KR20150016870A - Transmitter, receiver and controlling method thereof - Google Patents

Abstract

A transmitter is disclosed. The transmitter includes: a frame creation unit creating a frame which includes a frame start symbol, a data symbol and a frame closing symbol; a pilot and reserved-tone insertion unit inserting pilot into the frame start symbol, data symbol and frame closing symbol and inserting a reserved-tone in order not to overlap the insertion location of pilot; and a transmission unit transmitting a frame into which the pilot and reserved-tone have been inserted. Thus, it is possible to insert the reserved-tone without a collision between the pilot and the reserved-tone and it is possible to decrease PAPR based on the pilot and reserved-tone inserted.

Description

TECHNICAL FIELD [0001] The present invention relates to a transmitting apparatus, a receiving apparatus, and a control method therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting apparatus, a receiving apparatus, and a control method thereof, and more particularly to a transmitting apparatus, a receiving apparatus, and a control method thereof using an OFDM scheme.

Recently, broadcasting communication services are becoming multifunctional and broadband high quality. Particularly, with the development of electronic technology, the spread of mobile broadcasting devices such as high-definition digital TVs and high-end smartphones is increasing, and accordingly, there is a growing demand for various receiving methods and various services for broadcasting services.

In accordance with this demand, a broadcasting communication standard such as DVB-T2 (Digital Video Broadcasting Second Generation Terrestrial) has been developed as an example. DVB-T2 is a second-generation European terrestrial digital broadcasting standard that improves the performance of DVB-T, which is being adopted as a standard in more than 35 countries around the world including Europe. DVB- -T2 adopts the latest technologies such as LDPC (Low Density Parity Check) code and 256QAM modulation method to realize transmission capacity increase and high bandwidth efficiency, and thus it is possible to provide various high quality services such as HDTV in a limited bandwidth It has the advantage of being.

However, despite the advantages of the DVB-T2 system, there is a problem that the OFDM system used in the DVB-T2 system causes a high PAPR (Peak to Average Power Amplifier) due to multi-carrier modulation. That is, since the OFDM scheme transmits data using the multi-carriers, the amplitude of the final OFDM signal is the sum of the amplitudes of the respective carriers, so that the amplitude of the final OFDM signal is very large, and if the phases of the carriers coincide, . Such a high PAPR signal deviates from the linear operation range of the high power linear amplifier and the signal passing through the high output linear amplifier is distorted to degrade the performance of the system.

Various schemes have been proposed to solve the problem of PAPR of the OFDM system, and there have been proposed various schemes such as clipping technique, coding, SLM (Selected Mapping), PTS (Partial Transmit Sequence), TI (Tone Injection) There are abatement techniques.

The TR scheme, which is one of the PAPR reduction techniques, reserves L tones among N subcarriers, and the reserved L tones are used to reduce PAPR without transmitting data.

1 shows a frame structure of a general broadcast communication system. A plurality of OFDM symbols constitute one frame, and the structure of the pilot shows a distributed structure in which the positions of pilots vary for each OFDM symbol. Since these pilots are used for channel estimation, no interference or distortion should occur. However, in the case of using the reservation tone described above, there occurs a problem that the reserved tone and the pilot collide in the frame structure of FIG.

FIG. 2 shows a case where a collision occurs between the pilot and reservation tones when one reservation tone is used in the conventional tone reservation scheme in the frame structure as shown in FIG. That is, in the case of 201, the reservation tone does not collide with the pilot but the collision occurs between the pilot and reservation tones of 202, 203, and 204.

The necessity of inserting reserved tones has been increased while avoiding collisions between these pilots and reserved tones.

An object of the present invention is to provide a transmitting apparatus, a receiving apparatus, and a control method therefor, in which a reservation tone is inserted so as not to overlap with a pilot insertion position in a frame start symbol, a data symbol and a frame end symbol.

According to an embodiment of the present invention, a transmitting apparatus includes a frame generating unit that generates a frame including a frame start symbol, a data symbol, and a frame closing symbol, A pilot and reservation tone inserter for inserting a pilot into the data symbol, the data symbol and the frame end symbol, inserting a reserved tone so as not to overlap the insertion position of the pilot, And a transmitting unit for transmitting the data.

Here, the pilot and reserved tone inserting unit inserts the pilot into the data symbol according to a predetermined first arrangement pattern, inserts the reserved tone so as not to overlap with the inserted position of the pilot, Inserts the pilot into the frame start symbol and the frame end symbol, and inserts the reservation tone so as not to overlap the insertion position of the pilot.

The predetermined second arrangement pattern may be determined based on the predetermined first arrangement pattern.

The pilot and reservation tone inserting unit inserts a first reservation tone based on the arrangement pattern of the pilot inserted in the data symbol and adds the first reservation tone to a position shifted by a preset value from the insertion position of the first reservation tone The second reservation tone can be inserted.

In addition, reserved tones inserted into the frame start symbol and the frame end symbol may be inserted at the positions defined in Table 1.

In addition, the reservation tone inserted into the data symbol may be inserted at a position defined in Table 4.

In addition, the pilot can be inserted at the position defined in Table 6. < tb > < TABLE >

An IFFT unit for performing an inverse Fourier transform (IFFT) operation on the frame start symbol, the data symbol and the frame end symbol inserted with the pilot and reservation tones and outputting the parallel start signal, the parallel signal output from the IFFT unit as a serial signal And a PAPR reduction unit for reducing an average power to maximum power ratio (PAPR) based on the pilot and reserved tones.

Here, the PAPR reduction unit may calculate the reduction amount of the average power-to-maximum power ratio based on the pilot and reservation tones, and may output the sums of the calculated average power-to-maximum power ratio reduction amount to the serial signal.

