CN1228976C - Digital broadcasting system transmitter and method - Google Patents
Digital broadcasting system transmitter and method Download PDFInfo
- Publication number
- CN1228976C CN1228976C CN 03123479 CN03123479A CN1228976C CN 1228976 C CN1228976 C CN 1228976C CN 03123479 CN03123479 CN 03123479 CN 03123479 A CN03123479 A CN 03123479A CN 1228976 C CN1228976 C CN 1228976C
- Authority
- CN
- China
- Prior art keywords
- interleaver
- data
- symbol
- address
- dispensing device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
A transmission device of a digital broadcasting system having an inner interleaver with improved randomized properties is provided to modulate ECC-data of an inner interleaver into digital data by a modulator portion, and to transmit the modulated data, then to repeatedly interleave entire OFDM symbols by using interleaver patterns, thereby improving randomized properties. A symbol interleaver(33) comprises as follows. The first to fourth switches(331,332,333,334) perform switching operations by a predetermined control signal. The first and second memories(335,336) read/write a stream of inputted OFDM symbol units. An address generator(337) has LUTs(Look Up Tables) having interleaving addresses. A controller(338) controls an operation of the symbol interleaver(33) by corresponding to the LUTs.
Description
Technical field
The present invention relates to a kind of dispensing device and method of digit broadcasting system, more specifically, relate to the digit broadcasting system and the method for the randomness that can improve interleaver.
Background technology
Compare with analog broadcasting, digital encoding system is used in digital broadcasting, has the advantage of system synthesis and interactive operation.Therefore, by means of computer and network, the requirement that so-called medium are concentrated the center has been satisfied in digital broadcasting.In addition, the also more unidirectional analog broadcasting of the interactive features of digital broadcasting has obtained great progress.
In order to guarantee the comprehensive and interactive operation of digital broadcasting, at first, need the introducing standard.At present, the sending method of the Digital Terrestrial Television Broadcast of recommendation has the 8-VSB (residual sideband) of the U.S. and the COFDM (OFDM of coding) in Europe.
Because digital broadcasting needs the compressed signal source sending mass data, so a small amount of mistake that occurs in the passage is appreciable to the influence of whole system.Therefore, must reduce the mistake that occurs in the passage.In order to reduce errors, can increase transmitted power to improve signal to noise ratio (snr).But this can bring the cost that causes such as the height output by big transmitted power and dispensing device to increase and interchannel interference.In order to alleviate these problems, digit broadcasting system uses error correcting code, can not increase transmitted power mistake is carried out error correction.Error correcting code can not increase transmitted power and correct the mistake that occurs in the passage, reduces the possibility that goes wrong in the receiver.
Error correcting code is divided into automatic repeat request (ARQ) and forward error correction (FEC) dual mode substantially.According to ARQ, if detect mistake in receiver, receiver sends the request signal of these data of request repeat to transmitter.Thereby transmitter is retransmitted this data.Because ARQ need allow the backward channel of receiver to transmitter transmission re-send request may signal, so this method is not suitable for using in digital broadcasting.Simultaneously based on FEC, signal is to send with the diacritic that is attached to this signal, thus the mistake that receiver occurs in can sense channel, and correct it with algebraic method.
FEC is divided into block code and convolutional code substantially.Block code carries out Code And Decode by block unit to information, and it comprises Hamming code, BCH code and RS (Rui De-Saloman) sign indicating number.In these sign indicating numbers, the RS sign indicating number is good on range performance, comprises effective Code And Decode algorithm, is therefore used widely in digit broadcasting system.The RS sign indicating number is very outstanding in correcting burst error, because it detects and correct mistake by block unit.
Simultaneously, for convolution code, its carry-out bit is subjected to over the influence of input position and current input position, and it is being effective aspect correction random error.Viterbi decoder is generally used for decode convolutional codes.
Usually, the interleaver according to European DVB-T standard has: the position interleaver is used for step-by-step unit's interleaving data; And symbol interleaver, be used for by the symbolic unit data that the OFDM subcarrier carries that interweave.For example, the symbol interleaver of 2K FFT pattern interweaves by the OFDM symbolic unit (quantity of available symbols) corresponding to the 2K pattern.So, all OFDM symbols are carried out identical interweaving.
