KR20180132525A - Method of transceiving broadcasting signal using combination of multiple antenna schemes with layed division multiplexing and apparatus for the same - Google Patents

Abstract

A method of transceiving a broadcasting signal using the combination of multiple antenna schemes with layered division multiplexing and an apparatus therefor are disclosed. A method of receiving broadcast signals according to an embodiment of the present invention comprises: a step of generating reception signals based on signals received through a plurality of receiving antennas; a step of estimating channels between the receiving antennas and the transmitting antennas; a step of reconstructing a core layer signal corresponding to the reception signals; and a step of recovering an enhanced layer signal based on a differently performed cancellation for each of the receiving antennas, which corresponds to the core layer signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for transmitting / receiving broadcast signals using a combination of multi-antenna schemes and layered division multiplexing, and apparatuses therefor. 2. Description of the Related Art Multi-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast signal transmitting / receiving technique, and more particularly, to a broadcast signal transmitting / receiving technique applied with layered division multiplexing.

In terrestrial broadcasting, a single frequency network (SFN) is emerging as an alternative to traditional multiple frequency network (MFN) modes. The SFN transmits multiple signals simultaneously on the same RF channel.

The SFN network provides coverage and increased spectral efficiency as well as a homogeneous distribution of the received signal strength over the coverage area. However, some regions may experience signal degradation. The amplitude of DTT (Digital Terrestrial Television) echoes with similar signal magnitudes but with different phases arriving at the receiver causes a severe multipath condition that creates destructive interferences.

To limit these unwanted situations, new features such as Multiple-Input Single-Output (MISO) are being applied to the new DTT generation.

MISO refers to a radio link that uses at least two transmitters and one receiver. A conventional topology consisting of one transmitter and one receiver is referred to as SISO. MISO improves the robustness of terrestrial transmission by using the spatial diversity of multiple antennas. In addition, a spatial multiplexing gain can be obtained if at least two antennas are provided in one receiver or two receivers cooperate (MIMO antenna scheme).

In order to support multiple services simultaneously, multiplexing, which is a process of mixing a plurality of signals, is required. Among these multiplexing techniques, layered division multiplexing (LDM) technology has been introduced which combines the signals of two layers by varying the power of each layer signal. LDM has been applied to next-generation broadcast services such as ATSC 3.0 and its applications are increasingly increasing, offering higher flexibility and superior performance than TDM and FDM.

Therefore, there is an urgent need for a new broadcast signal transmission / reception technique combining LDM with MISO or MIMO.

It is an object of the present invention to provide a broadcasting signal transmission / reception scheme combining multi-antenna schemes and layered division multiplexing.

It is also an object of the present invention to efficiently combine layered division multiplexing with multiple antenna schemes, even when an Alamouti encoding scheme is used, as well as a Transmit Diversity Code Filter Set (TDCFS) scheme.

It is also an object of the present invention to use an TDCFS scheme in combination with an Alamouti encoding scheme when Alamouti encoding is applied to a MISO scheme so that efficient broadcast signal transmission / reception is possible without increasing the complexity of the receiver even when the number of antennas is three or more .

It is also an object of the present invention to optimize the performance of the transmitter / receiver by appropriately performing layered division multiplexing / demultiplexing when spatial multiplexing gain is used for the enhanced layer.

According to an aspect of the present invention, there is provided a broadcast signal transmitting apparatus for dividing an enhanced layer data stream into two different enhanced layer sub-streams, and performing MIMO precoding corresponding to the enhanced layer sub- An enhanced layer BICM unit for generating a first enhanced layer signal and a second enhanced layer signal; A first combiner for combining a first core layer signal corresponding to a core layer data stream and the first enhanced layer signal at different power levels to generate a first multiplexed signal corresponding to a first antenna; A second combiner for combining a second core layer signal corresponding to the core layer stream and the second enhanced layer signal at different power levels to generate a second multiplexed signal corresponding to a second antenna; And an RF transmitter for generating a first RF transmit signal corresponding to the first multiplexed signal and transmitted via the first antenna and a second RF transmit signal corresponding to the second multiplexed signal and transmitted via the second antenna, Signal generating units.

At this time, the first RF transmission signal and the second RF transmission signal may be generated based on a transmission antenna process corresponding to the first antenna and the second antenna.

In this case, the transmit antenna process may be a pre-distortion process using a transmit diversity code filter set (TDCFS).

At this time, the transmission antenna process can be performed after the pilot pattern is inserted into the frequency interleaved signal.

At this time, the transmit antenna process may include Alamouti encoding to maintain orthogonality between a signal corresponding to the first antenna and a signal corresponding to the second antenna.

At this time, the transmit antenna process may insert pilot patterns into the Alamouti encoded signal.

At this time, the first core layer signal and the second core layer signal divide the core layer data stream into two different core layer sub-streams, perform MIMO precoding corresponding to the core layer sub-streams Lt; / RTI >

According to another aspect of the present invention, there is provided a broadcast signal receiving apparatus including: RF receiving units for generating received signals based on signals received through a plurality of receive antennas; Channel estimators for estimating channels between the reception antennas and the transmission antennas; A core layer BICM decoder for restoring a core layer signal corresponding to the received signals; And an enhanced layer decoder for recovering the enhanced layer signal based on the core layer signal, which is performed separately for each of the reception antennas.

At this time, the cancellation subtracts a first core layer channel component combination corresponding to the channels related to the first reception antenna among the reception antennas from the first buffer signal corresponding to the first reception antenna, 1 canceling signal and subtracting a second core layer channel component combination corresponding to channels associated with a second one of the receive antennas from a second buffer signal corresponding to the second receive antenna A second canceling signal can be generated. At this time, the enhanced layer signal can be restored by using both the first cancel signal and the second cancel signal.

At this time, the enhanced layer signal may be recovered by MIMO decoding corresponding to the first and second cancellation signals.

At this time, the core layer signal can be recovered based on Maximum-Ratio-Combining (MRC) corresponding to the channels.

Wherein the enhancement layer signal is generated based on Alamouti re-encoding corresponding to the core layer signal, and the enhanced layer signal corresponds to the first cancellation signal and the second cancellation signal, Lt; RTI ID = 0.0 > Alamouti < / RTI >

At this time, the Alamouti re-encoding is performed after interleaving, and deinterleaving can be performed after the Alamouti decoding.

At this time, the cancellation may be performed based on MIMO precoding corresponding to the core layer signal.

According to another aspect of the present invention, there is provided a broadcast signal transmission method including generating reception signals based on signals received through a plurality of reception antennas; Estimating channels between the receive antennas and the transmit antennas; Reconstructing a core layer signal corresponding to the received signals; And recovering the enhanced layer signal based on the core layer signal and the canceling performed separately for each of the reception antennas.

At this time, the cancellation subtracts a first core layer channel component combination corresponding to the channels related to the first reception antenna among the reception antennas from the first buffer signal corresponding to the first reception antenna, 1 canceling signal and subtracting a second core layer channel component combination corresponding to channels associated with a second one of the receive antennas from a second buffer signal corresponding to the second receive antenna A second canceling signal can be generated. At this time, the enhanced layer signal can be restored by using both the first cancel signal and the second cancel signal.

At this time, the enhanced layer signal may be recovered by MIMO decoding corresponding to the first and second cancellation signals.

At this time, the core layer signal may be recovered based on MRC (Maximum-Ratio-Combining) corresponding to the channels.

Wherein the enhancement layer signal is generated based on Alamouti re-encoding corresponding to the core layer signal, and the enhanced layer signal corresponds to the first cancellation signal and the second cancellation signal, Lt; RTI ID = 0.0 > Alamouti < / RTI >

At this time, the Alamouti re-encoding is performed after interleaving, and deinterleaving can be performed after the Alamouti decoding.

According to the present invention, a broadcasting signal transmission / reception scheme combining multi-antenna schemes and layered division multiplexing is provided.

In addition, the present invention can efficiently combine layered division multiplexing with multiple antenna schemes even when an Alamouti encoding scheme is used as well as a transmit diversity code filter set (TDCFS) scheme.

In addition, when Alamouti encoding is applied to the MISO scheme, the TDCFS scheme can be used in combination with the Alamouti encoding scheme, so that efficient broadcast signal transmission / reception is possible without increasing the complexity of the receiver even when the number of antennas is three or more.

In addition, the present invention can optimize the performance of the transmitter / receiver by appropriately performing layered division multiplexing / demultiplexing when spatial multiplexing gain is used for the enhanced layer.

1 is a block diagram illustrating a MISO broadcast signal transmitting apparatus according to an embodiment of the present invention.
2 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MISO according to an embodiment of the present invention.
3 is a block diagram illustrating a fixed broadcast signal receiver for MISO according to an embodiment of the present invention.
4 is a block diagram illustrating a MISO broadcast signal transmitting apparatus according to another embodiment of the present invention.
5 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MISO according to another embodiment of the present invention.
FIG. 6 is a block diagram illustrating a fixed broadcasting signal receiving apparatus for MISO according to another embodiment of the present invention. Referring to FIG.
7 and 8 are block diagrams of MISO broadcast signal transmitting apparatuses according to another embodiment of the present invention.
9 is a flowchart illustrating a method of transmitting a MISO broadcast signal according to an embodiment of the present invention.
10 is a flowchart illustrating a method of receiving a broadcast signal for a MISO according to an embodiment of the present invention.
Figures 11 and 12 show the first group case.
13 shows a mobile receiver of a second group case.
FIG. 14 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to an embodiment of the present invention. Referring to FIG.
15 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to an embodiment of the present invention.
16 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to an embodiment of the present invention.
17 is a block diagram of a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.
18 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.
FIG. 19 is a block diagram illustrating a fixed broadcasting signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.
20 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.
21 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.
22 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.
23 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.
FIG. 24 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.
25 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.
26 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.
FIG. 27 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.
28 is a flowchart illustrating a method of transmitting a MIMO broadcast signal according to an embodiment of the present invention.
29 is a flowchart illustrating a method of receiving a broadcast signal for MIMO according to an embodiment of the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

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

The MISO scheme can be roughly divided into phase / frequency pre-distortion and space-time block coding (STBC).

In the present invention, the MISO is a concept including not only receiving broadcasting signals from different transmission stations but also receiving broadcasting signals transmitted from one transmission station through a plurality of antennas.

Phase / frequency pre-distortion eliminates correlations of signals from different transmitters using a particular phase-distortion algorithm. At this time, the phase-distortion algorithm may be a linear phase-distortion algorithm. The elimination of this correlation reduces the presence of frequency-selective fades. One such technique is the Enhanced Single Frequency Network (eSFN).

The signal at the center of the SFN can offset each other at the receiver. To avoid this negative effect, a linear phase pre-distortion algorithm may be used on the transmitter side. This pre-distortion should be unique for each transmitter and different across OFDM subcarriers. Therefore, the transmitted signal can be expressed by the following equation (1).