Meanwhile, a receiving apparatus according to an embodiment of the present invention includes a receiving unit that receives a frame including a frame start symbol, a data symbol, and a frame ending symbol into which a pilot and reservation tone are inserted, and performs channel estimation based on the pilot And a signal processing unit for signal processing the frame start symbol, the data symbol and the frame ending symbol in consideration of the position of the reserved tone, and the reserved tone is inserted so as not to overlap with the insertion position of the pilot.

Here, reserved tones inserted into the frame start symbol and the frame end symbol are inserted at positions defined in Table 1.

Then, the reservation tone inserted in the data symbol is inserted at the position defined in Table 4.

In addition, the pilot is inserted at the position defined in Table 6.

Meanwhile, a method of controlling a transmitting apparatus according to an embodiment of the present invention includes generating a frame including a frame start symbol, a data symbol, and a frame closing symbol, Inserting a pilot into the data symbol and the frame end symbol, inserting a reserved tone so as not to overlap the insertion position of the pilot, and transmitting the frame in which the pilot and reservation tone are inserted can do.

The step of inserting the reserved tone may include inserting the pilot into the data symbol according to a predetermined first arrangement pattern, inserting the reserved tone so as not to overlap the inserted position of the pilot, Inserts the pilot into the frame start symbol and the frame end symbol according to the pilot symbol, and inserts the reserved tone so as not to overlap the insertion position of the pilot.

The predetermined second arrangement pattern is determined based on the predetermined first arrangement pattern.

The step of inserting the reserved tone may include inserting a first reserved tone based on the arrangement pattern of the pilots inserted in the data symbol and inserting the first reserved tone at a position shifted by a preset value from the inserted position of the first reserved tone In addition, a second reservation tone can be inserted.

In addition, reserved tones inserted into the frame start symbol and the frame end symbol may be inserted at the positions defined in Table 1.

In addition, the reservation tone inserted into the data symbol may be inserted at a position defined in Table 4.

And, the pilot can be inserted at the position defined in Table 6.

Meanwhile, a method of controlling a transmission apparatus according to an embodiment of the present invention includes performing an inverse Fourier transform (IFFT) operation on the frame start symbol, the data symbol, and the frame end symbol inserted with the pilot and reserved tones Converting the output parallel signal into a serial signal and outputting the parallel signal, and reducing the average power to maximum power ratio (PAPR) based on the pilot and reserved tones.

The step of decreasing the average power to maximum power ratio may include calculating a decrease amount of the average power to maximum power ratio based on the pilot and reserved tone and adding the calculated amount of decrease in average power to maximum power ratio to the serial signal And output it.

Meanwhile, a method of controlling a receiving apparatus according to an embodiment of the present invention includes receiving a frame including a frame start symbol, a data symbol, and a frame end symbol into which a pilot and reservation tone are inserted, And signal processing of the frame start symbol, the data symbol and the frame end symbol in consideration of the position of the reserved tone, and the reserved tone is inserted so as not to overlap the insertion position of the pilot .

Herein, the reservation tone inserted into the frame start symbol and the frame end symbol may be inserted at a position defined in Table 1.

In addition, the reservation tone inserted into the data symbol may be inserted at a position defined in Table 4.

And, the pilot can be inserted at the position defined in Table 6.

According to various embodiments of the present invention as described above, reservation tones can be inserted while avoiding collision between pilot and reservation tones, and PAPR can be reduced based on the inserted pilot and reservation tones.

Figs. 1 and 2 are diagrams for explaining the prior art.
3 is a block diagram showing a configuration of a transmitting apparatus according to an embodiment of the present invention.
4 is a view for explaining the structure of a frame according to an embodiment of the present invention.
5 is a diagram illustrating positions of scattered pilots inserted in a frame start symbol, a data symbol, and a frame end symbol according to an embodiment of the present invention.
FIG. 6 is a diagram for explaining a frame structure inserted so that the scattered pilot and the reserved tone do not collide with each other according to an embodiment of the present invention.
7 is a diagram showing an arrangement pattern of distributed pilots shifted by predetermined values according to an embodiment of the present invention.
8 is a block diagram showing a detailed configuration of a transmitting apparatus according to an embodiment of the present invention.
9 is a diagram illustrating a detailed configuration of a PAPR reduction unit according to an embodiment of the present invention.
10 is a block diagram illustrating a configuration of a receiving apparatus according to an embodiment of the present invention.
11 is a block diagram showing a detailed configuration of a signal processing unit according to an embodiment of the present invention.
12 is a flowchart illustrating a method of controlling a transmitting apparatus according to an embodiment of the present invention.
13 is a flowchart illustrating a method of controlling a receiving apparatus according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

The structure of the pilot shown in FIG. 2 is composed of a continuous pilot, which is maintained over several OFDM symbols, and a distributed pilot, which is present in one OFDM symbol and uniformly distributed in the frequency domain. In this frame structure, since the positions of pilots are different for each OFDM symbol, the position of reservation tone must be changed. Therefore, each OFDM symbol must have a different reservation tone.

However, since each OFDM symbol has a different reserved tone, the impulse waveform generated by the reserved tone also has different signals. Therefore, in the OFDM system, information about all the impulse waveforms must be stored in the memory, thereby increasing the memory size.

The present invention proposes a method of applying a reservation tone to a frame without having different reservation tones for each OFDM symbol. In the structure of the scattered pilot in FIG. 2, it can be seen that each OFDM symbol moves at regular intervals. If the position of the reserved tone is moved at the same interval as the scattered pilot using the above characteristic, collision between the reserved tone and the scattered pilot can be avoided .

3 is a block diagram showing a configuration of a transmitting apparatus according to an embodiment of the present invention.

3, the transmitting apparatus 300 includes a frame generating unit 310, a pilot and reserved tone inserting unit 320, and a transmitting unit 330.

