WO2010041886A2 - Appareil servant à transmettre et à recevoir un signal et procédé de transmission et de réception d'un signal utilisant des qam modifiées - Google Patents

Appareil servant à transmettre et à recevoir un signal et procédé de transmission et de réception d'un signal utilisant des qam modifiées Download PDF

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WO2010041886A2
WO2010041886A2 PCT/KR2009/005764 KR2009005764W WO2010041886A2 WO 2010041886 A2 WO2010041886 A2 WO 2010041886A2 KR 2009005764 W KR2009005764 W KR 2009005764W WO 2010041886 A2 WO2010041886 A2 WO 2010041886A2
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points
data
bits
preamble
constellation
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PCT/KR2009/005764
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WO2010041886A3 (fr
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Woo Suk Ko
Sang Chul Moon
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Lg Electronics Inc.
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/36—Modulator circuits; Transmitter circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits

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  • the present invention provides a method for transmitting and receiving a signal and an apparatus for transmitting and receiving a signal, and more particularly, to a method for transmitting and receiving a signal and an apparatus for transmitting and receiving a signal using modified QAMs (Quadrature Amplitude Modulations).
  • modified QAMs Quadrature Amplitude Modulations
  • the present invention suggests a method for combining a modified QAM using BRGC (Binary Reflected Gray Code) and a non-unifrom QAM, which provides more efficient modulation method and broadcasting and communication method.
  • BRGC Binary Reflected Gray Code
  • a digital television (DTV) system can receive a digital broadcasting signal and provide a variety of supplementary services to users as well as a video signal and an audio signal.
  • Digital Video Broadcasting (DVB)-C2 is the third specification to join DVB's family of second generation transmission systems. Developed in 1994, today DVB-C is deployed in more than 50 million cable tuners worldwide. In line with the other DVB second generation systems, DVB-C2 uses a combination of Low-density parity-check (LDPC) and BCH codes. This powerful Forward Error correction (FEC) provides about 5dB improvement of carrier-to-noise ratio over DVB-C. Appropriate bit-interleaving schemes optimize the overall robustness of the FEC system. Extended by a header, these frames are called Physical Layer Pipes (PLP). One or more of these PLPs are multiplexed into a data slice. Two dimensional interleaving (in the time and frequency domains) is applied to each slice enabling the receiver to eliminate the impact of burst impairments and frequency selective interference such as single frequency ingress.
  • PLP Physical Layer Pipes
  • the present invention is directed to a method for transmitting and receiving a signal and an apparatus for transmitting and receiving a signal that substantially obviate one or more problems due to limitations and disadvantages of the related art.
  • An object of the present invention is to provide a method of transmitting broadcasting signal to a receiver having data for service and preamble data, the method comprising: mapping bits of data into preamble data symbols and bits of data into data symbols; building at least one data slice based on the data symbols; building a signal frame based on the preamble data symbols and the data slice; modulating the signal frame by an Orthogonal Frequency Division Multiplexing (OFDM) method; and transmitting the modulated signal frame, wherein the mapping is performed by a QAM in which the bits of preamble data and bits of data are mapped into points in a constellation which is formed such that average power of the points is minimized while maintaining gray mapping rule.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Another aspect of the present invention provides a method of receiving broadcasting signal, the method comprising; demodulating received signals by use of an Orthogonal Frequency Division Multiplexing(OFDM) method; detecting a signal frame from the demodulated signals, the signal frame comprising preamble symbols and data symbols; demapping the preamble symbols and data symbols into bits for the preamble symbols and bits for the data symbols; and decoding the bits for the preamble symbols by a shortened and a Punctured LDPC(Low Density Parity Check) decoding scheme, wherein the demapping is perforemd based upon a QAM method used during mapping in a corresponding transmitter, and wherein in the QAM method, bits of preamble data and bits of data are mapped into points in a constellation whichis formed such that average power of the points is minimized while maintaining gray mapping rule.