] At this time, the core layer MIMO precoder (1116) may include a streaming combiner, an IQ polarization interleaving unit, and a phase hopping unit. At this time, the stream combiner may combine two data cells inputted and output them. At this time, the IQ polarization interleaving unit may exchange the quadrature components of the two data cells inputted and output them. At this time, the phase hopping unit may change the phase of the data cells inputted and output them. At this time, all three sub-blocks may be activated and operated, all may be deactivated and operated, or only some of the blocks may be activated and operated. In addition, each sub-block may output a different signal or the same signal depending on the channel coding rate and modulation order applied to the data cells inputted to each sub-block. The core layer MIMO precoder (1116) illustrated in FIG. 11 can output two data cells to be output through the first antenna (ANTENNA 1) and the second antenna (ANTENNA 2). That is, two output signals are generated from the core layer MIMO signal generation unit (1110), one of which is a signal for transmission using the first antenna (ANTENNA 1), and the other is a signal for transmission using the second antenna (ANTENNA).

[0181] The first antenna (ANTENNA 1) and the second antenna (ANTENNA 2) may correspond to a first polarization and a second polarization, respectively. That is, the first antenna (ANTENNA 1) may correspond to a first polarization, and the second antenna (ANTENNA 2) may correspond to a second polarization. For example, the first polarization may be vertical polarization, and the second polarization may be horizontal polarization.

[0182] Here, polarization can be the orientation of the electric field vector of a radiated electromagnetic wave with respect to the horizon as seen from the antenna. In other words, polarization can describe the orientation of the wave emitted from. This orientation can be planar or circular.

[0183] Hereinafter, the first antenna may be replaced with the first polarization, and the second antenna may be replaced with the second polarization.

[0184] The enhanced layer MIMO signal generation unit (1120) generates enhanced layer MIMO signals.

[0185] At this time, the enhanced layer MIMO signal generation unit (1120) may include an enhanced layer FEC (Forward Error Correction) encoder (1121), an enhanced layer bit-interleaver (1122), an enhanced layer MIMO demux (DEMUX; Demultiplexer) (1123), enhanced layer symbol mappers (1124, 1125), and an enhanced layer MIMO precoder (1126).

[0186] The enhanced layer FEC encoder (1121) can apply channel coding to baseband packets corresponding to the enhanced layer to generate FEC frames (FEC packets), which are groups of bits. At this time, the channel coding may be a single-structure method or a method composed of multiple stages, such as inner and outer coding.

[0187] The enhanced layer bit-interleaver (1122) can perform bit interleaving on FEC frames output from the enhanced layer FEC encoder (1121).

[0188] The enhanced layer MIMO demux (1123) and the enhanced layer symbol mappers (1124, 1125) can generate data cells for transmitting output to each of the multiple antennas for the output bit stream of the enhanced layer bit-interleaver (1122). That is, the enhanced layer MIMO demux (1123) can group the input bit stream according to the modulation order and the number of multiple antennas in order to convert it into data cells. At this time, the enhanced layer MIMO demux (1123) can map even index bits in the FEC-encoded bit stream that has undergone bit interleaving to the first antenna (polarization) and odd index bits to the second antenna (polarization). At this time, the bit stream corresponding to each group can be different depending on the modulation order and the number of multiple antennas. Enhanced layer symbol mappers (1124, 1125) map the output of the enhanced layer MIMO demux (1123) to constellations corresponding to groups of bits corresponding to each antenna (polarization) output, and generate data cells corresponding to each antenna output. In one embodiment, even-numbered bits in a bit group may be mapped to data cells for a first antenna (ANTENNA 1), and odd-numbered bits may be mapped to data cells for a second antenna (ANTENNA 2). At this time, the grouping of each bit or the constellation mapping of the bits using the same in the enhanced layer symbol mappers (1124, 1125) may be performed using various methods not illustrated.

[0189] Groups of two different data cells are input to an enhanced layer MIMO precoder (1126). At this time, the enhanced layer MIMO precoder (1126) can perform signal processing for spatial multiplexing and can adjust the first antenna (polarization) signal and the second antenna (polarization) signal in units of OFDM cells (constellation symbols).

[0190] At this time, the enhanced layer MIMO precoder (1126) may include a streaming combiner, an IQ polarization interleaving unit, and a phase hopping unit. At this time, the stream combiner may combine two data cells inputted and output them. At this time, the IQ polarization interleaving unit may exchange the quadrature components of the two data cells inputted and output them. At this time, the phase hopping unit may change the phase of the data cells inputted and output them. At this time, all three sub-blocks may be activated and operated, all may be deactivated and operated, or only some of the blocks may be activated and operated. In addition, each sub-block may output a different signal or the same signal depending on the channel coding rate and modulation order applied to the data cells inputted to each sub-block. The enhanced layer MIMO precoder (1126) illustrated in FIG. 11 can output two data cells to be output through the first antenna (ANTENNA 1) and the second antenna (ANTENNA 2). That is, two output signals are generated from the enhanced layer MIMO signal generation unit (1120), one of which is a signal for transmission using the first antenna (ANTENNA 1), and the other is a signal for transmission using the second antenna (ANTENNA).

