KR101343073B1 - Apparatus for transmitting RF signal and receiving RF signal and Method for generating RF signal - Google Patents

Abstract

The present invention relates to a signal transmission and reception apparatus and a method for generating an RF signal, and more particularly to generating a first subcarrier block using a subcarrier including a first symbol; Dividing a subcarrier included in the first subcarrier block; And inserting the divided subcarriers into a plurality of second subcarrier inter-block guard bands, wherein the second subcarrier blocks are generated using subcarriers including a second symbol. It provides a block RF signal generation method.

Description

Apparatus for transmitting RF signal and receiving RF signal and Method for generating RF signal

The present invention relates to an RF signal transmission and reception apparatus and an RF signal generation method, and more particularly, to an RF signal transmission and reception apparatus and digital signal generation method for digital broadcasting.

1 is a diagram illustrating an embodiment of frequency allocation of terrestrial DMB.

The frequency bandwidth of a terrestrial DMB system using an Eureka-147 DAB as a transmission system is 1.536 MHz, and when placed in the 6 MHz TV frequency band 102, three blocks, that is, block A (110) and block B (120) Block C 130 is placed. In this case, each of the blocks 110, 120, and 130 has 1536 subcarriers arranged at intervals of 1 KHz. Each block is spaced from each other through guardbands (0.512 MHz (104), 0.192 MHz (106), 0.192 MHz (114), and 0.496 MHz (122)), so that each block Reduce mutual interference between RF signals. For terrestrial DMB, except for each block used for mobile multimedia services within 6 MHz, the frequency band wasted for the guardband is 1.392 MHz (= 6-1.536X3), which is different for other TV frequency bands such as 8 MHz. Has a value.

2 is a diagram for explaining a generation process of an OFDM signal in terrestrial DMB.

The 1536 subcarriers carrying the phase information by QPSK modulation are converted to 2048 subcarriers through a zero padding process 202 every OFDM symbol time. The signal is converted into an OFDM signal through the IFFT process 204 and the guard interval insertion process 206 of the 2048-pointer.

On the other hand, the effective transmission capacity that can be provided by one block is about 1.152Mbps, it is difficult to provide a high-definition high-definition AV service of the HD in the conventional case. Accordingly, there is a need for a method for providing a variable high quality service by utilizing guard bands consumed on a frequency and combining services provided by each block.

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The present invention for achieving the above object, generating a first subcarrier block using a subcarrier comprising a first symbol; Generating a plurality of second subcarrier blocks without guardband; And inserting the first subcarrier block into a remaining frequency band except for a frequency band in which the plurality of second subcarrier blocks are disposed in a preset frequency band, wherein the second subcarrier block includes a second symbol. Provided is a method for generating an RF signal, which is a subcarrier block generated using a subcarrier including the subcarrier.

In addition, the present invention for achieving the above object, the first differential modulation unit for generating a first symbol by performing differential modulation on the received first service stream; A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream; A distribution unit dividing the first symbol; And a frequency multiplexing unit inserting the divided first symbols at both ends of the second symbol to multiplex the inserted first symbol and the second symbol.

In addition, the present invention for achieving the above object, the first differential modulation unit for generating a first symbol by performing differential modulation on the received first service stream; A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream; An arrangement unit for disposing a plurality of second symbols generated by the plurality of second differential modulation units without a frequency interval; And a frequency multiplexing unit inserting the first symbol into one end of the plurality of second symbols disposed without the frequency interval, and multiplexing the inserted first symbol with the plurality of second symbols disposed without the frequency interval. Provided is an RF signal transmission apparatus.

In addition, the present invention for achieving the above object, in the symbol comprising a plurality of second subcarrier block and the first subcarrier block inserted into the guard band between the second subcarrier block, the first subcarrier block A frequency redistribution unit for extracting a symbol for the unit; And a differential demodulation unit for demodulating a symbol for the extracted first subcarrier block.

In addition, the present invention for achieving the above object is, a plurality of second subcarrier blocks arranged without a guard band in the predetermined frequency band and the second frequency carrier is inserted into the remaining frequency band of the frequency band in which the second subcarrier block is arranged; A frequency redistribution unit configured to extract a symbol for the first subcarrier block from a symbol including one subcarrier block; And a differential demodulation unit for demodulating a symbol for the extracted first subcarrier block.

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The present invention for achieving the above object, generating a first subcarrier block using a subcarrier comprising a first symbol; Generating a plurality of second subcarrier blocks without guardband; And inserting the first subcarrier block into a remaining frequency band except for a frequency band in which the plurality of second subcarrier blocks are disposed in a preset frequency band, wherein the second subcarrier block includes: a second symbol; A subcarrier block is generated using a subcarrier that includes.

In addition, the present invention for achieving the above object, the first differential modulation unit for generating a first symbol by performing differential modulation on the received first service stream; A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream; A distribution unit dividing the first symbol; And a frequency multiplexing unit inserting the divided first symbols at both ends of the second symbol to multiplex the inserted first symbol and the second symbol.

In addition, the present invention for achieving the above object, the first differential modulation unit for generating a first symbol by performing differential modulation on the received first service stream; A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream; An arrangement unit for disposing a plurality of second symbols generated by the plurality of second differential modulation units without a frequency interval; And a frequency multiplexing unit inserting the first symbol into one end of the plurality of second symbols disposed without the frequency interval, and multiplexing the inserted first symbol with the plurality of second symbols disposed without the frequency interval. .

