Broadcast signal transmission device using multiple transmitting antennas and hierarchical division multiplexing, and method using same

Abstract

A broadcast signal transmission device, according to one embodiment of the present invention, comprises: a core layer signal generation unit that generates a core layer signal; an enhanced layer MIMO signal generation unit that generates enhanced layer MIMO signals; an LDM combiner that generates a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal and a second polarization signal corresponding to the other of the enhanced layer MIMO signals; and a transmission signal generation unit that generates a first polarization transmission signal using the first polarization signal and a second polarization transmission signal corresponding to the second polarization using the second polarization signal.

Description

Broadcast signal transmission device using multiple transmission antennas and hierarchical division multiplexing and method using the same

[0001] The present invention relates to a broadcast signal transmission / reception system, and more particularly, to a broadcast signal transmission / reception system that simultaneously supports layered division multiplexing technology and MIMO (Multiple-Input Multiple-Output) technology.

[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 utilizing LDM and MIMO technologies together while ensuring compatibility with existing single-antenna receivers, the core layer can adopt the Single-Input Single-Output (SISO) method, while the enhanced layer can adopt the MIMO method. In this case, SISO may not separate a single service into multiple streams and transmit them independently. In this case, even if two antennas apply the same signal, it can 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] In terrestrial broadcasting, the Single Frequency Network (SFN) is emerging as an alternative to traditional Multiple Frequency Network (MFN) modes. An SFN allows multiple transmitters to transmit signals simultaneously on the same RF channel.

[0015] SFN networks offer increased spectral efficiency as well as a homogeneous distribution of received signal strength across the coverage area. However, some areas may experience signal degradation. The amplitude of Digital Terrestrial Television (DTT) echoes, which have similar signal strength but different phases, reach the receiver, causing severe multipath conditions that generate destructive interference.

[0016] To limit these undesirable situations, new features such as Multiple-Input Single-Output (MISO) are being implemented in new generations of DTT.

[0017] MISO refers to a radio link that utilizes at least two transmitters and one receiver. MISO utilizes the spatial diversity of multiple antennas to improve the robustness of terrestrial transmission. This MISO technology is described in detail in Korean Patent Publication No. 10-2018-0128851.

[0018] However, all of the above-mentioned prior arts are completely silent about environments where MIMO, LDM, and MISO are used together.

[0019] An object of the present invention is to enable a broadcast signal transmission / reception system to operate efficiently when MISO operation is applied in an environment where layered division multiplexing (LDM) and MIMO technology are used together.

[0020] 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.

[0021] Additionally, it is an object of the present invention to prevent pilots included in preambles and subframes from being used inefficiently.

[0022] In order to achieve the above object, a broadcast signal transmission device according to the present invention includes a core layer signal generation unit that generates a core layer signal; an enhanced layer MIMO signal generation unit that generates enhanced layer MIMO (Multiple-Input Multiple-Output) signals; an LDM combiner that generates a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal and a second polarization signal corresponding to the other of the enhanced layer MIMO signals; and a transmission signal generation unit that generates a first polarization transmission signal corresponding to the first polarization using the first polarization signal and a second polarization transmission signal corresponding to the second polarization using the second polarization signal.

[0023] At this time, when MISO (Multiple-Input Single-Output) is applied, the first polarization may correspond to a first MISO code index, and the second polarization may correspond to a second MISO code index that is different from the first MISO code index.

[0024] At this time, the first MISO code index and the second MISO code index may be set to correspond to MISO code index fields included in a timing and management packet transmitted through a studio-to-transmitter link (STL).

[0025] At this time, the timing and management packet may include structure data including first data fields that are commonly applied to the transmitters and include a field regarding whether MIMO is applied, and transmitter-specific data including second data fields for one of the transmitters.

[0026] At this time, the data for each transmitter may be composed of the same number of bits for each transmitter, regardless of the number of polarizations corresponding to the transmitter.

[0027] At this time, the data for each transmitter may include 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

[0028] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble, and the preamble may include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

[0029] 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.

[0030] In addition, in one embodiment of the present invention, a broadcast signal transmission method includes the steps of: generating a core layer signal; generating enhanced layer MIMO (Multiple-Input Multiple-Output) signals; generating a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal, and a second polarization signal corresponding to another of the enhanced layer MIMO signals; and generating a first polarization transmission signal corresponding to the first polarization using the first polarization signal, and generating a second polarization transmission signal corresponding to the second polarization using the second polarization signal.

[0031] At this time, when MISO (Multiple-Input Single-Output) is applied, the first polarization may correspond to a first MISO code index, and the second polarization may correspond to a second MISO code index that is different from the first MISO code index.

[0032] At this time, the first MISO code index and the second MISO code index may be set to correspond to MISO code index fields included in a timing and management packet transmitted through a studio-to-transmitter link (STL).

[0033] At this time, the timing and management packet may include structure data including first data fields that are commonly applied to the transmitters and include a field regarding whether MIMO is applied, and transmitter-specific data including second data fields for one of the transmitters.

[0034] At this time, the data for each transmitter may be composed of the same number of bits for each transmitter, regardless of the number of polarizations corresponding to the transmitter.

[0035] At this time, the data for each transmitter may include 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

[0036] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble, and the preamble may include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

[0037] 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.