[0191] At this time, the core layer MIMO signals may be generated based on core layer MIMO precoding, and the enhanced layer MIMO signals may be generated based on enhanced layer MIMO precoding.

[0192] At this time, the core layer MIMO precoding and the enhanced layer MIMO precoding may be performed using at least one of stream combining, IQ polarization interleaving, and phase hopping, respectively.

[0193] At this time, if the IQ polarization interleaving corresponding to the core layer is activated, the IQ polarization interleaving corresponding to the enhanced layer can be activated.

[0194] At this time, if phase hopping corresponding to the core layer is activated, phase hopping corresponding to the enhanced layer can be activated.

[0195] At this time, the stream combining, the IQ polarization interleaving and the phase hopping may correspond to the first MIMO field, the second MIMO field and the third MIMO field, respectively.

[0196] At this time, the second MIMO field corresponding to the core layer and the second MIMO field corresponding to the enhanced layer may be set identically, and the third MIMO field corresponding to the core layer and the third MIMO field corresponding to the enhanced layer may be set identically.

[0197] The LDM combiner (1130) performs layered division multiplexing on the core layer MIMO signals and the enhanced layer MIMO signals to generate a first superposition signal (first polarization signal) corresponding to the first polarization and a second superposition signal (second polarization signal) corresponding to the second polarization.

[0198] At this time, the LDM coupling unit (1130) may include injection level controllers (1131, 1132), couplers (1133, 1134) and power normalizers (1135, 1136).

[0199] That is, through the LDM coupling unit, the transmission power of the enhanced layer MIMO signals for the first antenna (ANTENNA 1) and the second antenna (ANTENNA 2) is adjusted by the injection level controllers (1131, 1132) according to a predetermined power injection level (IL). At this time, the power of the enhanced layer MIMO signal for the first antenna (ANTENNA 1) is adjusted by the injection level controller (1131), and the power of the enhanced layer MIMO signal for the second antenna (ANTENNA 2) is adjusted by the injection level controller (1132).

[0200] Therefore, in the LDM coupling unit (1130) illustrated in FIG. 11, two injection levels are used.

[0201] At this time, the injection levels can each represent a power ratio of the enhanced layer to the core layer, and information for signaling the injection level can be included in the L1 signaling fields.

[0202] The enhanced layer MIMO signal for the first antenna (ANTENNA 1) with adjusted power is added to the core layer MIMO signal for the first antenna (ANTENNA 1) by a combiner (1133), and the enhanced layer MIMO signal for the second antenna (ANTENNA 2) with adjusted power is added to the core layer MIMO signal for the second antenna (ANTENNA 2) by a combiner (1134).

[0203] The signal added through the coupler (1133) goes through transmission power normalization by the power normalizer (1135) and is output as a first superposition signal (first polarization signal), and the signal added through the coupler (1134) goes through transmission power normalization by the power normalizer (1136) and is output as a second superposition signal (second polarization signal).

[0204] The transmission signal generation unit (1150) generates a first polarization transmission signal including a first preamble corresponding to the first polarization and a second polarization transmission signal including a second preamble corresponding to the second polarization.

[0205] At this time, the transmission signal generation unit (1150) includes framing & interleaving units (1151, 1152) and waveform generators (1153, 1154).

[0206] Time interleaving, frame generation (including preamble), and frequency interleaving can be performed in the framing & interleaving unit (1151) on the first superposition signal output through the power normalizer (1135). The output of the framing & interleaving unit (1151) is input to the waveform generator (1153) and output to the first antenna as the first polarization transmission signal.

[0207] Time interleaving, frame generation (including preamble), and frequency interleaving can be performed in the framing & interleaving unit (1152) on the second superposition signal output through the power normalizer (1136). The output of the framing & interleaving unit (1152) is input to the waveform generator (1154) and output to the second antenna as a second polarization transmission signal.

[0208] The framing & interleaving units (1151, 1152) illustrated in FIG. 11 can each generate a signal corresponding to a frame to be transmitted via an antenna using data cells inputted as input. At this time, the framing & interleaving units (1151, 1152) may or may not activate and perform time interleaving for each input data cell. At this time, the framing & interleaving units (1151, 1152) may perform framing for each data cell, configuring a preamble symbol and a subframe. At this time, the preamble symbol may not include a data cell. At this time, frequency interleaving may or may not be activated and applied.

[0209] The grouped data cells, which are the outputs of the framing & interleaving units (1151, 1152), are input to the waveform generators (1153, 1154). At this time, the waveform generators (1153, 1154) may each perform an inverse fast Fourier transform (IFFT) after pilot insertion and insert a guard interval symbol. In addition, the waveform generators (1153, 1154) may each generate a bootstrap symbol and output it by positioning it at the very beginning of the transmission frame. At this time, each of the waveform generators (1153, 1154) may activate and apply the MISO (Multiple-Input Single-Output) signal processing function or may deactivate and not apply it.

[0210] The L1 signaling generation unit (1140) can generate injection level signaling information regarding two injection levels corresponding to the enhanced layer MIMO signals.