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Yet another aspect of the present invention provides a transmitter of transmitting broadcasting signal having data for service and preamble data to a receiver, the transmitter comprising: a mapper configured to map bits of preamble data into preamble data symbols and bits of data into data symbols; a data slice builder configured to build at least one data slice based on the data symbols; a frame builder configured to build a signal frame based on the preamble data symbols and the data slice; a modulator configured to Modulate the signal frame by an Orthogonal Frequency Division Multiplexing (OFDM) method; and a transmission unit configured to transmit the modulated signal frame, wherein the mapper performs mappying based upon a QAM in which the bits of preamble data and bits of data are mapped into points in a constellation which is formed such that average power of the points is minimized while maintaining gray mapping rule.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Yet another aspect of the present invention provides a receiver of receiving broadcasting signal, the receiver comprising: a demodulator configured to demodulate received signals by use of an Orthogonal Frequency Division Multiplexing(OFDM) method; a frame parser configured to obtain a signal frame from the demodulated signals, the signal frame comprising preamble symbols and data symbols, a demapper configured to demap the obtained signal frame into bits for the preamble symbols and bits for the data symbols; and a decoder configured to decode the bits for the preamble symbols by a shortened and punctured LDPC(low density parity check) decoding scheme, wherein the demapper performs the demapping based upon a QAM method used during mapping in a corresponding transmitter, and wherein in the QAM method, bits of preamble data and bits of data are mapped into points in a constellation which is formed such that average power of the points is minimized while maintaining gray mapping rule.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Fig. 1 is an example of 64- Quadrature amplitude modulation (QAM) used in European DVB-T.
  • QAM Quadrature amplitude modulation
  • Fig. 2 is a method of Binary Reflected Gray Code (BRGC).
  • BRGC Binary Reflected Gray Code
  • Fig. 3 is an output close to Gaussian by modifying 64-QAM used in DVB-T.
  • Fig. 4 is Hamming distance between Reflected pair in BRGC.
  • Fig. 5 is characteristics in QAM where Reflected pair exists for each I axis and Q axis.
  • Fig. 6 is a method of modifying QAM using Reflected pair of BRGC.
  • Fig. 7 is an example of modified 64/256/1024/4096-QAM.
  • Figs. 8-9 are an example of modified 64-QAM using Reflected Pair of BRGC.
  • Figs. 10-11 are an example of modified 256-QAM using Reflected Pair of BRGC.
  • Figs. 12-13 are an example of modified 1024-QAM using Reflected Pair of BRGC(0 ⁇ 511).
  • Figs. 14-15 are an example of modified 1024-QAM using Reflected Pair of BRGC(512 ⁇ 1023).
  • Figs. 16-17 are an example of modified 4096-QAM using Reflected Pair of BRGC(0 ⁇ 511).
  • Figs. 18-19 are an example of modified 4096-QAM using Reflected Pair of BRGC(512 ⁇ 1023).
  • Figs. 20-21 are an example of modified 4096-QAM using Reflected Pair of BRGC(1024 ⁇ 1535).
  • Figs. 22-23 are an example of modified 4096-QAM using Reflected Pair of BRGC(1536 ⁇ 2047).
  • Figs. 24-25 are an example of modified 4096-QAM using Reflected Pair of BRGC(2048 ⁇ 2559).
  • Figs. 26-27 are an example of modified 4096-QAM using Reflected Pair of BRGC(2560 ⁇ 3071).
  • Figs. 28-29 are an example of modified 4096-QAM using Reflected Pair of BRGC(3072 ⁇ 3583).
  • Figs. 30-31 are an example of modified 4096-QAM using Reflected Pair of BRGC(3584 ⁇ 4095).
  • Fig. 32 is an example of Bit mapping of Modified-QAM where 256-QAM is modified using BRGC.
  • Fig. 33 is an example of transformation of MQAM into Non-uniform constellation.
  • Fig. 34 is an example of digital transmission system.
  • Fig. 35 is an example of an input processor.
  • Fig. 36 is an information that can be included in Base band (BB).
  • Fig. 37 is an example of BICM.
  • Fig. 38 is an example of applying various constellations.
  • Fig. 39 is another example of cases where compatibility between conventional systems is considered.
  • Fig. 40 is an example of frame builder.
  • Fig. 41 is an example of modulator based on OFDM.
  • Fig. 42 is an example of analog processor.
  • Fig. 43 is an example of digital receiver system.
  • Fig. 44 is an example of analog processor used at receiver.