Usually, symbol interleaver produces interleaving address in two ways, that is, use question blank (LUT) and use logical circuit of arithmetic.Europe DVB-T standard uses logical circuit of arithmetic to produce predetermined interleaving address usually, and all OFDM symbols are carried out identical interweaving.
Symbol interleaver with same interlace address makes mis-behave at random.Therefore, when frequency selects decline to occur, zero (null) will appear in some zone of frequency in the OFDM of error correction coding symbol.Null range as shown in Figure 1 can cause the data of carrying in producing zero frequency field all to damage.The data of damaging need be corrected by the error correcting code of receiver.But when occurring exceeding the burst error of error correcting capability, receiver can't use error correcting code to carry out error correction.The problem that this has caused receptivity to worsen.
Summary of the invention
Exploitation of the present invention is in order to solve the aforementioned problems in the prior.Therefore, an object of the present invention is to provide a kind of dispensing device and method thereof of digit broadcasting system of the randomness that can improve the symbol interleaver in the interleaver.
Above-mentioned purpose is to realize by the dispensing device that a kind of digit broadcasting system is provided, and described dispensing device comprises: first and second outer encoders, respectively first and second transmission (TS) streams of input are carried out coding; First and second external interleavers, execution interweaves to the first and second outer encoder coded datas respectively; First and second inner encoders are carried out coding to the data that first and second external interleavers interweave respectively; Interleaver comprises: the position interleaver, be used for using the convolutional deinterleaver execute bit to interweave to the first and second inner encoder coded datas, and symbol interleaver, be used to use N group interleaving address contraposition interleaver to carry out a data that interweave and carry out symbol interleaving; And modulating unit, the data that are used for that interleaver is interweaved are carried out digital modulation and are sent this data.
Convolutional deinterleaver has B branch and is used for memory M with the bit location delayed data of pre-determined bit, and B and pre-determined bit are to select to adjust according to the operating environment of transmitting system.
Symbol interleaver comprises: first and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit; Address generator has N group polling table (LUT), is used to use N group LUT to produce N group interleaving address; And controller, be used for the control address generator, make reading of first and second memories carry out according to N group interleaving address with write operation.
In addition, symbol interleaver can comprise: first and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit; N address generator, each has logical circuit of arithmetic, is used to use their logical circuit of arithmetic separately to produce N group interleaving address; Controller is used to control N address generator, makes reading with write operation of first and second memories carry out according to N group interleaving address; And first and second Port Multipliers, be used for one of the N group interleaving address that will produce by N address generator and pass to first and second memories respectively.
N group interleaving address is corresponding to N pattern inserting pilot tone in symbol.
Modulating unit comprises: mapping/OFDM modulator block is used for according to mapping method the data that interleaver interweaves being shone upon, and carries out the OFDM modulation; Pilot tone/system information is inserted piece, is provided for the information of signal Synchronization and passage estimated pilot signal and relevant sending mode to mapping/OFDM modulator block; Piece is inserted in protection (GI) at interval, is used for GI is inserted into from the signal of mapping/OFDM modulator block output; Numeral is used for the signal that has inserted GI is carried out the D/A conversion to simulation (D/A) conversion block; And radio frequency (RF) piece, be used for the conversion of signals through the D/A conversion is become high-frequency signal and sends this signal.
Dispensing device also comprises: first and second scramblers are used for respectively the first and second TS streams being carried out randomization, so that the first and second TS streams after the randomization are provided to first and second outer encoders.
First and second outer encoders are to use Rui De-Saloman (RS) encoder of Rui De-Solomon code.
Dispensing device also comprises second interleaver.Second interleaver comprises: second interleaver is used for the second inner encoder coded data execute bit is interweaved; And second symbol interleaver, be used to use N group interleaving address that second interleaver carried out the data that the position interweaves and carry out symbol interleaving; Wherein said position interleaver is used for the first inner encoder coded data execute bit is interweaved; And described symbol interleaver is used to use N group interleaving address that institute's rheme interleaver is carried out a data that interweave and carries out symbol interleaving.
Above-mentioned purpose is to realize by the sending method that a kind of digit broadcasting system is provided, and described sending method comprises step: (a) respectively transmission (TS) stream of first and second inputs is carried out error correction coding and exported first and second coded datas; (b) execution interweaves to first and second coded datas respectively, and exports first and second interleaving datas; (c) respectively first and second interleaving datas are carried out coding; (d) use convolutional deinterleaver to interweave to carrying out the position from first and second coded datas of step (c); (e) use N group interleaving address that the data that interweave through the position are carried out symbol interleaving; And (f) to carrying out digital modulation and send this data through the data of symbol interleaving.
