WO2015170819A1

WO2015170819A1 - Signal multiplexing apparatus using layered division multiplexing and signal multiplexing method

Info

Publication number: WO2015170819A1
Application number: PCT/KR2015/001832
Authority: WO
Inventors: 박성익; 이재영; 권선형; 김흥묵; 허남호
Original assignee: 한국전자통신연구원
Priority date: 2014-05-09
Filing date: 2015-02-25
Publication date: 2015-11-12

Abstract

A signal multiplexing apparatus using layered division multiplexing and a signal multiplexing method are disclosed. A signal multiplexing method according to one embodiment of the present invention comprises: a combiner for generating a multiplexed signal by combining a core layer signal and an enhanced layer signal at different power levels; a power normalizer for lowering the power level of the multiplexed signal to a power level corresponding to the power level of the core layer signal; and a time interleaver for performing interleaving applied to both the core layer signal and the enhanced layer signal.

Description

Signal Multiplexing Device and Signal Multiplexing Method Using Layered Division Multiplexing

The present invention relates to a broadcast signal transmission / reception technology used in a broadcast system, and more particularly, to a broadcast signal transmission / reception system for multiplexing / demultiplexing two or more signals to transmit / receive.

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 general, time division multiplexing (TDM) or frequency division multiplexing (FDM) is widely used to multiplex signals. 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).

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; And a time interleaver for performing interleaving applied to the core layer signal and the enhanced layer signal together.

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 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; And performing interleaving applied to the core layer signal and the enhanced layer signal together.

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 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, 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 block diagram illustrating another example of the signal multiplexing apparatus illustrated in FIG. 1.

FIG. 5 is a block diagram illustrating an example of the signal demultiplexing apparatus shown in FIG. 1.

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

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

FIG. 8 is a block diagram illustrating another example of the signal multiplexing apparatus of FIG. 1.

FIG. 9 is a block diagram illustrating another example of the signal multiplexing apparatus shown in FIG. 1.

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

FIG. 11 is a block diagram illustrating another example of the signal demultiplexing apparatus shown in FIG. 1.

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.

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 combines the core layer signal and the enhanced layer signal with the core layer signal. Interleaving is applied together to generate a multiplexed signal.

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.

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, 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 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.

Referring to FIG. 3, a signal multiplexing apparatus according to an embodiment of the present invention may include a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, and a time interleaver. 350).

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.

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, 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.

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 the power reduced enhanced layer signal.

In this case, the combiner 340 may be regarded as generating a multiplexed signal by combining the core layer signal and the power reduced enhanced layer signal.

The data combined by the combiner 340 passes through a time interleaver 350 to distribute the burst errors occurring in the channel, and then multi-path and Doppler. It is transmitted through a robust OFDM transmitter.

In this case, it can be seen that the time interleaver 350 performs 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 a cancellation corresponding to reconstruction of core layer data corresponding to the core layer signal.

Referring to FIG. 4, 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. 4 includes N extension layers in addition to the core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, and the time interleaver 350. BICM units 410, ..., 430 and injection level controllers 440, ..., 460.

The core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, and the time interleaver 350 illustrated in FIG. 4 have 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 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. 4 may correspond to a large power reduction as it descends.

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

Referring to FIG. 5, the signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a core layer BICM decoder 520, an enhanced layer symbol extractor 530, and an enhanced layer BICM decoder 540. ).

In this case, the signal demultiplexing apparatus illustrated in FIG. 5 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 synchronization, channel estimation, and equalization, and relates to distribution of burst errors occurring in a channel. Perform the action.

The output of the time deinterleaver 510 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 enhanced layer symbol extractor 530 receives the entire bits from the core layer error correction decoder of the core layer BICM decoder 520 and extracts the enhanced layer symbols from the output signal of the time deinterleaver 510.

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. 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 enhanced layer BICM decoder 540.

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. 3.

The enhanced layer BICM decoder 540 receives the enhanced layer symbol 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.

