WO2017155304A1

WO2017155304A1 - Transmitter and subframe arrangement method therefor

Info

Publication number: WO2017155304A1
Application number: PCT/KR2017/002516
Authority: WO
Inventors: 박정현; 김남현; 박성우; 유정필; 정성규
Original assignee: 삼성전자 주식회사
Priority date: 2016-03-08
Filing date: 2017-03-08
Publication date: 2017-09-14

Abstract

Disclosed is a transmitter. The present transmitter comprises: a frame generation unit for generating a frame including a plurality of subframes, each of which includes data and a pilot; and a transmission unit for transmitting a frame to a receiver, wherein, when the plurality of subframes have the same FFT size, the frame generation unit determines an arrangement order of the plurality of subframes on the basis of the number of subcarriers used for transmission of the data and the pilot, and arranges the plurality of subframes according to the determined arrangement order.

Description

Transmitter and subframe arrangement method thereof

The present disclosure relates to a transmitter and a subframe arrangement method thereof, and more particularly, to a transmitter and a subframe arrangement method thereof for transmitting a frame in which a plurality of subframes are arranged to a receiver.

Recently, broadcast communication services have become high quality, multifunctional and broadband. In particular, with the development of electronic technology, the spread of portable broadcasting devices such as high-definition digital TVs and high-end smart phones is increasing, and accordingly, demands for various reception methods and various service support for broadcast services are increasing.

In response to this requirement, as one example, broadcast communication standards such as Advanced Television System Committee (ATSC) 3.0 have been developed. Accordingly, the use of the method proposed by ATSC 3.0 requires a search for a method for processing signals more efficiently.

The present disclosure is in accordance with the above-described needs, and an object of the present disclosure is to provide a transmitter and a subframe arrangement method thereof capable of arranging a plurality of subframes in a frame based on the number of subcarriers.

According to an embodiment of the present disclosure, a transmitter for generating a frame including a plurality of subframes including data and pilot and a transmitter for transmitting the frame to a receiver are provided. The frame generation unit determines the arrangement order of the plurality of subframes based on the number of subcarriers used for transmission of the data and the pilot when the FFT sizes of the plurality of subframes are the same. The plurality of subframes are arranged in an arrangement order.

Here, the frame generation unit may arrange the plurality of subframes in order of subframes having the largest number of subcarriers.

The frame generation unit may determine an arrangement order of the plurality of subframes based on a Dx value representing an interval on a frequency axis of a distributed pilot, and arrange the plurality of subframes according to the determined arrangement order.

In this case, the frame generation unit arranges a first subframe having the smallest Dx value among the plurality of subframes, and generates a second subframe having a Dx value that is an integer multiple of the Dx value of the first subframe. Can be placed after the subframe.

Here, the second subframe may be a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the first subframe.

The frame generation unit may arrange a third subframe next to the second subframe having a Dx value of an integer multiple of the Dx value of the second subframe among the plurality of subframes.

Here, the third subframe may be a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the second subframe.

The frame generation unit may arrange a fourth subframe having the smallest Dx value among the Dx values, which is not an integer multiple of the Dx value of the first subframe, after the second subframe.

On the other hand, when there is no subframe having an integer multiple of the Dx value of the first subframe among the plurality of subframes, the frame generation unit has a Dx value smaller than the Dx value of the first subframe. The fifth subframe may be disposed after the first subframe.

The frame generation unit may arrange the plurality of subframes in order of subframes having small FFT sizes to subframes based on FFT sizes of the plurality of subframes, and the data may include audio data and first image data. And additional data for generating second image data of higher quality than the first image data based on the first image data, wherein the audio data is included in at least one subframe having a first FFT size. The first image data is included in at least one subframe having a second FFT size larger than the first FFT size, and the additional data is at least one subframe having a third FFT size larger than the second FFT size. May be included in the frame.

Meanwhile, a method of arranging subframes of a transmitter according to an embodiment of the present disclosure includes generating a frame including a plurality of subframes each including data and pilot, and transmitting the frame to a receiver. The generating of the frame may include determining an arrangement order of the plurality of subframes based on the number of subcarriers used for transmission of the data and the pilot when the FFT sizes of the plurality of subframes are the same. The plurality of subframes may be arranged in an arrangement order.

In the generating of the frame, the plurality of subframes may be arranged in order of subframes having the largest number of subcarriers.

The generating of the frame may include determining an arrangement order of the plurality of subframes based on a Dx value representing an interval on a frequency axis of a distributed pilot and arranging the plurality of subframes according to the determined arrangement order. Can be.

In this case, the generating of the frame may include disposing a first subframe having the smallest Dx value among the plurality of subframes, and generating a second subframe having a Dx value that is an integer multiple of the Dx value of the first subframe. It may be disposed after the first subframe.

The generating of the frame may include, after the second subframe, a third subframe having a Dx value of an integer multiple of the Dx value of the second subframe among the plurality of subframes.

In the generating of the frame, the fourth subframe having the smallest Dx value among the Dx values, which is not an integer multiple of the Dx value of the first subframe, may be disposed after the second subframe.

In the generating of the frame, when there is no subframe having a Dx value of an integer multiple of the Dx value of the first subframe among the plurality of subframes, a Dx smaller than the Dx value of the first subframe A fifth subframe having a value may be disposed after the first subframe.