[Equation 1]

Where i is an index representing an OFDM subcarrier, S (i) is a non-distorted complex symbol, _Cx (i) is a complex predistortion function of a transmitter x corresponding to subcarrier i, T _x (i) is a transmitted complex symbol for transmitter x.

One of the phase / frequency pre-distortion schemes is the Transmit Diversity Code Filter Set (TDCFS). TDCFS provides high signal correlation removal performance in the frequency domain. The TDCFS uses linear frequency domain filters to compensate at the receiver in an equalization process. Linear frequency domain filters may be all-pass filters with minimized cross-correlation under the constraints of the number of transmitters (up to four transmitters) and the time domain span of the filters (64 or 256 filter lengths).

These pre-distortion schemes do not require special signal processing at the receiver, and therefore receivers can view the predistortion function _Cx (i) as part of the channel.

When the MISO and the LDM are used together, the enhanced layer (EL) subcarriers are considered as additional noise for core layer (CL) decoding, so that the core layer (CL) gains the main MISO gains. However, since the filters are applied to the sum of the two layers, there is a gain in both layers.

In the case of STBC, the data stream to be transmitted may be encoded with a pair of orthogonal blocks distributed over and between spaced-apart antennas. During STBC, Alamouti encoding or variant is actively used in digital terrestrial broadcasting. The Alamouti encoding variant used in DVB-T2 or DVB-NGH is replaced with a pair of frequency indices by a pair of time indices to construct an orthogonal space frequency block code (SFBC).

The DVB Alamouti encoding divides the available transmitters into two groups. The signals from the first group of transmitters are transmitted without any modification but the signals transmitted from the second group of transmitters are modified into two QAM symbols blocks to maintain orthogonality between the two transmit groups. do. The encoded subcarriers Y _mi (Tx1) for MISO transmitters group 1 and Y _mi (Tx2) encoded for MISO transmitters group 2 are expressed as: " (2) "

&Quot; (2) "

Here, * denotes a complex conjugate operation, N _data is the number of data subcarriers from the current m OFDM symbols, and X _mi denotes i subcarrier data before encoding.

In addition to requiring additional complexity in the transmitter, Alamouti decoding also has to change the receiver structure. Although only one receive antenna is required, it is necessary to estimate the channel frequency response (CFR) of the two transmit MISO groups. Therefore, orthogonal pilot patterns should be used between transmitter groups. Thus, compared to the phase / frequency pre-distortion scheme, Alamouti requires additional complexity because the pilot overhead is doubled and the receiver must recover the components from the combined signals.

When the LDM and Alamouti are used in combination, the receiver may require a more complex channel estimation process (requiring two channel estimates) and additional Alamouti decoding.

MISO Distributed Alamouti divides the transmitters of the SFN into two groups. Thus, networks with more than two transmitters suffer from degraded Alamouti performance because the same signal is transmitted from more than one transmitter. To reduce this performance degradation, a TDCFS scheme that provides filter sets for up to four transmitters can be combined with Alamouti. Combining the TDCFS scheme with Alamouti allows transmission of SFN networks containing up to eight transmitters. At this time, the receiver does not greatly increase the complexity as compared with the case where only Alamouti is used.

1 is a block diagram illustrating a MISO broadcast signal transmitting apparatus according to an embodiment of the present invention.

1, the MISO broadcast signal transmission apparatus includes core layer BICM units 111 and 112, enhanced layer BICM units 121 and 122, injection level controllers 131 and 132, Power combiners 141 and 142, power normalizers 151 and 152, time interleavers 161 and 162, frequency interleavers 171 and 172, pilot pattern inserters 181 and 182, (191, 192) and RF signal generators (117, 118).

The core layer BICM units 111 and 112, the enhanced layer BICM units 121 and 122, the injection level controllers 131 and 132, the couplers 141 and 142, the power normalizers 151 Specific details related to the time interleavers 161 and 162, the frequency interleavers 171 and 172 and the pilot pattern inserting units 181 and 182 are disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

The same core layer stream is input to the core layer BICM units 111 and 112, and the same enhanced layer stream is input to the enhanced layer BICM units 121 and 122. The core layer BICM units 111 and 112 and the enhanced layer BICM units 121 and 122 perform channel coding, bit interleaving, and modulation on the input data.

The injection level controllers 131 and 132 reduce the power of the enhanced layer signal to generate a power-reduced enhanced layer signal. At this time, the magnitude of the signal adjusted by the injection level controllers 131 and 132 may be determined according to the injection level.

The combiners 141 and 142 combine the core layer signal and the enhanced layer signal at different power levels to generate a multiplexed signal.

Each of the power normalizers 151 and 152 lowers the power of the multiplexed signal to a power corresponding to the core layer signal to generate a power normalized signal.

The time interleavers 161 and 162 time-interleave the power normalized signals to generate time interleaved signals.

The frequency interleavers 171 and 172 respectively frequency interleave the time interleaved signal to generate a frequency interleaved signal.

The pilot pattern inserters 181 and 182 insert pilot patterns into the frequency interleaved signals, respectively.

In Fig. 1, the output xi of the pilot pattern inserters 181 and 182 is data (layered division multiplexed data) corresponding to the _i < th > subcarrier and is the object of the MISO process.

The predistortion units 191 and 192 respectively pre-distort the data to reduce correlation between the signals corresponding to the two antennas ANTENNA ₁ and ANTENNA ₂ . At this time, the pre-distortion units 191 and 192 may perform a pre-distortion process using a Transmit Diversity Code Filter Set (TDCFS).

In the example shown in FIG. 1, the pre-distortion units 191 and 192 may correspond to a MISO processing unit.

The RF signal generators 117 and 118 each generate an RF transmission signal transmitted through an antenna using a pre-distorted (MISO-processed) signal.

In the example shown in Fig. 1, a signal corresponding to the antenna ANTENNA ₁ and a signal corresponding to the antenna ANTENNA ₂ are generated based on the same data stream.

The antenna ANTENNA ₁ shown in FIG. 1 is independent of the antenna ANTENNA ₂ , and the antennas ANTENNA ₁ and ANTENNA ₂ may be provided in different transmitters or in a single transmitter.

1, the signals input to the pre-distortion units 191 and 192 are separately generated. However, the core layer BICM unit 112, the enhanced layer BICM unit 122, the injection level controller 132 The power interleaver 162, the frequency interleaver 172, and the pilot pattern inserting unit 182 may not be separately provided. In this case, the signal input to the pre-distortion unit 192 may be the same signal as that input to the pre-distortion unit 191, or a signal obtained by replicating a signal input to the pre-distortion unit 191.

2 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MISO according to an embodiment of the present invention.

2, a mobile broadcast signal receiver for MISO according to an exemplary embodiment of the present invention includes an RF receiver 210, an estimation and equalizer 220, a frequency deinterleaver 230, a time deinterleaver 240, And a core layer BICM decoder 250.

The mobile broadcast signal receiving apparatus shown in FIG. 2 restores only the core layer signal without restoring the enhanced layer signal even when the LDM broadcast signal is transmitted.

The RF receiver 210 receives the signals transmitted through the two antennas and generates a received signal.

The estimation and equalization unit 220 performs channel estimation and equalization. At this time, the estimation and equalization unit can regard the pre-distortion performed in the transmitter as a part of the channel and compensate it in the equalization process.

The frequency deinterleaver 230 performs deinterleaving in the frequency domain, and the time deinterleaver 240 deinterleaves the time domain.

The core layer BICM decoder 250 performs an inverse process of the core layer BICM portion of the transmitter. Concrete contents related to the core layer BICM decoder 250 are disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

3 is a block diagram illustrating a fixed broadcast signal receiver for MISO according to an embodiment of the present invention.

3, an apparatus for receiving a fixed broadcast signal for MISO according to an exemplary embodiment of the present invention includes an RF receiver 310, an estimator and equalizer 320, a frequency deinterleaver 330, a time deinterleaver 340, A core layer BICM decoder 350, a core layer BICM 360, an LDM buffer 370, a subtractor 380, and an enhanced layer BICM decoder 390.

The fixed broadcast signal receiving apparatus shown in FIG. 3 receives the LDM broadcast signal and restores the core layer signal and the enhanced layer signal.

The RF receiver 310 receives the signals transmitted through the two antennas and generates a received signal.

At this time, the signals corresponding to each of the two antennas may correspond to the same data stream.

The estimation and equalization unit 320 performs channel estimation and equalization. At this time, the estimation and equalization unit can regard the pre-distortion performed in the transmitter as a part of the channel and compensate it in the equalization process.

The MISO processing unit may correspond to the estimation and equalization unit 320 shown in FIG. At this time, the MISO processing performed by the MISO processing unit may be compensation of the pre-distortion performed in the transmitter. At this time, the MISO process can be performed in the equalization process, considering the pre-distortion as a part of the channel. At this time, the MISO processing may correspond to the TDCFS.

The frequency deinterleaver 330 performs deinterleaving in the frequency domain, and the time deinterleaver 340 deinterleaves the time domain.

The core layer BICM decoder 350 performs a reverse process of the core layer BICM portion of the transmitter.

The core layer BICM unit 360 again performs BICM on the restored core layer stream, and the corresponding cancellation of the core layer is performed through the LDM buffer 370 and the subtractor 380. The signal that has been subjected to the cancellation corresponding to the core layer is restored to the enhanced layer output stream through the enhanced layer BICM decoder 390.

The restoration of the enhanced layer signal through the core layer BICM decoder 350, the enhanced layer BICM decoder 390, and the cancellation corresponding to the core layer is disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

Although not explicitly shown in FIGS. 2 and 3, a power denormalizer may be provided in front of the core layer BICM decoder to perform the inverse function of the power normalizer.

The received signal transmitted through the transmitter shown in FIG. 1 and received through the receiver shown in FIG. 2 and FIG. 3 is expressed by Equation (3).

&Quot; (3) "

(I) is a subcarrier index, h is a channel, C is a predistortion function, and (CL _i + EL _i ) is data in which core layer data and enhanced layer data are combined. x _i , and n represents noise.

The channel estimators of the receivers shown in FIGS. 2 and 3 provide corresponding filtering and a combination of the two channels with their corresponding filtering in a single channel frequency response.

4 is a block diagram illustrating a MISO broadcast signal transmitting apparatus according to another embodiment of the present invention.

4, the MISO broadcast signal transmission apparatus includes core layer BICM units 411 and 412, enhanced layer BICM units 421 and 422, injection level controllers 431 and 432, Frequency interleavers 471 and 472, Alamouti encoders 491 and 492, pilot pattern inserting units 441 and 442, power normalizers 451 and 452, time interleavers 461 and 462, frequency interleavers 471 and 472, (481, 482) and RF signal generators (417, 418).

4 includes the core layer BICM units 411 and 412, the enhanced layer BICM units 421 and 422, the injection level controllers 431 and 432, the combiners 441 and 442, the power normalizers 451 The time interleavers 461 and 462 and the frequency interleavers 471 and 472 and the pilot pattern inserters 481 and 482 have already been described with reference to FIG. Patent No. 2017-0009737 and the like.