The frame generation unit 310 may generate a frame including a frame start symbol, a data symbol, and a frame closing symbol.

A frame according to an embodiment of the present invention is a frame structure of an ATSC 3.0 system. Specifically, this will be described with reference to FIG.

4 is a view for explaining the structure of a frame according to an embodiment of the present invention.

Referring to FIG. 4, one frame 400 includes one preamble symbol 440, one frame start symbol 410, a plurality of data symbols 420, and one frame end symbol 430.

Here, the frame 400 may correspond to a frame used in the DVB-T2 scheme, and accordingly, the T2 frame structure will be described in detail.

One T2 frame is composed of a P1 preamble symbol indicating a start position of a frame, a P2 preamble symbol transmitting an L1 signal, and data symbols transmitting a broadcast signal.

Specifically, the P1 preamble symbol is located at the beginning of the T2 frame and can be used to detect the start point of the T2 frame. In addition, the P1 preamble symbol uses a 1K FFT size and is a guard interval type signal. The P1 preamble symbol in the frequency domain uses 384 subcarriers in 853 subcarriers among 1K FFTs and can transmit 7 bits of information.

The preamble symbol 440 according to an embodiment of the present invention corresponds to the P1 preamble symbol and the P2 preamble symbol described above and can be used to perform a synchronization function by notifying the start position of a frame, Can be used to detect data.

The frame start symbol 410 indicates the start point of the data symbol 420 and the positions of the pilot and reserve tones inserted in the frame start symbol 410 and the data symbol 420 are different from each other. This will be described later.

The frame end symbol 430 identifies the end point of the data symbol 420 and the positions of the pilot and reserve tones inserted in the frame end symbol 430 and the data symbol 420 are different from each other, do.

The pilot and reservation tone inserting unit 320 may insert a pilot into a frame start symbol, a data symbol, and a frame end symbol, and insert a reserved tone so as not to overlap the insertion position of the pilot.

Here, the pilot and reservation tone inserting unit 320 may correspond to the pilot inserting unit of the DVB-T2 transmission system. The DVB-T2 transmission system may include an input processor (not shown), a BICM encoder (not shown), a frame builder (not shown), and a modulator (not shown).

The configuration is the same as that defined in DVB-T2, which is one of digital broadcasting standards. For details, refer to "Digital Video Broadcasting (DVB) Frame Structure Channel Coding and Modulation for a Second Generation Digital Terrestrial Television Broadcasting System (DVB-T2) ".

An input processor (not shown) can process the input broadcast signal to generate a signal in the form of a baseband frame format.

A BICM encoder (not shown) performs encoding by determining a FEC coding rate and a constellation order according to an area (fixed PHY frame or mobile PHY frame) to which data to be served is to be transmitted. The signaling information for the data to be served may be encoded through a separate BICM encoder (not shown) or may be encoded by sharing the BICM encoder (not shown) with the data to be served.

A frame builder (not shown) and a modulator (not shown) determine an OFDM parameter for a signaling region and an OFDM parameter for an area to which data to be transmitted is to be transmitted to construct a frame, and add a sink area to generate a frame. Then, modulation is performed to modulate the generated frame with the RF signal, and the RF signal is transmitted to the receiver.

Here, the T2 frame structure may be composed of a data subcarrier for transmitting a modulated signal, a pilot for channel estimation, and reserved tones for reducing Peak to Average Power Ratio (PAPR).

These pilot and reserved tones may be performed in a pilot inserting portion (not shown) of a modulator (not shown). Specifically, the pilot inserting unit (not shown) inserts the pilot of the predetermined pilot pattern at the corresponding position in the frame and outputs it to the OFDM generating unit (not shown). The various cells in the OFDM frame are modulated with reference information of the transmitted value known to the receiver. Cells containing reference information are transmitted at the boosted power level. The information transmitted in such a cell may be a scattered pilot cell, a continuous pilot cell, an edge pilot cell, a P2 pilot cell or a frame-closing pilot, Cell. The value of the pilot information is obtained from a reference sequence which is a series of values.

The pilot and reservation tone inserting unit 320 according to an embodiment of the present invention may correspond to a pilot inserting unit (not shown) of a modulator (not shown).

Then, the transmitter 330 can transmit the frame in which the pilot and reservation tone are inserted.

Meanwhile, the pilot and reservation tone inserting unit 320 inserts a pilot for channel estimation and synchronization. In general, the pilot includes not only a Scattered Pilot, a Continuous Pilot, but also a P2 pilot , A frame closing symbol of a frame closing symbol, and the like.

The scattered pilot is used for channel estimation and equalization mainly as a pilot inserted constantly in the frequency direction as well as in time. The distributed pilot pattern of the existing DVB-T is inserted uniformly irrespective of the FFT size or the guard interval, but DVB-T2 is flexible in applying 8 patterns from PP1 to PP8 according to FFT and guard interval. These patterns are designed according to the maximum guard interval length (1 / Dx) and the channel Doppler limit (1 / Dy), and the pilot size is 2.5 ~ 7.4dB higher than the normal data for each pattern. And the overhead due to pilot insertion can be reduced.

In addition, the continuous pilot pattern is inserted constantly in the time direction, and the number of inserted pilots is relatively small as compared with DVB-T. However, since the size of the pilot is about 2.5 to 8.5 dB according to the FFT, In the 8K, 16K, and 32K modes, the overhead due to pilot insertion was reduced from 2.5% to 0.7% without degrading the frequency synchronization and CPE detection performance. Also, the overhead was further reduced by sharing the positions of some continuous pilots and distributed pilots.