The generating of the frame may include arranging the plurality of subframes in order from subframes having small FFT sizes to subframes based on FFT sizes of the plurality of subframes. And additional data for generating second image data of higher quality than the first image data based on one image data and the first image data, wherein the audio data includes at least one subframe having a first FFT size. Wherein the first image data is included in at least one subframe having a second FFT size larger than the first FFT size, and the additional data is at least having a third FFT size larger than the second FFT size. It may be included in one subframe.

According to various embodiments of the present disclosure as described above, since a plurality of subframes are arranged in the frame based on the number of subcarriers, more accurate channel estimation may be performed in the receiver.

1 is a view showing a frame structure defined in the ATSC 3.0 standard,

2 is a block diagram illustrating a configuration of a transmitter according to an embodiment of the present disclosure;

3 to 9 are views for explaining a method of arranging a plurality of subframes in a frame according to various embodiments of the present disclosure, and

10 is a flowchart illustrating a subframe arrangement method according to an embodiment of the present disclosure.

-

The terms used in the present disclosure selected general terms widely used as far as possible in consideration of functions in the present disclosure, but may vary according to the intention or precedent of a person skilled in the art, the emergence of new technologies, and the like. In addition, in certain cases, there is also a term arbitrarily selected by the applicant, in which case the meaning will be described in detail in the description of the invention. Therefore, the terms used in the present disclosure should be defined based on the meanings of the terms and the contents throughout the present disclosure, rather than simply the names of the terms.

When any part of the specification is to "include" any component, this means that it may further include other components, except to exclude other components unless otherwise stated. In addition, the terms components, units, modules, and the like described in the specification mean units that process at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present disclosure. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

A transmitter (100 of FIG. 2) according to an embodiment of the present disclosure may process and transmit a broadcast service to a receiver according to a method defined in the Advanced Television System Committee (ATSC) 3.0 standard.

Hereinafter, a description will be given of a method for processing a broadcast service in the ATSC 3.0 standard.

The link layer receives a packet including broadcast data and signaling thereof, generates an ASC 3.0 Link layer Protocol (ALP) packet by processing the input packet, and delivers the ALP packet to the physical layer. In this case, the input packet may be a TS packet or an IP packet.

The physical layer receives an ALP packet, processes the ALP packet to generate a physical layer frame (hereinafter, referred to as a frame), and converts the frame into a broadcast signal for transmission.

Here, the physical layer may include at least one physical layer pipe (PLP). Here, PLP means a logical channel in the physical layer that carries service data or related metadata that can carry one or multiple services or service components. In this case, specific coding parameters and modulation may be applied for each PLP.

Meanwhile, in the physical layer, a broadcast service is provided through an input formatting module, a BICM module, a bit interleaved coding and modulation module, a framing & interleaving module, and a waveform generation module. Will be processed.

The input formatting module input formats the input packet to generate baseband packets for each of the PLPs, and the BICM module forwards, interleaves, and modulates the baseband packets to cells for each PLP. (Or data cells).

The framing and interleaving module can time interleave the cells of each PLP and map the time-interleaved cells to a frame on the frequency domain. At this point, in some cases, the framing and interleaving module (not shown) may frequency interleave cells mapped to orthogonal frequency division multiplexing (OFDM) symbols of the frame.

The waveform generation module inserts a pilot into the frame, transforms the OFDM symbols of the frame into the time domain through an inverse fast fourier transform (IFFT), performs a peak to average power ratio (PAPR) reduction using the reserved tone, The guard interval may be inserted into a frame to transmit a broadcast signal to a receiver (not shown).

This process outlines a broadcast service defined in the ATSC 3.0 standard and a signaling method thereof, and the transmitter 100 according to an embodiment of the present disclosure transmits the broadcast data and the broadcast data according to the method defined in the ATSC 3.0 standard. Signaling can be processed.

Meanwhile, according to the ATSC 3.0 standard, as shown in FIG. 1, a frame includes a bootstrap 10, a preamble 20, and at least one subframe 30-1,... -n).

In this case, the bootstrap 10 is located at the beginning of the frame, the preamble 20 is located after the bootstrap 10, and the at least one subframe 30-1,..., 30-n is a preamble ( 20) It will be located next.

These are composed of at least one OFDM symbol, and the number of subcarriers (or carriers) of each OFDM symbol may be determined according to the FFT mode (ie, indicating the FFT size and may include 8K, 16K, and 32K). have.

In this case, a subcarrier used for transmission of broadcast data, signaling, and pilot in an OFDM symbol is called a valid carrier, and the number of available carriers (ie, number of (useful) carriers) may be different even in the same FFT size. In this case, even with the same FFT size, the larger the NoC value, the more frequency can be used as the subcarrier.

For example, at 8K FFT, NoCs are 6913, 6817, 6721, 6625, 6529, and at 16K FFT, NoCs are 13825, 13633, 13441, 13249, 13057, and at 32K FFT, NoCs are 27649, 27265, 26881, 26497, 26113. This can be

In this case, the transmitter 100 may configure the frame by selecting the NoC according to the channel environment.