The same core layer stream is input to the core layer BICM units 411 and 412 and the same enhanced layer stream is input to the enhanced layer BICM units 421 and 422. [ The core layer BICM units 411 and 412 and the enhanced layer BICM units 421 and 422 perform channel coding, bit interleaving, and modulation on the input data.

Injection level controllers 431 and 432 reduce the power of the enhanced layer signal to generate a power-reduced enhanced layer signal. At this time, the magnitude of the signal adjusted by the injection level controllers 431 and 432 may be determined according to the injection level.

The combiners 441 and 442 combine the core layer signal and the enhanced layer signal at different power levels to generate a multiplexed signal.

The power normalizers 451 and 452 respectively lower the power of the multiplexed signal to a power corresponding to the core layer signal to generate a power normalized signal.

The time interleavers 461 and 462 time-interleave the power normalized signals to generate time interleaved signals.

The frequency interleavers 471 and 472 frequency-interleave the time interleaved signals to generate frequency interleaved signals.

In FIG. 4, the output (x _i ) of the frequency interleavers 471 and 472 is data (layered division multiplexed data) corresponding to the i-th subcarrier and is the object of MISO processing.

Alamouti encoders 491 and 492 divide the signals transmitted by the two antennas ANTENNA ₁ and ANTENNA ₂ into two groups and the signals (first group) transmitted to the first antenna ANTENNA ₁ are modified And the signals transmitted to the second antenna ANTENNA ₂ (the second group) are modified into two QAM symbols blocks to maintain the orthogonality between the groups. For example, Alamouti encoders 491 and 492 may perform the encoding represented by Equation (2) above.

Each of the pilot pattern inserting units 481 and 482 inserts a pilot pattern into the Alamouti encoded signal. At this time, the pilot pattern inserters 481 and 482 can insert different pilot patterns, and more pilot patterns can be inserted into the complex structure than the pilot pattern inserters shown in FIG.

In the example shown in FIG. 4, the Alamouti encoders 491 and 492 and the pilot pattern inserters 481 and 482 may correspond to a MISO processing unit. That is, the Alamouti encoders 491 and 492 perform Alamouti encoding to reduce the correlation between the signal corresponding to the antenna ANTENNA ₁ and the signal corresponding to the antenna ANTENNA ₂ , and the pilot pattern inserters 481 and 482 May perform pilot pattern insertion for each group signal to perform MISO processing. At this time, the Alamouti encoding may be to maintain orthogonality between a signal corresponding to the antenna ANTENNA ₁ and a signal corresponding to the antenna ANTENNA ₂ . In other words, Alamouti encoding, which allows two transmission signals to be orthogonal to each other, can be viewed as a process of reducing correlation between two transmission signals.

The RF signal generators 417 and 418 generate an RF transmission signal, which is transmitted through an antenna using an Alamouti-encoded signal having a pilot pattern inserted therein.

In the example shown in Fig. 4, a signal corresponding to the antenna ANTENNA ₁ and a signal corresponding to the antenna ANTENNA ₂ are generated based on the same data stream.

The antenna ANTENNA ₁ shown in FIG. 4 is independent of the antenna ANTENNA ₂ , and the antennas ANTENNA ₁ and ANTENNA ₂ may be provided in different transmitters or in a single transmitter.

4, the signals input to the Alamouti encoders 491 and 492 are separately generated. However, the core layer BICM unit 412, the enhanced layer BICM unit 422, the injection level controller 432 ), The combiner 442, the power normalizer 452, the time interleaver 462, and the frequency interleaver 472 may not be separately provided. In this case, the signal input to the Alamouti encoder 492 may be the same signal as the signal input to the Almouti encoder 491 or the signal input to the Alamouti encoder 491.

5 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MISO according to another embodiment of the present invention.

Referring to FIG. 5, a mobile broadcast signal receiver for MISO according to another embodiment of the present invention includes an RF receiver 510, a channel estimator 520, an Alamouti decoder 525, a frequency deinterleaver 530, A deinterleaver 540 and a core layer BICM decoder 550.

The mobile broadcast signal receiving apparatus shown in FIG. 5 restores only the core layer signal without restoring the enhanced layer signal even when the LDM broadcast signal is transmitted.

The RF receiver 510 receives the signals transmitted through the two antennas and generates a received signal.

The channel estimation unit 520 estimates a channel frequency response (CFR) for all of the channels from the two transmit antennas (both). To this end, the transmitter may use orthogonal pilot patterns between the two antennas.

The Alamouti decoder 525 performs a decoding operation corresponding to the Alamouti encoding of the transmitter.

At this time, the Alamouti decoder 525 performs Alamouti decoding based on the channel estimation for both the channel h ₁ corresponding to the antenna ANTENNA ₁ signal and the channel h ₂ corresponding to the antenna ANTENNA ₂ signal .

The frequency deinterleaver 530 performs deinterleaving in the frequency domain, and the time deinterleaver 540 deinterleaves the time domain.

The core layer BICM decoder 550 performs a reverse process of the core layer BICM portion of the transmitter. Concrete contents related to the core layer BICM decoder 550 are disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

FIG. 6 is a block diagram illustrating a fixed broadcasting signal receiving apparatus for MISO according to another embodiment of the present invention. Referring to FIG.

6, the fixed broadcast signal receiving apparatus according to another embodiment of the present invention includes an RF receiver 610, a channel estimator 620, an Alamouti decoder 625, a frequency deinterleaver 630, a time deinterleaver 630, 640, a core layer BICM decoder 650, a core layer BICM unit 660, an LDM buffer 670, a subtractor 680 and an enhanced layer BICM decoder 690.

The fixed broadcast signal receiving apparatus shown in FIG. 6 receives an LDM broadcast signal and restores a core layer signal and an enhanced layer signal.

The RF receiver 610 receives the signals transmitted through the two antennas and generates a received signal.

At this time, the signals corresponding to each of the two antennas may correspond to the same data stream.

The channel estimator 620 estimates a channel frequency response (CFR) for all of the channels from the two transmit antennas (both). To this end, the transmitter may use orthogonal pilot patterns between the two antennas.

The Alamouti decoder 625 performs a decoding operation corresponding to the Alamouti encoding of the transmitter.

At this time, the Alamouti decoder 625 performs Alamouti decoding based on channel estimation for both the channel h ₁ corresponding to the antenna ANTENNA ₁ signal and the channel h ₂ corresponding to the antenna ANTENNA ₂ signal .

The MISO processing unit may correspond to the channel estimation unit 620 and the Alamouti decoder 625 shown in FIG. At this time, the MISO processing performed by the MISO processing unit may be channel estimation and Alamouti decoding for Alamouti decoding.

The frequency deinterleaver 630 performs deinterleaving in the frequency domain, and the time deinterleaver 640 deinterleaves the time domain.

The core layer BICM decoder 650 performs a reverse process of the core layer BICM portion of the transmitter.

The core layer BICM unit 660 performs the BICM again on the restored core layer stream, and the corresponding cancellation is performed on the core layer through the LDM buffer 670 and the subtractor 680. The signal with the canceled corresponding to the core layer is restored to the enhanced layer output stream through the enhanced layer BICM decoder 690.

The restoration of the enhanced layer signal through the core layer BICM decoder 650, the enhanced layer BICM decoder 690, and the cancellation corresponding to the core layer is disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

Although not explicitly shown in FIGS. 5 and 6, a power denormalizer may be provided at the front end of the core layer BICM decoder to perform the inverse function of the power normalizer.

The received signal transmitted through the transmitter shown in FIG. 4 and received through the receiver shown in FIG. 5 and FIG. 6 is expressed by Equation (4).

&Quot; (4) "

Here, i denotes a subcarrier index, h denotes a channel, * denotes a complex conjugate operation, and (CL _i + EL _i ) denotes a combination of core layer data and enhanced layer data Corresponding to x _i in FIG. 4, and n denotes noise.

The channel estimators of the receivers shown in Figures 5 and 6 independently provide two channel frequency responses. To use orthogonalization, Alamouti decoding is required. The Alamouti decoding may be equivalent to Equation (5).

&Quot; (5) "

The meaning of each code is as described above.

In general, when combining LDM and MISO schemes, Alamouti has twice the pilot overhead compared to TDCFS, but using Alamouti encoding can have higher gain than using TDCFS.

7 and 8 are block diagrams of MISO broadcast signal transmitting apparatuses according to another embodiment of the present invention.

FIG. 7 and FIG. 8 show an example in which an LDM is combined with a MISO scheme combined with a TDCFS and an Alamouti. FIG. 7 shows a case where four transmission antennas are used, and FIG.

Referring to FIG. 7, it can be seen that the pre-distortion is added after the pilot pattern inserting unit in the structure of the broadcast signal transmitter shown in FIG.

That is, the example shown in FIG. 7 applies the four pre-distortion functions C ₁ [i], C ₂ [i], C ₃ [i], C ₄ [i] Even if Alamouti encoding is applied to the signal transmission using the OFDM scheme, the degradation of the Alamouti performance can be reduced.

Referring to FIG. 8, the structure for the upper four antennas is the same as that in FIG. 7, and the structure for the lower four antennas is inversely applied to the MISO encoding. That is, the structure for the lower four antenna Alamouti encoding after ₁ C ₂ [i] and C ₄ [i], and the follow-up, ₂ Alamouti encoding, then is followed by a C ₁ [i] and C ₃ [i].

The signals transmitted through the broadcast signal transmitter shown in FIGS. 7 and 8 may be received and reconstructed through the receiver structure shown in FIGS. 5 and 6. FIG. At this time, the channel estimator may perform compensation corresponding to the pre-distortion through equalization.

The signal transmitted through the broadcast signal transmitter shown in FIG. 7 and received by the receiver is expressed by Equation (6).

&Quot; (6) "

Where CL denotes a subcarrier index, h denotes a channel, C denotes a predistortion function, * denotes a complex conjugate operation, (CL _i + EL _i ) denotes core layer data and Enhanced layer data refers to combined data, corresponding to x _i in FIG. 7, where n denotes noise.

The channel estimators of the receiver provide in pairs of two channel frequency responses. Alamouti decoding is required to use orthogonalization. The Alamouti decoding may be equivalent to Equation (7).

&Quot; (7) "

The meaning of each code is as described above.

The signal transmitted through the broadcast signal transmitter shown in FIG. 8 and received by the receiver is expressed by Equation (8).

&Quot; (8) "

Where CL denotes a subcarrier index, h denotes a channel, C denotes a predistortion function, * denotes a complex conjugate operation, (CL _i + EL _i ) denotes core layer data and Means data combined with enhanced layer data, corresponding to x _i in FIG. 8, and n denotes noise.

The Alamouti decoding may be equivalent to Equation (9).