In addition, the present invention for achieving the above object, in the symbol comprising a plurality of second subcarrier block and the first subcarrier block inserted into the guard band between the second subcarrier block, the first subcarrier block A frequency redistribution unit for extracting a symbol for the unit; And a differential demodulation unit for demodulating a symbol for the extracted first subcarrier block.

In addition, the present invention for achieving the above object is, a plurality of second subcarrier blocks arranged without a guard band in the predetermined frequency band and the second frequency carrier is inserted into the remaining frequency band of the frequency band in which the second subcarrier block is arranged; A frequency redistribution unit configured to extract a symbol for the first subcarrier block from a symbol including one subcarrier block; And a differential demodulation unit for demodulating a symbol for the extracted first subcarrier block.

According to the present invention, the frequency utilization efficiency can be improved by arranging blocks on a pre-allocated frequency adjacent to each other without a guard band between blocks or by additionally allocating blocks within an interblock guard band.

In addition, according to the present invention, it is possible to provide a high quality service in addition to the mobile service of basic quality.

In addition, according to the present invention, backward compatibility with the current terrestrial DMB service which is pre-allocated and serviced in the 6 MHz TV band can be maintained.

In addition, according to the present invention, a service provider can conceive a more diverse service model through a variable frequency bandwidth, and from the user's point of view, a basic service can be provided with a high quality mobile multimedia service according to the terminal situation.

1 is a view for explaining an embodiment of frequency allocation of terrestrial DMB;
2 is a view for explaining a process of generating an OFDM signal in terrestrial DMB;
3 is a view for explaining the concept of an RF signal generation method according to an embodiment of the present invention;
4 is a view for explaining the RF signal generation method of the RF signal transmitting apparatus 700 according to an embodiment of the present invention;
5 is a view for explaining the concept of the RF signal generation method according to an embodiment of the present invention;
6 is a view for explaining the RF signal generation method of the RF signal transmitting apparatus 1000 according to an embodiment of the present invention;
7 is a view for explaining the RF signal transmitting apparatus 700 according to an embodiment of the present invention;
8 is a view for explaining an RF signal transmission apparatus 700 according to an embodiment of the present invention in detail,
9 is a view for explaining an OFDM symbol generation process of the RF signal transmitting apparatus 700 according to an embodiment of the present invention;
10 is a view for explaining the RF signal transmitting apparatus 1000 according to an embodiment of the present invention;
11 is a view for explaining an RF signal transmitting apparatus 1000 according to an embodiment of the present invention;
12 is a diagram illustrating an arrangement of subcarriers for OFDM symbol generation in an RF signal transmitting apparatus 1000 according to an embodiment of the present invention;
13 is a view for explaining the RF signal receiving apparatus 1300 according to an embodiment of the present invention;
14 is a view for explaining a redistribution unit 1310 of the RF signal receiving apparatus 1300 according to an embodiment of the present invention;
15 is a view for explaining a service using the RF signal received by the RF signal receiving apparatus 1300 according to an embodiment of the present invention;
16 is a view for explaining in detail the RF signal receiving apparatus 1300 according to an embodiment of the present invention;
17 is a view for explaining the RF signal receiving apparatus 1700 according to an embodiment of the present invention;
18 is a view for explaining in detail the RF signal receiving apparatus 1700 according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: The detailed description thereof will be omitted.

Korea currently provides a terrestrial DMB service based on the ATSC scheme, and the present invention can be equally applied to a scheme such as DVB-T and ISDB-T as well as the ATSC scheme. Hereinafter, the present invention will be described with reference to the frequency arrangement of the terrestrial DMB based on the ATSC scheme.

3 is a view for explaining the concept of the RF signal generation method according to an embodiment of the present invention. In FIG. 3, a method of generating an RF signal by inserting a subcarrier only into guard bands 304, 306, 314, and 322 in a 6 MHz frequency band is described as an embodiment.

3 maintains the block arrangement (center frequency), carrier frequency, etc. of the conventional terrestrial DMB as shown in FIG. 1, and subcarriers are additionally inserted only in the guard band.

That is, in order to utilize the frequency band of the guard band, a block D 390 is generated using subcarriers, and subcarriers included in the block D 390 are divided and inserted into each guard band. Here, block D 390 is not for transmitting an existing T-DMB service stream, but for transmitting a newly added additional service stream. The creation of block D 390 allows the service provider to provide more diverse services, and the user may be provided with a high quality mobile multimedia service.

In order to generate the block D 390, the number of subcarriers equal to or different from the number of subcarriers included in the plurality of blocks 360, 370, and 380 pre-arranged in the preset frequency band 302 (1536). A carrier may be used, or a subcarrier of a frequency interval equal to or different from the frequency interval (1 KHz) of the subcarriers included in the plurality of blocks 360, 370, and 380 may be used.

Between each block 360, 370, 380 a guardband (0.512 MHz (304), 0.192 MHz (306), 0.192 MHz 314) and 0.496 MHz (322) exists to reduce mutual interference between the RF signals of the block. In the 6MHz TV frequency band, the guardband has a frequency bandwidth of 1.392MHz (= 0.512MHz + 0.192MHz + 0.192MHz + 0.496MHz). Since the guardband's frequency bandwidth (1.392MHz) is narrower than the frequency bandwidth (1.536MHz) of each of the blocks 360, 370, and 380 generated within the 6MHz TV frequency band, partitioning block D 390 to guardband the subcarrier In order to be inserted into the, the number of subcarriers must be reduced or the frequency interval must be adjusted.