Step (d) is to use to be had B branch and is used for carrying out with the convolutional deinterleaver of the memory M of the bit location delayed data of pre-determined bit, and B and pre-determined bit are to select to adjust according to the operating environment of transmitting system.
In the step (e), use the N group interleaving address that produces by N group polling table (LUT) data that interweave through the position to be interweaved by symbolic unit.
In the step (e), use the N group interleaving address that produces by N group logical circuit of arithmetic the data that interweave through the position to be interweaved by symbolic unit.
Step (f) comprises step: (f1) shine upon the data of process symbol interleaving and carry out the OFDM modulation by mapping method; (f2) be provided for the information of signal Synchronization and passage estimated pilot signal and relevant sending mode to the data in mapping/OFDM modulation step; (f3) GI is inserted into the signal of from mapping/OFDM modulation step, exporting; (f4) signal that has inserted GI is carried out the D/A conversion; And (f5) will become high-frequency signal and send this signal through the conversion of signals of D/A conversion.
Described sending method also comprises step before in step (a): respectively the first and second TS streams are carried out scrambling.
According to the present invention, the improvement of the randomness of symbol interleaver makes the error correction coding performance more effective.Especially, when the frequency of occurrences in static channel was selected decline, random interleaving was more effective, has improved error-correcting performance thus.
Description of drawings
To the detailed description of the preferred embodiments of the present invention, it is clearer that above-mentioned purpose of the present invention and advantage will become by with reference to the accompanying drawings, wherein:
Fig. 1 is the corrupted data schematic diagram that null range caused that produces in the frequency field of dispensing device of traditional digit broadcasting system;
Fig. 2 is the block diagram of the dispensing device of digit broadcasting system according to the preferred embodiment of the invention;
Fig. 3 is the block diagram according to the dispensing device of the digit broadcasting system of another preferred embodiment of the present invention;
Fig. 4 A is the schematic diagram of convolutional deinterleaver of the position interleaver that is used as Fig. 2 that provides of mode by way of example;
Fig. 4 B equals 2 as B, and M equals the structure chart of 1 o'clock convolutional deinterleaver;
Fig. 5 A and 5B are the more detailed block diagram of symbol interleaver of dispensing device of the digit broadcasting system of Fig. 2;
Fig. 6 shows according to the data of the distribution of the dispensing device of digit broadcasting system (distribution) pattern and the schematic diagram of pilot tone; And
Fig. 7 is the flow chart of method of operation of dispensing device of the digit broadcasting system of Fig. 2.
Embodiment
Hereinafter, will be with reference to the accompanying drawings, describe the preferred embodiments of the present invention in detail.
Fig. 2 is the block diagram according to the dispensing device of the digit broadcasting system of the embodiment of the invention.
With reference to Fig. 2, comprise according to the dispensing device of the digit broadcasting system of this embodiment: first and second scramblers 10 and 11, forward error correction (FEC) unit 40 and modulating unit 50.FEC unit 40 comprises: first and second outer encoders 12 and 22, first and second external interleavers 14 and 24, first and second inner encoders 16 and 26 and interleaver 30.Modulating unit 50 comprises: pilot tone/system information is inserted piece 51, mapping/OFDM modulator block 53, protection (GI) insertion piece 55, digital simulation (D/A) conversion block 57 and radio frequency (RF) piece 59 at interval.
According to this embodiment, the dispensing device of this digit broadcasting system is supported the Delamination Transmission pattern, so the separator (not shown) is divided into high priority (HP) layer and low priority (LP) layer with transport stream (TS stream).A TS stream that sends by the HP layer is input to first scrambler 10, and the 2nd TS stream that sends by the LP layer is input to second scrambler 11.
First and second scramblers 10 and 11 are according to the data value randomization of preassigned pattern with the first and second input TS streams.That is,, can remove the correlation between the input signal by the pseudo-random binary sequence scrambling being become input TS stream.This has prevented owing to send the problem that the system synchronization that causes such as 00000000b or 11111111b during the synchrodata is lost.Reversibly carry out this processing at the receiver place to recover original value.