[0038] In addition, a gateway signaling method according to an embodiment of the present invention includes the steps of: generating structure data including first data fields that are commonly applied to transmitters and include a field regarding whether MIMO is applied; generating transmitter-specific data including second data fields for one of the transmitters; generating a timing and management packet including the structure data and the transmitter-specific data; and transmitting the timing and management packet to the transmitters via a studio-to-transmitter link (STL). At this time, the timing and management packet may include two MISO code index fields allocated for each of two polarizations when the field regarding whether MIMO is applied satisfies a preset condition.

[0039] At this time, one of the two polarizations may correspond to one of the enhanced layer MIMO signals and the core layer signal, and the other of the two polarizations may correspond to the other of the enhanced layer MIMO signals.

[0040] At this time, the above MISO code index fields may be set differently from each other.

[0041] At this time, the data for each transmitter may include 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

[0042] According to the present invention, when MISO operation is applied in an environment where layered division multiplexing (LDM) and MIMO technology are used together, a broadcast signal transmission / reception system can be made to operate efficiently.

[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] Additionally, the present invention can prevent pilots included in a preamble and subframe from being used inefficiently.

[0045] 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.

[0046] FIG. 3 is a block diagram showing an example of a broadcast signal transmission device according to one embodiment of the present invention.

[0047] Fig. 4 is a block diagram showing an example of the LDM coupling unit illustrated in Fig. 3.

[0048] Figure 5 is a diagram showing an example of a SISO distributed pilot pattern corresponding to SP3_2.

[0049] FIG. 6 is a diagram showing an example of a Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0050] FIG. 7 is a diagram showing an example of a null pilot encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0051] 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.

[0052] FIG. 9 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted through both MIMO antennas.

[0053] Figure 10 is a diagram comparing a SISO distributed pilot pattern and a MIMO distributed pilot pattern.

[0054] FIG. 11 is a diagram illustrating a single frequency network system according to one embodiment of the present invention.

[0055] Fig. 12 is a block diagram showing an example of the broadcast gateway device illustrated in Fig. 11.

[0056] Figure 13 is an operational flowchart illustrating a gateway signaling method according to one embodiment of the present invention.

[0057] Figure 14 is a flowchart illustrating a broadcast signal transmission method according to one embodiment of the present invention.

[0058] Figure 15 is a block diagram showing a computer system configuration according to one embodiment of the present invention.

[0059] 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 are 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.

[0060] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] FIG. 3 is a block diagram showing an example of a broadcast signal transmission device according to one embodiment of the present invention.

[0068] 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.

[0069] 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).

[0070] The core layer signal generation unit (310) generates a core layer signal (SISO signal).

[0071] The core layer signal generation unit (310) includes an input formatting unit (311) and a core layer BICM (Bit-Interleaved Coded Modulation) unit (312).

[0072] 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).

[0073] 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 output to be transmitted through an antenna for the output bit string of the BIL unit, and output them as core layer signals.

[0074] The enhanced layer MIMO signal generation unit (320) generates enhanced layer MIMO (Multiple-Input Multiple-Output) signals.

[0075] 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).

[0076] 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).

[0077] The enhanced layer BICM unit (322) may include an FEC (Forward Error Correction) unit, a BIL (Bit Interleaver) unit, and a MIMO (Multiple-Input Multiple-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.

[0078] 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.

[0079] Hereinafter, the first antenna may be replaced with the first polarization, and the second antenna may be replaced with the second polarization.

[0080] Two groups of data cells are input to the MIMO precoder (323).

[0081] 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).

[0082] 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).

[0083] At this time, the LDM coupling unit (330) can output the second polarization signal with unity power.

[0084] The transmission signal generation unit (340) generates a first polarization transmission signal corresponding to the first polarization using the first polarization signal, and generates a second polarization transmission signal corresponding to the second polarization using the second polarization signal.

[0085] The transmission signal generation unit (340) includes framing & interleaving units (341, 342) and waveform generators (345, 346).

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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).

[0095] FIG. 4 is a block diagram showing an example of the LDM coupling unit (330) illustrated in FIG. 3.

[0096] Referring to FIG. 4, the LDM coupling unit (330) includes an injection level controller (410), a coupler (420), and a power normalizer (430).

[0097] 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.

[0098] 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.

[0099] 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.

[0100] The power normalizer (430) performs transmission power normalization and outputs a first polarization signal.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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).

[0110] 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.

[0111] 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.

[0112] At this time, L1B_first_sub_mimo and L1D_mimo can indicate whether MIMO transmission is applied to the corresponding subframe.

[0113] 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.

[0114] 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

[0115] Table 1 shows the signaling formats of L1D_scattered_pilot_pattern and L1B_first_sub_scattered_pilot_pattern for SISO.

[0116] 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

[0117] Table 2 shows the signaling formats of L1D_scattered_pilot_pattern and L1B_first_sub_scattered_pilot_pattern for MIMO.

[0118] In Tables 1 and 2, SP represents SISO Pilot and MP represents MIMO Pilot.

[0119] Ultimately, when combining LDM and MIMO technologies to transmit SISO and MIMO signals in the same subframe, considering the existing SISO receiver, 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.

[0120] 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.

[0121] 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).

[0122] The MIMO distributed pilot pattern used in ATSC 3.0 systems is defined using either Walsh-Hadamard encoding or null-pilot encoding.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] This relationship can be summarized as shown in Table 3 below.

