WO2016003221A1 - Signal multiplexing device and signal multiplexing method using layered division multiplexing - Google Patents

Abstract

A signal multiplexing device and method using layered division multiplexing are disclosed. The signal multiplexing device according to one embodiment of the present invention comprises: a combiner for combining a core layer signal and an enhanced layer signal at different power levels so as to generate a multiplexed signal; a power normalizer for lowering power of the multiplexed signal to power corresponding to the core layer signal; a time interleaver performing interleaving to be applied to both the core layer signal and the enhanced layer signal so as to generate a time-interleaved signal; and a frame builder for generating a broadcast signal frame by using the time-interleaved signal and L1 signaling information.

Description

Signal Multiplexing Device and Signal Multiplexing Method Using Layered Division Multiplexing

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

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

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

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

It is an object of the present invention to provide a novel signal multiplexing technique that can provide higher levels of flexibility and better performance than time division multiplexing (TDM) or frequency division multiplexing (FDM).

In addition, an object of the present invention is to allow each service to use 100% of time and frequency resources while simultaneously supporting multiple services in the next generation broadcasting system.

It is also an object of the present invention to efficiently multiplex / demultiplex signals by combining each of two or more signals corresponding to each of the two or more layers to different power levels.

A signal multiplexing apparatus according to the present invention for achieving the above object comprises: a combiner for combining a core layer signal and an enhanced layer signal to different power levels to generate a multiplexed signal; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And a frame builder generating a broadcast signal frame using the time interleaved signal and the L1 signaling information.

In this case, the signal multiplexing apparatus may further include an injection level controller which generates a power reduced enhanced layer signal by reducing the power of the enhanced layer signal. In this case, the combiner may combine the core layer signal and the power reduced enhanced layer signal to generate a multiplexed signal.

In this case, the signal multiplexing apparatus may further include an L1 signaling generator configured to generate the L1 signaling information including the injection level information of the injection level controller.

In this case, the signal multiplexing apparatus includes a core layer BICM unit corresponding to the core layer signal; And an enhanced layer BICM unit that performs different BICM encoding from the core layer BICM unit.

At this time, the core layer BICM unit may have a lower bit rate than the enhanced layer BICM unit and the core layer BICM unit may be more robust than the enhanced layer BICM unit.

At this time, the power normalizer corresponds to a normalizing factor, and may lower the power of the multiplexed signal by the coupler.

At this time, the injection level controller may correspond to a scaling factor. At this time, the normalizing factor and the scaling factor are each greater than 0 and less than 1, and the scaling factor decreases as the power reduction corresponding to the injection level controller increases, and the normalizing factor decreases the power corresponding to the injection level controller. May increase as

At this time, the injection level controller can change the injection level in 0.5dB steps from 3.0dB to 10.0dB.

In this case, the enhanced layer signal may correspond to the enhanced layer data, which is restored based on a cancellation corresponding to the restoration of the core layer data corresponding to the core layer signal.

In this case, the core layer BICM unit may include a core layer error correction encoder for error correction encoding the core layer data; A core layer bit interleaver for performing bit interleaving corresponding to the core layer data; And a core layer symbol mapper for performing modulation corresponding to the core layer data.

In this case, the enhanced layer BICM unit may include an enhanced layer error correction encoder configured to perform error correction encoding on the enhanced layer data; An enhanced layer bit interleaver for performing bit interleaving corresponding to the enhanced layer data; And an enhanced layer symbol mapper for performing modulation corresponding to the enhanced layer data.

In this case, the enhanced layer error correction encoder may have a higher code rate than the core layer error correction encoder, and the enhanced layer symbol mapper may be less robust than the core layer symbol mapper.

In this case, the combiner may combine one or more extension layer signals having a lower power level than the core layer signal and the enhanced layer signal together with the core layer signal and the enhanced layer signal.

In addition, the signal multiplexing method according to an embodiment of the present invention comprises the steps of combining the core layer signal and the enhanced layer signal at different power levels to generate a multiplexed signal; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And generating a broadcast signal frame using the time interleaved signal and L1 signaling information.

In this case, the signal multiplexing method may further include generating a power reduced enhanced layer signal by reducing the power of the enhanced layer signal. In this case, the combining may include combining the core layer signal and the power reduced enhanced layer signal to generate a multiplexed signal.

In this case, the signal multiplexing method may further include generating the L1 signaling information including injection level information corresponding to generating the power reduced enhanced layer signal.

In this case, the step of lowering the power of the multiplexed signal may be lowered as much as it is increased by the step of combining the power of the multiplexed signal.