&Quot; (9) "

9 is a flowchart illustrating a method of transmitting a MISO broadcast signal according to an embodiment of the present invention.

Referring to FIG. 9, in a method of transmitting a MISO broadcast signal according to an exemplary embodiment of the present invention, a core layer signal and an enhanced layer signal are combined at different power levels to generate a multiplexed signal (S910).

At this time, the signal corresponding to the first antenna and the signal corresponding to the second antenna may be generated based on the same data stream.

In this case, the first antenna and the second antenna may be independent of each other.

In addition, the MISO broadcast signal transmission method according to an embodiment of the present invention generates a power normalized signal by lowering the power of the multiplexed signal to a power corresponding to the core layer signal (S920).

In addition, the MISO broadcast signal transmission method according to an embodiment of the present invention performs interleaving on the power normalized signal to generate an interleaved signal (S930).

At this time, the interleaving may be time interleaving, frequency interleaving, or a combination of two interleaving.

Also, the MISO broadcast signal transmission method according to an embodiment of the present invention may include a MISO process for reducing the correlation between the signal corresponding to the first antenna and the signal corresponding to the second antenna, corresponding to the interleaved signal, (S940).

At this time, the MISO process may be a pre-distortion process using a Transmit Diversity Code Filter Set (TDCFS).

At this time, the MISO process may be performed after the pilot pattern is inserted into the frequency-interleaved signal.

At this time, the MISO process may include Alamouti encoding to maintain orthogonality between the signal corresponding to the first antenna and the signal corresponding to the second antenna.

At this time, the MISO process may insert pilot patterns into the Alamouti encoded signal.

In addition, the MISO broadcast signal transmission method according to an embodiment of the present invention generates an RF transmission signal transmitted through the first antenna using the MISO-processed signal (S950).

10 is a flowchart illustrating a method of receiving a broadcast signal for a MISO according to an embodiment of the present invention.

10, a method for receiving a broadcast signal for MISO according to an embodiment of the present invention receives a first antenna signal and a second antenna signal corresponding to the same data stream and generates a received signal (S1010).

In addition, the broadcast signal receiving method for MISO according to an embodiment of the present invention performs MISO processing corresponding to the received signal (S1020).

At this time, the MISO process can be performed in the equalization process, considering the pre-distortion as a part of the channel.

At this time, the MISO process may include channel estimation for both the first channel corresponding to the first antenna signal and the second channel corresponding to the second antenna signal, and Alamouti decoding based on the channel estimation.

Also, in the method of receiving a broadcast signal for MISO according to an embodiment of the present invention, deinterleaving is applied to the MISO-processed signal to generate a deinterleaved signal (S 1030).

In this case, the deinterleaving may be time deinterleaving, frequency deinterleaving or a combination thereof.

In addition, the method for receiving a broadcast signal for MISO according to an embodiment of the present invention restores a core layer signal from the deinterleaved signal (S1040).

In addition, the method for receiving a broadcast signal for MISO according to an embodiment of the present invention restores an enhanced layer signal based on a cancellation corresponding to the core layer signal (S1050).

Hereinafter, the combination of MIMO and LDM will be described in detail.

Unlike multiple-input single-output (MISO) and single-input multiple-output (SIMO) can only improve the reliability of a multipath link by using two or more antennas only at a transmitter or a receiver, Multiple-input multiple-output (MIMO) using two or more antennas on both sides can also improve bit-rate of service.

Layered Division Multiplexing (LDM), on the other hand, superimposes two or more signals at different powers to form a multi-layer signal, thereby increasing frequency efficiency.

Single-input multiple-output (SIMO) has only two or more antennas at the receiver only. SIMO array gains can be obtained using combining techniques such as Maximum-Ratio-Combining (MRC).

MISO-SIMO means a case where the transmitter and the receiver do not desire to obtain spatial multiplexing gain in a MIMO system having two or more antennas on both sides of transmission / reception. At this time, the transmitter can obtain the diversity gain and the receiver can obtain the array gain. This scheme is also called diversity-MIMO (MIMO).

MIMO spatial multiplexing (MIMO SM) refers to the case of using a spatial multiplexing gain in a MIMO system having two or more antennas on both sides of transmission / reception.

MIMO broadcasts require co-located antennas with cross-polar (horizontal and vertical). A MIMO transmitter may require two BICM chains, a MIMO demultiplexer and a MIMO precoder. The MIMO precoder may perform an operation to increase spatial diversity. As in the case of MISO Alamouti, MIMO can use orthogonal pilot patterns for orthogonality between the antennas, which in this case can have twice the pilot pattern overhead.

Given that the bit-rate increase provided by MIMO spatial multiplexing is expected in the enhanced layer, the combination of LDM and MIMO is grouped into two cases depending on the number of antennas of mobile receivers.

The first group is where the mobile receiver has only one antenna (in this case also the stationary receiver has two antennas), and the second group is where the mobile receiver has two antennas.

Figures 11 and 12 show the first group case.

Referring to FIG. 11, it can be seen that there are two transmit antennas and one receive antenna of the mobile receiver, and that there are two channels between the transmitter and the receiver.

Referring to FIG. 12, it can be seen that there are two transmission antennas and two reception antennas of the fixed receiver, and there are four channels between the transmitter and the receiver.

The example shown in FIGS. 11 and 12 can obtain the MISO diversity gain at the core layer without increasing the complexity of the mobile receiver. Furthermore, fixed receivers can utilize MIMO spatial multiplexing to provide higher bit rates at the enhanced layer.

11 and 12 use MISO for the core layer and MIMO spatial multiplexing for the enhanced layer, the single antenna of the mobile receiver is for the core layer only and the two of the fixed receivers Four cross-polarized antennas are for the core layer and the enhanced layer.

As shown in Figures 11 and 12, two cross-polar antennas are provided in the transmitter.

Depending on the polarization of the receive antenna, the received signal may consist of only one of the contributions, or may be composed of their sum.

The first group of use cases can be divided into the following three cases.

1) Plain MISO in CL + MIMO in EL

In this case, there is no uncorrelation or orthogonalization process at the transmitter. Therefore, the expected MISO diversity gain is limited. Mobile receivers can be implemented with baseline receivers.

2) MISO TDCFS in CL + MIMO in EL

Although TDCFS filter sets are used in the transmitter, the receiver is simply implemented. However, it can provide better performance than the Plain MISO scheme and provides diversity gain.

3) MISO Alamouti in CL + MIMO in EL

This case can provide better performance in the case of TDCFS, and diversity gain is provided. However, the complexity of the mobile receiver increases. Receivers must first obtain two channel estimates, and then perform Alamouti decoding. In other contexts, if the receive antenna has the same polarization as the transmit antenna, these two additional blocks may be unnecessary.

13 shows a mobile receiver of a second group case.

In the second group case, the fixed receiver is as shown in Fig.

Referring to FIG. 13, it can be seen that there are four channels between the transmitter and the receiver with two transmit antennas and two mobile antennas with two receive antennas (two cross-polar antennas).

The example shown in FIG. 13 is suitable for the case where the complexity of the mobile receivers is not limited.

The second group case shown in FIG. 13 can utilize both fixed and mobile receivers as well as diversity gain as well as array gain and even multiplexing gain.

The second group of use cases can be divided into the following two cases.

1) MISO-SIMO (Diversity MIMO) in CL + MIMO SM in EL

In this case, not only the MISO diversity gain due to the MISO schemes (Plane MISO, MISO TDCFS or MISO Alamouti) for the core layer, but also the SIMO array gain can be used. In this case, the mobile receivers do not require other complicated configurations in addition to the additional receive antenna, tuner and MRC block.

2) MIMO SM in both layers

This case is suitable when the bitrate of the desired core layer can not be obtained with only one antenna in the mobile receivers. In this case, since the MIMO multiplexing gain (core layer) is very small in the low SNR region which is the normal core layer SNR region, it is preferable to apply the MISO Alamouti to the core layer.

If a plain MISO or MISO TDCFS is used for the core layer and a MIMO spatial multiplexing is used for the enhanced layer, then at the transmitter the core layer (CL) cell stream is duplicated and the same information is transmitted through the H and V polarizations H and V polarizations. An enhanced layer (EL) cell stream exploiting MIMO spatial multiplexing performs MIMO demultiplexing and precoding first, and then each EL sub-stream is injected into one of the two CL streams . Therefore, there are two LDM signals (CL + EL _H for horizontal polarity and CL + EL _{V for} vertical polarity) that are transmitted to the other polarizations. When TDCFS is used, the two LDM signals are filtered by the corresponding filter sets. Orthogonal pilot patterns SP3_4 and SP6_2 may be used. Although this is not intended for channel estimation of the core layer, it may be necessary for correct demodulation in fixed receivers.

Although the other enhanced layer (EL) cells EL _{H, i} and EL _{V, i} are transmitted to each antenna, the two enhanced layers are in the same way as they are in the same way the same can be assumed to interfere with the core layer. Thus, the enhanced layer can be treated as additional noise, and mobile receivers with one antenna can be a baseline receiver.

If the mobile receiver has two antennas, the core layer may obtain an array gain using an MRC combining process.

The same core layer MRC combination may be used for core layer (CL) demodulation in fixed receivers. Next, to demultiplex EL _H and EL _V , the core layer must be restored and canceled from the global LDM signal. However, this cancellation is not straightforward like SISO. The received symbols for each of the antennas (y _H, and y _V) are to a combination of (y _H of the core layer cell filter to the other channel coefficient _{h HH, i · C H [} i] + h HV, i · C V [ i] and y _V , h _{VH, i} C _H [i] + h _{VV, i} C _V [i]). Therefore, the same combination must be applied for proper cancellation. Eventually, EL _H and EL _V can be demultiplexed as in a MIMO SM system.

When MISO Alamouti is used for the core layer and MIMO spatial multiplexing is used for the enhanced layer, the same core layer cell stream is transmitted in both the H and V polarizations (both) A layer (EL) cell stream can be inserted into the two core layer streams. Therefore, there are two LDM signals (CL + EL _H for horizontal polarity and CL + EL _{V for} vertical polarity) that are transmitted to the other polarizations. Finally, instead of TDCFS frequency pre-distortion, Alamouti encoding is performed on the second antenna.

Again, orthogonal PPs (Preamble Patterns) are used. This is also necessary for enhanced layer channel estimation and also for core layer Alamouti decoding.

Based on the number of receive antennas of the mobile receiver, the received symbols may vary.

In mobile receivers with one antenna, the enhanced layer (EL) cells EL _H and EL _V can be treated as additional AWGN noise. Thus, the Alamouti decoding process can obtain Alamouti's spatial diversity gain. However, if the receive antennas are completely horizontally or vertically polarized, the system can be simplified. In this case, the cross-polar channel coefficients can be ignored. In such a scenario, Alamouti decoding may not be necessary, and therefore MISO Alamouti spatial diversity is not obtained, and a baseline receiver may be used.