Meanwhile, in accordance with an embodiment of the present invention, a continuous pilot means a pilot that is continuously inserted in a frame start symbol 410, a data symbol 420, and a frame end symbol 430, Means a pilot whose position is changed according to a certain pattern in the frame start symbol 410, the data symbol 420, and the frame end symbol 430, and is inserted.

5 is a diagram illustrating positions of scattered pilots inserted in a frame start symbol, a data symbol, and a frame end symbol according to an embodiment of the present invention.

For example, when the pilot pattern is P4,4, the scattered pilots inserted in the data symbol 420 are set to be arranged in a pattern of Dx = 4 and Dy = 4. This means that scattered pilots inserted in the data symbols 420 are shifted and arranged at equal intervals by the size of 4, and are arranged in four rows.

In addition, the scattered pilots inserted in the Frame Starting Symbol (FSS) 410 and the Frame Closing Symbol (FCS) 430 are set to be arranged in a pattern of Dx = 4 and Dy = 1 . This means that the scattered pilots inserted in the frame start symbol 410 and the frame ending symbol 430 are arranged at equal intervals by the size of 4 and arranged in one column.

That is, the allocation pattern of the scattered pilot inserted in the data symbol 420 is different from the allocation pattern of the scattered pilot inserted in the frame start symbol 410 and the frame end symbol 430.

Accordingly, the allocation pattern of the reservation tone inserted in the data symbol 420 and the allocation pattern of the reserved tone inserted in the frame start symbol 410 and the frame end symbol 430 are different from each other.

The pilot and reservation tone inserting unit 320 inserts a pilot into the data symbol 420 according to a predetermined first arrangement pattern, inserts a reserved tone so as not to overlap the insertion position of the pilot, A pilot tone is inserted into the frame start symbol 410 and the frame end symbol 430, and a reservation tone is inserted so as not to overlap with the insertion position of the pilot.

Here, the predetermined second arrangement pattern is determined based on the predetermined first arrangement pattern. That is, the predetermined first arrangement pattern means an arrangement pattern of scattered pilots inserted in the data symbol 420, and the predetermined second arrangement pattern indicates a dispersion pattern inserted into the frame start symbol 410 and the frame end symbol 430, May refer to a placement pattern of pilots.

The predetermined first arrangement pattern and the predetermined second arrangement pattern may be arrangement patterns including not only the arrangement pattern of dispersion pilots but also the arrangement pattern of continuous pilots. The reserved tone inserted in the frame start symbol 410, the data symbol 420 and the frame end symbol 430 must not overlap the insertion position of the continuous pilot as well as the scattered pilot.

That is, the pilot and reservation tone inserting unit 320 may insert reservation tones in the data symbols 420 so as not to overlap the scattered pilot and continuous pilots inserted in the data symbols 420 according to a predetermined first arrangement pattern, A reservation tone is inserted in the frame start symbol 410 and the frame end symbol 430 so as not to overlap with the scattered pilot and continuous pilot inserted in the frame start symbol 410 and the frame end symbol 430 according to the predetermined second arrangement pattern. can do.

When the first placement pattern and the second placement pattern include only the placement pattern of the distributed pilots, the reservation tone can be inserted in consideration of the placement pattern of the continuous pilots, and the first placement pattern and the second placement pattern can be arranged In the case of including the pattern and the arrangement pattern of the continuous pilots, the reservation tone can be inserted considering only the first arrangement pattern and the second arrangement pattern.

FIG. 6 is a diagram for explaining a frame structure inserted so that the scattered pilot and the reserved tone do not collide with each other according to an embodiment of the present invention.

By setting the positions of the reserved tones designed in the OFDM symbol to be equal to the shift intervals of the distributed pilots, conflicts with each other are avoided and the problem of increasing the memory that occurs when one reservation tone is reused as mentioned above is solved .

When the position where the reserved tone is inserted is circularly shifted in the frequency domain, the impulse waveform generated by the reserved tone changes only in phase without changing the magnitude of the complex value. Since the change of the phase is different by the separation interval, if the initial phase information is known, the change of phase according to the separation interval can be known. Therefore, the method of inserting the reservation tone considering the arrangement pattern of pilots according to an embodiment of the present invention is applicable to all OFDM symbols in a frame.

6, the arrangement patterns of the pilots inserted in the frame start symbol 610 and the frame end symbol 630 are the same. In consideration of the arrangement pattern of pilots, the arrangement of reserved tones inserted so as not to overlap The patterns are the same.

On the other hand, the arrangement pattern of the pilot inserted into the data symbol 620 is different from the arrangement pattern of the pilot inserted into the frame start symbol 610 and the frame end symbol 630, The allocation pattern of reserved tones is also different from the allocation pattern of reserved tones inserted in frame start symbol 610 and frame end symbol 630. [

In addition, it can be seen that the pilots and reservation tones inserted in all the symbols 610, 620, and 630 shown in FIG. 6 do not overlap with each other.

On the other hand, the placement pattern of the pilot inserted into the frame start symbol 610 and the frame end symbol 630 may be determined based on the placement pattern of the pilot inserted into the data symbol 620. [

For example, if the placement pattern of the pilot inserted in the data symbol 620 is Dx = 4 and Dy = 4, the placement pattern of the pilot inserted into the frame start symbol 610 and the frame end symbol 630 is Dx = 4 , Dy = 1, which means a placement pattern arranged in one row while maintaining the shift interval of inserted pilots.

That is, pilots are inserted into the frame start symbol 610 and the frame end symbol 630 at all the subcarrier positions corresponding to the placement pattern of the pilot inserted into the data symbol 620. [

On the other hand, the pilot and reservation tone inserting unit 320 inserts the first reservation tone based on the placement pattern of the pilot inserted into the data symbol 620, and inserts a position shifted from the insertion position of the first reservation tone by a preset value The second reservation tone can be inserted in addition to the second reserved tone.