  • Fig. 45 is an example of demodulator.
  • Fig. 46 is an example of frame parser.
  • Fig. 47 is an example of BICM demodulator.
  • Fig. 48 is an example of output processor.
  • service is indicative of either broadcast contents which can be transmitted/received by the signal transmission/reception apparatus.
  • Quadrature amplitude modulation using Binary Reflected Gray Code (BRGC) is used as modulation in a broadcasting transmission environment where conventional Bit Interleaved Coded Modulation (BICM) is used.
  • BICM Bit Interleaved Coded Modulation
  • Fig. 1 shows an example of 64-QAM used in European DVB-T.
  • BRGC can be made using the method shown in Fig. 2.
  • An n bit BRGC can be made by adding a reverse code of (n-1) bit BRGC (i.e., reflected code) to a back of (n-1) bit, by adding 0s to a front of original (n-1) bit BRGC, and by adding 1s to a front of reflected code.
  • the BRGC code made by this method has a Hamming distance between adjacent codes of one (1).
  • the Hamming distance between a point and the four points which are most closely adjacent to the point is one (1) and the Hamming distance between the point and another four points which are second most closely adjacent to the point, is two (2).
  • Such characteristics of Hamming distances between a specific constellation point and other adjacent points can be dubbed as Gray mapping rule in QAM.
  • AWGN Additive White Gaussian Noise
  • Fig. 3 shows an output close to Gaussian by modifying 64-QAM used in DVB-T.
  • Such constellation can be dubbed as Non-uniform QAM (NU-QAM).
  • Gaussian Cumulative Distribution Function can be used to make a constellation of Non-uniform QAM.
  • QAM can be divided into two independent N-PAM.
  • N-PAM By dividing Gaussian CDF into N sections of identical probability and by allowing a signal point in each section to represent the section, a constellation having Gaussian distribution can be made.
  • coordinate xj of newly defined non-uniform N-PAM can be defined as follows:
  • Fig. 3 is an example of transforming 64QAM of DVB-T into NU-64QAM using the above methods.
  • Fig. 3 represents a result of modifying coordinates of each I axis and Q axis using the above methods and mapping the previous constellation points to newly defined coordinates.
  • Pj is cumulative probability value which makes the distribution of probability close to Gaussian distribution.
  • Xj the coordinate value in the constellation can be obtained from Eq. 1.
  • One embodiment of the present invention can modify QAM using BRGC by using characteristics of BRGC.
  • the Hamming distance between Reflected pair in BRGC is one because it differs only in one bit which is added to the front of each code.
  • Fig. 5 shows the characteristics in QAM where Reflected pair exists for each I axis and Q axis. In this figure, Reflected pair exists on each side of the dotted black line.
  • an average power of a QAM constellation can be lowered while keeping Gray mapping rule in QAM.
  • the minimum Euclidean distance in the constellation can be increased.
  • Fig. 6 shows a method of modifying QAM using Reflected pair of BRGC.
  • Fig. 6a shows a constellation and
  • Fig. 6b shows a flowchart for modifying QAM using Reflected pair of BRGC.
  • a target point which has the highest power among constellation points needs to be found.
  • Candidate points are points where that target point can move and are the closest neighbor points of the target point's reflected pair.
  • an empty point i.e., a point which is not yet taken by other points
  • the power of the target point and the power of a candidate point are compared. If the power of the candidate point is smaller, the target point moves to the candidate point.
  • Fig. 7 shows an example of modified 64/256/1024/4096-QAM.
  • the Gray mapped values correspond to Figs. 8 ⁇ 31 respectively.
  • other types of modified QAM which enables identical power optimization can be realized. This is because a target point can move to multiple candidate points.
  • the suggested modified QAM can be applied to, not only the 64/256/1024/4096-QAM, but also cross QAM, a bigger size QAM, or modulations using other BRGC other than QAM.
  • Fig. 32 shows an example of Bit mapping of Modified-QAM where 256-QAM is modified using BRGC.
  • Fig. 32a and Fig. 32b show mapping of Most Significant Bits (MSB). Points designated as filled circles represent mappings of ones and points designated as blank circles represent mappings of zeros. In a same manner, each bit is mapped as shown in figures from (a) through (h) in Fig. 32, until Least Significant Bits(LSB) are mapped.