Accordingly, the block D 390 is generated with subcarriers smaller than the number of subcarriers (1536) of the plurality of blocks 360, 370, and 380 that are previously arranged when the interval of the subcarriers, that is, Δf is 1 KHz. If the number of blocks is 1536, the block D 390 may be generated by narrowing the subcarrier interval of the block D 390, that is, Δf to be less than 1 KHz. However, if the frequency bandwidth of the guardband is equal to or wider than the frequency bandwidth of each block generated within the TV frequency band, the number of subcarriers generating block D is equal to or different from the number of subcarriers included in each block. Can be. In addition, the frequency spacing of the subcarriers generating block D may also be the same as or different from the frequency spacing of the subcarriers generating block D. FIG.

Next, the subcarriers included in the block D 390 are divided. Since the guardbands of the pre-allocated blocks 360, 370, and 380 have different bandwidths and are distributed among the blocks, they are included in the block D 390 to insert subcarriers of the block D 390 in each guardband. Split subcarriers.

Next, the divided subcarriers are inserted into the guard bands 304, 306, 314. That is, the subcarriers of the block D 390 divided according to the bandwidth of the guard band are inserted into the guard bands 304, 306, 314, and 322 between the plurality of blocks 360, 370, and 380 previously allocated. The subcarrier of the block D 390 is inserted into the guard band, and an RF signal as shown in FIG. 3A is generated through the high output Amp. The RF signal is an RF signal for digital broadcasting, and the subcarriers of the block D 390 can be inserted into the guard bands 304, 306, 314, and 322 at a frequency at which the subcarriers are orthogonal to each other according to the characteristics of OFDM. Because it is configured.

In addition, the above-described block D 390 is for transmitting a newly added additional service stream, and a plurality of pre-allocated blocks 360, 370, and 380 have been described for transmitting an existing T-DMB service stream. . However, the present invention is not limited thereto, and the additional service stream may be transmitted through one or more blocks among the plurality of blocks 360, 370, and 380 previously allocated.

4 is a view for explaining a method of generating an RF signal according to an embodiment of the present invention. In FIG. 4, an RF signal transmission apparatus is described as an embodiment of a method of generating an RF signal by inserting a subcarrier in addition to only a guard band. To describe the RF signal generation method of FIG. 4, reference is made to FIG.

In operation S410, the apparatus for transmitting an RF signal generates a first subcarrier block using a subcarrier including a first symbol. The number of subcarriers of the first subcarrier block is determined by the frequency bandwidth of the entire guard band and may be different from the number of subcarriers of the second subcarrier block. In order to maintain the same number of subcarriers as the second subcarrier block, the subcarrier frequency interval of the first subcarrier block must be adjusted. In the case of terrestrial DMB, a number of subcarriers different from the number of subcarriers included in the second subcarrier block is used to generate the first subcarrier block, or the frequency of the subcarriers included in the second subcarrier block. Frequency carriers other than the interval, i.e., narrower subcarriers, may be used.

In operation S420, the RF signal transmission apparatus divides the subcarrier included in the first subcarrier block. The subcarriers included in the first subcarrier block may be divided according to bandwidths of guard bands between the plurality of second subcarrier blocks.

In operation S430, the apparatus for transmitting an RF signal inserts a subcarrier partitioned from the first subcarrier block into a plurality of second subcarrier interblock guardbands that are previously arranged to generate an RF signal. Here, the second subcarrier block is generated using a subcarrier including the second symbol. The RF signal may be an RF signal for digital broadcasting.

5 is a view for explaining the concept of the RF signal generation method according to an embodiment of the present invention. In FIG. 5, a method in which a plurality of blocks are generated without a guard band in the 6 MHz frequency band 502 and a block D 590 is inserted into the remaining frequency band 550 to generate an RF signal is described as an embodiment.

Block D 590 is generated using the subcarriers. Block D 590 is not for transmitting an existing T-DMB service stream, but for transmitting a newly added additional service stream.

To generate block D 590 using subcarriers, equal to or different from the number of subcarriers included in a plurality of blocks 560, 570, and 580 pre-arranged without guardbands in the preset frequency band 502. A number of subcarriers may be used, or subcarriers of a frequency interval equal to or different from that of the subcarriers included in the plurality of blocks 560, 570, and 580 may be used. In the terrestrial DMB using the 6 MHz frequency band, the frequency band (1.392 MHz) of the guard band into which the block D (590) is to be inserted is the frequency bandwidth of each block (560, 570, 580) generated without the guard band in the 6 MHz TV frequency band. 1.536 MHz).

Accordingly, the block D 590 is generated with a subcarrier frequency different from the number of subcarriers (1536) of the plurality of pre-arranged blocks 560, 570, and 580 when Δf is 1 KHz. If the number of subcarriers is 1536 equal to the number of subcarriers of the pre-arranged blocks 560, 570, and 580, block D 590 is made smaller by subcarrier spacing of block D 590, that is, Δf is smaller than 1 KHz. Can be generated.