[0211] That is, the injection level information (IL INFO) for the enhanced layer MIMO signal for the first antenna (or polarization) and the injection level information (IL INFO) for the enhanced layer MIMO signal for the second antenna (or polarization) are used by the injection level controllers (1131, 1132) and are also transmitted to and used by the power normalizers (1135, 1136). At this time, the power normalizers (1135, 1136) each multiply the size of the combined signal by a normalizing factor calculated from the injection level information to adjust the power of the input signal to an appropriate level.

[0212] At this time, the injection level information (IL INFO) for the enhanced layer MIMO signal for the first antenna (or polarization) and the injection level information (IL INFO) for the enhanced layer MIMO signal for the second antenna (or polarization) are transmitted to the L1 signaling generation unit (1140), so that L1 signaling information to be included in the preamble and transmitted is generated. That is, the injection level signaling information included in the L1 signaling information is modulated and transmitted by the framing & interleaving units (1135, 1136) by being included in the preamble.

[0213] At this time, since there are two injection level controllers (1131, 1132), there are two injection levels used, and there are also two preambles generated from the framing & interleaving units (1151, 1152).

[0214] The injection levels of the injection level controllers (1131, 1132) may be set to the same injection level or may be set to different injection levels.

[0215] The first preamble generated by the framing & interleaving unit (1151) and the second preamble generated by the framing & interleaving unit (1152) may each include only the first injection level information (when the injection levels of the injection level controllers (1131, 1132) are the same) or may include both the first injection level information and the second injection level information (when the injection levels of the injection level controllers (1131, 1132) are different). In this case, the first injection level signaling information included in the first preamble and the first injection level signaling information included in the second preamble may be the same. Similarly, the second injection level signaling information included in the first preamble and the second injection level signaling information included in the second preamble may be the same. Furthermore, the entire L1 signaling information included in the first preamble may be identical to the entire L1 signaling information included in the second preamble. That is, the first preamble transmitted for the first polarization and the second preamble transmitted for the second polarization may be configured with the same modulation signals and set identically, and their transmission powers may be identical or different.

[0216] At this time, the first preamble and the second preamble may include the same 5-bit injection level signaling information corresponding to the injection levels.

[0217] The enhanced layer MIMO signal for the first antenna / polarization and the enhanced layer MIMO signal for the second antenna / polarization may be power-regulated corresponding to the same injection level or may be power-regulated corresponding to different injection levels.

[0218] At this time, the first preamble corresponding to the first antenna (polarization) and the second preamble corresponding to the second antenna (polarization) may include the same 5-bit injection level field (L1D_plp_ldm_injection_level).

[0219] At this time, the injection level controllers (1131, 1132) and power normalizers (1135, 1136) illustrated in FIG. 11 can all operate based on an injection level corresponding to the same 5-bit injection level field (L1D_plp_ldm_injection_level). That is, the same injection level value can be shared for the first antenna (polarization) and the second antenna (polarization).

[0220] Depending on the embodiment, different injection levels may be used for the first antenna / polarization and the second antenna / polarization. In this case, if the L1-Detail signaling for the first antenna / polarization and the L1-Detail signaling for the second antenna / polarization are the same, a signaling field separate from the aforementioned 5-bit injection level field (L1D_plp_ldm_injection_level) may be required. In this case, an injection level corresponding to L1D_plp_ldm_injection_level may be used for the first antenna (polarization), and an injection level corresponding to another signaling field may be used for the second antenna (polarization).

[0221] The LDM coupling unit (1130) illustrated in FIG. 11 and the LDM coupling unit (330) illustrated in FIG. 3 can output a first polarization signal corresponding to the first polarization and a second polarization signal corresponding to the second polarization. At this time, the LDM coupling unit (1130) illustrated in FIG. 11 and the LDM coupling unit (330) illustrated in FIG. 3 may correspond to a subframe signal generation unit.

[0222] Furthermore, the subframe signal generation unit may correspond to a MIMO signal generation unit (same structure as 1110 or 1120 of FIG. 11) that generates the output of the MIMO precoder as a first polarization signal and a second polarization signal in a MIMO transmission structure according to the existing ATSC 3.0 standard for a Non-MIMO subframe to be described later. In this case, the first polarization signal and the second polarization signal, which are the outputs of the MIMO precoder, may be input to the first framing & interleaving unit and the second framing & interleaving unit, respectively. At this time, the output of the first framing & interleaving unit may be input to the first waveform generator, and the output of the second framing & interleaving unit may be input to the second waveform generator. At this time, the output of the first waveform generator can become the first polarization transmission signal, and the output of the second waveform generator can become the second polarization transmission signal. At this time, the first framing & interleaving unit, the second framing & interleaving unit, the first waveform generator, and the second waveform generator can constitute a transmission signal generation unit. In this way, the existing MIMO transmission method that is not LDM can be referred to as single-layer MIMO transmission.

[0223] That is, the subframe signal generation unit can output a first polarization signal corresponding to the first polarization and a second polarization signal corresponding to the second polarization.