[0129] Pilot EncodingAlgorithmAntennaScatteredPilotSubframeBoundaryPilotCommonContinualPilotAdditionalContinualPilotEdgePilotWalsh-Hadamard#1SISOSISOSISOSISOSISO#2WHWHSISOSISO / WHWHNull Pilot#1NPSISOSISOSISO / NPSISO#2NPWHSISOSISO / NPWH

[0130] In Table 3, WH represents Walsh-Hadamard and NP represents Null Pilot.

[0131] 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.

[0132] Figure 5 is a diagram showing an example of a SISO distributed pilot pattern corresponding to SP3_2.

[0133] Referring to Figure 5, D for SISO X = 3 and D Y = You can find out the pilot positions in case 2.

[0134] FIG. 6 is a diagram showing an example of a Walsh-Hadamard encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] FIG. 7 is a diagram showing an example of a null pilot encoded MIMO distributed pilot pattern corresponding to MP3_2.

[0139] 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 for the grouping.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] - When the Walsh-Hadamard pilot pattern is used

[0147] - If there is no subframe with MIMO applied within the transmission frame

[0148] 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.

[0149] 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.

[0150] If there are no MIMO subframes in a transmission frame other than the subframes in which SISO and MIMO are combined with LDM, and a 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] FIG. 9 is a diagram showing an example of a transmission signal configuration when a SISO signal is transmitted through both MIMO antennas.

[0159] 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).

[0160] 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.

[0161] Figure 10 is a diagram comparing a SISO distributed pilot pattern and a MIMO distributed pilot pattern.

[0162] 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.

[0163] When the same signal waves are transmitted from different locations, the signal quality may deteriorate at some receiving locations due to destructive interference between multiple transmitted signal waves, resulting in a decrease in reception efficiency.

[0164] To solve this, filtering can be applied to intentionally distort the transmission signal of each transmitter through MISO (Multiple-Input Single-Output) operation, and the filtering codes used for this filtering are called Transmit Diversity Code Filter Set (TDCFS).

[0165] MISO filtering can be applied per transmitter and per subframe, and TDCFS can be selected in one of three ways: two enabling options using filters with 64 filter coefficients and two disabling options using filters with 256 filter coefficients.

[0166] At this time, whether {disabled, 64-tap filtering, 256-tap filtering} is applied is conveyed to the receiver through L1 signaling, and the signaling field used is L1D_miso (if it is not the first subframe) or L1B_first_sub_miso (if it is the first subframe).

[0167] ValueMISO option00No MISO01MISO with 64 coefficients10MISO with 256 coefficients11Reserved

[0168] Table 4 above shows the signaling formats of L1D_miso and L1D_first_sub_miso.

[0169] Once the MISO scheme corresponding to the signaling field L1D_miso (if not the first subframe) or L1B_first_sub_miso (if the first subframe) is determined, each transmitter (or polarization) composing the SFN can select and use one of up to four MISO filter codes.

[0170] For example, when 64-tap filtering is applied to the transmitters that constitute a single SFN, each transmitter can use different filter coefficient combinations. In this case, one of up to four combinations can be selected and used.

[0171] Which filter coefficient combination (i.e., MISO filter code) each transmitter uses can be determined based on the MISO code index.

[0172] At this time, the MISO code index (MISO filter code index) can be defined by the MISO code index field (miso_filt_code_index) included in the timing and management packet transmitted via the Studio to Transmitter Link (STL). As will be described later, the MISO code index field can be set for each polarization.

[0173] The frequency-domain pre-distortion function of the code filter may correspond to time-domain impulse response vectors. In this case, the time-domain impulse response vectors may contain as many complex numbers as the filter length. For example, if the filter length is 64, the time-domain impulse response vectors may contain 64 complex numbers, and if the filter length is 256, the time-domain impulse response vectors may contain 256 complex numbers.

[0174] At this time, the time domain impulse response vectors are the number of different MISO filter codes (N TX ∈ {2, 3, 4}) and MISO code index (h x ) can be determined. At this time, x ∈ {1, ..., N TX} can be determined. That is, when the number of different MISO filter codes and the MISO code index are determined, complex numbers corresponding to the filter length can be determined.

[0175] For example, when the number of different MISO filter codes is 2 and a MISO mode using 64 coefficients is used, 64 complex numbers corresponding to the MISO code index h1 and 64 complex numbers corresponding to the MISO code index h2 are stored in a table, and when MISO is performed, the complex numbers corresponding to the transmitter can be read from the table.

[0176] For example, when the number of different MISO filter codes is 3 and a MISO mode using 64 coefficients is used, 64 complex numbers corresponding to MISO code index h1, 64 complex numbers corresponding to MISO code index h2, and 64 complex numbers corresponding to MISO code index h3 are stored in a table, and when MISO is performed, complex numbers corresponding to the corresponding transmitter can be read from the table.

[0177] For example, when the number of different MISO filter codes is 4 and a MISO mode using 64 coefficients is used, 64 complex numbers corresponding to MISO code index h1, 64 complex numbers corresponding to MISO code index h2, 64 complex numbers corresponding to MISO code index h3, and 64 complex numbers corresponding to MISO code index h4 are stored in a table, and when MISO is performed, the complex numbers corresponding to the corresponding transmitter can be read from the table.

[0178] For example, when the number of different MISO filter codes is 2 and a MISO mode using 256 coefficients is used, 256 complex numbers corresponding to the MISO code index h1 and 256 complex numbers corresponding to the MISO code index h2 are stored in a table, and when MISO is performed, the complex numbers corresponding to the transmitter can be read from the table.