In this case, the generating of the power reduced enhanced layer signal may change the injection level at 0.5 dB intervals from 3.0 dB to 10.0 dB.

In this case, the combining may combine one or more extension layer signals of a lower power level than the core layer signal and the enhanced layer signal together with the core layer signal and the enhanced layer signal.

According to the present invention, it is possible to provide a new signal multiplexing technique capable of providing higher levels of flexibility and better performance than time division multiplexing (TDM) or frequency division multiplexing (FDM).

In addition, in the present invention, each service can use 100% of time and frequency resources while simultaneously supporting multiple services in the next generation broadcasting system.

In addition, the present invention can efficiently multiplex / demultiplex signals by combining each of two or more signals corresponding to each of the two or more layers to different power levels.

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

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

3 is a block diagram illustrating an example of the signal multiplexing apparatus illustrated in FIG. 1.

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

FIG. 5 is a block diagram illustrating another example of the signal multiplexing apparatus illustrated in FIG. 1.

FIG. 6 is a block diagram illustrating an example of the signal demultiplexing apparatus illustrated in FIG. 1.

FIG. 7 is a block diagram illustrating an example of a core layer BICM decoder and an enhanced layer symbol extractor illustrated in FIG. 6.

FIG. 8 is a block diagram illustrating another example of the core layer BICM decoder and the enhanced layer symbol extractor illustrated in FIG. 6.

FIG. 9 is a block diagram illustrating another example of the core layer BICM decoder and the enhanced layer symbol extractor illustrated in FIG. 6.

FIG. 10 is a block diagram illustrating another example of the signal demultiplexing apparatus illustrated in FIG. 1.

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

12 is a flowchart illustrating a signal multiplexing method according to an embodiment of the present invention.

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

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

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

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

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

The signal multiplexing device 111 combines the core layer signal corresponding to the core layer data and the enhanced layer signal corresponding to the enhanced layer data into different power levels, and together with the core layer signal and the enhanced layer signal. The applied interleaving is performed to generate a multiplexed signal. In this case, the signal multiplexing apparatus 111 may generate a broadcast signal frame using the time interleaved signal and the L1 signaling information. In this case, the broadcast signal frame may be an ATSC 3.0 frame.

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

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

The signal demultiplexing apparatus 131 first recovers core layer data from a signal received through the OFDM receiver 133, and then restores enhanced layer data through cancellation corresponding to the recovered core layer data. In this case, the signal demultiplexing apparatus 131 may first generate a broadcast signal frame, restore the L1 signaling information from the broadcast signal frame, and then use the L1 signaling information to restore the data signal. In this case, the L1 signaling information may include injection level information, normalizing factor information, and the like.

As will be described later, the signal multiplexing device 111 shown in FIG. 1 includes: a combiner for generating a multiplexed signal by combining the core layer signal and the enhanced layer signal at different power levels; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And a frame builder generating a broadcast signal frame using the time interleaved signal and L1 signaling information. In this case, the broadcast signal transmission apparatus 110 shown in FIG. 1 includes a combiner for generating a multiplexed signal by combining the core layer signal and the enhanced layer signal with different power levels; A power normalizer for lowering the power of the multiplexed signal to a power corresponding to the core layer signal; A time interleaver for generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; A frame builder for generating a broadcast signal frame using the time interleaved signal and L1 signaling information; And an OFDM transmitter for transmitting the broadcast signal frame through an antenna using an OFDM communication scheme.

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

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

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

2, in the broadcast signal transmission / reception method according to an embodiment of the present invention, the core layer signal and the enhanced layer signal are combined and multiplexed at different power levels (S210).

In this case, the multiplexed signal generated by step S210 may include a data signal and L1 signaling information. In this case, the L1 signaling information may include injection level information and normalizing factor information.

In addition, the broadcast signal transmission / reception method according to an embodiment of the present invention transmits the multiplexed signal by OFDM (S220).

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

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

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

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

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

As will be described later, step S210 illustrated in FIG. 2 may include combining a core layer signal and an enhanced layer signal at different power levels to generate a multiplexed signal; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; And generating a broadcast signal frame using the time interleaved signal and L1 signaling information. In this case, the method of transmitting a broadcast signal in step S210 may include: generating a multiplexed signal by combining the core layer signal and the enhanced layer signal at different power levels; Lowering the power of the multiplexed signal to a power corresponding to the core layer signal; Generating a time interleaved signal by performing interleaving applied to the core layer signal and the enhanced layer signal together; Generating a broadcast signal frame using the time interleaved signal and L1 signaling information; And transmitting the broadcast signal frame through an antenna using an OFDM communication scheme.