[0224] The transmission signal generation unit (1150) illustrated in FIG. 11 and the transmission signal generation unit (340) illustrated in FIG. 3 can generate a first polarization transmission signal corresponding to the first polarization and a second polarization transmission signal corresponding to the second polarization. At this time, in the case of a non-MIMO subframe, the transmission signal generation unit can include the first framing & interleaving unit, the second framing & interleaving unit, the first waveform generator, and the second waveform generator described above.

[0225] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble.

[0226] The subframes described in the present invention may be one of the following four types.

[0227] 1) Non-MIMO subframe

[0228] A Non-MIMO subframe refers to a subframe to which MIMO is not applied, and can refer to a transmission method that can be received with a single reception antenna because spatial multiplexing (SM) or polarization multiplexing (PM) is not applied. In this case, a Non-MIMO subframe may correspond to a SISO (Spatial-Input Single-Output) transmission signal and a MISO (Multiple-Input Single-Output) transmission signal.

[0229] 2) MIMO subframe

[0230] A MIMO subframe is a MIMO subframe corresponding to the existing ATSC 3.0 standard, and may refer to a single layer (SL) MIMO subframe to which layered division multiplexing (LDM) is not applied. In other words, the MIMO subframe may correspond to the MIMO transmitter structure of the existing ATSC 3.0 standard.

[0231] 3) Type 1 layered MIMO subframe

[0232] A first type layered MIMO subframe may correspond to a transmitter structure in which MIMO is applied to both the core layer and the enhanced layer. That is, a first type layered MIMO subframe may correspond to the transmitter structure illustrated in FIG. 11.

[0233] 4) Type 2 layered MIMO subframe

[0234] The second type layered MIMO subframe may correspond to a transmitter structure in which SISO is applied to the core layer and MIMO is applied to the enhanced layer. That is, the second type layered MIMO subframe may correspond to the transmitter structure illustrated in FIGS. 3 and 4.

[0235] At this time, the preamble may include a final preamble symbol including at least one cell position.

[0236] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0237] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0238] At this time, the MIMO processing may not be applied to the preamble.

[0239] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0240] At this time, the power of the last preamble symbol may refer to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

[0241] At this time, the first preamble and the second preamble may include the same preamble symbols.

[0242] At this time, the power of the preamble symbol corresponding to the first preamble may reference the data symbol power of the first subframe activating the first polarization.

[0243] At this time, the power of the preamble symbol corresponding to the second preamble may reference the data symbol power of the first subframe activating the second polarization.

[0244] At this time, the power of the preamble symbol refers to the power of the data symbol, which may mean that the power of the preamble symbol is set to be equal to the power of the data symbol.

[0245] At this time, the subframe signal generation unit can generate the first polarization signal and the second polarization signal based on one or more of one or more Non-MIMO subframes; one or more MIMO subframes; one or more first type layered MIMO subframes; or one or more second type layered MIMO subframes.

[0246] At this time, if the first subframe that activates the first polarization is the Non-MIMO subframe and the Non-MIMO subframe is not transmitted with the second polarization, the power of the preamble symbol corresponding to the second preamble may refer to the data symbol power of the first subframe that activates the second polarization after the mute corresponding to the Non-MIMO subframe.

[0247] At this time, if the first subframe that activates the first polarization is the second type layered MIMO subframe, the power of the preamble symbol corresponding to the second preamble may be lower than the power of the preamble symbol corresponding to the first preamble.

[0248] When a broadcast signal with MIMO technology is transmitted (when a MIMO subframe, a type 1 layered MIMO subframe, or a type 2 layered MIMO subframe is used), the bootstrap and preamble can be transmitted in one of the two ways below.

[0249] - Both the first polarization (ANT1) and the second polarization (ANT2) transmit bootstrap and preamble.

[0250] - A method of transmitting bootstrap and preamble only through one of the first polarization (ANT1) and the second polarization (ANT2).

[0251] That is, when a broadcast signal to which MIMO technology is applied is transmitted, one of two methods can be used for bootstrap and preamble transmission: a method in which the first polarization (ANT1) and the second polarization (ANT2) transmit the same signal, and a method in which only one of the first polarization (ANT1) and the second polarization (ANT2) transmits the bootstrap and preamble signal and the other is muted.

[0252] FIG. 12 is a diagram showing a physical layer frame of a broadcast signal according to an embodiment of the present invention.

[0253] Referring to FIG. 12, it can be seen that the physical layer frame of a broadcast signal according to one embodiment of the present invention has a structure in which a bootstrap, a preamble, and a data subframe are connected in time series.

[0254] In particular, data within the physical layer frame illustrated in FIG. 12 can be transmitted using multiple data subframes.

[0255] At this time, even if MIMO is applied to the data and the subframe(s) corresponding to the data are MIMO subframe(s), first type layered MIMO subframe(s), or second type layered MIMO subframe(s), the preamble may not be transmitted in MIMO mode (using spatial multiplexing).

[0256] Therefore, if the first subframe after the preamble is a MIMO subframe, a type 1 layered MIMO subframe, or a type 2 layered MIMO subframe, a transmission mode discontinuity between the SISO mode and the MIMO mode may occur.