[0179] For example, when the number of different MISO filter codes is 3 and a MISO mode using 256 coefficients is used, 256 complex numbers corresponding to MISO code index h1, 256 complex numbers corresponding to MISO code index h2, and 256 complex numbers corresponding to MISO code index h3 are stored in a table, and when MISO is performed, complex numbers corresponding to the corresponding transmitter can be read from the table.

[0180] For example, when the number of different MISO filter codes is 4 and a MISO mode using 256 coefficients is used, 256 complex numbers corresponding to MISO code index h1, 256 complex numbers corresponding to MISO code index h2, 256 complex numbers corresponding to MISO code index h3, and 256 complex numbers corresponding to MISO code index h4 are stored in a table, and when MISO is performed, the complex numbers corresponding to the corresponding transmitter can be read from the table.

[0181] Details regarding the code filter frequency domain pre-distortion function applied to MISO are disclosed in detail in Korean Patent Publication No. 10-2018-0128851.

[0182] FIG. 11 is a diagram illustrating a single frequency network (SFN) system according to one embodiment of the present invention.

[0183] Referring to FIG. 11, a single frequency network system according to one embodiment of the present invention includes a broadcast gateway device (1110) and a plurality of transmitters (1121, 1122, 1123).

[0184] To utilize MISO in a single frequency network (SFN), the number of different MISO filter codes (M) and the MISO code index (h) are required. x ) Two MISO parameters must be sent to the transmitters (1121, 1122, 1123). At this time, the MISO code index (h x) may need to be provided per antenna (polarization). That is, for convenience of explanation, the explanation focuses on the use of different filter coefficient combinations per transmitter when MISO is applied, but different filter coefficient combinations may be used per polarization (antenna) rather than per transmitter. That is, the MISO code index may be set per polarization (antenna) rather than per transmitter.

[0185] Each of the transmitters (1121, 1122, 1123) has a number (M) of different MISO filter codes used in MISO and its own MISO code index (h x ) to read complex numbers corresponding to filter coefficients from the table. For example, the transmitter (1121) must know that the number of different MISO filter codes M is 3 and its MISO code index is 1 (h1) to generate filter coefficients for TDCFS. For example, the transmitter (1122) must know that the number of different MISO filter codes M is 3 and its MISO code index is 2 (h2) to generate filter coefficients for TDCFS. For example, the transmitter (1123) must know that the number of different MISO filter codes M is 3 and its MISO code index is 3 (h3) to generate filter coefficients for TDCFS.

[0186] In the example illustrated in Fig. 11, a case in which the MISO code index is different for each transmitter is taken as an example, but the MISO code index can only be indexed up to 0, 1, 2, or 3, and therefore, when the number of transmitters or antennas used for MISO exceeds 4, the same MISO code index may be assigned to two or more transmitters or antennas.

[0187] The total number of different MISO filter codes used in MISO (M) and their MISO code index (MISO filter coefficient index or MISO filter index) (h x ) do not need to be included in the preamble, but are required for SFN design and configuration.

[0188] At this time, MISO parameters can be transmitted to transmitters.

[0189] The broadcast gateway device (1110) transmits the MISO parameters required for each transmitter to the transmitters (1121, 1122, 1123) via a studio-to-transmitter link (STL).

[0190] That is, the transmitters (1121, 1122, 1123) can receive the necessary MISO parameters from the broadcast gateway device (1110) through a studio-to-transmitter link (STL) and perform TDCFS using the received MISO parameters.

[0191] At this time, the studio-to-transmitter link may be a data transmission / reception link between a broadcast gateway device (1110) and transmitters (1121, 1122, 1123) in a broadcast transmission system, and may be a fiber, satellite, or microwave link. At this time, the studio-to-transmitter link may be a wired link or a wireless link, and may be a link in which data is transmitted / received using a packet-based protocol such as RTP / UDP / IP.

[0192] Fig. 12 is a block diagram showing an example of the broadcast gateway device illustrated in Fig. 11.

[0193] Referring to FIG. 12, the broadcast gateway device (1110) illustrated in FIG. 11 includes a structure data generation unit (1210), a transmitter-specific data generation unit (1220), a packet generation unit (1230), and an STL transmission unit (1240).

[0194] The structure data generation unit (1210) generates structure data (Structure_Data()) that includes first data fields that are commonly applied to transmitters and include a field (mimo_flag) regarding whether MIMO is applied. At this time, the first data fields may be data fields that are commonly used by all transmitters.

[0195] At this time, the structure data generation unit (1210) may generate a first MISO field (num_miso_filt_codes) indicating the number of different MISO filter codes used for the MISO as one of the first data fields. That is, the first data fields may include the first MISO field. In addition, the structure data generation unit (1210) may generate a field (mimo_flag) regarding whether the MIMO is applied as one of the first data fields. That is, the first data fields may include a field regarding whether the MIMO is applied.

[0196] At this time, the field regarding whether MIMO is applied (mimo_flag) can indicate that the identified frame includes at least one PLP configured for transmission in MIMO form. If this value is set to 0, the SISO form can be applied exclusively to the entire identified frame. If this value is set to 1, at least one PLP in the frame can be transmitted by the MIMO signal.

[0197] The per-transmitter data generation unit (1220) generates per-transmitter data including second data fields for one of the transmitters used in MISO. At this time, the second data fields may be fields that can have different values ​​for each transmitter. At this time, the second data fields may be provided for each transmitter with the same field name. For example, the second data fields may be defined within a for loop that is repeated as many times as the total number of transmitters.