The 40 pairs of data by first and second scramblers 10 and 11 inputs in FEC unit are carried out coding to be corrected in the mistake that occurs during data send.That is, first and second outer encoders 12 and 22 use the RS encoder to receive from the data of first and second scramblers 10 and 11 outputs, and these data are pressed block unit carry out the RS coding so that error correction.RS coding adds the parity check code that is used for error correction, is same to each other or different to each other by the size of first and second outer encoders 12 and 22 parity check codes that add.
First and second external interleavers 14 and 24 pairs first and second outer encoders 12 and 22 are carried out by each data of module unit coding and are interweaved, and thus, break up potential burst error.First and second inner encoders 16 and 26 use convolution coder that first and second external interleavers 14 and 24 are carried out convolutional encoding by the data of symbol interleaving respectively.
Interweaved once more by interleaver 30 by first and second inner encoders 16 and 26 coded datas.
Interleaver 30 has an interleaver 31 and symbol interleaver 33.
Fig. 3 is the dispensing device of digit broadcasting system according to a further advantageous embodiment of the invention.In Fig. 3, except the first and second interleaver 30-1 and 30-2, remainder is identical with Fig. 2's, omits the explanation of same section at this.
The first interleaver 30-1 comprises first the interleaver 31-1 and the first symbol interleaver 33-1, interweaved once more by the first interleaver 30-1 by first inner encoder, 16 coded datas, first interleaver 31-1 step-by-step carried out and interweaved, and the first symbol interleaver 33-1 interweaves by the symbol execution of carrying in the OFDM subcarrier.
The second interleaver 30-2 comprises second the interleaver 31-2 and the second symbol interleaver 33-2, interweaved once more by the second interleaver 30-2 by second inner encoder, 26 coded datas, second interleaver 31-2 step-by-step carried out and interweaved, and the second symbol interleaver 33-2 interweaves by the symbol execution of carrying in the OFDM subcarrier.
The structure of first and second interleaver 31-1 and 33-2 is identical with the position interleaver 31 of Fig. 2, and the first and second symbol interleaver 33-1 are identical with the symbol interleaver 33 of Fig. 2 with 33-2.
Fig. 4 A is to use the structure chart of the position interleaver 31 of convolutional interleave method.Shown in Fig. 4 A, the convolutional deinterleaver 310 that is adopted is made up of the fifo shift register of B branch and pre-determined bit.
That is, along with the increase of the figure place (size) of branches and fifo shift register, the randomness that interweaves is improved manyly more.The figure place of branches and fifo shift register is represented by B and M respectively.The value of B and M can change by various selections according to the operating environment of system.
With reference to Fig. 4 B, will describe the interleaving process that convolutional deinterleaver 311 is carried out in detail, wherein B equals 2, and M equals 1.
When the data bit that is input to convolutional deinterleaver 311 is ... b
6, b
5, b
4, b
3, b
2, b
1The time, data bit alternately is input to branch 0 and 1.That is, b1 is input to branch 0, and b2 is input to branch 1, and b3 is input to branch 0, and b4 is input to branch 1, and b5 is input to branch 0 etc.Data bit is exported from the same branches of its input.That is, the data bit that is input to branch 0 is exported from branch 0.
The data bit of input ... b
6, b
5, b
4, b
3, b
2, b
1By B=2, the convolutional deinterleaver 311 of M=1 position is such as according to ... b
7, b
4, b
5, b
2, b
3, b
0, b
1Order export b wherein at random
0Be at b
1Shu Ru data bit before.
That is, work as data bit ... b
9, b
7, b
5, b
3, b
1When being input to branch 0, they are just immediately from branch's 0 output, and data bit ... b
10, b
8, b
6, b
4, b
2Postponed 1 and be output by fifo shift register (M).Therefore, along with branches, i.e. the figure place of B, and fifo shift register, i.e. M, increase, the randomness that interweaves is improved.
Because the feature of convolutional deinterleaver, promptly B and M can adjust according to the operating environment of system, therefore can carry out various interlace operations.
Fig. 5 A and 5B show the more detailed block diagram of the symbol interleaver 33 of Fig. 2.
Fig. 5 A shows the block diagram that uses question blank (LUT) to produce the symbol interleaver 33 of interleaving address.