[0257] Unlike SISO, MIMO requires each of the multiple antenna units to independently obtain information on the corresponding channel, so a pilot signal for a time period corresponding to a data subframe can be transmitted independently for each of the first polarization transmission channel and the second polarization transmission channel.

[0258] However, since MIMO is not applied to the preamble, the acquired integrated channel information can be used for decoding for the preamble without distinguishing between the channel corresponding to the first polarization and the channel corresponding to the second polarization.

[0259] At this time, when a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe is used, preamble transmission can be done in one of the two ways below.

[0260] - Both the first polarization and the second polarization transmit a preamble.

[0261] - Transmit preamble only in either the first or second polarization.

[0262] Even when both the first polarization and the second polarization transmit preambles, the receiver may not be able to distinguish and obtain channel information corresponding to the first polarization and channel information corresponding to the second polarization in the time interval corresponding to the preambles because the transmitter applies the same pilot signal to both the preambles of the first polarization and the second polarization.

[0263] When channel information acquired in the preamble signal section is used for decoding data signals to which MIMO, type 1 layered MIMO, or type 2 layered MIMO is applied in the subsequent subframe section, serious errors or performance degradation may occur.

[0264] Therefore, when MIMO, type 1 layered MIMO or type 2 layered MIMO is applied, the receiver may be prohibited from reusing channel estimation information used in the preamble to demodulate subframe data.

[0265] FIG. 13 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a MIMO subframe.

[0266] Referring to FIG. 13, it can be seen that a preamble is positioned following a bootstrap, and the first subframe following the preamble is a MIMO subframe.

[0267] FIG. 14 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a first type layered MIMO subframe.

[0268] Referring to FIG. 14, it can be seen that a preamble is positioned following a bootstrap, and the first subframe following the preamble is a type 1 layered MIMO subframe.

[0269] FIG. 15 is a diagram showing an example of a broadcast signal frame when the first subframe after the preamble is a second type layered MIMO subframe.

[0270] Referring to FIG. 15, it can be seen that a preamble is positioned following a bootstrap, and the first subframe following the preamble is a type 2 MIMO subframe.

[0271] When both the first polarization and the second polarization transmit a preamble, the channel estimation information obtained by the receiver through the preamble pilot in the preamble period may be prevented from being interpolated with the channel estimation information obtained through the pilot signal of MIMO or the first type layered MIMO to obtain channel estimation information for MIMO or the first type layered MIMO.

[0272] Similarly, when both the first polarization and the second polarization transmit a preamble, when the receiver decodes the enhanced layer of the second type layered MIMO, the channel estimation information obtained by the receiver through the preamble pilot in the preamble section may be prevented from being interpolated with the channel estimation information obtained through the pilot signal of the second type layered MIMO to obtain channel estimation information for the second type layered MIMO.

[0273] However, when only the first polarization transmits the preamble, the enhanced layer receiver of MIMO, type 1 layered MIMO, or type 2 layered MIMO may reuse the channel estimation information obtained from the preamble pilot in the following situations:

[0274] - For information about the channel between the first polarization of the transmitter and the first polarization of the receiver and information about the channel between the first polarization of the transmitter and the second polarization of the receiver, interpolation of information obtained from the preamble pilot signal and information obtained from the subframe MIMO pilot may be allowed.

[0275] When only the second polarization transmits the preamble, the enhanced layer receiver of MIMO, type 1 layered MIMO, or type 2 layered MIMO can reuse the channel estimation information obtained from the preamble pilot in the following situations:

[0276] - For information about the channel between the second polarization of the transmitter and the first polarization of the receiver and for information about the channel between the second polarization of the transmitter and the second polarization of the receiver, interpolation of information obtained from the preamble pilot signal and information obtained from the subframe MIMO pilot may be allowed.

[0277] When only one of the first polarization and the second polarization transmits the preamble and the transmission example of FIG. 1 is applied, the core layer receiver of the second type layered MIMO may not use interpolation of the channel information obtained from the preamble pilot and the channel information obtained from the subframe pilot.

[0278] According to cell multiplexing based on ATSC 3.0, if there are spare cell(s) remaining after filling the preamble data in the last symbol of the OFDM symbols of the preamble, the data cell(s) of the first subframe can be allocated to the spare preamble cell(s).

[0279] FIG. 16 is a diagram illustrating an example of data cell addressing when a preamble symbol is associated with a subframe.

[0280] Referring to Fig. 16, some cell positions (0, 1, ..., N) of the last preamble symbol C P -1) You can see that data cells are assigned.

[0281] At this time, N C P may be the number of available data cells within the last symbol of the preamble.

[0282] At this time, N C D may be the number of available data cells within a data symbol.

[0283] At this time, N C B may be the number of available data cells of a subframe boundary symbol.

[0284] However, if the first subframe after the preamble is a MIMO subframe, a type 1 layered MIMO subframe, or a type 2 layered MIMO subframe, allocating data cell(s) to the preamble cell(s) may be prohibited.