Next, a plurality of blocks 560, 570, 580 for transmitting the existing T-DMB service stream in the 6 MHz frequency band 502 are created without guardband. Since the plurality of blocks 560, 570, and 580 are generated without the guardband, the block D 590 may be used for the frequency bandwidth occupied by the previous guardband in the 6 MHz TV frequency band 502.

In addition, the above-described block D 590 is for transmitting a newly added additional service stream, and a plurality of pre-allocated blocks 560, 570, and 580 are described for transmitting an existing T-DMB service stream. . However, the present invention is not limited thereto, and the additional service stream may be transmitted through one or more blocks among the plurality of blocks 560, 570, and 580 previously allocated.

Next, blocks 560, 570, and 580 in the frequency band (1.392 MHz = 6 MHz-1.536 MHz * 3: 550) except for the frequency band in which the plurality of blocks 560, 570, and 580 are disposed without the guard band in the 6 MHz TV frequency band 502. D 590 is inserted. Then, an RF signal as shown in FIG. 5 (a) is generated through the high output amplifier Amp. The RF signal is an RF signal for digital broadcasting, in which a plurality of blocks 560, 570, and 580 are generated without a guard band in a preset frequency band, except for a frequency band in which a plurality of second subcarrier blocks are disposed. The block D 690 can be inserted at 550 because the subcarriers are configured to be orthogonal to each other according to the characteristics of the OFDM.

Therefore, the RF signal receiving apparatus can receive and demodulate the RF signal in units of blocks.

6 is a view for explaining a method of generating an RF signal according to an embodiment of the present invention. In FIG. 6, a method in which an RF signal transmission apparatus arranges a plurality of blocks without a guardband and inserts blocks to generate an RF signal is described as an embodiment. Reference will be made to FIG. 5 to describe the RF signal generation method of FIG. 6.

In operation S610, the RF signal transmission apparatus generates a first subcarrier block using a subcarrier including a first symbol. In order to generate the first subcarrier block, a subcarrier equal to or different from the number of subcarriers included in the second subcarrier block is used, or a frequency interval of the subcarriers included in the second subcarrier block is used. Subcarriers of the same or different frequency intervals may be used.

In operation S620, the RF signal transmission apparatus generates a plurality of second subcarrier blocks without guardband. Here, the second subcarrier block is generated using a subcarrier including the second symbol.

In operation S630, the apparatus for transmitting an RF signal inserts the first subcarrier block into the remaining frequency band except for the frequency band in which the plurality of second subcarrier blocks are disposed in the preset frequency band. The RF signal may be an RF signal for digital broadcasting.

7 is a diagram illustrating an RF signal transmission apparatus 700 according to an embodiment of the present invention. 8 and 9 will be described to explain the RF signal transmitting apparatus 700 of FIG. The RF signal transmitting apparatus 700 of FIG. 7 corresponds to the RF signal transmitting apparatus described with reference to FIG. 4.

As shown in FIG. 7, the RF signal transmitting apparatus 700 according to the present invention includes a first differential modulator 710, a second differential modulator 720, a distribution unit 730, and a frequency multiplexer 740. It includes.

The first differential modulator 710 generates a first symbol by performing differential modulation on the received first service stream.

The second differential modulation unit 720 generates a second symbol by performing differential modulation on the received second service stream.

The first differential modulator 710 generates the same or different number of first symbols as the number of second symbols generated by the second differential modulator 720 or is generated by the second differential modulator 720. A first symbol having a frequency interval equal to or different from that of the second symbol may be generated. This is because the frequency bandwidth of the guardband may be the same as or different from the frequency bandwidth of the pre-located block.

In the current terrestrial DMB service that is already allocated and being serviced, the RF signal transmitting apparatus 700 transmits an RF signal by adding one block 390 to three existing blocks 360, 370, and 380 and transmits an RF signal. Four types of service streams are input to generate a subcarrier signal of the subcarrier.

Three of the four types of service streams are the existing T-DMB service streams 801, 803, and 805, and the other one is the additional service stream 807 newly added in the present invention. That is, the first differential modulator 710 receives the newly added additional service stream 807 to generate a first symbol, and the second differential modulator 720 receives the existing service stream 801 to generate the first symbol. Create 2 symbols. Here, the existing T-DMB service stream is a bit-stream encoded and multiplexed for various T-DMB services, and conforms to the T-DMB standard and the Eureka-147 DAB (ETSI EN 300 401 V1.4.1) standard. It is produced by the multiplexing structure accordingly. The newly added additional service stream 807 may be defined by the existing multiplexing structure or newly defined.

A second energy spreading scrambler 802, a convolutional encoder 812, a second time interleaver 822, a second symbol mapper 832, and a second frequency interleaver for processing one T-DMB service stream 801 ( 842), the second differential modulator 720 may follow the method described in Sections 10 to 14 of the Eureka-147 DAB (ETSI EN 300 401 V1.4.1) standard. Existing T-DMB service streams 803 and 805 may also be processed according to the same method.

A first energy spreading scrambler 808, an internal encoder 818, a first time interleaver 828, a first symbol mapper 838, a first frequency interleaver 848, The primary modulation unit 710 may be implemented in the same manner as processing three T-DMB service streams 801, 803, and 805 for ease of system implementation or newly defined to increase transmission efficiency.

The distribution unit 730 divides the first symbol generated by the first differential modulator 710.