Specifically, as described above, the pilot and reservation tone inserter 320 may reserve the first reservation tone so as not to overlap the position of the pilot inserted in the data symbol 620. [ Here, the inserted pilot is a concept including both a distributed pilot and a continuous pilot. Accordingly, the pilot and reservation tone inserter 320 can reserve the first reservation tone so as not to overlap the positions of the scattered pilot and the continuous pilot inserted in the data symbol 620. [

In addition, the pilot and reservation tone inserting unit 320 can additionally reserve the second reservation tone in consideration of the distribution pattern of the scattered pilots. Specifically, the pilot and reservation tone inserting section 320 can reserve the second reservation tone considering the amount by which the scattered pilot is shifted. This will be described in detail with reference to FIG.

7 is a diagram showing an arrangement pattern of distributed pilots shifted by predetermined values according to an embodiment of the present invention.

Referring to FIG. 7, when the scattered pilot is located at 20 subcarrier intervals, it can be seen that the OFDM symbols are cyclically moved at four subcarrier intervals.

Therefore, the pilot and reserved tone inserting unit 320 inserts the first reservation tone so as not to overlap with the scattered pilot inserted in the second column shown in FIG. 7, and the scattered pilot inserted in the first column shown in FIG. It is possible to insert a second reservation tone at a position shifted by four subcarrier intervals from the insertion position of the first reservation tone inserted in the second column because the channel is shifted by four subcarrier intervals based on the scattered pilot inserted in the column .

Equation (1) below is a mathematical expression representing the insertion position of the reserved tone inserted in consideration of the above-described distributed pilot allocation pattern.

Where S ₀ represents the location of the reserved tone, and N _RT represents Indicates the number of reserved tones.

Accordingly, when the pilot and reservation tone inserting unit 320 determines only the insertion position of the first reservation tone without calculating the insertion position of the reservation tone every time for every data symbol, the shifted value of the distributed pilot is considered The insertion position of the second reservation tone can be determined and the amount of calculation can be reduced and the amount of memory for storing the impulse signal corresponding to each reservation tone can be reduced as described above.

On the other hand, reserved tones inserted into the frame start symbol 610 and the frame end symbol 630 may be inserted at positions defined in Table 1 below.

Table 1 is a table showing indexes indicating positions of reservation tones inserted in a frame start symbol (FSS) and a frame end symbol (FCS) according to an embodiment of the present invention. That is, the positions of the reserved tones shown in Table 1 are determined for each mode by using a frame start symbol 610 and a frame end symbol 610, which are designed in consideration of insertion positions of scattered pilots and continuous pilots according to modes of FFT sizes of 8K, 16K, 630). ≪ / RTI >

Meanwhile, DVB-T2, which is a European broadcasting standard, considers various OFDM sizes, and there are 1K, 2K, 4K, 8K, 16K and 32K modes as follows. Table 2 below shows the number of OFDM sizes and data symbols and the number of reserved tones.

1K mode 2K mode 4K mode 8K mode 16K mode 32K mode Number of subcarriers 1024 2048 4096 8192 16384 32766 Number of data symbols 853 1705 3409 6517 13833 27265 Reservation tone count 9 18 36 72 144 288

That is, the number of reservation tones and the insertion position that can be inserted according to the above-described mode can be changed. The scatter pilot may be inserted in various modified forms according to the above mode while having a similar form to the structure shown in FIG. For example, unlike FIG. 7, a distributed pilot may be inserted at 12 subcarrier intervals. Then, a reserved tone can be inserted so as not to overlap with the insertion position of such distributed pilot. Accordingly, the number of reservation tones and the insertion position that can be inserted for each mode are different.

The reserved tones inserted into the frame start symbol and the frame ending symbol according to an embodiment of the present invention may be inserted differently for each mode, such as reserved tones inserted differently for each mode of the DVB-T2.

Table 3 summarizes the number of reservation tones inserted for each mode shown in Table 1. Table 3

8K mode 16K mode 32K mode Number of subcarriers 8192 16384 32766 Reservation tone count 72 144 288

The indices shown in each mode indicate the positions of reserved tones inserted in the frame start symbol 610 and the frame end symbol 630.

It can be seen that the positions of the reserved tones displayed for each mode are different.

On the other hand, the reservation tone inserted into the data symbol may be inserted at a position defined in Table 4 below.

Table 4 is a table showing indexes indicating positions of reservation tones inserted into data symbols according to an embodiment of the present invention. That is, the reserved tone positions shown in Table 4 are allocated to reserved symbols inserted in the data symbols 620 designed in consideration of the insertion positions of the scattered pilot and the continuous pilot according to the mode of FFT size of 8K, 16K, .

Similarly, reserved tones inserted into data symbols according to an embodiment of the present invention may be inserted differently for each mode, such as reserved tones inserted differently for each mode of DVB-T2.

The number of reservation tones to be inserted for each mode shown in Table 4 is summarized in Table 5 below.

8K mode 16K mode 32K mode Number of subcarriers 8192 16384 32766 Reservation tone count 72 144 288

In addition, the index indicated by each mode represents the position of the reserved tone inserted in the data symbol 620. Likewise, the positions of reserved tones displayed for each mode are different.

On the other hand, the pilots can be inserted at positions defined in Table 6 below.

Table 6 is a table showing indexes indicating insertion positions of continuous pilots according to a mode of FFT size of 8K, 16K, 32K according to an embodiment of the present invention.

That is, the indices indicating the positions of the reserved tones inserted in the frame start symbol 610, the frame end symbol 630, and the data symbol 620 defined in Tables 1 and 4 are the same as those of the continuous pilots defined in Table 6 Are designed not to overlap each other in consideration of the index indicating the insertion position and the insertion position of the scattered pilot, that is, the arrangement pattern.