  • Modified-QAM can enable bit decision using only I or Q axes as conventional QAM, except for a bit which is next to MSB (Fig. 32c and Fig. 32d).
  • a simple receiver can be made by partially modifying a receiver for QAM.
  • An efficient receiver can be implemented by checking both I and Q values only when determining bit next to MSB and by calculating only I or Q for the rest of bits. This method can be applied to Approximate LLR, Exact LLR, or Hard decision.
  • Non-uniform constellation or NU-MQAM can be made.
  • Pj can be modified to fit MQAM.
  • MQAM two PAMs having I axis and Q axis can be considered.
  • Pj is cumulative probability value which makes the distribution of probability close to Gaussian distribution.
  • xj the coordinate value in the constellation can be obtained from Eq. 2 as follows. Unlike QAM where a number of points corresponding to a value of each PAM axis are identical, the number of points changes in MQAM.
  • the new Pj can be defined considering the total number of points in the constellation and the number of points corresponding to jth value of a PAM(Pulse Amplitude Modulation). And more preferably, the new Pj can be defined as the number of points corresponding to jth value of a PAM divided by the total number of points in the constellation. More preferably, if a number of points that corresponds to jth value of PAM is defined as nj in a MQAM where a total of M constellation points exist, then Pj can be defined as follows:
  • Pj is cumulative probability value
  • xj is coordinate of points
  • M is the total number of points in the constellation
  • nj is the number of points corresponding to jth value of a PAM (Pulse Amplitude Modulation).
  • MQAM can be transformed into Non-uniform constellation.
  • Pj can be defiend as follows for the example of 256-MQAM.
  • Fig. 33 is an example of transformation of MQAM into Non-uniform constellation.
  • the NU-MQAM made using these methods can retain characteristics of MQAM receivers with modified coordinates of each PAM.
  • an efficient receiver can be implemented.
  • a more noise-robust system than the previous NU-QAM can be implemented.
  • hybridizing MQAM and NU-MQAM is possible.
  • a more noise-robust system can be implemented by using MQAM for an environment where an error correction code with high code rate is used and by using NU-MQAM otherwise.
  • a transmitter can let a receiver have information of code rate of an error correction code currently used and a kind of modulation currently used such that the receiver can demodulate according to the modulation currently used.
  • Fig. 34 shows an example of digital transmission system.
  • Inputs can comprise a number of MPEG-TS streams or GSE (General Stream Encapsulation) streams.
  • An input processor module 101 can add transmission parameters to input stream and perform scheduling for a BICM module 102.
  • the BICM module 102 can add redundancy and interleave data for transmission channel error correction.
  • a frame builder 103 can build frames by adding physical layer signaling information and pilots.
  • a modulator 104 can perform modulation on input symbols in efficient methods.
  • An analog processor 105 can perform various processes for converting input digital signals into output analog signals.
  • Fig. 35 shows an example of an input processor.
  • Input MPEG-TS or GSE stream can be transformed by input preprocessor into a total of n streams which will be independently processed.
  • Each of those streams can be either a complete TS frame which includes multiple service components or a minimum TS frame which includes service component (i.e., video or audio).
  • each of those streams can be a GSE stream which transmits either multiple services or a single service.
  • Input interface module 202-1 can allocate a number of input bits equal to the maximum data field capacity of a Baseband (BB) frame. A padding may be inserted to complete the LDPC/BCH code block capacity.
  • the input stream sync module 203-1 can provide a mechanism to regenerate, in the receiver, the clock of the Transport Stream (or packetized Generic Stream), in order to guarantee end-to-end constant bit rates and delay.
  • the input Transport Streams are delayed by delay compensators 204-1 ⁇ n considering interleaving parameters of the data PLPs in a group and the corresponding common PLP.
  • Null packet deleting modules 205-1 ⁇ n can increase transmission efficiency by removing inserted null packet for a case of VBR (variable bit rate) service.
  • Cyclic Redundancy Check (CRC) encoder modules 206-1 ⁇ n can add CRC parity to increase transmission reliability of BB frame.
  • BB header inserting modules 207-1 ⁇ n can add BB frame header at a beginning portion of BB frame. Information that can be included in BB header is shown in Fig. 36.