The frequency multiplexer 740 inserts the first symbols divided by the distribution unit 730 at both ends of the second symbol to multiplex the first symbol and the second symbol. That is, the distribution unit 730 divides the first symbol generated by the first differential modulator 710, and the frequency multiplexer 740 divides the first subdivided into a plurality of second subcarrier inter-block guard bands. The first symbol and the second symbol are multiplexed to obtain the effect of inserting the subcarriers of the carrier block. Through this, a new additional service stream 807 may be added. Here, the second subcarrier block is generated using a subcarrier including the second symbol.

The second symbols generated by the second differential modulator 720 are first symbols generated by the first differential modulator 710 for additional service, that is, symbols to be inserted into a plurality of pre-allocated guardbands. After multiplexing in the over-frequency multiplexing unit 740, as shown in FIG. 9, symbols generated in the PRS generator 912 and the null symbol generator 914 are multiplexed in the multiplexing unit 916 to generate a transmission frame. Configure.

At this time, the PRS generator 912, the null symbol generator 914, and the transmission frame comply with the conventional Eureka-147 DAB standard. Here, the subcarriers by the generated symbols are as shown in FIG.

In addition, the RF signal transmission apparatus 700 may further include a zero padding unit 750, and the zero padding unit 750 inserts zeros at both ends of the symbol multiplexed by the frequency multiplexer 740.

The first symbols generated by the first differential modulator 710 are located at both ends of the second symbol generated by the second differential modulator 720. Accordingly, the zero padding unit 750 undergoes a zero padding process to configure a 2048-pointer IFFT unit, which is different from the conventional method.

That is, in FIG. 9A, the subcarrier 950 for the supplementary service is inserted into the subbands b, 2, 306, 314, and 322 of the left and right guard bands of the blocks of FIG. sub-carriers).

The zero padding unit 750 inserts 256-b / 2 zeros and 960s at both ends of the symbol 952 multiplexed by the frequency multiplexer 740 to form 2048 subcarriers. Here, b is the number of subcarriers to be inserted into a plurality of inter-block guard bands previously allocated in the frequency band of the conventional terrestrial DMB.

In addition, the RF signal transmitting apparatus 700 may further include an I / Q modulator 760, and the I / Q modulator 760 uses a local oscillator 872 of the same source signal. .

By using the local oscillator 872 of the same source signal in the I / Q modulator 760, the subcarriers of each block can be placed on frequency without mutual interference.

That is, the local oscillator 872 supplies oscillation signals of frequencies f1, f2, and f3 for blocks A 360, B 370, and C 380 to each I / Q modulator 760. (See FIG. 3) The local oscillator 872 divides or multiplies from the same source to generate each oscillation signal internally to generate the oscillation signal. Here, the frequencies f1, f2, and f3 correspond to the center frequencies of blocks A 360, B 370, and C 380. The signals I / Q modulated by each center frequency are combined in combiner 862 to produce an RF signal in one TV frequency band 6MHZ.

In addition, the first differential modulator 710 receives a newly added additional service stream 807 to generate a first symbol, and the second differential modulator 720 receives an existing service stream 801. It has been described as creating a second symbol. However, the present invention is not limited thereto, and the second differential modulator 720 may generate a second symbol by receiving a newly added additional service stream.

10 is a diagram illustrating an RF signal transmission apparatus 1000 according to an embodiment of the present invention. Referring to FIG. 11 to describe the RF signal transmitting apparatus 1000 of FIG. 10. The RF signal transmitting apparatus 1000 of FIG. 10 corresponds to the RF signal transmitting apparatus described with reference to FIG. 6.

The RF signal transmitting apparatus 1000 includes a first differential modulator 1010, a second differential modulator 1020, an arrangement unit 1030, and a frequency multiplexer 1040.

The first differential modulator 1010 generates a first symbol by performing differential modulation on the received first service stream.

The second differential modulator 1020 generates a second symbol by performing differential modulation on the received second service stream.

The first differential modulator 1010 generates the same or different number of first symbols as the number of second symbols generated by the second differential modulator 1020, or is generated by the second differential modulator 1020. A first symbol having a frequency interval equal to or different from that of the second symbol may be generated. This is because the frequency bandwidth of the guardband may be the same as or different from the frequency bandwidth of the pre-located block.

In the current terrestrial DMB service that is already allocated and serviced in the 6 MHz TV band, the RF signal transmitting apparatus 1000 transmits an RF signal by adding one block to three existing blocks, and transmits four blocks of subcarrier signals. Four types of service streams 1101, 1103, 1105, and 1107 are input to generate them. Three of the four types of service streams are the existing T-DMB service streams 1101, 1103 and 1105, and the other one is the additional service stream 1107 newly added in the present invention. That is, the first differential modulator 1010 receives the newly added additional service stream 1107 to generate a first symbol, and the second differential modulator 1020 receives the existing service stream 1101 to generate the first symbol. Create 2 symbols.

Here, the T-DMB service streams 1101, 1103, and 1105 are encoded and multiplexed bitstreams for various T-DMB services, and the T-DMB standard and Eureka-147 DAB (ETSI EN 300 401 V1). .4.1) generated by a multiplexing scheme according to the specification. The additional additional service stream 1107 may be newly defined or based on an existing multiplexing structure.