8 is a block diagram showing a detailed configuration of a transmitting apparatus according to an embodiment of the present invention.

8, a transmitter 300 includes a frame generator 310, a pilot and reservation tone inserter 320, an IFFT unit 340, a parallel / serial converter 350, a PAPR reduction unit 360, And a transmission unit 330. [

More specifically, the N-L point input signal and the L reserve tone signals may be input to the pilot and reservation tone inserting unit 320. [ Here, no data is transmitted to L reserved tones, and 0 is inserted.

The IFFT unit 340 may perform an inverse Fourier transform (IFFT) operation on the frame start symbol, the data symbol, and the frame end symbol inserted with the pilot and reserved tones. Specifically, when the input signal of the N-L point, which is a parallel signal, and the sum of the L reservation tones are input to the IFFT unit 340, the IFFT operation can be performed.

The parallel / serial converter 350 converts the parallel signal output from the IFFT unit 340 into a serial signal and outputs the serial signal. Specifically, the parallel / serial converter 350 converts the parallel signal into a serial signal, thereby outputting the output signal in the time domain.

The PAPR reduction section 360 may reduce the average power to maximum power ratio (PAPR) based on the pilot and reserved tone.

Specifically, the PAPR reduction unit 360 calculates a reduction amount of the average power-to-maximum power ratio based on the pilot and reservation tone, and outputs the sum of the reduction amount of the average power to the maximum power ratio calculated in the serial signal.

The PAPR reduction unit 360 may include a gradient algorithm unit (not shown), and may output a signal generated by a gradient algorithm unit (not shown) to an output signal output from the IFFT unit 340 . Here, the gradient algorithm unit (not shown) may reduce the average power-to-maximum power ratio of the output signal output from the IFFT unit 340 using the impulse signal corresponding to the reserved tone.

8, the transmitting apparatus 300 may further include a memory (not shown) and a controller (not shown).

The memory (not shown) may store information about the number of reserved tones and the location of reserved tones according to the OFDM size. The gradient algorithm unit (not shown) generates a signal having the form of an impulse using the information stored in the memory, and the generated impulse signal is stored in a memory (not shown).

A memory (not shown) transmits information about the number of reserved tones and the location of reserved tones to a control unit (not shown), and the control unit (not shown) And transmit information about the number of reservation tones and the location of reservation tones to the pilot and reservation tone inserter 320 so that reservation tones are allocated.

Accordingly, the pilot and reservation tone inserting unit 320 can allocate and insert subcarriers so that collision does not occur between the pilot and reserved tones.

Also, the control unit (not shown) may adjust the position of the reservation tone and the phase of the impulse signal by calculating the shift interval of the scattered pilot according to the OFDM symbol index. The same PAPR reduction performance can be maintained because the magnitude of the impulse signal does not change even if the reservation tone is circulated. In addition, the shift interval may be calculated by the pilot and reservation tone inserting unit 320 itself, not by a control unit (not shown), and then sent to a control unit (not shown) to calculate the phase.

9 is a diagram illustrating a detailed configuration of a PAPR reduction unit according to an embodiment of the present invention.

9, the PAPR reduction unit 360 includes a P waveform generating unit 361, a peak detecting unit 362, a position circulating moving unit 363, a phase rotating unit 364, a scaling unit 365, a complex adder 366, a PAPR operation unit 367, and a control unit 367.

The P waveform generating unit 361 can generate a P waveform having an impulse characteristic with the reserved L tones except for the NL point input signal which is a parallel signal among all N signals. Here, P wave is at least one of the repeating perform implemented to randomly select one reserved L tones after that from the remaining P ₁ ~ except for the peak value of P ₀ P _N in the entire signal _- the electric power from the _first values, values best I chose the small case.

On the other hand, the peak detecting section 362 can detect the maximum peak value of the input signal of the N-L point.

Then, the position cyclic shifter 363 cyclically moves the position of the P waveform to the position of the detected maximum peak value.

The phase rotation unit 364 coincides the circulated P waveform with the phase of the peak value detected on the complex plane.

The scaling unit 365 scales the value of the P waveform so that the peak value of the signal output after the N-L point input signal is subjected to the IFFT operation is less than or equal to a predetermined PAPR value.

The complex adder 366 compares the calculated value to reduce the maximum peak value of the signal output after the IFFT operation and the maximum peak value of the P waveform to a value less than a predetermined level by using the input signal of the NL point, And can be transmitted as an input value of the PAPR operation unit 367.

The control unit 368 can feed back the calculated PAPR calculated value to be less than a predetermined PAPR value. This iteration is repeated until the input PAPR calculation value becomes less than a predetermined PAPR value.

10 is a block diagram illustrating a configuration of a receiving apparatus according to an embodiment of the present invention.

Referring to FIG. 10, the receiving apparatus 1300 may include a receiving unit 1310 and a signal processing unit 1320.

Receiver 1310 may receive a frame including a frame start symbol, a data symbol, and a frame end symbol into which a pilot and reservation tone are inserted.

The signal processing unit 1320 performs channel estimation based on the pilot, and can process the frame start symbol, the data symbol, and the frame ending symbol in consideration of the position of the reserved tone to detect the data. Here, the reserved tone is inserted so as not to overlap with the insertion position of the pilot.

11 is a block diagram showing a detailed configuration of a signal processing unit of a receiving apparatus according to an embodiment of the present invention.

11, the signal processing unit 1320 includes a parallel / serial conversion unit 1321, an FFT unit 1322, a data symbol detection unit 1323, a data demodulation unit 1324, a memory 1325, and a control unit 1326, . ≪ / RTI >

The parallel / serial converter 1321 may parallel-convert received signals on the input time and output the parallel signals to the FFT unit 1332.