Meanwhile, the subframes 30-1,..., And 30-n are data symbols positioned between a subframe boundary symbol located at a boundary between other subframes and a subframe boundary symbol. ) May be included. However, this is merely an example, and the subframe may be composed of only data symbols. In addition, only the first symbol or the last symbol in the subframe may correspond to the subframe boundary symbol, and the remaining symbols may be configured as data symbols.

In this case, broadcast data may be mapped to subframes 30-1,..., 30-n and transmitted to the receiver.

In this case, the broadcast data may include additional data for generating second image data of higher quality than the first image data based on audio data, first image data, and first image data for at least one content.

In addition, the broadcast data may include audio data, first image data, and second image data for at least one content. That is, the broadcast data may include the second image data itself rather than the additional data.

Here, the first image data may be high definition (HD) image data, and the second image data may be ultra high definition (UHD) image data. In addition, the additional data may be a difference value between the HD image data and the UHD image data. The audio data may be audio for HD image data and UHD image data.

Meanwhile, according to the ATSC 3.0 standard, pilots are inserted into the preamble and subframe for channel estimation and synchronization.

The types of pilots inserted into the preamble and subframe are shown in Table 1 below.

Symbol TypeSymbol type	Preamble PilotPreamble pilot	Scattered PilotScattered Pilot	Subframe Boundary PilotSubframe Boundary Pilot	Continual PilotContinual Pilot	Edge PilotEdge pilot
PreamblePreamble	∨∨			∨∨
DataData		∨∨		∨∨	∨∨
Subframe BoundarySubframe Boundary			∨∨	∨∨	∨∨

Referring to Table 1, a preamble pilot is inserted into a preamble, a scattered pilot (SP) is inserted into a data symbol, and a subframe boundary pilot is inserted into a subframe boundary symbol. . A continuous pilot (CP) is inserted in the preamble, the data symbol and the sub frame boundary symbol, and an edge pilot is inserted in the data symbol and the sub frame boundary symbol.

Meanwhile, the position at which the pilot is inserted may be defined by the index itself of the subcarriers into which the pilot is inserted, or may be determined based on a specific pilot pattern (eg, Dx, Dy).

Here, Dx means the difference of carrier indices between adjacent carriers in which the pilot is inserted in the frequency direction (for this, in ATSC 3.0, it is defined as Separation of pilot bearing carriers (that is, in the frequency direction). have). That is, Dx is a value representing the interval between pilots on the frequency axis. Therefore, the smaller the Dx value, the more pilots can be inserted into the OFDM symbol.

In addition, Dy means the difference in the number of symbols between successive pilots on a specific carrier in the time direction (in this case, the ATSC 3.0 is defined as a number of symbols forming one scattered pilot sequence (time direction)).

For example, in the case of a distributed pilot, a position at which a distributed pilot is inserted may be determined based on Dx and Dy. In more detail, a distributed pilot may be inserted into a subcarrier having an index k in an l-th OFDM symbol satisfying Equation 1 below.

Here, Dx and Dy may be defined as shown in Table 2 below, and SPa_b means a pilot pattern with a = Dx and b = Dy.

Pilot Pattern Pilot pattern	DxDx	DyDy	Pilot Pattern Pilot pattern	Dx Dx	DyDy

SP3_2SP3_2	33	22	SP12_2 SP12_2	1212	22
SP3_4 SP3_4	33	44	SP12_4 SP12_4	1212	44
SP4_2 SP4_2	44	22	SP16_2 SP16_2	1616	22
SP4_4 SP4_4	44	44	SP16_4 SP16_4	1616	44
SP6_2 SP6_2	66	22	SP24_2 SP24_2	2424	22
SP6_4 SP6_4	66	44	SP24_4 SP24_4	2424	44
SP8_2 SP8_2	88	22	SP32_2SP32_2	3232	22
SP8_4 SP8_4	88	44	SP32_4SP32_4	3232	44

Meanwhile, the transmitter 100 may configure the frame by selecting SPa_b according to the channel environment.

Meanwhile, in the ATSC 3.0 standard, content, FFT size, NoC, and pilot patterns (ie, Dx and Dy) may be applied for each subframe. That is, the transmitter 100 may map the same or different content for each subframe. In addition, the transmitter 100 may determine an FFT size, a NoC, a pilot pattern applied to each subframe, and generate each subframe using the determined FFT size, NoC, and pilot pattern. Accordingly, the subframe may have different content, FFT size, NoC, and pilot pattern for each subframe.

In this case, according to various embodiments of the present disclosure, the transmitter 100 may determine a method of aligning subframes within a frame based on the content of the subframe, the FFT size, the NoC, and the pilot pattern, which will be described in more detail below. Do it.

2 is a block diagram illustrating a configuration of a transmitter according to an embodiment of the present disclosure.

Referring to FIG. 2, the transmitter 100 includes a frame generator 110 and a transmitter 120.

In this case, the transmitter 100 shown in FIG. 2 may process and transmit a broadcast service to a receiver according to the ATSC 3.0 standard. On the other hand, since the general method for processing a broadcast service in the ATSC 3.0 standard has been described above, a detailed description thereof will be omitted.

The frame generator 110 generates a frame including a plurality of subframes each including data and pilot.

Here, the data may include broadcast data, and the pilot may include a distributed pilot.

The transmitter 120 transmits the frame to the receiver. To this end, the transmitter 120 may include at least one transmit antenna to convert the frame into a radio signal and transmit the converted signal. In addition, the transmitter 120 may convert a frame into a signal that can be transmitted through a wired or optical cable and transmit the converted frame to a receiver.