A second energy spreading scrambler 1102, a convolutional encoder 1112, a second time interleaver 1122, a second symbol mapper 1132, and a second frequency interleaver for processing one T-DMB service stream 1101 1142), the second differential modulator 1020 follows the method described in sections 10 to 14 of the Eureka-147 DAB (ETSI EN 300 401 V1.4.1) standard. The other two T-DMB service streams 1103 and 1105 also follow the same method.

A first energy spreading scrambler 1108, an internal encoder 1118, a first time interleaver 1128, a first symbol mapper 1138, a first frequency interleaver 1148, a first to process the supplementary service stream 1107. The primary modulation unit 1010 may be implemented in the same manner as the existing T-DMB service streams 1101, 1103, and 1105 for easy system implementation, or may be newly defined to increase transmission efficiency.

The arranging unit 1030 arranges the plurality of second symbols generated by the plurality of second differential modulation units 1020 without a frequency interval.

The frequency multiplexer 1040 inserts a first symbol into one end of a plurality of second symbols arranged without frequency spacing, and multiplexes the plurality of second symbols and one symbol arranged without frequency spacing. By multiplexing the first symbol and the plurality of second symbols, the first subcarrier block may be inserted into the remaining frequency band except for the frequency band in which the plurality of second subcarrier blocks are arranged in the preset frequency band.

When the frequency interval of the first symbol is set to 1 KHz as the second symbol, a maximum of 1392 (1.392 MHz = 6 MHz-1.536 MHz * 3) first symbols are provided at one end of a plurality of second symbols arranged without a frequency interval. Can be inserted.

In addition, when the frequency interval of the first symbol is narrower than 1 KHz, the first differential modulator 1010 may generate 1536 symbols, as in the second symbol generated by the second differential modulator 1020, and 1536 symbols. The symbol may be inserted into the remaining frequency bands except for the frequency band in which blocks A, B, and C are arranged within the 6 MHz TV frequency band (see FIG. 5).

In addition, the RF signal transmitting apparatus 1000 may further include a zero padding unit 1050, and the zero padding unit 1050 inserts zeros at both ends of the multiplexed symbol in the frequency multiplexer 1040.

As shown in FIG. 12, the zero padding unit 1050 combines subcarriers to convert four block signals into one OFDM symbol by inserting zeros at both ends of the multiplexed symbol in the frequency multiplexer 1040. do. The combined subcarriers are 4X2048, and the IFFT unit 1162 undergoes a 4X2048-pointer IFFT process and a guard interval insertion 1172 process. Here, the number c of zeros inserted to the left and right of one OFDM symbol is 4X2048- (1536 * 3 + 1392) = 4X2048-6000 = 2192 in the case of terrestrial DMB. As a result, zero padding is necessary for transmitting an OFDM signal IFFT with an 8K size and a sampling frequency of 1 KHz in a 6 MHz band.

The number of zeros above is a case where the frequency interval of the first symbol is 1 KHz, and the number of zeros may vary according to the frequency interval of the first symbol.

The I / Q modulator 1182 up-converts the guard interval insertion processed signals using a local oscillator (not shown) corresponding to the center frequency of the pre-allocated 6 MHz frequency band. Through this, an RF signal of a TV frequency band 6MHZ for digital broadcasting can be generated.

In addition, the first differential modulator 1010 receives the newly added additional service stream 1107 to generate a first symbol, and the second differential modulator 1020 receives the existing service stream 1101. It has been described as creating a second symbol. However, the present invention is not limited thereto, and the second differential modulator 1020 may generate a second symbol by receiving a newly added additional service stream.

FIG. 13 is a diagram illustrating an RF signal receiving apparatus 1300 according to an embodiment of the present invention. 14 to 16, the RF signal receiving apparatus 1300 of FIG.

The RF signal receiving apparatus 1300 includes a frequency redistributor 1310 and a differential demodulator 1320. Hereinafter, the differential demodulation unit 1320 is referred to as a first differential demodulation unit 1320.

As illustrated in FIG. 16, an example of receiving an RF signal transmitted by the RF signal transmitting apparatus 700 of FIG. 7 using an RF filter of a 6 MHz band for high-definition service will be described. The processor 1610 performs signal processing such as filtering, intermediate frequency (IF) conversion, and A / D conversion using a 6MHz RF filter.

The fast Fourier transform unit 1620 performs an FFT of a 4 × 2048 (N = 4) pointer. In this case, since the RF signal transmitting apparatus 700 of FIG. 7 arranges 3X2048 subcarriers in the RF transmission signal, oversampling is required before performing the FFT of the 4X2048 (N = 4) pointer so that the subcarriers are 4X2048.

The frequency redistribution unit 1310 may include guard bands 1404 and 1406 between the plurality of second subcarrier blocks 1460, 1470, and 1480 and the second subcarrier blocks 1460, 1470, and 1480 in a preset frequency band. The symbols for the first subcarrier block 1490 are extracted from the symbols including the first subcarrier block 1490 inserted into the subcarriers 1414 and 1422. In addition, the frequency redistribution unit 1310 may extract not only a symbol for the first subcarrier block but also a symbol for the second subcarrier block. In the preset frequency band, since the second subcarrier blocks 1460, 1470, and 1480 and the first subcarrier block 1490 are composed of symbols, the frequency redistributor 1310 may extract a symbol for each block.