That is, the apparatus for demultiplexing the signal shown in FIG. 5 first recovers the core layer data, cancels the core layer symbols from the received signal symbol, and restores the enhanced layer data after leaving only the enhanced layer symbols. As described above with reference to FIGS. 3 and 4, since signals corresponding to each layer are combined at different power levels, the data having the lowest error may be recovered only from the signal having the strongest power.

Referring to FIG. 6, a signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a core layer BICM decoder 520, an enhanced layer symbol extractor 530, and an enhanced layer BICM decoder 540. ), One or more enhancement

layer symbol extractors

650, 670 and one or more enhancement

layer BICM decoders

660, 680.

In this case, the signal demultiplexing apparatus illustrated in FIG. 6 may correspond to the signal multiplexing apparatus illustrated in FIG. 4.

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. 4.

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 extends the extension layer symbol from the output signal of the subtractor of the enhanced layer symbol extractor 530. Extract them.

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 subtractor of the enhanced layer symbol extractor. 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 passing it to the enhancement layer BICM decoder 660.

In this case, the enhanced layer bit interleaver and the enhanced layer symbol mapper included in the enhancement layer symbol extractor 650 may be the same as the bit interleaver and the symbol mapper of the enhanced layer shown in FIG. 4.

The enhancement layer BICM decoder 660 receives the enhancement layer symbol 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. 6, 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 and the enhancement layer BICM decoder 680 can be easily understood from the structures and operations of the enhancement layer symbol extractor 650 and the enhancement layer BICM decoder 660 described above.

The signal demultiplexing apparatus illustrated in FIG. 6 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.

Since the signal multiplexing apparatus shown in FIGS. 3 and 4 is essentially combining two or more signals at different power levels, it may be necessary to adjust the power level after the combining. That is, when combining the core layer signal and the enhanced layer signal by the combiner, the power of the combined multiplexing signal may have a higher power level than the core layer signal or the enhanced layer signal before combining. Problems such as distortion of the signal due to the same power increase may occur.

Referring to FIG. 7, when a multiplexed signal is generated by combining an enhanced layer signal whose power is reduced by an injection level with a core layer signal, the power level of the multiplexed signal is determined by the core layer signal or the enhanced layer signal. It can be seen that the power level is higher.

In this case, the injection level controlled by the injection level controller shown in FIGS. 3 and 4 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.

Referring to FIG. 8, 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. 810 and a time interleaver 350.

As shown in FIG. 8, the core layer data and the enhanced layer data pass through different BICM units and then merge through the combiner 340.

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 code 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 code or symbol mapping that is less robust than the core layer BICM unit 310.

At this time, the injection level controller 330 may adjust the injection power level in 0.5dB steps from 3.0dB to 10.0dB.

The signal coupled by the combiner 340 is provided to the power normalizer 810 to lower the power by the power increase generated by the combination of the core layer signal and the enhanced layer signal to perform power adjustment. That is, the power normalizer 810 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 810 is necessary to prevent amplitude clipping and the like in the rest of the broadcast signal transmission / reception system.

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 810 must mitigate this power increase.

The output of the power normalizer 810 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 810 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).

EL Injection level relative to CLEL Injection level relative to CL	Scaling factor αScaling factor α	Normalizing factor βNormalizing factor β
3.0 dB3.0 dB	0.70794580.7079458	0.81617360.8161736
3.5 dB3.5 dB	0.66834390.6683439	0.83140610.8314061
4.0 dB4.0 dB	0.63095730.6309573	0.84572620.8457262
4.5 dB4.5 dB	0.59566210.5956621	0.85913270.8591327
5.0 dB5.0 dB	0.56234130.5623413	0.87163460.8716346
5.5 dB5.5 dB	0.53088440.5308844	0.88324950.8832495
6.0 dB6.0 dB	0.50118720.5011872	0.89400220.8940022
6.5 dB6.5 dB	0.47315130.4731513	0.90392410.9039241
7.0 dB7.0 dB	0.44668360.4466836	0.91305120.9130512
7.5 dB7.5 dB	0.42169650.4216965	0.92142310.9214231
8.0 dB8.0 dB	0.39810720.3981072	0.92908190.9290819
8.5 dB8.5 dB	0.37583740.3758374	0.93607120.9360712
9.0 dB9.0 dB	0.35481340.3548134	0.94243530.9424353
9.5 dB9.5 dB	0.33496540.3349654	0.94821800.9482180
10.0 dB10.0 dB	0.31622780.3162278	0.95346260.9534626

That is, the power normalizer 810 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 for distributing burst errors occurring in the channel, and then uses an OFDM transmitter that is robust to multipath and Doppler. Is sent over.