[0285] FIG. 17 is a diagram showing an example of a broadcast signal frame when the first subframe is a MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0286] Referring to FIG. 17, it can be seen that some of the data cells of the first subframe (SL) MIMO subframe are allocated to cell positions of the preamble.

[0287] FIG. 18 is a diagram showing an example of a broadcast signal frame when the first subframe is a first type layered MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0288] Referring to FIG. 18, it can be seen that some of the data cells of the first type layered MIMO subframe, which is the first subframe, are allocated to cell positions of the preamble.

[0289] When the broadcast signal frames of the examples illustrated in FIGS. 17 and 18 are used, whether each subframe within the transmitted broadcast signal frame is a MIMO subframe or a first-type layered MIMO subframe is conveyed to the receiver via signaling field(s) signaled within the preamble. In addition, considering compatibility with SISO receivers, it is preferable that the MIMO method not be applied to cells containing signaling information among the preamble and bootstrap signal.

[0290] Additionally, a transmitter supporting MIMO transmission may transmit the same preamble signal in the first polarization and the second polarization, or may transmit the preamble signal in only one of the first polarization and the second polarization.

[0291] When there are extra cell(s) in the last symbol of the OFDM symbols of the preamble and MIMO or type 1 layered MIMO is applied to the first PLP (Physical Layer Pipe) of the first subframe, the following cell allocation method may be used.

[0292] - MIMO is not applied to cells containing preamble data necessary for signaling, etc., among the preamble cells, and data cells of the first subframe with MIMO (SL MIMO, type 1 layered MIMO) applied are allocated to the extra cell positions within the last preamble symbol.

[0293] However, in this case, additional limitations and problems may arise in aspects such as channel estimation, and problems may also arise in the operation of existing single-antenna receivers.

[0294] Additionally, additional functionality may be required to include pilot transmissions for MIMO in the preamble section as well.

[0295] Therefore, when the first subframe is an SL MIMO subframe or a type 1 layered MIMO subframe, allocating data cells to the spare cells may be prohibited even if spare cells occur in the last symbol of the preamble.

[0296] That is, the start position field (L1D_plp_start) indicating the start of the first PLP of the first subframe to which MIMO (SL MIMO) or type 1 layered MIMO is applied may correspond to a subframe section other than a preamble section.

[0297] FIG. 19 is a diagram showing an example of a broadcast signal frame when the first subframe is a second type layered MIMO subframe when the cell addressing illustrated in FIG. 16 is applied.

[0298] Referring to FIG. 19, it can be seen that some of the data cells of the second type layered MIMO subframe, which is the first subframe, are allocated to the cell positions of the preamble. That is, in the example of FIG. 19, if the first subframe is a second type layered MIMO subframe and extra cells occur in the last symbol of the preamble, the data cells of the first subframe can be allocated to the corresponding extra preamble cell positions.

[0299] At this time, MIMO (Type 2 Layered MIMO) modulation may not be applied to cells containing signaling information among the preamble and bootstrap signals.

[0300] At this time, a transmitter supporting MIMO transmission may transmit the same preamble signal in the first polarization and the second polarization, or may transmit the preamble signal in only one of the first polarization and the second polarization.

[0301] At this time, the pilot signal transmitted in the preamble section may not use a pilot configuration for MIMO. To receive a MIMO transmission signal, the first polarization channel and the second polarization channel must be distinguished and estimated, but the pilot signal in the preamble section may not support this.

[0302] If the first subframe following the preamble is a type 2 layered MIMO subframe, unlike the cases of FIGS. 17 and 18, 0 may be assigned to the MIMO signaling field (L1B_first_sub_mimo) (indicating that MIMO is not applied to the first subframe). In this case, pilot signals may also be transmitted continuously for core layer signals.

[0303] At this time, since the core layer signal of the second type layered MIMO uses the SISO transmission method, it may be possible to use the resource of the preamble symbol as a data cell.

[0304] If the first subframe after the preamble is a type 2 layered MIMO subframe and spare cells occur in the last symbol of the preamble, the following two options may be considered for allocating data cells to the preamble spare cells.

[0305] - L1D_plp_start of the core layer and L1D_plp_start of the enhanced layer are the same, and they are both located in the preamble spare cell section.

[0306] - L1D_plp_start of the core layer and L1D_plp_start of the enhanced layer are different, and L1D_plp_start of the core layer physical layer pipe is located in the preamble spare cell section, but L1D_plp_start of the enhanced layer PLP is located in the subframe section.

[0307] If both L1D_plp_start of the core layer and L1D_plp_start of the enhanced layer are located in the preamble spare cell section, the core layer receiver does not experience any operation problems, but the receiver receiving the enhanced layer of the second type layered MIMO may experience reception problems. In this case, since the enhanced layer signal of the second type layered MIMO applies MIMO, a problem may arise in that a MIMO pilot transmission must be newly defined in the preamble section. If this is not accompanied, the enhanced layer receiver may experience a problem in that it cannot independently estimate the channel of the first polarization and the channel of the second polarization during the decoding process.