Shown in Fig. 5 A, symbol interleaver 33 comprises: first to fourth switch 331,332,333 and 334, and control it by predetermined control signal and open and close; First and second memories 335 and 336 are used to read and write the OFDM symbolic unit (available data symbol number) of input; Address generator 337 has N group LUT (LUT
0, LUT
1..., LUT
N-1), N group LUT has N group interleaving address; And controller 338, be used for (LUT with N group LUT
0, LUT
1..., LUT
N-1) operation of control character interleaver 33 accordingly.
As shown in Figure 6, in the flow data of input, according to 2K, 4K and 8K FFT pattern, distribute by data available (zero) and pilot data (●), data available (zero) is input to symbol interleaver 33.For example, when the data available symbolic number of 2K FFT pattern was 1512, first and second memories 335 and 336 size (frame number interweaves) were 1512, and correspondingly, the frame number that interweaves of 8K FFT pattern is 6048 (1512 * 4).That is, 33 pairs of data available symbolic units of symbol interleaver are carried out and are interweaved.
For example, under the control of controller 338, when OFDM symbol 2 write first memory 335, second memory 336 read and output OFDM symbol 1, and OFDM symbol 1 is transfused to prior to OFDM symbol 2.When first memory 335 uses LUT
2In the interleaving address that provides when the OFDM symbol of being imported 2 is write, second memory 336 uses LUT
1In the interleaving address that provides read and export the OFDM symbol 1 that in second memory 336, writes.That is, when one of first and second memories 335 and 336 were in reading state, another memory was in write state, thus according to the corresponding LUT of OFDM symbol (LUT for example
1) in the interleaving address that provides, carry out by OFDM symbolic unit (for example symbol 1) and to interweave.
That is, for N group OFDM symbol (symbol 1, symbol 2 ..., symbol N-1), use respectively at N group LUT (LUT
1, LUT
2..., LUT
N-1) in the interleaving address that provides carry out respectively and interweave.For whole OFDM symbols, use N group LUT to repeat and interweave.Therefore, the randomness of symbol interleaving can improve.
Simultaneously, Fig. 5 B is to use N group logical circuit of arithmetic to produce the more detailed block diagram of the symbol interleaver 33 ' of interleaving address.
Symbol interleaver 33 ' comprising: first and second switches 351 and 352, and control it by the control signal of controller 358 and open and close; First and second memories 355 and 356, be used to read and write the OFDM symbolic unit (data available symbolic number) of input, N address generator 357-1,357-2, ..., 357-n, each address generator has the predetermined logical circuit of arithmetic such as shift register, is used for producing respectively N group interleaving address; Controller 358 is used to control N address generator 357-1,357-2 ..., 357-n produces N group interleaving address, and organizes the operation of interleaving address control character interleaver 33 ' corresponding to N; First and second Port Multipliers 353 and 354 are used for by N address generator 357-1,357-2 ..., an address in the N group interleaving address that 357-n produces passes to first and second memories 355 and 356 respectively.
For N group OFDM symbol (symbol 0, symbol 1 ..., symbol N-1), symbol interleaver 33 ' is according at N address generator 357-1,357-2 ..., the N group interleaving address execution that 357-n produces interweaves.For whole OFDM symbols, symbol interleaver 33 ' use N group interleaving address repeats and interweaves.Therefore, the randomness of symbol interleaving improves.
As shown in Figure 6, in common OFDM symbol, there is pattern four kinds of repetitions, that be used to distribute pilot tone (●).Therefore, provide four groups of interleaving address, the interleaving address that making symbol interleaver 33 ' to use provides at identical LUT is carried out the OFDM symbol of identical pilot frequency distribution pattern and is interweaved.That is, according to pilot frequency mode, the address generator 357 of Fig. 5 A only has four LUT (LUT
0, LUT
1, LUT
2, LUT
3) interweave with execution.And, under the situation of the N group logical circuit of arithmetic that uses Fig. 5 B, N address generator 357-1,357-2 ..., 357-n produces four interleaving address under the control of controller 358.
50 pairs of data combine digital modulation that interweaved by the symbol interleaver 33 or 33 ' of improving randomness of modulating unit, this digital modulation is suitable for the sending method of described digit broadcasting system.Fig. 2 mode by way of example shows the modulation based on for example DVB-T that modulating unit 50 is carried out.