If the mobile receiver has two antennas, the core layer may obtain an array gain using an MRC combining process. Also, the system can be simplified if the polarization of the received symbol is not modified through the channel. At this time, the diversity gain is not obtained by using the MRC combining block, and the array gain can be obtained.

In fixed receivers, core layer (CL) cells are first demodulated, then modulated again, and then canceled. However, the cancellation is somewhat complicated. The re-modulated core layer signal must perform MISO Alamouti. Therefore, a time interleaver (TI) and a frequency interleaver (FI) must be implemented for remodulation of core layer cells. Then, Alamouti encoding is performed. Next, the co-polar and cross-polar channel coefficients are combined accordingly. Finally, to obtain EL _H and EL _V , this combination is subtracted from the received LDM signal. After the cancellation process _, EL _{H, i} and EL _{V, i + 1} ^* may be extracted by applying a particular Alamouti decoding to y _{EL1, i} and y _{EL2, i} . Likewise, EL _{H, i + 1} and EL _{V, i} ^* can be extracted by applying other specific Alamouti decoding to y _{EL1, i + 1} and y _{EL2, i + 1} .

If MIMO spatial multiplexing is applied to both layers, a common-layer MIMO precoder or a layer-independent MIMO precoder may be used in the transmitter. Using an independent precoder is a more flexible solution, but increases the complexity of the transmission. However, the MIMO precoder gain is dependent on the CNR threshold (ModCod of the layer). Therefore, the use of independent precoder provides optimized performance for both layers.

A mobile receiver with two antennas can perform the corresponding MIMO decoding regardless of whether it is a common or independent MIMO precoder, although it is intended for the core layer.

In this case too, the core layer cancellation process of the fixed receiver is complicated. The core layer re-modulation symbols require a likewise MIMO demultiplexer and a MIMO precoder (for common and independent MIMO precoders). In addition, since the received LDM signals are a combination of the two transport components, the re-modulated symbols must be combined in consideration of the channel coefficients. After the core layer cancellation process, a second MIMO BICM- ¹ chain is performed to demodulate the enhanced layer.

FIG. 14 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to an embodiment of the present invention. Referring to FIG.

14, a MIMO broadcast signal transmission apparatus according to an embodiment of the present invention includes a core layer BICM unit 1410, a signal replication unit 1415, an enhanced layer BICM unit 1420, an injection level controller 1431 1432, combiners 1441 and 1442, power normalizers 1451 and 1452, time interleavers 1461 and 1462, frequency interleavers 1471 and 1472, pilot pattern inserters 1481 and 1482, Pre-distortion parts 1491 and 1492 and RF signal generators 1417 and 1418. [

The injection level controllers 1431 and 1432, the combiners 1441 and 1442, the power normalizers 1451 and 1452, the time interleavers 1461 and 1462, Concrete contents related to the frequency interleavers 1471 and 1472 and the pilot pattern inserting parts 1481 and 1482 are disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

The enhanced layer BICM unit 1420 shown in FIG. 14 applies MIMO to the enhanced layer. The channel-encoded and bit-interleaved bit streams are divided into two sub-streams by a MIMO demultiplexer (MIMO demultiplexer) Modulation is applied to each of the streams. The modulated signals are combined via a MIMO precoder (EL MIMO PRECODER) and divided into two signals for two antennas. More details regarding MIMO are disclosed in Korean Patent Laid-Open Publication No. 2016-0084832.

14 is a case where a plain MISO or a MISO TDCFS is applied to a core layer and a MIMO SM (Spatial Multiplexing) is applied to an enhanced layer. In this case, a horizontal polarization antenna transmits an LDM signal x _H = C _H (CL + EL _H ) (C _H = 1 when the plane is MISO) and a vertical polarization antenna transmits LDM The signal x _V = C _v · (CL + EL _V ) is transmitted (C _V = 1 when the plane is MISO).

The core layer BICM unit 1410 performs channel coding, bit interleaving, and modulation on the input data.

The enhanced layer BICM unit 1420 includes a MIMO demultiplexer (MIMO demultiplexer) to divide the channel-encoded and bit-interleaved bit stream into two sub-streams in addition to the operation similar to the core layer BICM unit 1410, Modulate each. At this time, the modulation of the sub-streams may be performed by two modulators, or may be performed by sharing one modulator. Further, the enhanced layer BICM unit 1420 combines the modulated signals through the MIMO precoder (EL MIMO PRECODER) and divides the signals into two signals for the two antennas again.

That is, the enhanced layer BICM unit 1420 divides the enhanced layer data stream into two different enhanced layer sub-streams, performs MIMO precoding corresponding to the enhanced layer sub-streams, Layer signal and a second enhanced layer signal.

Injection level controllers 1431 and 1432 reduce the power of the two divided signals to generate power-reduced enhanced layer signals EL _H and EL _V. At this time, the magnitude of the signal adjusted by the injection level controllers 1431 and 1432 can be determined according to the injection level.

The signal replicator 1415 replicates the input core layer signal and outputs two identical core layer signals.

The combiners 1441 and 1442 combine the core layer signal and the enhanced layer signal at different power levels to generate a multiplexed signal. That is, the combiner 1441 combines the core layer signal and the enhanced layer signal EL _H , and the combiner 1442 combines the core layer signal and the enhanced layer signal EL _V.

 The power normalizers 1451 and 1452 respectively lower the power of the multiplexed signal to a power corresponding to the core layer signal to generate a power normalized signal.

Time interleavers 1461 and 1462 time-interleave the power normalized signals to generate time interleaved signals.

The frequency interleavers 1471 and 1472 respectively frequency interleave the time interleaved signal to generate a frequency interleaved signal.

The pilot pattern inserting units 1481 and 1482 insert pilot patterns into the frequency interleaved signals, respectively. At this time, the pilot pattern inserting units 1481 and 1482 can insert different pilots.

In FIG. 14, the outputs of the pilot pattern inserting units 1481 and 1482 may be data corresponding to the i-th subcarrier (layered division multiplexed data), and may be subjected to a transmission antenna process.

The pre-distortions 1491 and 1492 each pre-distort the data to reduce correlation between the signals corresponding to the two antennas. At this time, the pre-distortion units 1491 and 1492 can perform a pre-distortion processing using a Transmit Diversity Code Filter Set (TDCFS).

In the example shown in FIG. 14, the pre-distortions 1491 and 1492 can be seen as performing the transmit antenna processing described in the claims.

The RF signal generators 1417 and 1418 each generate an RF transmission signal transmitted through an antenna using a pre-distorted (transmit antenna processed) signal.

At this time, the RF transmission signals generated by the RF signal generators 1417 and 1418 may be generated based on the transmission antenna process corresponding to the antennas.

The two antennas shown in FIG. 14 may be provided in one transmitter.

15 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to an embodiment of the present invention.

15, a mobile broadcast signal receiver for MIMO according to an embodiment of the present invention includes an RF receiver 1510, an estimation and equalizer 1520, a frequency deinterleaver 1530, a time deinterleaver 1540, And a core layer BICM decoder 1550.

The mobile broadcast signal receiving apparatus shown in FIG. 15 can recover only the core layer signal without restoring the enhanced layer signal even when the LDM broadcast signal is transmitted.

The RF receiving unit 1510 receives the signals transmitted through the two antennas and generates a received signal.

The estimation and equalization unit 1520 performs channel estimation and equalization. At this time, the estimation and equalization unit can regard the pre-distortion performed in the transmitter as a part of the channel and compensate it in the equalization process.

The frequency deinterleaver 1530 performs deinterleaving in the frequency domain, and the time deinterleaver 1540 deinterleaves in the time domain.

The core layer BICM decoder 1550 performs an inverse process of the core layer BICM portion of the transmitter. Concrete details related to the core layer BICM decoder 1550 are disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

The example shown in FIG. 15 is a case where plain MISO or MISO TDCFS is applied to the core layer and MIMO SM (Spatial Multiplexing) is applied to the enhanced layer. At this time, the polarization of the reception antenna may not affect the performance.

16 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to an embodiment of the present invention.

16, a stationary broadcasting signal receiving apparatus for MIMO according to an embodiment of the present invention includes RF receiving units 1611 and 1612, channel estimation units 1621 and 1622, an MRC combining unit 1623, A deinterleaver 1630, a time deinterleaver 1640, a core layer BICM decoder 1650, a core layer BICM unit 1660, LDM buffers 1671 and 1672, an LDM cancellation unit 1680 and an enhanced layer BICM Decoder 1690. < / RTI >

The fixed broadcast signal receiving apparatus shown in FIG. 16 can recover the core layer signal and the enhanced layer signal by receiving the LDM broadcast signal.

The example shown in FIG. 16 is a case where plain MISO or MISO TDCFS is applied to the core layer and MIMO SM (Spatial Multiplexing) is applied to the enhanced layer.

The RF receivers 1611 and 1612 receive the signals transmitted through the two antennas and generate reception signals.

The channel estimation units 1621 and 1622 estimate the channel between the reception antennas and the transmission antennas. At this time, the channel estimation units 1621 and 1622 can estimate the channel by considering the pre-distortion performed in the transmitter as a part of the channel.

The MRC combining unit 1623 is for obtaining the array gain based on the estimated channels, and the detailed operation of the MRC combining unit 1623 will be described later with reference to Equation (12).

The frequency deinterleaver 1630 performs deinterleaving in the frequency domain, and the time deinterleaver 1640 deinterleaves the time domain.

The core layer BICM decoder 1650 performs a reverse process of the core layer BICM portion of the transmitter.

The core layer BICM unit 1660 performs the BICM again on the restored core layer stream and performs a corresponding cancellation through the two LDM buffers 1671 and 1672 and the LDM cancel unit 1680 do. The signal that has been subjected to the cancellation corresponding to the core layer is restored to the enhanced layer output stream through the enhanced layer BICM decoder 1690.

At this time, the cancellation corresponds to the core layer signal and can be performed separately for each of the receive antennas.

At this time, the core layer cancellation process requires a combination of the core layer and corresponding channel coefficients. In other words, the cancellation is performed by selecting a core layer channel component combination corresponding to channels (h _HH C _H , h _HV C _V ) associated with the reception antenna (RF _H ) of the reception antennas (RF _H , RF _V ) generating a receive antenna (RF _H) corresponding LDM buffer 1671 buffers signal canceling illustration signal (y _H ') by subtracting from the to the, receiving antennas and a reception antenna (RF _V) of the (RF _H, RF _V) Subtracts a core layer channel component combination corresponding to the associated channels (h _VH C _H , h _VV C _V ) from the buffer signal of the LDM buffer 1672 corresponding to the receive antenna (RF _V ) (y _V ').

At this time, the enhanced layer BICM decoder 1690 can recover the enhanced layer signal using all of the cancellation signals y _H ', y _V '.

The enhanced layer BICM decoder 1690 performs MIMO decoding using all of the cancellation signals y _H ', y _V ' and demodulates the MIMO decoded result by a MIMO demapper (MIMO MAP- ¹ ) Multiplexes the demodulated result into a single stream, performs bit deinterleaving and FEC decoding on the result, and generates an enhanced layer signal.