[0198] At this time, the transmitter-specific data generation unit (1220) may generate a second MISO field (MISO code index field; miso_filt_code_index) indicating the MISO code index (MISO filter code index) of the transmitter as one of the second data fields. That is, the second data fields may include a MISO code index field (miso_filt_code_index).

[0199] At this time, the MISO code index field can be set for each polarization. For example, if mimo_flag is 0, it may correspond to a case where SISO is applied, in which case one MISO code index field may be included. For example, if mimo_flag is 1, it may correspond to a case where MIMO with two polarizations is applied, in which case two MISO code index fields for the two polarizations may be included.

[0200] At this time, the MISO code index field may correspond to a specific MISO filter code assigned to each transmitter (or each polarization if mimo_flag = 1).

[0201] The packet generation unit (1230) is one of the transmitters used for MISO, and generates a timing and management packet for signaling the number of different MISO filter codes and the MISO code index.

[0202] At this time, the timing and management packets may contain structure data and transmitter-specific data.

[0203] The STL transmission unit (1240) transmits the timing and management packets to transmitters via a studio-to-transmitter link (STL).

[0204] At this time, MISO can be performed through pre-distortion processing using a Transmit Diversity Code Filter Set (TDCFS).

[0205] Table 5 below shows an example of timing and management packets.

[0206] SyntaxNo. of BitsFormatTiming and Management_Packet (TMP) (){Structure_Data (){length16Uimsbfversion_major4Uimsbfversion_minor4Uimsbfmaj_log_rep_cnt_pre4Uimsbfmaj_log_rep_cnt_tim4Uimsbfbootstrap_major4Uimsbfbootstrap_minor4Uimsbfmin_time_to_next5Uimsbfsystem_bandwidth2Uimsbfbsr_coefficient7Uimsbfpreamble_structure8Uimsbfea_wakeup2Bslbfnum_emission_tim6Uimsbfnum_xmtrs_in_group_minus_16Uimsbfxmtr_group_num7Uimsbfmaj_log_override3Bslbfnum_miso_filt_codes2Bslbftx_carrier_offset2Tcimsbfmimo_flag1Uimsbfreserved5for (i=0; i<5; i++) '1'}Bootstrap_Timing_Data (){for (i=0; i<=num_emission_tim; i++) {seconds32Uimsbfnanoseconds32Uimsbf}}Per_Transmitter_Data (){for (i=0; i<=num_xmtrs_in_group_minus_1; i++) {tx_time_offset16TcimsbfPer_Transmit_Polarization_Data() {for (j=0; j<=mimo_flag;j++) {xmtr_id13uimsbftxid_injection_lvl4Uimsbfmiso_filt_code_index2Bslbf}If (mimo_flag == 0) {reserved2929 Х '1'} else {reserved10'1111111111'}}Packet_Release_Time (){pkt_rls_seconds4Uimsbfpkt_rls_a-milliseconds10Uimsbfreserved2'11'}Error_Check_Data (){crc1616uimsbf}};

[0207] In Table 5, uimsbf represents unsigned integer, most significant bit first, bslbf represents bit stream, left-most bit first, and Tcimsbf represents two's complement integer, msb first.

[0208] In the example in Table 5, the timing and management packet may correspond to Timing & Management_Packet (TMP) (), the structure data may correspond to Structure_Data (), and the transmitter-specific data may correspond to Per_Transmitter_Data ().

[0209] At this time, the first data fields may be length, version_major, version_minor, maj_log_rep_cnt_pre, maj_log_rep_cnt_tim, bootstrap_major, bootstrap_minor, min_time_to_next, system_bandwidth, bsr_coefficient, preamble_structure, ea_wakeup, num_emission_tim, num_xmtrs_in_group_minus_1, xmtr_group_num, maj_log_override, num_miso_filt_codes, tx_carrier_offset, and mimo_flag.

[0210] At this time, mimo_flag may indicate that the identified frame includes at least one PLP configured for transmission in MIMO form. If this value is set to 0, the SISO form may be applied exclusively to the entire identified frame. If this value is set to 1, at least one PLP in the frame may be carried by the MIMO signal.

[0211] At this time, the second data fields may be tx_time_offset, xmtr_id, txid_injection_lvl, and miso_filt_code_index.

[0212] At this time, the MISO code index field can be a 2-bit miso_filt_code_index.

[0213] At this time, among the second data fields, xmtr_id, txid_injection_lvl and miso_filt_code_index may be defined within a for loop that is repeated a number of times (mimo_flag + 1) determined corresponding to mimo_flag. At this time, among the second data fields, xmtr_id, txid_injection_lvl and miso_filt_code_index may be included in per-polarization data (Per_Transmit_Polarization_Data ()), and the per-polarization data may be data that is applied independently to each antenna (polarization) of the transmitter. That is, the per-polarization data (Per_Transmit_Polarization_Data ()) may include information that is individually addressed to each transmitter or transmitting antenna (polarization) based on the state of the mimo_flag field. When mimo_flag is 0, the per-polarization data contains only one set of xmtr_id, txid_injection_lvl, and miso_filt_code_index. When mimo_flag is 1, the per-polarization data contains two sets of xmtr_id, txid_injection_lvl, and miso_filt_code_index. The first set may be for polarization #1, and the second set may be for polarization #2.

[0214] Therefore, when a transmitter used for MIMO includes two or more antennas (polarizations), independent xmtr_id, txid_injection_lvl and miso_filt_code_index signaling for each antenna (polarization) is possible.