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

3 is a block diagram illustrating an example of the signal multiplexing apparatus illustrated in FIG. 1.

Referring to FIG. 3, the signal multiplexing apparatus according to an embodiment of the present invention includes a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, and a power normalizer. 345, a time interleaver 350, an L1 signaling generator 360, and a frame builder 370.

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

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

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

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

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

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

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

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

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

[Equation 1]

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

In this case, the injection level controller 330 may adjust the power level of the enhanced layer signal at 0.5 dB intervals from 3.0 dB to 10.0 dB.

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

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

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

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

[Equation 2]

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

It can be expressed as

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

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

It can be expressed as

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

The output of the power normalizer 345 is

It can be expressed as

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

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

It can be expressed as

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

[Equation 3]

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

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

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

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

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

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

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

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

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

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

The frame builder 370 combines the L1 signaling signal and the data signal to generate a broadcast signal frame.

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

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

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

FIG. 5 is a block diagram illustrating another example of the signal multiplexing apparatus illustrated in FIG. 1.

Referring to FIG. 5, it can be seen that the signal multiplexing apparatus multiplexes data corresponding to N extension layers with N (N is one or more natural numbers) in addition to core layer data and enhanced layer data.

That is, the signal multiplexing apparatus illustrated in FIG. 5 includes a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, a power normalizer 345, and a time interleaver ( In addition to the 350, the L1 signaling generator 360, and the frame builder 370, the N enhancement layer BICM units 410,..., 430, and injection level controllers 440,..., 460 are included.

Core layer BICM unit 310, enhanced layer BICM unit 320, injection level controller 330, combiner 340, power normalizer 345, time interleaver 350, L1 signaling generation shown in FIG. The unit 360 and the frame builder 370 have already been described in detail with reference to FIG. 3.

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

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

In particular, the power reduction corresponding to each of the injection level controllers 440,... 460 is preferably greater than the power reduction of the injection level controller 330. That is, the injection level controllers 330, 440,..., 460 illustrated in FIG. 5 may correspond to a large power reduction as it descends.

The injection level information provided from the injection level controllers 330, 440, and 460 illustrated in FIG. 5 is included in the broadcast signal frame of the frame builder 370 via the L1 signaling generator 360 and transmitted to the receiver. That is, the injection level of each layer is delivered to the receiver in the L1 signaling information.

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

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

In the example shown in FIG. 5, the power normalizer 345 may adjust the signal power to an appropriate signal size by multiplying the normalizing factor by the magnitude of the signal combined with the signals of each layer using Equation 4 below. .

[Equation 4]

Normalizing Factor =

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

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

Referring to FIG. 6, the signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, and an enhanced layer symbol extractor 530. A de-injection level controller 1020 and an enhanced layer BICM decoder 540.

In this case, the signal demultiplexing apparatus illustrated in FIG. 6 may correspond to the signal multiplexing apparatus illustrated in FIG. 3.

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

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

In the example shown in FIG. 6, the de-normalizer 1010 is shown to adjust the power of the output signal of the time interleaver 510, but according to an embodiment the de-normalizer 1010 may be a time interleaver 510. It can also be placed in front of to allow power adjustment to be performed before interleaving.

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

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

In this case, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, and a core layer error correction decoder. The core layer symbol demapper calculates the Log-Likelihood Ratio (LLR) values associated with the symbol, the core layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error, and the core layer error correction decoder Correct.

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

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

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

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

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

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

In this case, the enhanced layer symbol extractor 530 includes a buffer, a subtracter, a core layer symbol mapper, and a core layer bit interleaver. The buffer stores the output signal of the time deinterleaver 510 or de-normalizer 1010. The core layer bit interleaver receives the entire bits (information bits + parity bits) of the core layer BICM decoder and performs the same core layer bit interleaving as the transmitter. The core layer symbol mapper generates the same core layer symbol as the transmitter from the interleaved signal. The subtractor subtracts the output signal of the core layer symbol mapper from the signal stored in the buffer, thereby obtaining the enhanced layer symbol and passing it to the de-injection level controller 1020. In particular, when the LDPC information bits are provided, the enhanced layer symbol extractor 530 may further include a core layer LDPC encoder. In addition, when the BCH information bits are provided, the enhanced layer symbol extractor 530 may further include a core layer BCH encoder as well as a core layer LDPC encoder.