Meanwhile, hereinafter, the order in which the plurality of subframes are arranged in the frame will be described in more detail.

The frame generation unit 110 may determine the arrangement order of the plurality of subframes based on the FFT size, the NoC, and the pilot pattern, and generate the frame generation unit in a frame including the plurality of subframes based on the determined arrangement order.

In this case, the frame generator 110 may generate a plurality of subframes arranged on the time axis according to the determined arrangement order, or rearrange the generated plurality of subframes according to the determined arrangement order to generate a frame.

First, the frame generation unit 110 may determine an arrangement order of subframes based on the FFT size, and may arrange a plurality of subframes according to the determined arrangement order.

In detail, the frame generator 110 may arrange the plurality of subframes in the order of the subframes having the smallest FFT size to the larger subframes in the time axis.

For example, as illustrated in FIG. 3, the frame generation unit 110 arranges

subframes

311, 312, and 313 having an 8K FFT size, and follows the

subframes

311, 312 and 313 having an 8K FFT size. The subframe 314 having the 16K FFT size may be disposed, and the

subframes

315 and 316 having the 32K FFT size may be disposed after the subframe 314 having the 16K FFT size.

In this case, when the FFT sizes of the plurality of subframes are the same, the frame generation unit 110 determines the arrangement order of the plurality of subframes based on the number of subcarriers used for data and pilot transmission, and determines the arrangement order. According to the present invention, a plurality of subframes can be arranged.

Here, the number of subcarriers used for data and pilot transmission represents NoC.

In detail, the frame generation unit 110 may arrange the plurality of subframes in the order from the subframes having the largest number of subcarriers to the subframes in the time axis.

For example, assume that the NoCs of the three subframes A, B, and C having the 8K FFT size are 6529, 6721, and 6913.

In this case, the frame generation unit 110 may arrange the subframes A, B, and C in the order of the subframes having the largest NoC value to the subframes. That is, as shown in FIG. 4, the frame generation unit 110 includes a subframe C 411 having 6913 subcarriers, a subframe B 412 having 6721 subcarriers, and a subframe A having 6529 subcarriers ( 413) subframes may be arranged in order.

In this way, the subframes are arranged in order from subframes having the largest NoC to the subframes in order to more accurately estimate the channel at the receiver.

Specifically, a pilot is inserted in the subframe for channel estimation. In this case, when estimating a channel using a pilot of a subframe (that is, a current subframe), when using channel information estimated through a pilot of a subframe before the current subframe (that is, a previous subframe), Accurate channel estimation can be made. For example, when estimating a channel in the current subframe, a linear combination of the channel information estimated through the pilot of the previous subframe and the channel information estimated through the pilot of the current subframe enables more accurate channel estimation. Become.

However, when channel estimation in the current subframe is not available, channel performance of the previous subframe may be relatively degraded.

For example, suppose that subframes are arranged in order from subframes with small NoC values to large subframes. That is, as shown in FIG. 5A, the subframes A, B, and C are in the order of subframe A having 6529 subcarriers, subframe B having 6721 subcarriers, and subframe C having 6913 subcarriers. Assume a deployed case.

In this case, the receiver sequentially receives subframe A, subframe B, and subframe C, and estimates a channel using pilots inserted in each subframe in order of subframe A, subframe B, and subframe C. have.

At this time, when the receiver estimates a channel using pilots inserted into

edge portions

511 and 512 of subframe B, subcarrier having a frequency of the edge portion of subframe B does not exist in subframe A. In this regard, the channel information estimated in the subframe A cannot be used in the edge portion of the subframe B.

In addition, when the receiver estimates a channel using pilots inserted in the

edge portions

521 and 522 of the subframe C, in the subframe B, there is no subcarrier having a frequency of the edge portion of the subframe C. In the edge portion of the subframe C, the channel information estimated in the subframe B cannot be used.

On the contrary, it is assumed that subframes are arranged in order from subframes having a large NoC value to small subframes. That is, as shown in FIG. 5B, subframes A, B, and C are in the order of subframe C having 6913 subcarriers, subframe B having 6721 subcarriers, and subframe A having 6529 subcarriers. Assume a deployed case.

In this case, the subframes C and B have a larger NoC value than the subframes B and A arranged after the subframes B and A. Accordingly, when the receiver estimates a channel through pilots inserted into subframes C and B, the receiver can use channel information estimated through pilots inserted into previous subframes, thereby enabling more accurate channel estimation.

6 is a flowchart illustrating a method in which a transmitter arranges a plurality of subframes based on a NoC value according to an embodiment of the present disclosure.

First, a set of NoC values of a plurality of subframes is set to Set_NoC (S610).

Then, it is determined whether the largest NoC value exists in Set_NoC (S620).

At this time, when the largest NoC value exists in Set_NoC (S620-Y), the largest NoC is output and the corresponding NoC value is removed from Set_NoC (S630).

In this case, a subframe having an output NoC value may be selected, and the selected subframe may be disposed first. In this case, when there are a plurality of subframes having the largest NoC value, they may be arranged adjacent to each other.

Thereafter, the process returns to step S620 to determine whether the largest NoC value exists in Set_NoC.