At this time, the MIMO demapper (MIMO MAP ^-1 ) may correspond to the modulator in the enhanced layer BICM part of the transmitter.

The restoration of the enhanced layer signal through the core layer BICM decoder 1650, the enhanced layer BICM decoder 1690, and the cancellation corresponding to the core layer is disclosed in detail in Korean Patent Laid-Open Publication No. 2017-0009737.

Although not explicitly shown in FIGS. 15 and 16, a power denormalizer may be provided in front of the core layer BICM decoder to perform the inverse function of the power normalizer.

The received signal transmitted through the transmitter shown in FIG. 14 and received through the receiver shown in FIG. 15 is expressed by Equation (10).

&Quot; (10) "

Where i denotes a subcarrier index and h denotes a channel, where C _H [i] and C _V [i] denote TDCFS coding filter sets and n denotes noise. For plane MISO, C _H [i] and C _V [i] are 1.

The channel estimators of the receivers shown in FIGS. 2 and 3 provide corresponding filtering and a combination of the two channels with their corresponding filtering in a single channel frequency response.

The received signal transmitted through the transmitter shown in FIG. 14 and received through the receiver shown in FIG. 16 is expressed by Equation (11).

&Quot; (11) "

Where i denotes a subcarrier index and h denotes a channel, where C _H [i] and C _V [i] denote TDCFS coding filter sets and n denotes noise. For plane MISO, C _H [i] and C _V [i] are 1.

Since there are two receive antennas, the core layer can also exploit the array gain using the MRC combining process as shown in Equation (12).

&Quot; (12) "

A to cancel migration process, to re-encode as shown in Equation 13 (re-encoded) core layer symbols are to be combined and, a cancel from y _H and y _V (should be combined and cancelled from y _H and y _V).

&Quot; (13) "

After the core layer symbols are removed, the received symbols are expressed as: < EMI ID = 14.0 >

&Quot; (14) "

Finally, EL _H and EL _V can be demultiplexed as in a MIMO SM system (as in MIMO SM system).

17 is a block diagram of a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.

17, a MIMO broadcast signal transmission apparatus according to another embodiment of the present invention includes a core layer BICM unit 1710, a signal replication unit 1715, an enhanced layer BICM unit 1720, an injection level controller 1731 1721, 1742, 1721, 1742, power normalizers 1751, 1752, time interleavers 1761, 1762, frequency interleavers 1771, 1772, Alamouti encoder 1790, 1781, and 1782, and RF signal generators 1717 and 1718, respectively.

A signal replication unit 1715, an enhanced layer BICM unit 1720, injection level controllers 1731 and 1732, combiners 1741 and 1742, a power normalizer 1710, The time interleavers 1761 and 1762 and the frequency interleavers 1771 and 1772 have already been described with reference to FIG.

In the example shown in Fig. 17, MISO Alamouti is applied to the core layer and MIMO SM (Spatial Multiplexing) is applied to the enhanced layer. At this time, the horizontal polarization antenna transmits the LDM signal CL + EL _H without any modification, and the vertical polarization antenna transmits the LDM signal CL + EL _V according to Alamouti encoding. Conjugated and interleaved in pairs (pairwise interleave).

The Alamouti encoder 1790 divides the signals transmitted by the two antennas into two groups and outputs signals (first group) transmitted by the horizontally polarized antenna as they are without modification, The second group) modifies the two QAM symbol blocks to maintain orthogonality between the groups.

The pilot pattern inserters 1781 and 1782 insert a pilot pattern into the Alamouti encoded signal, respectively. At this time, the pilot pattern inserters 1781 and 1782 can insert different pilot patterns, and more pilot patterns can be inserted into the complex structure than the pilot pattern inserters shown in FIG.

The Alamouti encoder 1790 and the pilot pattern inserters 1781 and 1782 shown in FIG. 17 can perform transmission antenna processing. That is, the Alamouti encoder 1790 performs Alamouti encoding to reduce correlation between the signal corresponding to the horizontal polarization antenna and the signal corresponding to the vertical polarization antenna, and the pilot pattern inserters 1781 and 1782 perform the Alamouti encoding, It is possible to perform the transmission antenna process by performing the pilot pattern insertion for the pilot pattern. At this time, the Alamouti encoding may be to maintain orthogonality between the signal corresponding to the horizontal polarization antenna and the signal corresponding to the vertical polarization antenna.

The RF signal generator 1717 generates an RF transmission signal corresponding to the signal multiplexed by the combiner 1741 and transmitted through the horizontally polarized antenna and the RF signal generator 1718 generates the RF transmission signal multiplexed by the combiner 1742 And generates an RF transmit signal that corresponds to the signal and is transmitted via a vertically polarized antenna. At this time, the RF transmission signals may be generated based on the transmission antenna processing corresponding to the antennas.

The two antennas shown in FIG. 17 may be provided in one transmitter.

18 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.

Referring to FIG. 18, a mobile broadcast signal receiver for MIMO according to another embodiment of the present invention includes an RF receiver 1810, a channel estimator 1820, an Alamouti decoder 1825, a frequency deinterleaver 1830, A deinterleaver 1840 and a core layer BICM decoder 1850.

The mobile broadcast signal receiving apparatus shown in FIG. 18 can recover only the core layer signal without restoring the enhanced layer signal even when the LDM broadcast signal is transmitted.

The RF receiver 1810 receives the signals transmitted through the two antennas and generates a received signal.

The channel estimator 1820 estimates a channel frequency response (CFR) for all of the channels from both transmit antennas. To this end, the transmitter may use orthogonal pilot patterns between the two antennas.

The Alamouti decoder 1825 performs a decoding operation corresponding to the Alamouti encoding of the transmitter. The operation of the Alamouti decoder 1825 will be described later with reference to Equation (16).

At this time, the Alamouti decoder 1825 may perform Alamouti decoding based on channel estimation for both channels corresponding to the two transmit antennas.

The frequency deinterleaver 1830 performs deinterleaving in the frequency domain, and the time deinterleaver 1840 deinterleaves in the time domain.

The core layer BICM decoder 1850 performs a reverse process of the core layer BICM portion of the transmitter.

FIG. 19 is a block diagram illustrating a fixed broadcasting signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.

19, the fixed broadcasting signal receiving apparatus for MIMO according to another embodiment of the present invention includes RF receiving units 1911 and 1912, channel estimation units 1921 and 1922, an MRC and Alamouti decoding unit 1923, A frequency deinterleaver 1930, a time deinterleaver 1940, a core layer BICM decoder 1950, a core layer BICM unit 1960, a time interleaver 1961, a frequency interleaver 1962, an Alamouti re-encoder 1963, (1995, 1996) and an enhanced layer BICM decoder (1990), which are used in the case of an interleaver, .

The fixed broadcast signal receiving apparatus shown in FIG. 19 can recover the core layer signal and the enhanced layer signal by receiving the LDM broadcast signal.

In the example shown in Fig. 19, MISO Alamouti is applied to the core layer and MIMO SM is applied to the enhanced layer.

The RF receivers 1911 and 1912 receive the signals transmitted through the two antennas and generate reception signals.

The channel estimation units 1921 and 1922 estimate the channel between the reception antennas and the transmission antennas.

The MRC and Alamouti decoding unit 1923 is for obtaining the array and diversity gain based on the estimated channels, and the detailed operation of the MRC and Alamouti decoding unit 1923 will be described later with reference to Equation (18).

The frequency deinterleaver 1930 performs deinterleaving in the frequency domain, and the time deinterleaver 1940 deinterleaves in the time domain.

The core layer BICM decoder 1950 performs a reverse process of the core layer BICM portion of the transmitter.

The core layer BICM unit 1960 performs the BICM again on the restored core layer stream and performs the corresponding cancellation through the two LDM buffers 1971 and 1972 and the LDM canceling unit 1980 do. The signal with the canceled corresponding to the core layer is restored to the enhanced layer output stream through the enhanced layer BICM decoder 1990.

At this time, for the cancellation, the signal BICMed again by the core layer BICM unit 1960 is time interleaved and frequency interleaved again by the time interleaver 1961 and the frequency interleaver 1962, and the interleaved signal is re- Is again Alamouti-encoded by the LDM-canceling unit (1963) and provided to the LDM-canceling unit (1980).

That is, the cancellation process of the LDM Cancellation Part (1980) requires Alamouti re-encoding and combining with the corresponding channel coefficients.

At this time, the cancellation corresponds to the core layer signal and can be performed separately for each of the receive antennas.

At this time, the cancellation sends a core layer channel component combination corresponding to the channels (h _HH , h _HV ) associated with the receive antenna (RF _H ) of the receive antennas (RF _H , RF _V ) by subtracting from the buffer signal of the LDM buffer (1971) corresponding to the RF _H) and generates the cancel illustration signal (y _H '), the channel associated with the receiving antenna (RF _V) of the receiving antenna (RF _H, RF _V) (y _V ') by subtracting a core layer channel component combination corresponding to the received signal (h _VH , h _VV ) from the buffer signal of the LDM buffer 1972 corresponding to the receive antenna (RF _V ) can do.

At this time, the enhanced layer BICM decoder 1990 can recover the enhanced layer signal using all of the cancellation signals y _H ', y _V '. At this time, Alamouti decoding by the Alamouti decoder 1991 is performed using all of the cancellation signals y _H ', y _V ' after the LDM cancellation, and the Alamouti decoded signals are output to the frequency deinterleavers 1992, 1993), time deinterleaved by time deinterleavers (1995, 1996), and then provided to an enhanced layer BICM decoder (1990).

The Alamouti decoding of the Alamouti decoder 1991 will be described later with reference to Equations (21) and (22).

The enhanced layer BICM decoder 1990 performs MIMO decoding after performing Alamouti decoding, frequency deinterleaving, and time deinterleaving on the cancellation signals y _H ', y _V ', and outputs the MIMO decoded result Modulated by a MIMO demapper (MIMO MAP- ¹ ), MIMO multiplexes the demodulated result into one stream, bit deinterleaves the result, and FEC-decodes the result to generate an enhanced layer signal.

At this time, the MIMO demapper (MIMO MAP ^-1 ) may correspond to the modulator in the enhanced layer BICM part of the transmitter.

Although not explicitly shown in FIGS. 18 and 19, a power denormalizer for performing the inverse function of the power normalizer may be provided at the front end of the core layer BICM decoder.

The received signal transmitted through the transmitter shown in FIG. 17 and received through the receiver of FIG. 18 is expressed by the following equation (15).

&Quot; (15) "

Enhanced layer cells are treated as additional AWGNs (additional AWGNs). Therefore, the Alamouti decoding process is expressed by Equation (16).

&Quot; (16) "

The received signal transmitted through the transmitter shown in FIG. 17 and received through the receiver shown in FIG. 19 is expressed by Equation (17).