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

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

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

[Equation 5]

Enhanced Layer Gain =

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

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

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

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

The signal demultiplexing apparatus illustrated in FIG. 6 first restores core layer data, cancels core layer symbols from a received signal symbol to leave only enhanced layer symbols, and then increases power of an enhanced layer symbol to enhance it. Restores the layer data. As described above with reference to FIGS. 3 and 5, since signals corresponding to the respective layers are combined at different power levels, the data having the lowest error may be recovered only from the signal having the strongest power.

As a result, in the example shown in FIG. 6, the signal demultiplexing apparatus includes: a time deinterleaver 510 which applies time deinterleaving to a received signal to generate a time deinterleaving signal; A de-normalizer (1010) for increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; A core layer BICM decoder (520) for recovering core layer data from the signal adjusted by the de-normalizer (1010); Enhanced using the output signal of the core layer FEC decoder of the core layer BICM decoder 520 to perform cancellation corresponding to the core layer data with respect to the signal adjusted by the de-normalizer 1010. An enhanced layer symbol extractor 530 for extracting a layer signal; A de-injection level controller 1020 for raising the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And an enhanced layer BICM decoder 540 for restoring enhanced layer data by using the output signal of the de-injection level controller 1020.

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

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

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

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

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

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

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

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

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

A signal demultiplexing method according to an embodiment of the present invention through the configuration shown in FIG. 6 may include generating time deinterleaving signals by applying time deinterleaving to a received signal; Increasing the power of the received signal or the time deinterleaving signal by a power reduction by a power normalizer of the transmitter; Restoring core layer data from the power adjusted signal; Extracting an enhanced layer signal by performing cancellation on the core layer data with respect to the power adjusted signal; Increasing the power of the enhanced layer signal by a power reduction of the injection level controller of the transmitter; And restoring enhanced layer data by using the power-adjusted enhanced layer signal.

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

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

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

FIG. 7 is a block diagram illustrating an example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 6.

Referring to FIG. 7, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder.

That is, in the example shown in FIG. 7, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

In addition, in the example illustrated in FIG. 7, the core layer LDPC decoder provides a whole codeword including parity bits to the enhanced layer symbol extractor 530. That is, in general, the LDPC decoder outputs only information bits of the entire LDPC codeword, but may output the entire codeword.

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

FIG. 8 is a block diagram illustrating another example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 6.

Referring to FIG. 8, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder.

That is, in the example shown in FIG. 8, the core layer error correction decoder includes a core layer LDPC decoder and a core layer BCH decoder.

In addition, in the example illustrated in FIG. 8, the core layer LDPC decoder provides information bits that do not include parity bits to the enhanced layer symbol extractor 530.

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

The example illustrated in FIG. 8 may remove residual errors that may remain in the LDPC code parity portion as compared to the example illustrated in FIG. 7.

9 is a block diagram illustrating another example of the core layer BICM decoder 520 and the enhanced layer symbol extractor 530 illustrated in FIG. 6.

Referring to FIG. 9, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, a core layer LDPC decoder, and a core layer BCH decoder.

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

In the example shown in FIG. 9, the output of the core layer BCH decoder corresponding to the core layer data is provided to the enhanced layer symbol extractor 530.

In this case, since the enhanced layer symbol extractor 530 must include both the core layer LDPC encoder and the core layer BCH encoder, the complexity is high, but the highest performance is guaranteed compared to the examples of FIGS. 7 and 8.

FIG. 10 is a block diagram illustrating another example of the signal demultiplexing apparatus illustrated in FIG. 1.

Referring to FIG. 10, the signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, and an enhanced layer symbol extractor 530. Enhanced layer BICM decoder 540, one or more enhancement layer symbol extractors 650, 670, one or more enhancement layer BICM decoders 660, 680 and de-injection level controllers 1020, 1150, 1170. Include.

In this case, the signal demultiplexing apparatus illustrated in FIG. 10 may correspond to the signal multiplexing apparatus illustrated in FIG. 5.

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

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

[Equation 6]

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

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

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

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

In the example shown in FIG. 10, the de-normalizer 1010 is shown to adjust the power of the output signal of the time interleaver 510, but according to an embodiment the de-normalizer 1010 may be a time interleaver 510. It can also be placed in front of to allow power adjustment to be performed before interleaving.

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

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

In this case, the core layer BICM decoder 520 includes a core layer symbol demapper, a core layer bit deinterleaver, and a core layer error correction decoder. The core layer symbol demapper calculates the Log-Likelihood Ratio (LLR) values associated with the symbol, the core layer bit deinterleaver strongly mixes the calculated LLR values with the clustering error, and the core layer error correction decoder Correct.