In this case, the subframe having the output NoC value can be selected and the selected subframe can be placed after the previously selected subframe.

After that, the process returns to step S620 again, and the above-described process is repeated until the largest NoC value does not exist in Set_NoC, that is, until there is no element of Set_NoC, and when there is no largest NoC value in Set_NoC (S620). -N), the algorithm ends.

On the other hand, in the above-described example, when a plurality of subframes are arranged in order from subframes having small FFT size to large subframes, subframes having large NoC values from subframes having the same FFT size are arranged. It was described as arranging.

However, this is only an example, and the frame generation unit 110 does not arrange the plurality of subframes in order from the subframes having the smallest FFT size to the largest subframe based on the FFT size. Frames may be arranged from subframes with large NoC values to small subframes.

For example, the frame generator 110 may include a first subframe having an 8K FFT size, a second subframe having a 32K FFT size, a third subframe having a 16K FFT size, and a fourth subframe having an 8K FFT size. The six subframes may be arranged in the order of the fifth subframe having the 32K FFT size and the sixth subframe having the 8K FFT size.

In this case, when NoC values of the first subframe, the fourth subframe, and the sixth subframe having the 8K FFT size are NoC ₁ , NoC ₄ , and NoC ₆ , respectively, NoC ₁ ≥NoC ₄ ≥NoC ₆ may be satisfied. .

On the other hand, the frame generation unit 110 may determine the arrangement order of the plurality of subframes based on the Dx value indicating the interval on the frequency axis of the distributed pilot, and may arrange the plurality of subframes according to the determined arrangement order.

In this case, the frame generation unit 110 may determine the arrangement order of the plurality of subframes such that the subframes having the integer Dx value are arranged adjacent to each other based on the Dx values of the plurality of subframes.

As described above, the frame generation unit 110 may arrange a plurality of subframes in order from subframes having small FFT sizes to large subframes. In this case, subframes having the same FFT size are arranged adjacent to each other. .

In this case, when arranging a plurality of subframes having the same FFT size, the frame generator 110 may arrange subframes having the same NoC value adjacent to each other.

For example, the NoC of the first subframe having an 8K FFT size is 6913, the NoC of the second subframe having an 8K FFT size is 6913, the NoC of the third subframe having an 8K FFT size is 6817, and 8K. Assume that the NoC of the fourth subframe having the FFT size is 6721 and the NoC of the fifth subframe having the 8K FFT size is 6817.

In this case, the frame generator 110 arranges the first subframe and the second subframe having the Dx value of 6913 adjacent to each other, and the third subframe and the fifth subframe having the Dx value of 6817 are adjacent to each other. Can be placed.

As such, when the frame generation unit 110 arranges subframes having the same NoC value adjacent to each other, the frame generation unit 110 may arrange subframes having an integer multiple of Dx adjacent to each other.

In detail, the frame generation unit 110 arranges the first subframe having the smallest Dx value among the plurality of subframes, and the second subframe having the Dx value that is an integer multiple of the Dx value of the first subframe. Can be placed after the subframe. Here, the second subframe may be a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the first subframe.

The frame generator 110 may arrange a third subframe next to the second subframe having a Dx value of an integer multiple of the Dx value of the second subframe among the plurality of subframes. Here, the third subframe may be a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the second subframe.

The frame generation unit 110 repeats the above-described process, and includes at least one subframe having the smallest Dx value among the plurality of subframes, the Dx value of the first subframe, and an integer multiple of the Dx value. The frames can be placed adjacent to each other.

The frame generator 110 may arrange a fourth subframe having the smallest Dx value among the Dx values, not the integer multiple of the Dx value of the first subframe, after the second subframe.

That is, the frame generator 110 may include at least one subframe having an integer multiple of the smallest Dx value and a subframe having the smallest Dx value among the Dx values, rather than the smallest Dx value among the Dx values of the plurality of subframes. Can be placed after the last subframe placed.

Meanwhile, when there is no subframe having an integer multiple of the Dx value of the first subframe among the plurality of subframes, the frame generation unit 110 has the next smaller Dx value after the Dx value of the first subframe. The fifth subframe may be disposed after the first subframe.

The frame generator 110 may repeat the above-described process with respect to the fifth subframe.

As a result, the frame generation unit 110 repeats the above-described process, and arranges at least one subframe having a Dx value that is an integer multiple of the smallest Dx value among the Dx values of the plurality of subframes, and after the subframe, At least one subframe having a Dx value of an integer multiple of the smallest Dx value among the Dx values that do not correspond to an integer multiple of the smallest Dx value may be disposed.

For example, assume that the Dx value of each of eight subframes A to H having the same NoC value is 3, 4, 6, 6, 8, 12, 24, or 24.

That is, Dx value of subframe A is 3, Dx value of subframe B is 4, Dx value of subframe C is 6, Dx value of subframe D is 6, and Dx value of subframe E is 8 It is assumed that the Dx value of the subframe F is 12, the Dx value of the subframe G is 24, and the Dx value of the subframe H is 24.

In this case, as shown in FIG. 7, the frame generation unit 110 may arrange the subframe A having the smallest Dx value among the eight subframes on the time axis first.