[0215] At this time, the per-transmitter data (Per_Transmitter_Data()) may be composed of the same number of bits (64) for each transmitter, regardless of the number of antennas or polarizations corresponding to the transmitter.

[0216] At this time, the data per transmitter (Per_Transmitter_Data()) may include 29 reserved bits when the number of antennas or polarizations corresponding to the transmitter is 1, and may include 10 reserved bits when the number of antennas or polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of antennas or polarizations corresponding to the transmitter.

[0217] Therefore, according to the present invention, even when MIMO is applied and a transmitter uses multiple antennas, the size of data per transmitter (Per_Transmitter_Data()) can be maintained the same regardless of the number of antennas or polarizations, thereby maximizing the efficiency of generating a transmission identifier signal for MIMO.

[0218] At this time, mimo_flag is defined within Structure_Data(), so it can be applied commonly to all transmitters receiving Timing & Management_Packet (TMP)().

[0219] At this time, xmtr_id, miso_filt_code_index and txid_injection_lvl are defined within Per_Transmitter_Data(), within a for loop corresponding to all transmitters in the group, within a for loop corresponding to all antennas (polarizations) corresponding to MIMO, so they can be applied to individual transmitters or individual antennas (polarizations) respectively.

[0220] At this time, miso_filt_code_index may indicate a specific MISO filter code assigned to the individual transmitter or polarization.

[0221] Although not explicitly shown in FIG. 3, the broadcast signal transmission device illustrated in FIG. 3 may further include a structure data extractor and a transmitter-specific data extractor (related to signaling flow).

[0222] At this time, the structure data extractor can extract structure data transmitted from the broadcast gateway device and including first data fields for all of the transmitters.

[0223] At this time, the structure data extractor can extract a field (mimo_flag) regarding whether MIMO is applied among the first data fields.

[0224] A transmitter-specific data extractor can extract transmitter-specific data transmitted from the broadcast gateway device and including second data fields for one of the transmitters.

[0225] At this time, the data extractor for each transmitter can extract the MISO code index field (miso_filt_code_index) signaled for each antenna or polarization among the second data fields.

[0226] Figure 13 is an operational flowchart illustrating a gateway signaling method according to one embodiment of the present invention.

[0227] Referring to FIG. 13, a gateway signaling method according to an embodiment of the present invention generates structure data including first data fields that are commonly applied to transmitters and include a field regarding whether MIMO is applied (S1310).

[0228] Additionally, a gateway signaling method according to one embodiment of the present invention generates transmitter-specific data including second data fields for one of the transmitters (S1320).

[0229] At this time, the data for each transmitter may include a MISO code index field within a for loop that is repeated a number of times determined corresponding to the field regarding whether or not the MIMO is applied.

[0230] At this time, the data for each transmitter may be composed of the same number of bits for each transmitter, regardless of the number of antennas or polarizations corresponding to the transmitter.

[0231] At this time, the data for each transmitter may include 29 reserved bits when the number of antennas or polarizations is 1, and 10 reserved bits when the number of antennas or polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of antennas or polarizations corresponding to the transmitter.

[0232] In addition, a gateway signaling method according to one embodiment of the present invention generates a timing and management packet including the structural data and the transmitter-specific data (S1330).

[0233] At this time, the timing and management packet may include two MISO code index fields allocated for each of the two polarizations when the field regarding whether the MIMO is applied satisfies a preset condition (mimo_flag == 1).

[0234] At this time, one of the two polarizations may correspond to one of the enhanced layer MIMO signals and the core layer signal, and the other of the two polarizations may correspond to the other of the enhanced layer MIMO signals.

[0235] At this time, the two MISO code index fields may be different from each other.

[0236] In addition, the gateway signaling method according to one embodiment of the present invention transmits the timing and management packets to the transmitters via a studio-to-transmitter link (STL) (S1340).

[0237] The LDM coupling unit (330) illustrated in FIG. 3 generates a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal and a second polarization signal corresponding to the other of the enhanced layer MIMO signals.

[0238] As described above, the broadcast signal transmission device illustrated in FIG. 3 can apply Walsh-Hadamard encoding to pilot transmission.

[0239] MIMO transmission uses 2x2 cross-polarized MIMO, which utilizes the orthogonality between horizontally and vertically polarized signals to secure two parallel transmission channels within the same radio band.

[0240] However, in real environments, interference occurs between horizontally polarized signals and vertically polarized signals due to insufficient cross-polarization discrimination (XPD) of antennas and distortion of radio waves.

[0241] In particular, the receiving antenna of the SISO receiving terminal generally does not consider the MIMO receiving situation, so it lacks cross-polarization separation performance and can be greatly affected by cross-polarization interference.

[0242] The SISO receiver, which receives the broadcast signal transmitted by the broadcast signal transmitting device of the structure of FIG. 3 described above, receives the core layer component of the first polarization. That is, the SISO receiver performs channel estimation by receiving the pilot signal included in the first polarization transmission signal. At this time, the SISO receiver uses an antenna (polarization) having the same polarization as the first polarization.