The FFT unit 1332 performs Fourier transform on the input signals, converts the signals into signals on the frequency domain, and transmits the converted signals to the data symbol detection unit 1323.

Here, the memory 1325 outputs the positions of reserved tones inserted in the frame start symbol 610, the data symbol 620, and the frame end symbol 630 according to an embodiment of the present invention, The position of the reserved tone is input to the control unit 1326. [

The control unit 1326 adjusts the position of the reserved tone inserted according to the pilot position in the OFDM symbol received by the receiving unit 1310 such that it does not collide with the pilot position and outputs it to the data symbol detecting unit 1323.

The data symbol detection unit 1323 extracts signals corresponding to the data symbols except for the positions of reserved tones inputted from the control unit 1326 among the signals on the frequency inputted from the FFT unit 1322 Can be output. Accordingly, the data symbol 620 extracted by the data symbol detection unit 1323 is input to the data demodulation unit 1324 and performs data demodulation operation.

On the other hand, the reservation tone inserted in the frame start symbol 610 and the frame end symbol 630 may be inserted at a position defined in Table 1. [

In addition, the reserved tone inserted in the data symbol 620 may be inserted at the position defined in Table 4.

In addition, the pilots may be inserted at the positions defined in Table 6.

12 is a flowchart illustrating a method of controlling a transmitting apparatus according to an embodiment of the present invention.

According to the control method of the transmitting apparatus shown in FIG. 12, a frame including a frame start symbol, a data symbol, and a frame closing symbol may be generated (S1510).

Then, a pilot may be inserted into the frame start symbol, the data symbol, and the frame end symbol, and a reservation tone may be inserted so as not to overlap the insertion position of the pilot (S1520).

Herein, the step of inserting the reserved tone may include inserting a pilot into the data symbol according to a predetermined first arrangement pattern, inserting a reserved tone so as not to overlap with the inserted position of the pilot, And insert a pilot into the end-of-frame symbol and insert a reservation tone so that it does not overlap with the insertion position of the pilot. The predetermined second arrangement pattern may be determined based on a predetermined first arrangement pattern.

In addition, the step of inserting the reservation tone may include inserting a first reservation tone based on the arrangement pattern of pilots inserted into the data symbols, adding a second reservation tone to the shift position by a preset value from the insertion position of the first reservation tone, Can be inserted.

Then, the frame in which the pilot and reservation tone are inserted can be transmitted (S1530).

Here, the reserved tone inserted in the frame start symbol and the frame end symbol can be inserted at the position defined in Table 1. [

In addition, the reserved tone inserted in the data symbol may be inserted at the position defined in Table 4. [

The pilots can be inserted at the positions defined in Table 6.

The control method of the transmitting apparatus shown in FIG. 12 includes the steps of outputting a frame start symbol, a data symbol and a frame end symbol inserted with a pilot and reservation tone by performing an inverse Fourier transform (IFFT) operation and performing an inverse Fourier operation Converting the output parallel signal into a serial signal and outputting the parallel signal, and reducing the average power to maximum power ratio (PAPR) based on the pilot and reservation tone.

Here, the step of decreasing the average power to maximum power ratio may include calculating a decrease amount of the average power to maximum power ratio based on the pilot and reservation tone, and outputting the sum of the average power to maximum power ratio calculated in the serial signal .

13 is a flowchart illustrating a method of controlling a receiving apparatus according to an embodiment of the present invention.

According to the control method of the receiving apparatus shown in FIG. 13, a frame including a frame start symbol, a data symbol, and a frame end symbol into which a pilot and reservation tone are inserted may be received (S1610).

Then, the channel estimation is performed based on the pilot, and the data of the frame start symbol, the data symbol, and the frame end symbol are processed in consideration of the position of the reserved tone to detect the data (S1620).

Here, the reserved tone is inserted so as not to overlap with the insertion position of the pilot.

In addition, reserved tones inserted in the frame start symbol and the frame ending symbol may be inserted at the positions defined in Table 1.

Then, the reserved tone inserted into the data symbol may be inserted at the position defined in Table 4.

In addition, the pilots may be inserted at the positions defined in Table 6.

Meanwhile, a plurality of frames received by the receiving apparatus 200 may be transmitted to the DVB-T2 transmission system, and the signaling region of the frame may be a region transmitting L1 signaling.

As described above, according to various embodiments of the present invention, the information included in the signaling region is increased by reconstructing the information included in the signaling region, and accordingly, the data can be processed in various ways.

Meanwhile, a non-transitory computer readable medium having a program for sequentially performing the control method according to the present invention may be provided.

In one example, generating a frame comprising a frame start symbol, a data symbol and a frame end symbol, inserting a pilot into a frame start symbol, a data symbol and a frame end symbol, and inserting a reservation tone so as not to overlap the insertion position of the pilot And transmitting the frame in which the pilot and reservation tone are inserted, may be provided.

In addition, for example, it is also possible to perform the steps of receiving a frame including a frame start symbol, a data symbol and a frame end symbol into which a pilot and reservation tone are inserted, perform channel estimation based on the pilot, A non-transitory computer readable medium may be provided which stores a program that performs the steps of signal processing symbols, data symbols, and frame end symbols to detect data.