&Quot; (17) "

The core layer can exploit the array gain using MRC combination as shown in Equation 18 below.

&Quot; (18) "

For the cancellation process, the re-encoded core layer symbols are again Alamouti encoded, combined, and canceled from y _H and y _V , as shown in Equation 19: < EMI ID = cancelled from y _H and _V y).

&Quot; (19) "

After the core layer symbols are removed, the received symbols are expressed as: < EMI ID = 20.0 >

&Quot; (20) "

Next, two separate Alamouti decoding processes are performed as shown in Equations (21) and (22) below.

&Quot; (21) "

&Quot; (22) "

Hereinafter, the case where the mobile receiver includes two antennas as in the fixed receiver will be described.

First, MISO schemes (Plain MISO, MISO TDCFS or MISO Alamouti) are used for the core layer, and MIMO SM is used for the enhanced layer.

In this case, the transmitter structure is the same as that shown in FIG. 14 or 17, and the fixed receiver structure is the same as that shown in FIG. 16 or 19.

20 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.

Referring to FIG. 20, it can be seen that a mobile receiver has two antennas when a plain MISO or a MISO TDCFS is applied to a core layer and a MIMO SM is applied to an enhanced layer.

In this case, in order to use the SIMO array gain for the core layer signal, the MRC combining method according to Equation (12) can be applied.

21 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.

Referring to FIG. 21, when the MISO Alamouti is applied to the core layer and the MIMO SM is applied to the enhanced layer, it can be seen that the mobile receiver has two antennas.

In this case, in order to use the SIMO array gain for the core layer signal, the MRC and Alamouti combining method according to Equation 18 can be applied.

20 and 21 correspond to parts of FIGS. 16 and 19, respectively, and the detailed description of the operation of each component will not be described again since each component has been described above.

The received symbols received by the receiver shown in FIG. 20 are expressed by Equation (11), and the received symbols received by the receiver shown in FIG. 21 are expressed by Equation (15). At this time, the MRC combining can be performed as Equation (12) or Equation (18).

At this time, the fixed receiver can perform the same cancellation process as Equation (13) or (19).

Hereinafter, a case where MIMO SM (Spatial Multiplexing) is used for both the core layer and the enhanced layer will be described.

22 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.

22, a MIMO broadcast signal transmission apparatus according to another embodiment of the present invention includes a core layer BICM unit 2210, an enhanced layer BICM unit 2220, injection level controllers 2231 and 2232, 2221, 2272, pilot pattern inserters 2281, 2282, and RF signal generators 2217, 2221, 2221, 2221, 2221, 2242, power normalizers 2251, 2252, time interleavers 2261, 2262, frequency interleavers 2271, 2272, , 2218).

The injection level controllers 2231 and 2232, the combiners 2241 and 2242, the power normalizers 2251 and 2252, the time interleavers 2261 and 2262, Frequency interleavers 2271 and 2272 and RF signal generators 2217 and 2218 have already been described above.

In the example shown in FIG. 22, MIMO SM is applied to the core layer as well as the enhanced layer. That is, the core layer BICM unit 2210, like the enhanced layer BICM unit 2220, includes a MIMO demultiplexer (MIMO demultiplexer) to divide the channel-encoded and bit-interleaved bit stream into two sub-streams, Modulate each. At this time, the modulation of the sub-streams may be performed by two modulators, or may be performed by sharing one modulator. Further, the core layer BICM unit 2210 combines the modulated signals through a MIMO precoder (CL MIMO PRECODER) and divides the signals into two signals again for two antennas.

That is, the core layer BICM unit 2210 divides the core layer data stream into two different core layer sub-streams, and performs MIMO precoding corresponding to the core layer sub-streams to generate a first core layer signal and a second And generates a core layer signal.

The pilot pattern inserters 2281 and 2282 insert a pilot pattern suitable for the LDM signal for the horizontal antenna and the LDM signal for the vertical antenna. At this time, the pilot pattern inserting units 2281 and 2282 can insert different pilot patterns.

In the example shown in FIG. 22, the transmit antenna process may insert a pilot pattern suitable for each of the first LDM signal for the horizontal antenna and the second LDM signal for the vertical antenna.

The two antennas shown in Fig. 22 may be provided in one transmitter.

23 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.

23, a mobile broadcast signal receiver for MIMO according to another embodiment of the present invention includes RF receivers 2311 and 2312, channel estimators 2321 and 2322, frequency deinterleavers 2331 and 2332, ), Time deinterleavers 2341 and 2342, and a core layer BICM decoder 2350.

At this time, the channel estimation unit 2321 estimates channels related to the horizontal polarization antenna, and the channel estimation unit 2322 estimates channels related to the vertical polarization antenna. At this time, the related channels may include cross channels.

In the example shown in FIG. 23, the frequency deinterleavers 2331 and 2332 and the time deinterleavers 2341 and 2342 perform frequency and time deinterleaving operations for the horizontal polarization antenna and the vertical polarization antenna, respectively.

In addition, the core layer BICM decoder 2350 performs MIMO decoding based on the two antenna signals as in the enhanced layer BICM decoder shown in FIGS. 16 and 19, and outputs the MIMO decoded result to the MIMO demapper (MIMO MAP ^{) 1} , demultiplexes the demodulated result into one stream, performs bit deinterleaving and FEC decoding on the result, and generates a core layer signal.

That is, the example shown in FIG. 23 requires a second receive chain and a more complex MIMO demapper for core layer MIMO.

FIG. 24 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.

Referring to FIG. 24, a fixed broadcast signal receiver for MIMO according to another embodiment of the present invention includes RF receivers 2411 and 2412, channel estimators 2421 and 2422, frequency deinterleavers 2431 and 2432 A core layer BICM decoder 2450, a core layer BICM unit 2460, LDM buffers 2471 and 2472, an LDM cancellation unit 2480, and an enhanced layer BICM decoder 2460. The time deinterleavers 2441 and 2442, the core layer BICM decoder 2450, (2490).

The fixed broadcasting signal receiving apparatus shown in FIG. 24 can receive the LDM broadcasting signal and recover the core layer signal and the enhanced layer signal.

The example shown in FIG. 24 is a case where MIMO SM is applied to the core layer and the enhanced layer.

The RF receivers 2411 and 2412 receive the signals transmitted through the two antennas and generate reception signals.

The channel estimation units 2421 and 2422 estimate the channel between the reception antennas and the transmission antennas.

In the example shown in FIG. 24, the frequency deinterleavers 2431 and 2432 and the time deinterleavers 2441 and 2442 perform frequency and time deinterleaving operations for the horizontal polarization antenna and the vertical polarization antenna, respectively.

The core layer BICM decoder 2450 performs a reverse process of the core layer BICM portion of the transmitter.

In the example shown in FIG. 24, the core layer BICM decoder 2450 performs MIMO decoding based on the two antenna signals as in the enhanced layer BICM decoder shown in FIGS. 16 and 19, and outputs the MIMO decoded result to the MIMO Demapper (MIMO MAP ^-1 ), demultiplexes the demodulated result into one stream, performs bit deinterleaving and FEC decoding on the result, and generates a core layer signal.

The core layer BICM unit 2460 performs BICM on the restored core layer stream. The core layer BICM unit 2460 includes a MIMO demultiplexer (MIMO demultiplexer) to divide the channel-encoded and bit-interleaved bit stream into two sub-streams, Modulate each. At this time, the modulation of the sub-streams may be performed by two modulators, or may be performed by sharing one modulator. In addition, the core layer BICM unit 2460 combines the modulated signals through a MIMO precoder (CL MIMO PRECODER) and divides the signals into two signals again for two antennas.

Corresponding to the core layer is performed through the two LDM buffers 2471 and 2472 and the LDM canceling section 2480. [ The signal that has been subjected to the cancellation corresponding to the core layer is restored to the enhanced layer output stream through the enhanced layer BICM decoder 2490.

At this time, the cancellation process of the LDM cancellation section 2480 requires a combination of the MIMO encoder and the corresponding channel coefficients.

At this time, the cancellation corresponds to the core layer signal and can be performed separately for each of the receive antennas.

At this time, the cancellation sends a core layer channel component combination corresponding to the channels (h _HH , h _HV ) associated with the receive antenna (RF _H ) of the receive antennas (RF _H , RF _V ) by subtracting from the buffer signal of the LDM buffer 2471 corresponding to the RF _H) and generates the cancel illustration signal (y _H '), the channel associated with the receiving antenna (RF _V) of the receiving antenna (RF _H, RF _V) (y _V ') by subtracting a core layer channel component combination corresponding to the received signal (h _VH , h _VV ) from the buffer signal of the LDM buffer 2472 corresponding to the receive antenna (RF _V ) can do.

At this time, the enhanced layer BICM decoder 2490 can recover the enhanced layer signal using all of the cancellation signals y _H ', y _V '.

The enhanced layer BICM decoder 2490 performs MIMO decoding using the cancellation signals y _H ', y _V ', demodulates the MIMO decoded result by a MIMO demapper (MIMO MAP- ¹ ) , Demultiplexes the demodulated result into a single stream, performs bit deinterleaving and FEC decoding on the result, and generates an enhanced layer signal.

At this time, the MIMO demapper (MIMO MAP ^-1 ) may correspond to the modulator in the enhanced layer BICM part of the transmitter.

Although not explicitly shown in FIGS. 23 and 24, a power denormalizer for performing the inverse function of the power normalizer may be provided at the front end of the core layer BICM decoder.

The received signal transmitted through the transmitter shown in FIG. 22 and received through the receiver shown in FIG. 23 or 24 is expressed by the following equation (23).

&Quot; (23) "

The mobile receiver shown in FIG. 23 assumes the enhanced layer (EL) symbols as additional AWGN noise and performs MIMO SM demapping on the received symbols of Equation (23).

The remodulated core layer symbols in the fixed receiver shown in FIG. 24 should be combined according to the MIMO antenna scheme. The necessary cancellation process is shown in Equation 24 below.

&Quot; (24) "

Of the MISO technologies used for MIMO, MISO Alamouti shows good performance. However, when the MISO Alamouti is applied as described with reference to FIG. 19, the core layer cancellation process becomes complicated. Since Alamouti encoding performs pairwise cell interleaving at the end of the transmit chain, time interleaving and frequency interleaving must be performed in the re-modulation process.

Therefore, a new technique is needed to simplify the core layer cancellation process while maintaining similar performance to using Alamouti.

25 is a block diagram illustrating a MIMO broadcast signal transmitting apparatus according to another embodiment of the present invention.

Referring to FIG. 25, a MIMO broadcast signal transmission apparatus according to another embodiment of the present invention is similar to the structure shown in FIG. 22 except that two different core layer signals are generated by a cell divider .

At this time, the cell divider block provided after the core layer BICM unit operates as a cell exchanger. That is, the even cells of the core layer are transmitted through the horizontal antenna, and the odd cells are transmitted through the vertical antenna. In this case, the coding rate of the core layer can be seen to be half as compared with the case shown in FIG.