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

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

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

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

In particular, the trade off between implementation complexity and performance depending on which of the outputs of the error correction decoder described with reference to FIGS. 7, 8 and 9 is to be used is the core layer BICM decoder 520 of FIG. In addition to the enhanced layer symbol extractor 530, the enhancement layer symbol extractors 650 and 670 and the enhancement layer BICM decoders 660 and 680 are applied.

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

In this case, the enhanced layer symbol extractor 530 includes a buffer, a subtracter, a core layer symbol mapper, and a core layer bit interleaver. The buffer stores the output signal of the time deinterleaver 510 or de-normalizer 1010. The core layer bit interleaver receives the entire bits (information bits + parity bits) of the core layer BICM decoder and performs the same core layer bit interleaving as the transmitter. The core layer symbol mapper generates the same core layer symbol as the transmitter from the interleaved signal. The subtractor subtracts the output signal of the core layer symbol mapper from the signal stored in the buffer, thereby obtaining the enhanced layer symbol and passing it to the de-injection level controller 1020.

In this case, the core layer bit interleaver and the core layer symbol mapper included in the enhanced layer symbol extractor 530 may be the same as the bit interleaver and symbol mapper of the core layer illustrated in FIG. 5.

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

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

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

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

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

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

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

In this case, the enhanced layer bit interleaver and the enhanced layer symbol mapper included in the enhancement layer symbol extractor 650 may be the same as the bit interleaver and symbol mapper of the enhanced layer illustrated in FIG. 5.

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

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

[Equation 7]

n-th Extension Layer Gain =

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

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

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

That is, in the example shown in FIG. 10, the enhancement layer error correction decoder of the enhancement layer BICM decoder 660 may output only information bits and output all bits in which the information bits and the parity bits are combined. It may be. In this case, the enhancement layer error correction decoder may output only information bits as enhancement layer data, and output all bits in which parity bits are combined with the information bits to the next enhancement layer symbol extractor 670.

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

The de-injection level controllers 1020, 1150, and 1170 shown in FIG. 10 may correspond to a greater power rise as it goes down. That is, the de-injection level controller 1150 increases power more than the de-injection level controller 1020, and the de-injection level controller 1170 increases the power more significantly than the de-injection level controller 1150. You can.

The signal demultiplexing apparatus illustrated in FIG. 10 first restores core layer data, restores enhanced layer data using cancellation of the core layer symbols, and extends the extended layer data using cancellation of the enhanced layer symbols. It can be seen that the restoration. Two or more enhancement layers may be provided, in which case they are restored from the combined enhancement layers at higher power levels.

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

Referring to FIG. 11, when an enhanced layer signal having a power reduced by an injection level is combined with a core layer signal to generate a multiplexed signal, the power level of the multiplexed signal is determined by the core layer signal or the enhanced layer signal. It can be seen that the power level is higher.

In this case, the injection level adjusted by the injection level controller shown in FIGS. 3 and 5 may be adjusted in 0.5dB steps from 3.0dB to 10.0dB. At an injection level of 3.0dB, the power of the enhanced layer signal is 3dB lower than the power of the core layer signal. At an injection level of 10.0 dB, the power of the enhanced layer signal is 10 dB lower than the power of the core layer signal. This relationship may be applied not only between the core layer signal and the enhanced layer signal but also between the enhanced layer signal and the enhancement layer signal or the enhancement layer signals.

The power normalizer shown in FIGS. 3 and 5 may adjust the power level after coupling to solve problems such as distortion of a signal that may be caused by power increase due to coupling.

12 is a flowchart illustrating a signal multiplexing method according to an embodiment of the present invention.

12, in the signal multiplexing method according to an embodiment of the present invention, BICM is applied to core layer data (S1210).

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

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

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

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

In this case, step S1230 may change the injection level in 0.5 dB intervals between 3.0 dB and 10.0 dB.

In addition, the signal multiplexing method according to an embodiment of the present invention combines the core layer signal and the power reduced enhanced layer signal to generate a multiplexed signal (S1240).

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

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

In addition, the signal multiplexing method according to an embodiment of the present invention lowers the power of the signal multiplexed by the step S1250 (S1250).

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

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

In addition, the signal multiplexing method according to an embodiment of the present invention generates a broadcast signal frame using the time interleaved signal and L1 signaling information (S1270).