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.

Referring to FIG. 9, it can be seen that the signal multiplexing apparatus multiplexes data corresponding to N extension layers with N (N is a natural number of 1 or more) in addition to core layer data and enhanced layer data.

That is, the signal multiplexing apparatus illustrated in FIG. 9 includes a core layer BICM unit 310, an enhanced layer BICM unit 320, an injection level controller 330, a combiner 340, a power normalizer 810, and a time interleaver ( In addition to 350, the N enhancement layer BICM units 410,..., 430, and injection level controllers 440,..., 460 are included.

The core layer BICM unit 310, the enhanced layer BICM unit 320, the injection level controller 330, the combiner 340, and the time interleaver 350 illustrated in FIG. 9 have been described in detail with reference to FIG. 3. .

injection level controllers

330, 440,..., 460 illustrated in FIG. 9 may correspond to a large power reduction as it descends.

The power normalizer 810 mitigates the power increase caused by combining the plurality of layer signals by the combiner 340.

The time interleaver 350 performs interleaving on signals of the layers by interleaving the normalized signal.

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. A de-injection level controller 1020 and an enhanced layer BICM decoder 540.

In this case, the signal demultiplexing apparatus illustrated in FIG. 10 may correspond to the signal multiplexing apparatus illustrated in FIG. 8.

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 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. 8.

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.

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.

That is, the signal demultiplexing apparatus shown in FIG. 10 first restores the core layer data, cancels the core layer symbols from the received signal symbol to leave only the enhanced layer symbols, and then increases the power of the enhanced layer symbol. To restore the enhanced layer data.

Referring to FIG. 11, a signal demultiplexing apparatus according to an embodiment of the present invention includes a time deinterleaver 510, a de-normalizer 1010, a core layer BICM decoder 520, and an enhanced layer symbol extractor 530. Enhanced layer BICM decoder 540, one or more enhancement

layer symbol extractors

650, 670, one or more enhancement

layer BICM decoders

660, 680 and

de-injection level controllers

1020, 1150, 1170. Include.

In this case, the signal demultiplexing apparatus illustrated in FIG. 11 may correspond to the signal multiplexing apparatus illustrated in FIG. 9.

In the example shown in FIG. 11, 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.

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. 9.

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 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. 9.

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

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.

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. 11 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. 11 first restores core layer data, restores enhanced layer data using cancellation of core layer symbols, and extends extended layer data using cancellation of 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.

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

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

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

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

In addition, the 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 performs interleaving applied to both the core layer signal and the enhanced layer signal (S1260).

The signal multiplexing method illustrated in FIG. 12 may correspond to the steps S240 and S250 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

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; And

A time interleaver for performing interleaving applied to the core layer signal and the enhanced layer signal together

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

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.
The method according to claim 3,

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.
The method according to claim 2,

The power normalizer

And a power of the multiplexed signal is lowered by the coupler, corresponding to a normalizing factor.
The method according to claim 5,

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.
The method according to claim 2,

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.
The method according to claim 2,

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.
The method according to claim 8,

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.
The method according to claim 9,

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.
The method according to claim 10,

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.
The method according to claim 11,

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.
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; And

Performing interleaving applied to the core layer signal and the enhanced layer signal together;

Signal multiplexing method comprising a.
The method according to claim 13

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.
The method according to claim 14,

Lowering the power of the multiplexed signal

And lowering the power of the multiplexed signal by an increase by the combining step.
The method according to claim 15,

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.
The method according to claim 16,

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.
The method according to claim 16,

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.