The first differential demodulator 1320 demodulates a symbol for the first subcarrier block 1490 extracted by the frequency redistributor 1310. That is, the reverse process of FIG. 9 is performed to output the symbols for the block A 1460 and the block D 1490 to the second differential demodulator 1621 and the first differential demodulator 1320 for each OFDM symbol. Second differential demodulation unit 1621, second frequency deinterleaver 1631, second symbol demapper 1641, second time deinterleaver 1651, convolutional decoder 1661, second energy diffusion scrambler 1671 And the like are the same as the conventional RF signal receiving apparatus according to the Eureka-147 DAB standard. The symbols for block B 1470 and block C 1480 are also performed in the same manner as the symbols for block A 1460 described above.

A first differential demodulator 1320, a first frequency deinterleaver 1634, a first symbol demapper 1622, a first time deinterleaver 1652, an internal decoder 1662, a first energy diffusion scrambler 1672. Performs the reverse process of the RF signal transmission apparatus (Fig. 8).

Accordingly, T-DMB service streams 1606, 1616, and 1626 and additional service streams 1636 are respectively generated and sent to higher-level modules for multimedia services such as an AV encoder or a data encoder. In addition, the service stream generated by the second differential demodulation unit 1621 is not limited to the T-DMB service stream but includes an additional service stream.

15 is a view for explaining a service using the RF signal received by the RF signal receiving apparatus 1300 according to an embodiment of the present invention. That is, in FIG. 15A, after filtering the RF signal using the same RF reception filter 1512 as the conventional terrestrial DMB, 1536 subcarriers are separated. This is due to orthogonal subcarrier frequency characteristics, and the extracted signal and data rate are the same as the conventional terrestrial DMB, and thus can basically provide a QVGA-class AV service.

15 (b) corresponds to a case where a subcarrier 1542 of a guard band adjacent to one block 1507 is utilized, and the RF signal is filtered through an RF filter 1532 of 1.536 MHz or more (1.536 + b). do. The frequency redistributor 1310 extracts symbols of a block inserted into the guardband region from a symbol including one block and a block inserted into an adjacent guardband region, and the first differential demodulator 1320 is a frequency redistributor. The symbols extracted at 1310 are demodulated. Through this, in addition to the services that can be provided by the conventional terrestrial DMB, it is possible to provide additional services through the guard band.

15 (c) is for providing a high quality AV service and providing a service using all 6 MHz frequency channels.

First, all the blocks are simultaneously received through the 6 MHz filter 1556, and the frequency redistribution 1310 is inserted into the guardband region, that is, the symbols of the block D 1560 are extracted, and the first differential demodulator 1320 is performed. In the present invention, an AV service of HD level may be provided by demodulating the symbols of the block D inserted in the guardband region.

In some cases, the provision of a QVGA class AV service from one block (block B 1507) and an SD class AV service or 3DTV service is provided from two blocks (block B 1507 and block D 1560). It is also possible.

17 is a diagram illustrating an RF signal receiving apparatus 1700 according to an embodiment of the present invention. Reference will be made to FIG. 18 to describe the RF signal receiving apparatus 1700 of FIG.

The RF signal receiving apparatus 1700 includes a frequency redistributor 1710 and a differential demodulator 1720. Hereinafter, the differential demodulation unit 1720 is called a first differential demodulation unit 1720.

As shown in FIG. 18, the RF signal processor 1810 performs signal processing such as filtering, intermediate frequency (IF) conversion, and A / D conversion using a 6 MHz RF filter.

The fast Fourier transform unit 1820 performs an FFT of the 4 × 2048 (N = 4) pointer.

The frequency redistribution unit 1710 includes a plurality of second subcarrier blocks disposed without a guard band in a preset frequency band and a first subcarrier block inserted into the remaining frequency bands of the frequency band in which the second subcarrier blocks are disposed. From the symbol, the symbol for the first subcarrier block is extracted. In addition, the frequency redistributor 1710 may extract not only a symbol for the first subcarrier block but also a symbol for the second subcarrier block.

That is, the inverse process of FIG. 12 is performed to transmit signals of four blocks (block A, block B, block C, and block D) to the second differential demodulator 1721 and the first differential demodulator 1720 for every OFDM symbol. Output

The first differential demodulator 1720 demodulates a symbol of the first subcarrier block extracted by the frequency redistributor 1710.

Second differential demodulator 1821, second frequency deinterleaver 1831, second symbol demapper 1841, second time deinterleaver 1851, convolutional decoder 1881, second energy diffusion scrambler 1871 And the like are the same as the conventional RF signal receiving apparatus according to the Eureka-147 DAB standard.

A first differential demodulator 1720, a first frequency deinterleaver 1832, a first symbol demapper 1842, a first time deinterleaver 1852, an internal decoder 1862, and a first energy diffusion scrambler 1872. Performs the reverse process of the RF signal transmission apparatus (Fig. 11).

Accordingly, T-DMB service trims 1606, 1616, and 1626 and additional service streams 1636 are finally generated and sent to higher-level modules for multimedia services such as an AV encoder or a data encoder, respectively. In addition, the service stream generated by the second differential demodulation unit 1821 is not limited to the T-DMB service stream but includes an additional service stream.

On the other hand, when the RF signal is transmitted to the RF signal transmitting apparatus 700 of Figure 7, the existing terminal may provide a service by receiving each block signal with an RF channel filter having the same center frequency as in the prior art.