A non-transitory readable medium is a medium that stores data for a short period of time, such as a register, cache, memory, etc., but semi-permanently stores data and is readable by the apparatus. In particular, the various applications or programs described above may be stored on non-volatile readable media such as CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM,

Although the buses are not shown in the above-described block diagrams for the transmitting apparatus and the receiving apparatus, the communication between the respective elements in the transmitting apparatus and the receiving apparatus may be performed via the bus. Further, each device may further include a processor such as a CPU, a microprocessor, or the like that performs the various steps described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

300: transmitting apparatus 310: frame generating unit
320: Pilot and reserved tone inserting unit 330: Transmitting unit
1300: Receiving apparatus 1310: Receiving unit
1320: Signal processor

Claims (26)

A frame generation unit for generating a frame including a frame start symbol, a data symbol, and a frame closing symbol;
A pilot and reservation tone inserter for inserting a pilot into the frame start symbol, the data symbol and the frame end symbol, and inserting a reserved tone so as not to overlap the insertion position of the pilot; And
And a transmitter for transmitting the frame in which the pilot and reservation tone are inserted. The method according to claim 1,
Wherein the pilot and reservation tone inserting unit comprises:
Inserting the pilot into the data symbol according to a predetermined first arrangement pattern, inserting the reserved tone so as not to overlap the insertion position of the pilot,
Inserting the pilot into the frame start symbol and the frame end symbol according to a predetermined second arrangement pattern, and inserting the reserved tone so as not to overlap the inserted position of the pilot. 3. The method of claim 2,
Wherein the predetermined second arrangement pattern includes:
And the transmission power is determined based on the predetermined first arrangement pattern. 3. The method of claim 2,
Wherein the pilot and reservation tone inserting unit comprises:
A first reservation tone is inserted based on the arrangement pattern of the pilots inserted in the data symbol and a second reservation tone is further inserted at a position shifted from the insertion position of the first reservation tone by a predetermined value, . The method according to claim 1,
Wherein the reserved tone inserted into the frame start symbol and the frame end symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

The method according to claim 1,
Wherein the reservation tone inserted in the data symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

The method according to claim 1,
Wherein the pilot is inserted in a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

The method according to claim 1,
An IFFT unit for performing an inverse Fourier transform (IFFT) operation on the frame start symbol, the data symbol and the frame end symbol inserted with the pilot and reserved tones;
A parallel / serial converter for converting a parallel signal output from the IFFT unit into a serial signal and outputting the serial signal; And
Further comprising: a PAPR reduction unit to reduce an average power to maximum power ratio (PAPR) based on the pilot and reserved tones. 9. The method of claim 8,
Wherein the PAPR reduction unit comprises:
Calculates a decrease amount of the average power to maximum power ratio based on the pilot and reserved tone, and adds the reduction amount of the calculated average power to maximum power ratio to the serial signal and outputs the sum. A receiving unit for receiving a frame including a frame start symbol, a data symbol and a frame ending symbol into which a pilot and reservation tone are inserted; And
And a signal processing unit for performing channel estimation based on the pilot and signal processing the frame start symbol, the data symbol and the frame ending symbol in consideration of the position of the reserved tone,
Wherein the reservation tone is inserted so as not to overlap the insertion position of the pilot. 11. The method of claim 10,
Wherein the reserved tone inserted in the frame start symbol and the frame end symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

11. The method of claim 10,
Wherein the reserved tone inserted in the data symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

11. The method of claim 10,
Wherein the pilot is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

Generating a frame including a frame start symbol, a data symbol, and a frame closing symbol;
Inserting a pilot into the frame start symbol, the data symbol, and the frame end symbol, and inserting a reserved tone so as not to overlap the insertion position of the pilot; And
And transmitting the frame in which the pilot and reservation tone are inserted. 15. The method of claim 14,
The step of inserting the reserved tone comprises:
Inserting the pilot into the data symbol according to a predetermined first arrangement pattern, inserting the reserved tone so as not to overlap the insertion position of the pilot,
Inserting the pilot into the frame start symbol and the frame end symbol according to a predetermined second arrangement pattern and inserting the reserved tone so as not to overlap with the inserted position of the pilot. 16. The method of claim 15,
Wherein the predetermined second arrangement pattern includes:
And wherein the predetermined pattern is determined based on the predetermined first arrangement pattern. 16. The method of claim 15,
The step of inserting the reserved tone comprises:
A first reservation tone is inserted based on the arrangement pattern of the pilots inserted in the data symbol and a second reservation tone is further inserted at a position shifted from the insertion position of the first reservation tone by a predetermined value, Of the transmitting apparatus. 15. The method of claim 14,
Wherein the reserved tone inserted in the frame start symbol and the frame end symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

15. The method of claim 14,
Wherein the reserved tone inserted into the data symbol is inserted at a position as shown in the following table according to a mode in which the FFT size is 8K, 16K, and 32K.

15. The method of claim 14,
Wherein the pilot is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

15. The method of claim 14,
Performing an inverse Fourier transform (IFFT) operation on the frame start symbol, the data symbol and the frame end symbol inserted with the pilot and reservation tones, and outputting;
Converting the parallel signal outputted by performing the inverse Fourier calculation into a serial signal and outputting the parallel signal; And
And decreasing the average power to maximum power ratio (PAPR) based on the pilot and reserved tones. 22. The method of claim 21,
The step of reducing the average power to maximum power ratio comprises:
Calculating a decrease amount of the average power to maximum power ratio based on the pilot and reservation tone, and adding the reduction amount of the calculated average power to the maximum power ratio to the serial signal and outputting the sum. Receiving a frame comprising a frame start symbol, a data symbol and a frame end symbol into which a pilot and reservation tone are inserted; And
Performing channel estimation based on the pilot and signal processing the frame start symbol, the data symbol, and the frame ending symbol in consideration of the position of the reserved tone to detect data;
Wherein the reservation tone is inserted so as not to overlap with the insertion position of the pilot. 24. The method of claim 23,
Wherein the reserved tone inserted into the frame start symbol and the frame end symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

24. The method of claim 23,
Wherein the reserved tone inserted in the data symbol is inserted at a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

24. The method of claim 23,
Wherein the pilot is inserted in a position as shown in the following table according to a mode in which FFT sizes are 8K, 16K, and 32K.

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