  • a Merger/slicer module 208 can perform BB frame slicing from each PLP, merging BB frames from multiple PLPs, and scheduling each BB frame within a transmission frame. Therefore, the merger/slicer module 208 can output L1 signaling information which relates to allocation of PLP in frame.
  • a BB scrambler module 209 can randomize input bitstreams to minimize correlation between bits within bitstreams.
  • the modules in shadow in Fig. 35 are modules used when transmission system uses a single PLP, the other modules in Fig. 35 are modules used when the transmission device uses multiple PLPs.
  • Fig. 37 shows an example of BICM module.
  • Fig. 37a shows data path and Fig. 37b shows L1 path of BICM module.
  • An outer coder module 301 and an inner coder module 303 can add redundancy to input bitstreams for error correction.
  • An outer interleaver module 302 and an inner interleaver module 304 can interleave bits to prevent burst error.
  • the Outer interleaver module 302 can be omitted if the BICM is specifically for DVB-C2.
  • a bit demux module 305 can control reliability of each bit output from the inner interleaver module 304.
  • a symbol mapper module 306 can map input bitstreams into symbol streams.
  • the Symbol mapper module 306 can use a proper constellation according to the code rate and constellation capacity.
  • Fig. 38 shows an example of such combinations.
  • Case 1 shows an example of using only NU-MQAM at low code rate such as 1/2, 2/3, 3/4 for simplified system implementation.
  • Case 2 shows an example of using optimized constellation at each code rate and an optimized QAM among several types of QAM can be used for each code rate.
  • the transmitter can send information about the code rate of the error correction code and the constellation capacity to the receiver such that the receiver can use an appropriate constellation.
  • Case 1 has advantages for a simplified system over Case 2 and Case 2 has advantages for a more efficient system over Case 1.
  • Fig. 39 shows another example of cases where compatibility between conventional systems is considered.
  • Fig. 39 it is assumed that 2 bit ⁇ 8 bit configurations have been used in conventional systems and 10 bit and 12 bit systems are newly introduced.
  • conventional QAM can be used for the 2 bit ⁇ 8 bit configurations
  • NU-MQAM or MQAM can be used for the newly introduced 10 bit and 12 bit configurations. That is, NU-QAM or NU-MQAM can be used for new combination of conventional QAM method and newly suggested QAM method can be applied for 10 bit and 12 bit configurations, while maintaining conventional QAM for the conventional 2 bit ⁇ 8 bit configurations.
  • further combinations for optimizing the system are possible.
  • the ModCod Header inserting module 307 shown in Fig. 37 can take Adaptive coding and modulation (ACM)/Variable coding and modulation (VCM) feedback information and add parameter information used in coding and modulation to a FEC block as header.
  • ACM Adaptive coding and modulation
  • VCM Variariable coding and modulation
  • the Modulation type/Coderate (ModCod) header can include the following information:
  • the Symbol interleaver module 308 can perform interleaving in symbol domain to obtain additional interleaving effects. Similar processes performed on data path can be performed on L1 signaling path but with possibly different parameters (301-1 ⁇ 308-1). At this point, a shortened/punctured code module (303-1) can be used for inner code.
  • Fig. 40 shows an example of a frame builder.
  • a frame header inserting module 401 can form a frame from input symbol streams and can add frame header at front of each transmitted frame.
  • the frame header can include the following information:
  • OFDM symbol slicer 402 slices input symbol sequences into symbol units which can be transmitted as an OFDM symbol and outputs the symbols units.
  • Frequency interleaver 403 performs interleaving on OFDM symbols unit by unit to obtain the effect of interleaving in frequency domain.
  • Pilot insert module 404 inserts pilot symbols in order to enable the receiver to estimate the transmission channel.
  • physical layer signalling can be transmitted as two parts. One part is transmitted as BB frame headers including only parameters for ACM/VCM and the other part is transmitted as transmission frame headers to minimize signalling overhead.
  • Fig. 41 shows an example of a modulator based on OFDM.
  • Input symbol streams can be transformed into time domain by IFFT module 501.