The mapping of modulating unit 50/OFDM modulator block 53 will become the symbol such as QPSK (Quadrature Phase Shift Keying), 16-QAM (quadrature amplitude modulation) and 64-QAM from the data map of interleaver 30 outputs, and use IFFT (invert fast fourier transformation) to carry out the OFDM modulation.Before carrying out the OFDM modulation, pilot tone/system information is inserted piece 51 and is inserted the information that is used for signal Synchronization and passage estimated pilot signal and relevant sending mode.GI inserts piece 55 and inserts the protection interval (GI) that prevents intersymbol interference in the multi-path environment (ISI).And 57 pairs of D/A conversion blocks have inserted the conversion of the signal combine digital of GI to simulation (D/A), and RF piece 59 will be amplified to high frequency through the signal of D/A conversion, and by this signal of antenna transmission.
As mentioned above, the interleaving address by predetermined quantity is provided in the symbol interleaver 33 of FEC unit 40 is also carried out different interweaving to the symbol of predetermined quantity, has improved randomness.Therefore, improved the error correction coding performance.
Fig. 7 is the flow chart of the method for operation of dispensing device according to digit broadcasting system of the present invention shown in Figure 2.
With reference to this flow chart, the separator (not shown) is divided into TS stream that sends by high priority (HP) layer and the 2nd TS stream that sends by low priority (LP) layer with the transport stream (TS stream) of input.The one TS stream is input to first scrambler 10, and carries out scrambling by first scrambler 10, and the 2nd TS stream is input to second scrambler 11, and by second scrambler, 11 scramblings (S100).First and second outer encoders 12 and 22 pairs of data from first and second scramblers 10 and 11 scramblings output are pressed block unit and are carried out the RS coding so that error correction (S200).
According to the RS coding, a piece that comprises k incoming symbol is encoded into the piece with n code sign, and wherein n is greater than k.Therefore, added n-k redundant symbol, it is called as Rui De-Saloman parity check code.The quantity of the parity check code that adds by RS coding depends on transmitting system, and for example, the symbol of each 188 byte adds 16 or 20.The data that the RS decoder uses the parity check code inspection to receive.If as check result for detecting mistake, then the position of this RS decoder searches mistake, correct the data of distortion and recover original symbol.Usually, the number of errors of correction be at most add half of parity check number of codes, and can not correct exceed add the mistake of half quantity of parity check number of codes.
First and second external interleavers 14 and 24 pairs first and second outer encoders 12 and 22 are carried out outer interweave (S300) by the block unit coded data.In the method for first and second external interleavers 14 and the 24 various interleaving datas that use, use convolutional deinterleaver usually.Convolutional deinterleaver is written in the symbol of input or position in one-period in the shift register of predetermined quantity one, and reads this shift register in one-period, thus the symbol that interweaves of output.The basic function of interleaver is farthest to break up burst error.
First and second inner encoders 16 and 26 pairs of data from first and second external interleavers 14 and 24 outputs are carried out convolutional encoding (S400).The line of input that convolution code is used for the k position that each is continuous is encoded into n carry-out bit, and should be made up of the convolution of input position and binary pulse response by coding.It is that 7 encoding rates are 1/2 convolution coder that the use of DVB-T transmitting system has limited length.At this, adopt first and second inner encoders 16 of convolution coder and 26 encoding rate to change, for example be 2/3,3/4,5/6 and 7/8.
31 pairs of the interleavers in position of interleaver 30 are from the data execute bits of first and second inner encoders 16 and 26 outputs interweave (S500).After this, the data of position after interweaving by the symbol interleaver 33 shown in Fig. 5 A and 5B or 33 ' by OFDM symbolic unit interweave (S600).
Symbol interleaver 33 has N group LUT (LUT
0, LUT
1..., LUT
N-1), have N group interleaving address respectively, and symbol interleaver 33 is used N group LUT (LUT
0, LUT
1..., LUT
N-1) the OFDM symbol is interweaved.That is, pass through LUT
0OFDM symbol 0 is carried out symbol interleaving ... pass through LUT
N-1N-1 carries out symbol interleaving to the OFDM symbol, passes through LUT
0N carries out symbol interleaving to the OFDM symbol, and passes through LUT
1N+1 carries out symbol interleaving to the OFDM symbol.Symbol interleaver 33 ' has N address generator 357-1,357-2 ... 357-n produces N group interleaving address by the operation of controller 358 by logical circuit of arithmetic, and can obtain the effect identical with symbol interleaver 33.