[0308] If the L1D_plp_start of the core layer physical layer pipe is located in the preamble spare cell section but the L1D_plp_start of the enhanced layer PLP is located in the subframe section, the core layer signal transmitted in the preamble section may be transmitted in combination with a dummy signal inserted at the same injection level as the enhanced layer signal. At this time, the dummy signal may refer to a randomly generated signal that does not carry data. At this time, the dummy signal being inserted at the same injection level as the enhanced layer signal may refer to the power ratio of the dummy signal to the core layer signal being the same as the power ratio of the enhanced layer signal to the core layer signal. At this time, the dummy signal of the first polarization and the dummy signal of the second polarization may be the same or different.

[0309] Figure 20 is a diagram showing a broadcast signal frame and transmission signals when a core layer signal is transmitted in combination with a dummy signal in the preamble section.

[0310] Referring to FIG. 20, it can be seen that L1D_plp_start (L1D_plp_start(CL)) of the core layer PLP of the second type layered MIMO subframe, which is the first subframe, is included in the preamble period, and L1D_plp_start (L1D_plp_start(EL)) of the enhanced layer PLP of the second type layered MIMO subframe, which is the first subframe, is included in the subframe period.

[0311] At this time, the core layer signal included in the preamble section can be layered division multiplexed with a dummy signal having the same injection level as the enhanced signal.

[0312] That is, in the embodiment illustrated in FIG. 20, when the first subframe after the preamble is a second type layered MIMO subframe and a data cell is allocated to the last preamble symbol, a dummy signal can be injected and transmitted during the preamble cell period in the enhanced layer of the second type layered MIMO.

[0313] However, for the efficiency of time interleaving in layered division multiplexing transmission, L1D_plp_start of the core layer and L1D_plp_start of the enhanced layer can be set to be the same.

[0314] Therefore, in order to prevent a functional problem of the enhanced layer of the second type layered MIMO when both L1D_plp_start of the core layer and L1D_plp_start of the enhanced layer are located in the preamble spare cell interval and an inefficiency when L1D_plp_start of the core layer physical layer pipe is located in the preamble spare cell interval but L1D_plp_start of the enhanced layer PLP is located in the subframe interval, when the first subframe following the preamble is a second type layered MIMO subframe, allocation of data cells to the spare cells may be prohibited even if spare cells occur in the last symbol of the preamble.

[0315] That is, the start position field (L1D_plp_start) indicating the start of the first PLP of the first subframe to which the second type layered MIMO is applied may correspond to a subframe section rather than a preamble section.

[0316] Figure 21 is a flowchart illustrating a broadcast signal transmission method according to one embodiment of the present invention.

[0317] Referring to FIG. 21, a broadcast signal transmission method according to one embodiment of the present invention outputs a first polarization signal corresponding to the first polarization and a second polarization signal corresponding to the second polarization (S2110).

[0318] In addition, a broadcast signal transmission method according to one embodiment of the present invention generates a first polarization transmission signal corresponding to the first polarization, and generates a second polarization transmission signal corresponding to the second polarization (S2120).

[0319] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble.

[0320] At this time, the preamble may include a final preamble symbol containing at least one cell position.

[0321] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0322] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0323] At this time, the MIMO processing may not be applied to the preamble.

[0324] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0325] At this time, the power of the last preamble symbol may refer to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

[0326] Figure 22 is a flowchart illustrating a broadcast signal receiving method according to one embodiment of the present invention.

[0327] Referring to FIG. 22, a broadcast signal receiving method according to an embodiment of the present invention receives a first polarization transmission signal corresponding to a first polarization and a second polarization transmission signal corresponding to a second polarization (S2210).

[0328] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble.

[0329] At this time, the preamble may include a final preamble symbol containing at least one cell position.

[0330] At this time, the at least one cell location may not be allocated to a data cell corresponding to the first subframe if MIMO processing is applied to the first subframe following the preamble.

[0331] At this time, the first subframe may be any one of a MIMO subframe, a first type layered MIMO subframe, or a second type layered MIMO subframe.

[0332] At this time, the MIMO processing may not be applied to the preamble.

[0333] At this time, the PLP (Physical Layer Pipe) start location field (L1D_plp_start) corresponding to the first subframe may correspond to a subframe section other than a preamble section.

[0334] At this time, the power of the last preamble symbol may refer to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

[0335] In addition, a broadcast signal receiving method according to one embodiment of the present invention restores a data stream through decoding corresponding to at least one of the first polarization and the second polarization (S2220).

[0336] At this time, step (S2220) may include a step of restoring a core layer stream through decoding corresponding to at least one of the first polarization and the second polarization; and a step of restoring an enhanced layer stream through MIMO decoding using first polarization enhanced layer symbols corresponding to the first polarization and second polarization enhanced layer symbols corresponding to the second polarization.

[0337] At this time, when the first polarization transmission signal and the second polarization transmission signal generated through the transmission structure of FIGS. 3 and 4 are received, the core layer stream can be restored through decoding corresponding to the first polarization.

[0338] At this time, when the first polarization transmission signal and the second polarization transmission signal generated through the transmission structure of FIG. 11 are received, the core layer stream can be restored through MIMO decoding corresponding to the first polarization and the second polarization.