  • PAPR peak-to-average power ratio
  • ACE Active constellation extension
  • GI inserting module 503 can copy a last part of effective OFDM symbol to fill guard interval in a form of cyclic prefix.
  • Preamble inserting module 504 can insert preamble at the front of each transmitted frame such that a receiver can detect digital signal, frame and acquire time/freq offset acquisition. At this time, the preamble signal can perform physical layer signaling such as FFT size (3 bits) and Guard interval size (3 bits). The Preamble inserting module 504 can be omitted if the modulator is specifically for DVB-C2.
  • Fig. 42 shows an example of an analog processor.
  • a DAC module 601 can convert digital signal input into analog signal. After transmission frequency bandwidth is up-converted (602) and analog filtered (603) signal can be transmitted.
  • Fig. 43 shows an example of a digital receiver system.
  • Received signal is converted into digital signal at an analog process module r105.
  • a demodulator r104 can convert the signal into data in frequency domain.
  • a frame parser r103 can remove pilots and headers and enable selection of service information that needs to be decoded.
  • a BICM demodulator r102 can correct errors in the transmission channel.
  • An output processor r101 can restore the originally transmitted service stream and timing information.
  • Fig. 44 shows an example of analog processor used at the receiver.
  • a Tuner/AGC module r603 can select desired frequency bandwidth from received signal.
  • a down converting module r602 can restore baseband.
  • An ADC module r601 can convert analog signal into digital signal.
  • Fig. 45 shows an example of demodulator.
  • a frame detecting module r506 can detect the preamble, check if a corresponding digital signal exists, and detect a start of a frame.
  • a time/freq synchronizing module r505 can perform synchronization in time and frequency domains. At this time, for time domain synchronization, a guard interval correlation can be used. For frequency domain synchronization, correlation can be used or offset can be estimated from phase information of a subcarrier that is transmitted in the frequency domain.
  • a preamble removing module r504 can remove preamble from the front of detected frame.
  • a GI removing module r503 can remove guard interval.
  • a FFT module r501 can transform signal in the time domain into signal in the frequency domain.
  • a channel estimation/equalization module r501 can compensate errors by estimating distortion in transmission channel using pilot symbol.
  • the Preamble removing module r504 can be omitted if the demodulator is specifically for DVB-
  • Fig. 46 shows an example of frame parser.
  • a pilot removing module r404 can remove pilot symbol.
  • a freq deinterleaving module r403 can perform deinterleaving in the frequency domain.
  • An OFDM symbol merger r402 can restore data frame from symbol streams transmitted in OFDM symbols.
  • a frame header removing module r401 can extract physical layer signaling from header of each transmitted frame and remove header. Extracted information can be used as parameters for following processes in the receiver.
  • Fig. 47 shows an example of a BICM demodulator.
  • Fig. 47a shows a data path and
  • Fig. 47b shows a L1 signaling path.
  • a symbol deinterleaver r308 can perform deinterleaving in the symbol domain.
  • a ModCod extract r307 can extract ModCod parameters from front of each BB frame and make the parameters available for following adaptive/variable demodulation and decoding processes.
  • a Symbol demapper r306 can demap input symbol streams into bit Log-Likelyhood Ratio (LLR) streams.
  • the Output bit LLR streams can be calculated by using a constellation used in a Symbol mapper 306 of the transmitter as reference point.
  • LLR Log-Likelyhood Ratio
  • the Symbol demapper r306 of the receiver can obtain a constellation using the code rate and constellation capacity information transmitted from the transmitter.
  • the bit mux r305 of the receiver can perform an inverse function of the bit demux 305 of the transmitter.
  • the Inner deinterleaver r304 and outer deinterleaver r302 of the receiver can perform inverse functions of the inner interleaver 304 and outer interleaver 302 of the transmitter, respectively to get the bitstream in its original sequence.
  • the outer deinterleaver r302 can be omitted if the BICM demodulator is specifically for DVB-C2.
  • the inner decoder r303 and outer decoder r301 of the receiver can perform corresponding decoding processes to the inner coder 303 and outer code 301 of the transmitter, respectively, to correct errors in the transmission channel. Similar processes performed on data path can be performed on L1 signaling path, but with different parameters (r308-1 ⁇ r301-1). At this point, as explained in the preamble part, a shortened/punctured code module r303-1 can be used for L1 signal decoding.