For example, N group interleaving address adopts be with general OFDM symbol in insert corresponding four interleaving address of four kinds of allocation models of pilot tone.The symbol interleaver 33 that is Fig. 5 A is used four LUT (LUT
0, LUT
1, LUT
2, and LUT
3) or the logical circuit of arithmetic of symbol interleaver 33 ' the control address generator 357 of Fig. 5 B produce four interleaving address.
For by having the data that the interleaver 30 that improves randomness carries out error correction coding, modulating unit 50 is carried out and is suitable for the digital modulation that data send, and sends these data (S700).
Therefore, interweave, can improve the randomness of interleaver by using N interleaver mode to repeat to whole OFDM symbols.Therefore, can improve the error correction coding performance at the receiver place.
According to the present invention, the improvement of the randomness of symbol interleaver makes the error correction coding performance more effective.Especially, when the frequency that occurs in static channel was selected decline, random interleaving was more effective, has improved error-correcting performance thus.
The foregoing description and advantage only are exemplary, are not limited to the present invention.This explanation can easily be applied to the device of other type.Specification of the present invention attempts to describe rather than limit the scope of claims.To those skilled in the art, it is obvious obtaining various deformation, improvement and change.In claims, device adds the statement of function and attempts to cover the structure of the described function of execution as described herein, and is not only structural equivalence, also comprises structure of equal value.
Claims (14)
1. the dispensing device of a digit broadcasting system comprises:
First and second outer encoders are carried out coding to first and second transport stream of input respectively;
First and second external interleavers, execution interweaves to the first and second outer encoder coded datas respectively;
First and second inner encoders are carried out coding to the data that first and second external interleavers interweave respectively;
Interleaver comprises: the position interleaver is used for using the convolutional deinterleaver execute bit to interweave to the first and second inner encoder coded datas; And symbol interleaver, be used to use N group interleaving address contraposition interleaver to carry out a data that interweave and carry out symbol interleaving; And
Modulating unit, the data that are used for that interleaver is interweaved carry out digital modulation and send this data.
2. dispensing device as claimed in claim 1, wherein convolutional deinterleaver has B branch and is used for memory M with the bit location delayed data of pre-determined bit, and B and pre-determined bit are to select to adjust according to the operating environment of transmitting system.
3. dispensing device as claimed in claim 1, wherein symbol interleaver comprises:
First and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit;
Address generator has N group polling table, is used to use N group polling table to produce N group interleaving address; And
Controller is used for the control address generator, makes reading with write operation of first and second memories carry out according to N group interleaving address.
4. dispensing device as claimed in claim 1, wherein symbol interleaver comprises:
First and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit;
N address generator, each has logical circuit of arithmetic, is used to use their logical circuit of arithmetic separately to produce N group interleaving address;
Controller is used to control N address generator, makes reading with write operation of first and second memories carry out according to N group interleaving address, and
First and second Port Multipliers, the N that is used for being produced by N address generator organizes one of interleaving address and passes to first and second memories respectively.
5. as the described dispensing device of any one claim of claim 1 to 4, wherein N group interleaving address is corresponding to N pattern inserting pilot tone in symbol.
6. dispensing device as claimed in claim 1, wherein modulating unit uses OFDM to carry out digital modulation.
7. dispensing device as claimed in claim 6, wherein modulating unit also comprises:
Mapping/OFDM modulator block is used for according to mapping method the data that interleaver interweaves being shone upon, and carries out the OFDM modulation;
Pilot tone/system information is inserted piece, is provided for the information of signal Synchronization and passage estimated pilot signal and relevant sending mode to mapping/OFDM modulator block;
Protection is inserted piece at interval, is used for protection is inserted at interval from the signal of mapping/OFDM modulator block output;
Numeral is used for having inserted protection signal combine digital at interval to analog-converted to the analog-converted piece; And
Radio block is used for and will becomes high-frequency signal and send this signal through the conversion of signals of numeral to analog-converted.
8. dispensing device as claimed in claim 1 also comprises:
First and second scramblers are used for respectively first and second transport stream being carried out randomization, so that first and second transport stream after the randomization are provided to first and second outer encoders.
9. dispensing device as claimed in claim 1, wherein first and second outer encoders are to use the Rui De-solomon encoder of Rui De-Solomon code.
10. dispensing device as claimed in claim 1 also comprises second interleaver, comprising: second interleaver is used for the second inner encoder coded data execute bit is interweaved; And second symbol interleaver, be used to use N group interleaving address that second interleaver carried out the data that the position interweaves and carry out symbol interleaving.