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

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

Although not explicitly illustrated in FIG. 12, the signal multiplexing method may further include generating L1 signaling information including injection level information corresponding to step S1230.

The signal multiplexing method illustrated in FIG. 12 may correspond to step S210 illustrated in FIG. 2.

As described above, the apparatus and method for signal multiplexing according to the present invention may not be limitedly applied to the configuration and method of the embodiments described as described above. Or some may be selectively combined.

Claims (20)

1. A combiner for combining the core layer signal and the enhanced layer signal to different power levels to produce a multiplexed signal;

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

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

   A frame builder for generating a broadcast signal frame using the time interleaved signal and L1 signaling information

   Signal multiplexing apparatus comprising a.
2. The method according to claim 1,

   The signal multiplexing device

   An injection level controller configured to reduce power of the enhanced layer signal to generate a power reduced enhanced layer signal;

   The combiner

   And combining the core layer signal and the power reduced enhanced layer signal to generate the multiplexed signal.
3. The method according to claim 2,

   The signal multiplexing device

   And an L1 signaling generator for generating the L1 signaling information including the injection level information of the injection level controller.
4. The method according to claim 3,

   The signal multiplexing device

   A core layer BICM unit corresponding to the core layer signal; And

   And an enhanced layer BICM unit for performing BICM encoding different from the core layer BICM unit.
5. The method according to claim 4,

   The core layer BICM unit has a lower bit rate than the enhanced layer BICM unit, and is stronger than the enhanced layer BICM unit.
6. The method according to claim 3,

   The power normalizer

   And a power of the multiplexed signal is lowered by the coupler, corresponding to a normalizing factor.
7. The method according to claim 6,

   The injection level controller corresponds to a scaling factor,

   The normalizing factor and the scaling factor are each greater than zero and less than one,

   The scaling factor decreases as the power reduction corresponding to the injection level controller increases.

   And the normalizing factor increases as the power reduction corresponding to the injection level controller increases.
8. The method according to claim 3,

   The injection level controller

   A signal multiplexing device, characterized in that the injection level is varied in 0.5 dB steps from 3.0 dB to 10.0 dB.
9. The method according to claim 3,

   The enhanced layer signal is

   And an enhanced layer data reconstructed based on a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.
10. The method according to claim 9,

    The core layer BICM unit

    A core layer error correction encoder for error correcting encoding the core layer data;

    A core layer bit interleaver for performing bit interleaving corresponding to the core layer data; And

    And a core layer symbol mapper for performing modulation corresponding to the core layer data.
11. The method according to claim 10,

    The enhanced layer BICM unit

    An enhanced layer error correction encoder for error correcting encoding the enhanced layer data;

    An enhanced layer bit interleaver for performing bit interleaving corresponding to the enhanced layer data; And

    And an enhanced layer symbol mapper for performing modulation corresponding to the enhanced layer data.
12. The method according to claim 11,

    The enhanced layer error correction encoder

    Higher bit rate than the core layer error correction encoder,

    The enhanced layer symbol mapper is

    And less robust than the core layer symbol mapper.
13. The method according to claim 12,

    The combiner

    And at least one extension layer signal of a lower power level than the core layer signal and the enhanced layer signal together with the core layer signal and the enhanced layer signal.
14. Combining the core layer signal and the enhanced layer signal at different power levels to produce a multiplexed signal;

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

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

    Generating a broadcast signal frame using the time interleaved signal and L1 signaling information

    Signal multiplexing method comprising a.
15. The method according to claim 14

    The signal multiplexing method

    Reducing the power of the enhanced layer signal to generate a power reduced enhanced layer signal,

    The combining step

    And combining the core layer signal and the power reduced enhanced layer signal to generate the multiplexed signal.
16. The method according to claim 15,

    The signal multiplexing method

    And generating the L1 signaling information including injection level information.
17. The method according to claim 15,

    Lowering the power of the multiplexed signal

    And lowering the power of the multiplexed signal by an increase by the combining step.
18. The method according to claim 17,

    Generating the power reduced enhanced layer signal

    A method of multiplexing a signal characterized by varying the injection level in 0.5 dB steps from 3.0 dB to 10.0 dB.
19. The method according to claim 18,

    The enhanced layer signal is

    And the enhanced layer data reconstructed on the basis of cancellation (cancellation) corresponding to reconstruction of core layer data corresponding to the core layer signal.
20. The method according to claim 18,

    The combining step

    And combining at least one extension layer signal of a lower power level than the core layer signal and the enhanced layer signal together with the core layer signal and the enhanced layer signal.

Images