[0339] Each step illustrated in FIGS. 21 and 22 may be performed in the order illustrated in FIGS. 21 and 22, in the reverse order, or simultaneously.

[0340] Figure 23 is a block diagram showing a computer system configuration according to one embodiment of the present invention.

[0341] The broadcast signal transmitting device, the broadcast signal receiving device and the individual components constituting these devices according to the embodiment can be implemented in a computer system (2300).

[0342] The computer system (2300) may include one or more processors (2310), memory (2330), user interface input devices (2340), user interface output devices (2350), and storage (2360) that communicate with each other via a bus (2320). The computer system (2300) may further include a network interface (2370) connected to a network (2380). The processor (2310) may be a central processing unit or a semiconductor device that executes programs or processing instructions stored in the memory (2330) or storage (2360). The memory (2330) and storage (2360) may be storage media that include at least one of a volatile medium, a nonvolatile medium, a removable medium, a non-removable medium, a communication medium, or an information transmission medium. For example, the memory (2330) may include a ROM (2331) or a RAM (2332).

[0343] At this time, at least one program can be recorded in the memory (2330).

[0344] At this time, the processor (2310) can execute the program. At this time, the program can perform each step illustrated in FIG. 21 or each step illustrated in FIG. 22.

[0345]

[0346] As described above, the broadcast signal transmission device, method, and broadcast signal reception method according to the present invention are not limited to the configurations and methods of the embodiments described above, but the embodiments may be configured by selectively combining all or part of the embodiments so that various modifications can be made.

Claims

1. A subframe signal generation unit that outputs a first polarization signal corresponding to the first polarization and a second polarization signal corresponding to the second polarization; and A transmission signal generation unit that generates a first polarization transmission signal corresponding to the first polarization and a second polarization transmission signal corresponding to the second polarization is included. A broadcast signal transmission device, wherein at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

2. In claim 1, A broadcast signal transmitting device, wherein the preamble includes a final preamble symbol including at least one cell position.

3. In claim 2, At least one cell location above A broadcast signal transmitting device that is not allocated to a data cell corresponding to the first subframe when MIMO processing is applied to the first subframe following the above preamble.

4. In claim 3, The first subframe above is MIMO subframe, Type 1 layered MIMO subframe or A broadcast signal transmitting device, one of the second type layered MIMO subframes.

5. In claim 3, The above MIMO processing is A broadcast signal transmitting device not applicable to the above preamble.

6. In claim 5, A broadcast signal transmitting device, wherein the PLP (Physical Layer Pipe) start position field (L1D_plp_start) corresponding to the first subframe corresponds to a subframe section other than a preamble section.

7. In claim 2, The power of the last preamble symbol above is A broadcast signal transmitting device, which references data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

8. A step of outputting a first polarization signal corresponding to the first polarization and a second polarization signal corresponding to the second polarization; and A step of generating a first polarization transmission signal corresponding to the first polarization and generating a second polarization transmission signal corresponding to the second polarization is included. A broadcast signal transmission method, wherein at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

9. In claim 8, A method for transmitting a broadcast signal, wherein the preamble includes a final preamble symbol including at least one cell position.

10. In claim 9, At least one cell location above A method for transmitting a broadcast signal, wherein, when MIMO processing is applied to the first subframe following the above preamble, the data cell corresponding to the first subframe is not allocated.

11. In claim 10, The first subframe above is MIMO subframe, Type 1 layered MIMO subframe or A method for transmitting a broadcast signal, wherein the method is any one of the second type layered MIMO subframes.

12. In claim 10, The above MIMO processing is A method of transmitting a broadcast signal, which does not apply to the above preamble.

13. In claim 12, A method for transmitting a broadcast signal, wherein the PLP (Physical Layer Pipe) start position field (L1D_plp_start) corresponding to the first subframe corresponds to a subframe section other than a preamble section.

14. In claim 13, The power of the last preamble symbol above is A method for transmitting a broadcast signal, which refers to the data symbol power of the first subframe activating the polarization in which the preamble is transmitted.

15. A step of receiving a first polarization transmission signal corresponding to the first polarization and a second polarization transmission signal corresponding to the second polarization; and A step of restoring a data stream through decoding corresponding to at least one of the first polarization and the second polarization, A method for receiving a broadcast signal, wherein at least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble.

16. In claim 15, A method for receiving a broadcast signal, wherein the preamble includes a final preamble symbol that includes at least one cell position.

17. In claim 16, At least one cell location above A method for receiving a broadcast signal, wherein MIMO processing is applied to the first subframe following the above preamble, and the data cell corresponding to the first subframe is not allocated.

18. In claim 17, The first subframe above is MIMO subframe, Type 1 layered MIMO subframe or A method for receiving a broadcast signal, wherein the method is one of the second type layered MIMO subframes.

19. In claim 17, The above MIMO processing is A method of receiving a broadcast signal, not applicable to the above preamble.

20. In claim 19, A method for receiving a broadcast signal, wherein the PLP (Physical Layer Pipe) start position field (L1D_plp_start) corresponding to the first subframe corresponds to a subframe section other than a preamble section.

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