Method for decoding ldpc-codes and device for its implementation

FIELD: physics.

SUBSTANCE: method for decoding LDPC-codes, comprising: determining the signal-to-noise ratio for each received signal codeword; and decoding the received signal codewords based on the "trust propagation" algorithm and "based on the "minimum-sum" algorithm, characterized in that decoding is introduced, based on the "posterior probabilities" algorithm, the range of signal-to-noise values is set for each algorithm. The algorithms are switched depending on the signal-to-noise value for each word, followed by the subsequent combining of the results of signal decoding according to different algorithms. The "trust propagation" algorithm is used for signal-to-noise ratio values of less than 1.8 dB, the "minimum-sum" algorithm for the signal-to-noise values in the range of 1.8 dB to 4.95 dB, the algorithm for the "posterior probabilities" with the signal-to-noise ratio to be greater than 4.95 dB.

EFFECT: reducing the average computational complexity of decoding while preserving the decoding quality of the received signal.

3 cl, 1 dwg

 



 

Same patents:

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to data encryption and specifically to encryption of image data organised into bit streams. A layered audiovisual packet data stream (CNT'), such as one obtained by a JPEG2000 encoder (810), is received together with information (metadata) about the contribution of each packet to the reduction of image distortion. The distortion-to-rate ratio for each packet is calculated (710) and the packets are ordered (720) in descending ratio. The non-encrypted packet having the highest ratio is encrypted (730) until the target distortion is obtained.

EFFECT: facilitating adaptation to a different type of applications and minimising the amount of data for encryption, while maximising protection of the encrypted content.

6 cl, 8 dwg

Optical encoder // 2471289

FIELD: physics.

SUBSTANCE: optical encoder, wherein distribution of the transmission coefficient or distribution of the reflection coefficient, provided in scale track on the displacement scale, has a first modulation period and a second modulation period in the direction of displacement of the scale; an array of photodetector elements is intended to detect a first group of signals which includes two phase signals which are antiphase with respect to each other during the first modulation period and a second group of signals which includes two phase signals which are antiphase with respect to each other during the second modulation period, wherein first positional information during the first modulation period is determined from the first group of signals, and second positional information during the second modulation period is determined from the second group of signals, the second modulation period being an odd-multiple of the first modulation period.

EFFECT: reduced error component of the detected waveform and determining positional information with high accuracy.

5 cl, 14 dwg

FIELD: information technology.

SUBSTANCE: asynchronous wavelet-cepstral method of selecting encoded information sent to user using packets of ultra-wideband pulses. The objective of the invention is: a) providing reliable selection of information in form of logic "zeros" and "ones" when sending messages using ultra-wideband pulses in a mode which does not require their synchronisation, with signal-to-noise ratio of not less than 2 dB; b) enabling use of ultra-wideband pulses of arbitrary shape in a code sequence of packets of ultra-wideband pulses by reducing the logarithmic nonlinearity effect in a cepstral processing algorithm.

EFFECT: high reliability of selecting received information through reverse wavelet signal recovery without coefficients which carry information on low-frequency changes in the logarithm of the energy spectrum of the received signal.

21 dwg

FIELD: information technology.

SUBSTANCE: invention relates to a multiple input multiple output (MIMO) communication system and particularly to codebook information in a MIMO communication system. The apparatus for generating a codebook includes a codebook generator. The codebook generator is configured to generate a 4-bit precoding codebook for eight transmitting antennae for use in a closed-loop single-user MIMO (SU-MIMO) scheme. According to aspects of the present invention, it is possible to generate a precoding codebook for use in systems with eight transmitting antennae.

EFFECT: high efficiency of transmitting and receiving data.

9 cl, 13 dwg

FIELD: physics, communications.

SUBSTANCE: invention relates to transmission of a media stream over an error-prone digital video broadcasting - handheld (DVB-H) channel in which media datagrams are labelled according to a priority, packed in a multiprotocol encapsulation section, unequally protected using forward error-correction codes packed into a traffic stream and transmitted into the channel using packets with time-division. A system and a method are proposed for transmitting a multiplexed service stream over a DVB-H channel. Media IP packets are priority labelled. For each packet with time division, the IP packets are grouped based upon the priority labels. Multi protocol encapsulation - forward error correction (MPE-FEC) matrices are made for different priority labels in each packet with time division. Reed-Solomon code data table (RSDT) columns are computed such that the average service bit rate does not overshoot the maximum allowed bit rate, and protection increases with priority. The application data table (ADT) and RSDT of the MPE-FEC matrices are then encapsulated into MPE-FEC sections.