[0243] When cross-polarization interference occurs, the pilot signal included in the second polarization transmission signal may interfere with the channel estimation of the SISO receiver. The pilot signal of the second polarization may have a Walsh-Hadamard relationship with the pilot signal of the first polarization. That is, although the pilot signal of the first polarization and the pilot signal of the second polarization are orthogonal in terms of code sequence, when the pilot elements of the first polarization and the pilot elements of the second polarization arranged in the same OFDM cell are compared one-to-one, they may be the same signal with the same or opposite phase. In MIMO channel estimation, it is possible to independently separate the channel components obtained from the first polarization pilot signal and the second polarization pilot signal. However, if the SISO receiver performs channel estimation between the first polarization of the transmitter and the receiver without considering the existence of the second polarization pilot, the channel estimation performance may be significantly degraded due to correlated pilot contamination.

[0244] In general, the degradation of channel estimation accuracy may be greater when correlated interference is applied to the pilot signal than when uncorrelated random interference is applied.

[0245] In MIMO transmission, when the first and second polarizations use different MISO filter codes, the effect of randomizing the second polarization pilot signal relative to the first polarization pilot signal can be expected. In particular, applying this method in the transmitter situation illustrated in FIG. 3 can reduce the correlation between the pilot signal received by the SISO receiver and the pilot interference signal. Furthermore, applying this method in the transmitter situation illustrated in FIG. 3 can minimize the channel estimation error of the SISO receiver.

[0246] Therefore, when applying MISO filtering in a situation where the transmitter structure (SISO+MIMO) illustrated in FIGS. 3 and 4 is applied, different MISO filter codes (different MISO code indices) can be applied to the first polarization and the second polarization. That is, when the transmission subframe transmitted from the transmitter illustrated in FIGS. 3 and 4 is the first subframe within the transmission frame, and L1B_first_sub_miso is "01" or "10", different MISO code indices (miso_filt_code_index) can be assigned to the first polarization and the second polarization. At this time, if the transmission subframe transmitted from the transmitter illustrated in FIGS. 3 and 4 is not the first subframe within the transmission frame, different MISO code indices (miso_filt_code_index) may be assigned to the first polarization and the second polarization when L1D_miso is “01” or “10”.

[0247] That is, when MISO (Multiple-Input Single-Output) is applied in the transmitter structure illustrated in FIGS. 3 and 4, the first polarization may correspond to a first MISO code index, and the second polarization may correspond to a second MISO code index that is different from the first MISO code index.

[0248] At this time, the first MISO code index and the second MISO code index may be set to correspond to the MISO code index field (miso_filt_code_index) included in the timing and management packet transmitted through the studio-to-transmitter link (STL).

[0249] At this time, the timing and management packet may include structure data including first data fields that are commonly applied to the transmitters and include a field regarding whether MIMO is applied, and transmitter-specific data including second data fields for one of the transmitters.

[0250] At this time, the data for each transmitter may be composed of the same number of bits for each transmitter, regardless of the number of polarizations corresponding to the transmitter.

[0251] At this time, the data for each transmitter may include 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

[0252] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble, and the preamble may include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

[0253] 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.

[0254] Figure 14 is a flowchart illustrating a broadcast signal transmission method according to one embodiment of the present invention.

[0255] Referring to FIG. 14, a broadcast signal transmission method according to one embodiment of the present invention generates a core layer signal (S1410).

[0256] In addition, a broadcast signal transmission method according to one embodiment of the present invention generates enhanced layer MIMO (Multiple-Input Multiple-Output) signals (S1420).

[0257] In addition, a broadcast signal transmission method according to one embodiment of the present invention generates a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal, and a second polarization signal corresponding to another one of the enhanced layer MIMO signals (S1430).

[0258] 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 using the first polarization signal, and generates a second polarization transmission signal corresponding to the second polarization using the second polarization signal (S1440).

[0259] At this time, when MISO (Multiple-Input Single-Output) is applied, the first polarization may correspond to a first MISO code index, and the second polarization may correspond to a second MISO code index that is different from the first MISO code index.

[0260] At this time, the first MISO code index and the second MISO code index may be set to correspond to MISO code index fields included in a timing and management packet transmitted through a studio-to-transmitter link (STL).

[0261] At this time, the timing and management packet may include structure data including first data fields that are commonly applied to the transmitters and include a field regarding whether MIMO is applied, and transmitter-specific data including second data fields for one of the transmitters.

[0262] At this time, the data for each transmitter may be composed of the same number of bits for each transmitter, regardless of the number of polarizations corresponding to the transmitter.

[0263] At this time, the data for each transmitter may include 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, in order to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

[0264] At this time, at least one of the first polarization transmission signal and the second polarization transmission signal may include a preamble, and the preamble may include a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

[0265] 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.

[0266] Each step illustrated in FIGS. 13 and 14 may be performed in the order illustrated in FIGS. 13 and 14, in the reverse order, or simultaneously.

[0267] Figure 15 is a block diagram showing a computer system configuration according to one embodiment of the present invention.

[0268] 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 (1600).

[0269] The computer system (1600) may include one or more processors (1610), memory (1630), user interface input devices (1640), user interface output devices (1650), and storage (1660) that communicate with each other via a bus (1620). The computer system (1600) may further include a network interface (1670) connected to a network (1680). The processor (1610) may be a central processing unit or a semiconductor device that executes programs or processing instructions stored in the memory (1630) or storage (1660). The memory (1630) and storage (1660) 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 (1630) may include a ROM (1631) or a RAM (1632).

[0270] At this time, at least one program can be recorded in the memory (1630).

[0271] At this time, the processor (1610) can execute the program. At this time, the program can perform each step illustrated in FIG. 13 or each step illustrated in FIG. 14.