Among the remaining subframes, a subframe having a Dx value corresponding to an integer multiple of the Dx value (Dx = 3) of the subframe A includes subframe C (Dx = 6), subframe D (Dx = 6), and subframes. Frame F (Dx = 12), subframe G (Dx = 24), and subframe H (Dx = 24).

Accordingly, the frame generation unit 110 may arrange the subframe C and the subframe D having the smallest Dx value among the subframes after the subframe A on the time axis.

Among the remaining subframes, a subframe having a Dx value corresponding to an integer multiple of the Dx value (Dx = 6) of the subframe C and the subframe D includes the subframe F (Dx = 12) and the subframe G (Dx = 24) and the subframe H (Dx = 24).

Accordingly, the frame generation unit 110 may arrange the subframe F having the smallest Dx value among these subframes after the subframe D on the time axis.

Since the Dx values of the remaining subframes, subframe G and subframe H, are integer multiples of the Dx value of the subframe F, the frame generation unit 110 moves the subframe G and the subframe H after the subframe F on the time axis. Can be placed.

On the other hand, the Dx values (Dx = 4,8) of the remaining subframes, subframe B and subframe E, do not correspond to integer multiples of the Dx values (Dx = 24) of the subframe G and the subframe H.

Therefore, the frame generator 110 arranges the subframe B having the smallest Dx value among the remaining subframes after the subframe H on the time axis.

Since the Dx value (Dx = 8) of the subframe E, which is the remaining subframe, is an integer multiple of the Dx value (Dx = 4) of the subframe B, the frame generation unit 110 determines the subframe E on the time axis. Can be placed next.

On the other hand, in Fig. 7, the number shown in each subframe indicates a subcarrier index into which a pilot (for example, a distributed pilot) is inserted in each subframe. For example, in FIG. 7, in the case of subframe A, a pilot is inserted into a subcarrier having an index of 3, 6, 9, 12, 15, 18, 21, 24 ... in that Dx value is 3. can see.

As such, arranging subframes having integer multiples of Dx values adjacent to each other is for more accurate channel estimation at the receiver.

In detail, when subframes having an integer multiple of Dx are arranged adjacent to each other, subcarriers with pilots inserted between adjacent subframes may be continuously arranged. Accordingly, when the channel is estimated in the current subframe, the channel information estimated through the pilot of the previous subframe can be used, thereby enabling more accurate channel estimation.

For example, it is assumed that a plurality of subframes are arranged in order from subframes having a small Dx value to large subframes. That is, as shown in FIG. 8A, the subframes A, B, and Dx have the following order: subframe A with Dx 3, subframe B with Dx 4, subframe C with Dx 6, subframe D with Dx 8, and so on. Assume that C and D are arranged.

In this case, pilots are continuously arranged in subcarriers with subcarrier indices of 0 811 and 12 812 between adjacent subframes.

In contrast, it is assumed that subframes having an integer multiple of Dx are arranged adjacent to each other. That is, as shown in (b) of FIG. 8, subframes A, B, and Dx have three subframes A, Dx has six subframes C, Dx has four subframes B, Dx has eight subframes D, and so on. Assume that C and D are arranged.

In this case, pilots are contiguous in subcarriers between adjacent subframes with subcarrier indices of 0821, 6822, 8823, 12824, 16825, 18826. Will be placed.

As described above, a plurality of subframes are arranged in order from subframes with small Dx value to large subframes, but the integer multiples of Dx are arranged. When the subframes are disposed adjacent to each other, the number of pilots continuously arranged between adjacent subframes becomes larger, thereby enabling more accurate channel estimation.

Meanwhile, FIG. 9 is a flowchart illustrating a method in which a transmitter arranges a plurality of subframes based on a Dx value according to an embodiment of the present disclosure.

First, a set of Dx values of a plurality of subframes is set to Set_Dx (S910).

In operation S920, it is determined whether DxA corresponding to the smallest Dx value exists in Set_Dx.

At this time, if a DxA value exists in Set_Dx (S920-Y), the DxA value is output and the DxA value is removed from Set_Dx (S930).

In this case, a subframe having the output DxA value may be selected and the selected subframe may be placed first. In this case, when there are a plurality of subframes having a DxA value, they may be arranged adjacent to each other.

Thereafter, it is determined whether there is a DxB corresponding to the smallest Dx value among the Dx values corresponding to integer multiples of the DxA value (S940).

At this time, if a DxB value exists in Set_Dx (S940-Y), the DxB value is output, the DxB value is removed from Set_Dx, and the DxBf value is set to DxA (S950).

In this case, a subframe having the output DxB value may be selected and the selected subframe may be disposed after the previously selected subframe.

Thereafter, the process returns to step S940, and the above-described process is repeated until there is no DxB which is the smallest Dx value among the Dx values corresponding to integer multiples of the DxA value.

Accordingly, subframes having Dx values corresponding to integer multiples of the DxA value may be disposed adjacent to each other.

On the other hand, if there is no DxB that is the smallest Dx value among the Dx values corresponding to the integer multiples of the DxA value (S940-N), that is, if there are no values corresponding to the integer multiples of the DxA value in Set_Dx, the process returns to step S920. The above-described process can be repeated. At this time, the above-described process may be repeated until there is no DxA value in Set_Dx, and if there is no DxA value in Set_Dx (S920-N), the algorithm is terminated.