However, when the RF signal is transmitted to the RF signal transmitting apparatus 1000 of FIG. 10, each block signal is received by an RF channel filter having a separately set center frequency to provide a service.

The present invention includes a method for providing next-generation mobile broadcasting services while ensuring backward compatibility with terrestrial DMB. Here, the next generation mobile broadcast refers to an evolved type of mobile broadcast provided by a more advanced broadcasting technology than the terrestrial DMB. Specifically, when generating and transmitting RF signals as shown in FIGS. 3 and 5, the conventionally released terrestrial DMB terminals can receive at least one block, and at the same time, a new receiver equipped with the next generation mobile broadcasting function Blocks may be received. As an example of this, blocks A 801 and 1101 in Fig. 8 or 11 are conventional terrestrial DMB transmission techniques (second energy spreading scrambler, convolutional encoder, second time interleaver, second symbol mapper, second frequency interleaver, differential). Generated using a modulator). And other blocks (block B, block C, block D) are new transmission technologies (first energy spreading scrambler, internal encoder, first time interleaver, first symbol mapper, first frequency) which are standardized in next generation mobile broadcasting technology. Interleaver, etc.).

Therefore, the conventional terrestrial DMB receiver will be able to receive only block A, and a terminal equipped with the next-generation mobile broadcasting function can receive all blocks, thereby providing a much wider variety of high quality mobile broadcasting services. Step by step, if the receivers possessed by users are changed to terminals equipped with next-generation mobile broadcasting functions, block A also generates and transmits signals using new transmission technologies like other blocks, thereby achieving the effect of evolving from previous broadcasting to next-generation mobile broadcasting. Can be.

In addition, although the present invention has been described by means of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains to the spirit and scope of the present invention. Of course, various modifications and variations are possible within the scope of the equivalent.

Claims (20)

delete delete delete delete Generating a first subcarrier block using a subcarrier including a first symbol;
Generating a plurality of second subcarrier blocks without guardband; And
Inserting the first subcarrier block into a remaining frequency band except for a frequency band in which the plurality of second subcarrier blocks are disposed in a preset frequency band;
The second subcarrier block,
An RF signal generation method, which is a subcarrier block generated using a subcarrier including a second symbol.
The method of claim 5,
Generating the first subcarrier block,
And generating the first subcarrier block using a subcarrier equal to or different from the number of subcarriers included in the second subcarrier block.
The method of claim 5,
Generating the first subcarrier block,
And generating the first subcarrier block using subcarriers having a frequency interval equal to or different from that of the subcarriers included in the second subcarrier block.
The method of claim 5,
The RF signal generation method,
An RF signal generation method for generating an RF signal for digital broadcasting.
A first differential modulation unit for generating a first symbol by performing differential modulation on the received first service stream;
A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream;
A distribution unit dividing the first symbol; And
A frequency multiplexer which inserts the divided first symbols at both ends of the second symbol and multiplexes the inserted first symbol and the second symbol;
RF signal transmission apparatus comprising a. 10. The method of claim 9,
The first differential modulator,
And generating the first symbol having a number equal to or different from the number of the second symbols generated by the second differential modulator.
10. The method of claim 9,
The first differential modulator,
And generating the first symbol having a frequency interval equal to or different from that of the second symbol generated by the second differential modulator.
10. The method of claim 9,
A zero padding unit inserting zeros at both ends of a symbol multiplexed in the frequency multiplexer
RF signal transmission device further comprising.
A first differential modulation unit configured to generate a first symbol by performing differential modulation on the received first service stream;
A second differential modulation unit for generating a second symbol by performing differential modulation on the received second service stream;
An arrangement unit for disposing a plurality of second symbols generated by the plurality of second differential modulation units without a frequency interval; And
A frequency multiplexer which inserts the first symbol into one end of the plurality of second symbols disposed without the frequency interval, and multiplexes the inserted first symbol with the plurality of second symbols disposed without the frequency interval;
RF signal transmission apparatus comprising a.
The method of claim 13,
The first differential modulator,
And generating the first symbol having a number equal to or different from the number of the second symbols generated by the second differential modulator.
The method of claim 13,
The first differential modulator,
And generating the first symbol having a frequency interval equal to or different from that of the second symbol generated by the second differential modulator.
The method of claim 13,
A zero padding unit inserting zeros at both ends of a symbol multiplexed by the frequency multiplexer
RF signal transmission device further comprising.
The method according to claim 9 or 13,
The RF signal transmission device,
An RF signal transmitting apparatus for transmitting an RF signal for digital broadcasting.
A frequency redistribution unit configured to extract a symbol for the first subcarrier block from a symbol including a plurality of second subcarrier blocks and a first subcarrier block inserted into the guard band between the second subcarrier blocks; And
A differential demodulator for demodulating the symbols for the extracted first subcarrier blocks
RF signal receiving apparatus comprising a.
In a symbol including a plurality of second subcarrier blocks arranged without a guard band and a first subcarrier block inserted into a remaining frequency band of a frequency band in which the second subcarrier block is disposed, A frequency redistribution unit for extracting symbols for one subcarrier block; And
A differential demodulator for demodulating the symbols for the extracted first subcarrier blocks
RF signal receiving apparatus comprising a.
20. The method according to claim 18 or 19,
The RF signal receiving device,
RF signal receiving apparatus for receiving an RF signal for digital broadcasting.

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