[0272]

[0273] As described above, the broadcast signal transmission device, method, and gateway signaling 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 core layer signal generation unit that generates a core layer signal; An enhanced layer MIMO signal generation unit that generates enhanced layer MIMO (Multiple-Input Multiple-Output) signals; An LDM combiner that generates a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal and a second polarization signal corresponding to another one of the enhanced layer MIMO signals; and A transmission signal generation unit that generates a first polarization transmission signal using the first polarization signal and generates a second polarization transmission signal corresponding to the second polarization using the second polarization signal. A broadcast signal transmitting device including:

2. In claim 1, When MISO (Multiple-Input Single-Output) is applied, A broadcast signal transmitting device, wherein the first polarization corresponds to a first MISO code index, and the second polarization corresponds to a second MISO code index different from the first MISO code index.

3. In claim 2, The first MISO code index and the second MISO code index are respectively A broadcast signal transmitting device, which is set corresponding to the MISO code index field included in the timing and management packet transmitted through the Studio to Transmitter Link (STL).

4. In claim 3, The above timing and management packets are Structure data including first data fields that are commonly applied to transmitters and include a field regarding whether MIMO is applied, and A broadcast signal transmitting device comprising transmitter-specific data including second data fields for one of the above transmitters.

5. In claim 4, The above transmitter-specific data is A broadcast signal transmitting device, which consists of the same number of bits for each transmitter, regardless of the number of polarizations corresponding to the transmitter.

6. In claim 5, The above transmitter-specific data is A broadcast signal transmission device, comprising 29 reserved bits when the number of polarizations is 1, and 10 reserved bits when the number of polarizations is 2, to maintain the same number of bits for each transmitter regardless of the number of polarizations corresponding to the transmitter.

7. In claim 1, At least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble, The above preamble is A broadcast signal transmitting device comprising a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

8. In claim 7, A broadcast signal transmitting device, wherein the 1-bit L1B_mimo_scattered_pilot_encoding field set to 0 indicates both a MIMO pilot pattern with Walsh-Hadamard encoding and the SISO pilot pattern simultaneously.

9. Step of generating core layer signal; A step of generating enhanced layer MIMO (Multiple-Input Multiple-Output) signals; generating a first polarization signal corresponding to one of the enhanced layer MIMO signals and the core layer signal, and a second polarization signal corresponding to another one of the enhanced layer MIMO signals; and A step of generating a first polarization transmission signal corresponding to the first polarization using the first polarization signal, and generating a second polarization transmission signal corresponding to the second polarization using the second polarization signal. A method for transmitting a broadcast signal including:

10. In claim 9, When MISO (Multiple-Input Single-Output) is applied, A method for transmitting a broadcast signal, wherein the first polarization corresponds to a first MISO code index, and the second polarization corresponds to a second MISO code index different from the first MISO code index.

11. In claim 10, The first MISO code index and the second MISO code index are respectively A method of transmitting a broadcast signal, wherein the method is set corresponding to the MISO code index field included in the timing and management packet transmitted through the Studio to Transmitter Link (STL).

12. In claim 11, The above timing and management packets are Structure data including first data fields that are commonly applied to transmitters and include a field regarding whether MIMO is applied, and A method for transmitting a broadcast signal, comprising transmitter-specific data including second data fields for one of the above transmitters.

13. In claim 12, The above transmitter-specific data is A method of transmitting a broadcast signal, wherein, for each transmitter, the broadcast signal is composed of the same number of bits regardless of the number of polarizations corresponding to the transmitter.

14. In claim 13, The above transmitter-specific data is A method for transmitting a broadcast signal, wherein, for each transmitter, the number of bits is maintained the same regardless of the number of polarizations corresponding to the transmitter, and the number of reserved bits is 29 bits when the number of polarizations is 1, and the number of reserved bits is 10 bits when the number of polarizations is 2.

15. In claim 9, At least one of the first polarization transmission signal and the second polarization transmission signal includes a preamble, The above preamble is A method for transmitting a broadcast signal, comprising a 1-bit L1B_mimo_scattered_pilot_encoding field set to 0.

16. In claim 15, A method for transmitting a broadcast signal, wherein the 1-bit L1B_mimo_scattered_pilot_encoding field set to 0 indicates both a MIMO pilot pattern with Walsh-Hadamard encoding and the SISO pilot pattern simultaneously.

17. A step of generating structure data including first data fields that are commonly applied to transmitters and include a field regarding whether MIMO is applied; generating transmitter-specific data comprising second data fields for one of the transmitters; generating a timing and management packet including the above structural data and the above transmitter-specific data; and A step of transmitting the timing and management packets to the transmitters via a studio to transmitter link (STL), A gateway signaling method, wherein the timing and management packet includes two MISO code index fields each allocated for two polarizations when the field regarding whether the MIMO is applied satisfies a preset condition.

18. In claim 17, One of the two polarizations above is One of the enhanced layer MIMO signals corresponds to a core layer signal, The other of the two polarizations above is corresponding to another one of the above enhanced layer MIMO signals, Gateway signaling method.

19. In claim 18, The above MISO code index fields are Gateway signaling methods that are configured differently from each other.

20. In claim 19, The above transmitter-specific data is A gateway signaling method, wherein, for each transmitter, the number of bits is maintained the same regardless of the number of polarizations corresponding to the transmitter, and the number of reserved bits is 29 bits when the number of polarizations is 1, and the number of reserved bits is 10 bits when the number of polarizations is 2.

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