On the other hand, as described above, the plurality of subframes may be arranged in the frame in the order of subframes with small FFE size to large subframes.

As such, when a plurality of subframes are arranged based on the FFT size, the receiver may more efficiently process subframes having a processable FFT size in consideration of its reception performance.

For example, a receiver capable of receiving a broadcast service may be a wearable device (eg, a smart watch), a mobile device (eg, a smartphone), or a stationary device (eg, depending on the type). , TV).

In this case, the performance of hardware processing signals in each device may vary depending on the size, manufacturing cost, and the like of each device. For example, a mobile device rather than a wearable device, and a fixed device than a mobile device may include hardware with relatively better performance.

In this case, the wearable device is configured to process the subframe having the lowest complexity 8K FFT size, the mobile device is configured to process the subframe having the 8K and 16K FFT sizes, the subframe having the 8K and 16K FFT sizes, and Fixed devices can be configured to handle subframes with the most complex 32K FFT sizes.

Accordingly, when the transmitter 100 generates a frame in which a plurality of subframes are arranged in order from subframes having a small FFT size to large subframes and transmits the frame to the receiver, the receiver may process a subframe that can be processed according to the FFT size. It will be easier to sort and process.

In this case, the frame generation unit 110 may map different data on the content for each subframe based on the FFT size.

In this case, the frame generator 110 maps audio data of the content to at least one subframe having a first FFT size (for example, a first FFT group) and maps the first image data of the content to the first FFT size. Map to at least one subframe having a larger second FFT size (e.g., a second FFT group) and map additional data to at least one subframe having a third FFT greater than a second FFT size (e.g., a third FFT) Group).

Here, the first FFT size may be 8K, the second FFT size may be 16K, and the third FFT size may be 32K.

The audio data includes audio for the content, and the first image data includes HD video data for the content. The additional data is data required for generating UHD image data based on the HD image data. For example, the additional data may be a difference value between the HD image data and the UHD image data.

When configuring a plurality of subframes in this manner, the wearable device can decode the audio data from the subframe having the 8K FFT size and reproduce the audio data. In addition, the mobile device may decode audio data and HD video data from subframes having 8K and 16K FFT sizes, and reproduce audio data and HD video data. In addition, the fixed device can decode audio data, HD video data, and difference values from subframes in 8K, 16K, and 32K FFT sizes. In this case, the fixed device may generate the UHD image data by adding the difference value to the HD image data, and reproduce the audio data and the UHD image data.

As such, according to an embodiment of the present disclosure, in that audio data and image data of one content are mapped to subframes having different FFT sizes, and transmitted to a receiver, the receiver according to its processing capability. The data can be processed and played back.

Meanwhile, in the above example, the additional data is transmitted to the receiver for reproducing the UHD image data, but this is only an example. That is, the frame generation unit 110 may map the UHD image data itself to subframes instead of the additional data and transmit the sub-frame to the receiver. In this case, the UHD image data may be mapped to at least one subframe having a 32K FFT size.

In addition, in the above-described example, the audio data and the image data of one content are described as being mapped to subframes having different FFT sizes, but this is merely an example. That is, the frame generation unit 110 may map audio data and image data of different contents to subframes having different FFT sizes. In this case, the receiver may select among subframes having an FFT size that can be processed. Only necessary content can be decoded by selecting.

In addition, in the above-described example, it has been described that audio data, image data, and additional data are mapped to subframes having different FFT sizes. However, the frame generator 110 may map at least two pieces of data of the audio data, the image data, and the additional data to subframes having the same FFT size.

First, a frame including a plurality of subframes each including data and pilot is generated (S1010).

Then, the frame is transmitted to the receiver (S1020).

Meanwhile, in operation S1010, when the FFT sizes of the plurality of subframes are the same, the order of arranging the plurality of subframes is determined based on the number of subcarriers used for data and pilot transmission, and the plurality of subframes are determined according to the determined arrangement order. Subframes can be arranged.

In this case, a plurality of subframes can be arranged in order from subframes having a large number of subcarriers to small subframes.

In operation S1010, the arrangement order of the plurality of subframes may be determined based on a Dx value representing an interval on the frequency axis of the distributed pilot, and the plurality of subframes may be arranged according to the determined arrangement order.

In this case, in step S1010, the first subframe having the smallest Dx value among the plurality of subframes is disposed, and the second subframe having the Dx value of an integer multiple of the Dx value of the first subframe is next to the first subframe. Can be placed.

In operation S1010, a third subframe having a Dx value that is an integer multiple of the Dx value of the second subframe may be disposed after the second subframe among the plurality of subframes.

Here, the subframe may have the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the second subframe.

In operation S1010, a fourth subframe having the smallest Dx value among the Dx values, which is not an integer multiple of the Dx value of the first subframe, may be disposed after the second subframe.

In operation S1010, when there is no subframe having an integer multiple of the Dx value of the Dx value among the plurality of subframes, the fifth subframe having the smaller Dx value after the Dx value of the first subframe. May be disposed after the first subframe.

Meanwhile, in operation S1010, a plurality of subframes may be arranged in order from subframes having small FFT sizes to subframes based on FFT sizes of the plurality of subframes.