11. dispensing device as claimed in claim 10, wherein said another convolutional deinterleaver have B branch and be used for memory M with the bit location delayed data of pre-determined bit, B and pre-determined bit are to select to adjust according to the operating environment of transmitting system.
12. dispensing device as claimed in claim 10, wherein second symbol interleaver comprises:
First and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit;
Address generator has N group polling table, is used to use N group polling table to produce N group interleaving address; And
Controller is used for the control address generator, makes reading with write operation of first and second memories carry out according to N group interleaving address.
13. as the dispensing device of claim 10, wherein second symbol interleaver comprises:
First and second memories are used for reading and write the data that interweaved by the position interleaver by symbolic unit;
N address generator, each has logical circuit of arithmetic, is used to use their logical circuit of arithmetic separately to produce N group interleaving address;
Controller is used to control N address generator, makes reading with write operation of first and second memories carry out according to N group interleaving address, and
First and second Port Multipliers, the N that is used for being produced by N address generator organizes one of interleaving address and passes to first and second memories respectively.
14. the sending method of a digit broadcasting system comprises step:
(a) respectively the transport stream of first and second inputs is carried out error correction coding and exported first and second coded datas;
(b) execution interweaves to first and second coded datas respectively, and exports first and second interleaving datas;
(c) respectively first and second interleaving datas are carried out coding;
(d) interweave to carrying out the position from first and second coded datas of step (c);
(e) use N group interleaving address that the data that interweave through the position are carried out symbol interleaving; And
(f) data through symbol interleaving are carried out digital modulation and are sent this data,
Wherein: step (d) is to use to be had B branch and is used for carrying out with the convolutional deinterleaver of the memory M of the bit location delayed data of pre-determined bit, and B and pre-determined bit are to select to adjust according to the operating environment of transmitting system.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020020064084A KR100918819B1 (en) | 2002-10-19 | 2002-10-19 | Apparatus and method for transmission of digital broadcasting system which has the inner interleaver of improving structure |
| KR64084/2002 | 2002-10-19 | ||
| KR64083/02 | 2002-10-19 | ||
| KR1020020064083A KR100927144B1 (en) | 2002-10-19 | 2002-10-19 | Apparatus and method for transmission of digital broadcasting system which has the inner interleaver of improving randomization |
| KR64083/2002 | 2002-10-19 | ||
| KR64084/02 | 2002-10-19 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA200510102840XA Division CN1738373A (en) | 2002-10-19 | 2003-05-09 | Digital broadcasting system transmitter and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1491037A CN1491037A (en) | 2004-04-21 |
| CN1228976C true CN1228976C (en) | 2005-11-23 |
Family
ID=34197299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 03123479 Expired - Fee Related CN1228976C (en) | 2002-10-19 | 2003-05-09 | Digital broadcasting system transmitter and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1228976C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100797176B1 (en) * | 2005-10-21 | 2008-01-23 | 삼성전자주식회사 | Digital broadcasting system and method thereof |
-
2003
- 2003-05-09 CN CN 03123479 patent/CN1228976C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1491037A (en) | 2004-04-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8468396B2 (en) | Channel interleaver having a constellation-based block-wise permuation module | |
| RU2216873C2 (en) | Digital signal transmission by orthogonal frequency-division multiplexing | |
| CN1245833C (en) | Transmitter for digital broadcasting system with comprehensive error correcting coding function and method thereof | |
| CN1228975C (en) | Transmitting device and method of digital broadcasting system with improved internal random mechanism | |
| JP2008295057A5 (en) | ||
| CN1280993C (en) | Digital broadcasting apparatus and method with different error correcting codes under communication environment | |
| CN1245835C (en) | Transmitting device and method of digital broadcasting system with improved internal rondam mechanism | |
| CN1271855C (en) | Sending device and method of digital broadcasting system | |
| CN1232117C (en) | Transmitter for digital broadcasting system with comprehensive error correcting coding function and method thereof | |
| CN1263299C (en) | Digital broadcasting system transmitter with assembled error correcting coding function and method thereof | |
| CN1228976C (en) | Digital broadcasting system transmitter and method | |
| CN100420170C (en) | Transmission device with simplified digital broadcasting system and method thereof | |
| CN1245834C (en) | Digital broadcasting transmitter for different error correcting code by communication environment and method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20051123 Termination date: 20170509 |