The example shown in Fig. 25 can be seen when a MISO FEC divider is applied to the core layer and MIMO SM is applied to the enhanced layer. In addition, additional TDCFS pre-distortion or Alamouti encoding is not performed in the transmit chain.

When the transmitter shown in Fig. 25 is used, the mobile receiver also has to use two reception antennas.

26 is a block diagram illustrating a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention.

Referring to FIG. 26, a mobile broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention is similar to the structure shown in FIG. 23, except that a cell combiner, instead of MIMO decoding, Are combined into one.

Comparing the example shown in FIG. 26 with the example shown in FIG. 21, it can be seen that the second frequency deinterleaver FI ^-1 and the time deinterleaver TI ^-1 are additionally required, which increases the complexity.

On the other hand, the complexity of fixed receivers is reduced because there is no need to perform time interleaving and frequency interleaving due to Alamouti interleaving in the core layer cancellation process.

FIG. 27 is a block diagram illustrating a fixed broadcast signal receiving apparatus for MIMO according to another embodiment of the present invention. Referring to FIG.

Referring to FIG. 27, the structure of the fixed broadcasting signal receiving apparatus for MIMO according to another embodiment of the present invention is simpler than the structure shown in FIG.

The example shown in FIG. 27 is an example in which a MISO FEC divider is applied to the core layer and MIMO SM is applied to the enhanced layer.

In FIG. 27, the cell divider performs the same operation as the cell divider shown in FIG. 25, and the operation of the cell combiner is as described with reference to FIG.

The received symbols transmitted through the transmitter shown in FIG. 25 and received through the receiver shown in FIG. 26 or 27 are expressed by the following equation (25).

&Quot; (25) "

Here, CL denotes a core layer, EL denotes an enhanced layer, i denotes a subcarrier index, h denotes a channel, and n denotes noise.

28 is a flowchart illustrating a method of transmitting a MIMO broadcast signal according to an embodiment of the present invention.

Referring to FIG. 28, a method for transmitting a MIMO broadcast signal according to an embodiment of the present invention includes dividing an enhanced layer data stream into two different enhanced layer sub-streams, and performing MIMO And performs a precoding to generate a first enhanced layer signal and a second enhanced layer signal (S2810).

In addition, according to an embodiment of the present invention, a broadcast signal transmission method includes combining a first core layer signal corresponding to a core layer data stream and a first enhanced layer signal at different power levels, 1 multiplexed signal and combines the second core layer signal corresponding to the core layer stream and the second enhanced layer signal at different power levels to generate a second multiplexed signal corresponding to the second antenna (S2820).

A method of transmitting a broadcast signal according to an exemplary embodiment of the present invention includes transmitting a first RF transmission signal corresponding to the first multiplexed signal and transmitted through the first antenna and a second RF transmission signal corresponding to the second multiplexed signal, And generates a second RF transmission signal transmitted through the antenna (S2830).

At this time, the first RF transmission signal and the second RF transmission signal may be generated based on a transmission antenna process corresponding to the first antenna and the second antenna.

In this case, the transmit antenna process may be a pre-distortion process using a transmit diversity code filter set (TDCFS).

At this time, the transmission antenna process can be performed after the pilot pattern is inserted into the frequency interleaved signal.

At this time, the transmit antenna process may include Alamouti encoding to maintain orthogonality between a signal corresponding to the first antenna and a signal corresponding to the second antenna.

At this time, the transmit antenna process may insert pilot patterns into the Alamouti encoded signal.

At this time, the first core layer signal and the second core layer signal divide the core layer data stream into two different core layer sub-streams, perform MIMO precoding corresponding to the core layer sub-streams Lt; / RTI >

29 is a flowchart illustrating a method of receiving a broadcast signal for MIMO according to an embodiment of the present invention.

Referring to FIG. 29, a method for receiving a broadcast signal for MIMO according to an embodiment of the present invention generates reception signals based on signals received through a plurality of reception antennas (S2910).

 In addition, the method for receiving a broadcast signal for MIMO according to an embodiment of the present invention estimates channels between the reception antennas and transmission antennas (S2920).

In addition, the method for receiving a broadcast signal for MIMO according to an embodiment of the present invention restores a core layer signal corresponding to the received signals (S2930).

At this time, the core layer signal can be recovered based on Maximum-Ratio-Combining (MRC) corresponding to the channels.

The method of receiving a broadcast signal for MIMO according to an embodiment of the present invention restores an enhanced layer signal based on a core layer signal and a cancelation performed separately for each of the reception antennas S2940).

At this time, the cancellation subtracts a first core layer channel component combination corresponding to the channels related to the first reception antenna among the reception antennas from the first buffer signal corresponding to the first reception antenna, 1 canceling signal and subtracting a second core layer channel component combination corresponding to channels associated with a second one of the receive antennas from a second buffer signal corresponding to the second receive antenna A second canceling signal can be generated. At this time, the enhanced layer signal can be restored by using both the first cancel signal and the second cancel signal.

At this time, the enhanced layer signal may be recovered by MIMO decoding corresponding to the first and second cancellation signals.

Wherein the enhancement layer signal is generated based on Alamouti re-encoding corresponding to the core layer signal, and the enhanced layer signal corresponds to the first cancellation signal and the second cancellation signal, Lt; RTI ID = 0.0 > Alamouti < / RTI >

At this time, the Alamouti re-encoding is performed after interleaving, and deinterleaving can be performed after the Alamouti decoding.

As described above, the broadcasting signal transmitting / receiving method and apparatus according to the present invention are not limited to the configuration and method of the embodiments described above, but the embodiments can be applied to various implementations All or some of the examples may be selectively combined.

111, 112: Core layer BICM part
121 and 122: Enhanced layer BICM section
131, 132: Injection level controller
141, 142: combiner
151, 152: Power normalizer
161, 162: time interleaver
171, 172: frequency interleaver
181, 182: pilot pattern inserting portion
191, 192: Predistortion section
117 and 118: RF signal generating unit

Claims (20)

Divides the enhanced layer data stream into two different enhanced layer sub-streams, and performs MIMO precoding corresponding to the enhanced layer sub-streams to generate a first enhanced layer signal and a second enhanced layer signal An enhanced layer BICM unit;
A first combiner for combining a first core layer signal corresponding to a core layer data stream and the first enhanced layer signal at different power levels to generate a first multiplexed signal corresponding to a first antenna;
A second combiner for combining a second core layer signal corresponding to the core layer stream and the second enhanced layer signal at different power levels to generate a second multiplexed signal corresponding to a second antenna; And
A first RF transmission signal corresponding to the first multiplexed signal and transmitted via the first antenna and an RF signal corresponding to the second multiplexed signal and generating a second RF transmission signal transmitted via the second antenna Generators
Wherein the broadcast signal transmitting apparatus includes: The method according to claim 1,
The first RF transmit signal and the second RF transmit signal
And the second antenna is generated based on a transmission antenna process corresponding to the first antenna and the second antenna. The method of claim 2,
Wherein the transmit antenna process is a pre-distortion process using a transmit diversity code filter set (TDCFS). The method of claim 3,
Wherein the transmit antenna process is performed after a pilot pattern is inserted into the frequency interleaved signal. The method of claim 2,
Wherein the transmit antenna processing includes Alamouti encoding to maintain orthogonality between a signal corresponding to the first antenna and a signal corresponding to the second antenna. The method of claim 5,
The transmit antenna processing
And inserts the pilot patterns into the Alamouti encoded signal. The method according to claim 1,
The first core layer signal and the second core layer signal are generated by dividing the core layer data stream into two different core layer sub-streams and performing MIMO precoding corresponding to the core layer sub-streams Wherein the broadcast signal transmission apparatus comprises: RF receivers for generating received signals based on signals received via a plurality of receive antennas;
Channel estimators for estimating channels between the reception antennas and the transmission antennas;
A core layer BICM decoder for restoring a core layer signal corresponding to the received signals; And
An enhancement layer decoder for recovering an enhanced layer signal based on the core layer signal and the canceling performed separately for each of the reception antennas,
The broadcast signal receiving apparatus comprising: The method of claim 8,
The above-
A first core layer channel component combination corresponding to channels associated with a first receive antenna of the receive antennas is subtracted from a first buffer signal corresponding to the first receive antenna to generate a first cancel signal ,
A second core layer channel component combination corresponding to channels associated with a second receive antenna of the receive antennas is subtracted from a second buffer signal corresponding to the second receive antenna to generate a second cancel signal ,
Wherein the enhanced layer signal is restored using both the first cancel signal and the second cancel signal. The method of claim 9,
The enhanced layer signal
Wherein the first signal is restored by MIMO decoding corresponding to the first cancel signal and the second cancel signal. The method of claim 10,
The core layer signal
Wherein the base station is restored based on Maximum-Ratio-Combining (MRC) corresponding to the channels. The method of claim 10,
The above-
Wherein the enhancement layer signal is performed based on an Alamouti re-encoding corresponding to the core layer signal, and the enhanced layer signal is restored using Alamouti decoding corresponding to the first cancel signal and the second cancel signal The broadcast signal receiving apparatus comprising: The method of claim 12,
Wherein the Alamouti re-encoding is performed after interleaving, and deinterleaving is performed after the Alamouti decoding. The method of claim 10,
The above-
And the MIMO precoding is performed based on MIMO precoding corresponding to the core layer signal. Generating received signals based on signals received via a plurality of receive antennas;
Estimating channels between the receive antennas and the transmit antennas;
Reconstructing a core layer signal corresponding to the received signals; And
Reconstructing the enhanced layer signal based on the core layer signal and the canceling performed separately for each of the reception antennas
And transmitting the broadcast signal. 16. The method of claim 15,
The above-
A first core layer channel component combination corresponding to channels associated with a first receive antenna of the receive antennas is subtracted from a first buffer signal corresponding to the first receive antenna to generate a first cancel signal ,
A second core layer channel component combination corresponding to channels associated with a second receive antenna of the receive antennas is subtracted from a second buffer signal corresponding to the second receive antenna to generate a second cancel signal ,
Wherein the enhanced layer signal is restored using both the first cancel signal and the second cancel signal. 18. The method of claim 16,
The enhanced layer signal
Wherein the first signal is restored by MIMO decoding corresponding to the first cancel signal and the second cancel signal. 18. The method of claim 17,
The core layer signal
And restored based on MRC (Maximum-Ratio-Combining) corresponding to the channels. 18. The method of claim 17,
The above-
Wherein the enhancement layer signal is performed based on an Alamouti re-encoding corresponding to the core layer signal, and the enhanced layer signal is restored using Alamouti decoding corresponding to the first cancel signal and the second cancel signal Wherein the broadcast signal is a broadcast signal. The method of claim 19,
Wherein the Alamouti re-encoding is performed after interleaving, and deinterleaving is performed after the Alamouti decoding.

Images