The data may include additional data for generating second image data having a higher quality than the first image data based on the audio data, the first image data, and the first image data. In this case, the audio data is included in at least one subframe having a first FFT size, the first image data is included in at least one subframe having a second FFT size larger than the first FFT size, and the additional data is included in the first frame. It may be included in at least one subframe having a third FFT size larger than 2 FFT sizes.

Meanwhile, a non-transitory computer readable medium may be provided in which a program for sequentially performing a subframe arrangement method according to the present disclosure is stored.

The non-transitory readable medium refers to a medium that stores data semi-permanently and is readable by a device, not a medium storing data for a short time such as a register, a cache, a memory, and the like. Specifically, the various applications or programs described above may be stored and provided in a non-transitory readable medium such as a CD, a DVD, a hard disk, a Blu-ray disk, a USB, a memory card, a ROM, or the like.

In addition, although the bus is not shown in the above-described block diagram of the transmitter, communication between each component in the transmitter may be performed through a bus. In addition, the transmitter may further include a processor such as a CPU, a microprocessor, or the like for performing the various operations described above, and the transmitter may further include a memory for performing the various operations described above.

In addition, components, modules, units, and the like in the embodiments of the present disclosure may be implemented in hardware, firmware, or software for performing at least one function or operation, or a combination thereof. For example, they may have direct circuit structures such as memory, processing logic, lookup tables, etc., which may execute each function through control of at least one microprocessor or other control device. In addition, they may be implemented by a program or code including at least one instruction executable to perform a particular logic function. In addition, they may include a processor, such as a CPU, a microprocessor, for executing each function. In addition, they may be integrated into at least one module or chip and implemented as at least one processor (not shown), except that each may need to be implemented in individual specific hardware.

In addition, while the preferred embodiments of the present disclosure have been shown and described, the present disclosure is not limited to the above-described specific embodiments, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present disclosure.

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Claims

In the transmitter,

A frame generator configured to generate a frame including a plurality of subframes each including data and pilot; And

And a transmitter for transmitting the frame to a receiver.

The frame generation unit,

When the FFT sizes of the plurality of subframes are the same, an order of arranging the plurality of subframes is determined based on the number of subcarriers used for transmission of the data and the pilot, and the plurality of subframes are arranged according to the determined order of arrangement. Transmitter characterized in that the arrangement of the sub-frame.
The method of claim 1,

The frame generation unit,

And the plurality of subframes are arranged in order from subframes having a large number of subcarriers to small subframes.
The method of claim 1,

The frame generation unit,

A transmitter for determining an arrangement order of the plurality of subframes based on a Dx value representing an interval on a frequency axis of a scattered pilot, and for arranging the plurality of subframes according to the determined arrangement order .
The method of claim 3,

The frame generation unit,

Arranging a first subframe having the smallest Dx value among the plurality of subframes, and arranging a second subframe having a Dx value that is an integer multiple of the Dx value of the first subframe after the first subframe; Characterized by a transmitter.
The method of claim 4, wherein

The second subframe,

And a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the first subframe.
The method of claim 4, wherein

The frame generation unit,

And a third subframe having a Dx value of an integer multiple of a Dx value of the second subframe, among the plurality of subframes, after the second subframe.
The method of claim 6,

The third subframe,

And a subframe having the smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the second subframe.
The method of claim 4, wherein

The frame generation unit,

And a fourth subframe having the smallest Dx value among the Dx values, which is not an integer multiple of the Dx value of the first subframe, after the second subframe.
The method of claim 4, wherein

The frame generation unit,

If a subframe having a Dx value of an integer multiple of the Dx value of the first subframe does not exist among the plurality of subframes, a fifth subframe having a Dx value next to the Dx value of the first subframe is determined. And disposed after the first subframe.
The method of claim 1,

The frame generation unit,

Based on the FFT size of each of the plurality of subframes, the plurality of subframes are arranged in order from subframes having small FFT sizes to large subframes,

The data may include additional data for generating second image data of higher quality than the first image data based on audio data, first image data, and the first image data.

The audio data is included in at least one subframe having a first FFT size,

The first image data is included in at least one subframe having a second FFT size larger than the first FFT size,

The additional data is included in at least one subframe having a third FFT size larger than the second FFT size.
In the subframe arrangement method of the transmitter,

Generating a frame comprising a plurality of subframes each comprising data and pilot; And

Transmitting the frame to a receiver;

Generating the frame,

When the FFT sizes of the plurality of subframes are the same, an order of arranging the plurality of subframes is determined based on the number of subcarriers used for transmission of the data and the pilot, and the plurality of subframes are arranged according to the determined order of arrangement. And a subframe of the subframe arrangement method.
The method of claim 11,

Generating the frame,

And a plurality of subframes arranged in descending order from subframes having a large number of subcarriers.
The method of claim 11,

Generating the frame,

A sub order of the plurality of subframes is determined based on a Dx value representing an interval on a frequency axis of a scattered pilot, and the plurality of subframes are arranged according to the determined arrangement order Frame arrangement method.
The method of claim 13,

Generating the frame,

Arranging a first subframe having the smallest Dx value among the plurality of subframes, and arranging a second subframe having a Dx value that is an integer multiple of the Dx value of the first subframe after the first subframe; Subframe arrangement method.
The method of claim 14,

The second subframe,

And a subframe having a smallest Dx value among at least one subframe having a Dx value of an integer multiple of the Dx value of the first subframe.