  • Fig. 48 shows an example of output processor.
  • a BB descrambler r209 can restore scrambled (209) bit streams at the transmitter.
  • a Splitter r208 can restore BB frames that correspond to multiple PLP that are multiplexed and transmitted from the transmitter according to PLP path.
  • a BB header remover r207-1 ⁇ n can remove the header that is transmitted at the front of the BB frame.
  • a CRC decoder r206-1 ⁇ n can perform CRC decoding and make reliable BB frames available for selection.
  • a Null packet inserting modules r205-1 ⁇ n can restore null packets which were removed for higher transmission efficiency in their original location.
  • a Delay recovering modules r204-1 ⁇ n can restore a delay that exists between each PLP path.
  • An output clock recovering modules r203-1 ⁇ n can restore the original timing of the service stream from timing information transmitted from the input stream synchronization modules 203-1 ⁇ n.
  • An output interface modules r202-1 ⁇ n can restore data in TS/GS packet from input bit streams that are sliced in BB frame.
  • An output postprocess modules r201-1 ⁇ n can restore multiple TS/GS streams into a complete TS/GS stream, if necessary.
  • the shaded blocks shown in Fig. 48 represent modules that can be used when a single PLP is processed at a time and the rest of the blocks represent modules that can be used when multiple PLPs are processed at the same time.
  • ModCod information in each BB frame header that is necessary for ACM/VCM By transmitting ModCod information in each BB frame header that is necessary for ACM/VCM and transmitting the rest of the physical layer signaling in a frame header, signaling overhead can be minimized.
  • Modified QAM for a more energy efficient transmission or a more noise-robust digital broadcasting system can be implemented.
  • the system can include transmitter and receiver for each example disclosed and the combinations thereof.
  • An Improved Non-uniform QAM for a more energy efficient transmission or a more noise-robust digital broadcasting system can be implemented.
  • a method of using code rate of error correction code of NU-MQAM and MQAM is also described.
  • the system can include transmitter and receiver for each example disclosed and the combinations thereof.
  • the suggested L1 signaling method can reduce overhead by 3 ⁇ 4% by minimizing signaling overhead during channel bonding.

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  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

La présente invention concerne un procédé de transmission et de réception d'une signalisation et un appareil correspondant. Un aspect de la présente invention concerne un procédé de réception d'un signal utilisant des QAM (modulations d'amplitude en quadrature) modifiées. La présente invention suggère un procédé servant à combiner une QAM modifiée en utilisant un BRGC (code de Gray/binaire réfléchi) et une QAM non uniforme, ce qui permet d'obtenir un procédé de modulation plus efficace et un procédé de communication et de diffusion.
PCT/KR2009/005764 2008-10-10 2009-10-08 Appareil servant à transmettre et à recevoir un signal et procédé de transmission et de réception d'un signal utilisant des qam modifiées WO2010041886A2 (fr)

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US10427208P 2008-10-10 2008-10-10
US61/104,272 2008-10-10

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WO2010041886A2 true WO2010041886A2 (fr) 2010-04-15
WO2010041886A3 WO2010041886A3 (fr) 2010-07-22

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108336999A (zh) * 2017-12-22 2018-07-27 中国电子科技集团公司第二十二研究所 映射输出值的确定方法、装置、存储介质及电子装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8144800B2 (en) * 2004-09-18 2012-03-27 Broadcom Corporatino Downstream transmitter and cable modem receiver for 1024 QAM
JP4516478B2 (ja) * 2005-05-20 2010-08-04 富士通株式会社 Ｍ−ａｒｙ−ＱＡＭＭＩＭＯ通信システムのための受信装置
US8149925B2 (en) * 2006-03-23 2012-04-03 Intel Corporation Chase algorithm based differential decoder for soft decision Reed Solomon decoding in a QAM system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108336999A (zh) * 2017-12-22 2018-07-27 中国电子科技集团公司第二十二研究所 映射输出值的确定方法、装置、存储介质及电子装置
CN108336999B (zh) * 2017-12-22 2021-08-06 中国电子科技集团公司第二十二研究所 映射输出值的确定方法、装置、存储介质及电子装置

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