EFFECT: shorter start delay during reception of an unequally protected priority service bit stream.

21 cl, 10 dwg

FIELD: radio engineering.

SUBSTANCE: invention relates to electric communication and may be used in discrete data transmission systems. According to the invention, the method provides for generating data encoded with jam-proof short concatenated code or long concatenated code on the transmitting side. The decoding starts from the data encoded with an internal code of the long jam-proof concatenated code. In the place of internal code words that are not transmitted for the data encoded by the short jam-proof concatenated code, the blocked length of the accepted concatenated code is more precisely defined in the channel by comparing with known sequences taking into account data distortions, when phased and numbering sequences are removed during data reading from storage device. Based on the results of more qualitative words selection in the internal code, the optimal algorithm of the external code decoding is selected.

EFFECT: improved data reliability when working in real channels.

FIELD: information technology.

SUBSTANCE: proposal is given of a device for transmitting data bits after coding data bits using a LDPC, with unequal values of error probability in a mobile communications system, carries out channel coding and transmits the data bits. The device consists of: a LDPC coder for converting high data bits to low variable nodes and low data bits to high variable nodes. The high data bits have higher priority, and low data bits have low priority. Low variable nodes are variable nodes with low error probability values, and high variable nodes are variable nodes with high error probability values on the graph of coefficients of LDPC codes.

EFFECT: design of a device and method of transmitting bits by application of various error probability values to the transmitted bits through use of unequal codes of sparse even-parity check.

36 cl, 9 dwg

FIELD: electrical communications; digital data transfer systems for decoding noise-immune variable-length concatenated code.

SUBSTANCE: proposed decoding device for noise-immune variable-length concatenated code has buffer memory and frame synchronization unit; their inputs are integrated to function as information input of device; outputs of buffer memory and frame synchronization unit are connected to internal-code decoder whose output is connected to external-code decoder; output of the latter functions as information output of device; newly introduced in device are time interval shaper, code word counter, and analysis unit; synchronization input of device is connected to input of time interval shaper whose control input is connected to output of frame synchronization unit; output of time interval shaper is coupled with inputs of code word counter and analysis unit whose other input is connected to output of code word counter whose synchronization input is coupled with internal-code decoder; output of analysis unit is connected to external-code decoder.

EFFECT: enhanced noise immunity of decoding device.

1 cl, 1 dwg

FIELD: engineering of data encoding systems.

SUBSTANCE: in accordance to method, signal is originally encoded for production of a flow of encoded data, while in the flow of encoded data information about importance of source is included, containing recommended speeds of protection of appropriate parts of flow of encoded data, while channel encoded may receive information about importance of source from the flow of encoded data, providing an advantage in case of presence of intermediate network levels, while a flow of encoded data contains appropriate packets, and information about importance of source is included in appropriate headers, connected to appropriate packets, given header pointing out recommended speeds of protected for appropriate portions (pin) of linked packet, to provide for easy detection of information about importance of source, first header is positioned at the beginning of flow of encoded data, alternatively, first header is provided with identifier.

EFFECT: creation of encoding method with consideration of importance of information from source.

8 cl, 9 dwg

FIELD: electrical communications; decoding noise-immune concatenated code in digital information transmission systems.

SUBSTANCE: proposed method includes formation of either short or long concatenated code on transmitting end which is decoded on receiving end starting from decoding internal code of long concatenation and determination of s number of internal code words in concatenation received in place of internal code words of concatenation which are not transmitted for short concatenated code. If s exceeds threshold value s1, decision is taken to receive long concatenated code, in which case external code of long concatenation is decoded. Otherwise, if s does not exceed threshold value s1, decision is taken to receive short concatenated code, and external code of short concatenation is decoded. Then number s2 of internal-code words of concatenation received in place of internal-code words of concatenation is determined using results of decoding internal code of concatenation which are transferred both for long concatenated code and for short one; communication channel quality is estimated, and threshold value s1 is varied depending on communication channel quality. Communication channel quality is estimated in this case by mean probability of receiving internal-code words of concatenation.

EFFECT: enhanced noise immunity.

1 cl

FIELD: digital data transfer systems including those using variable-parameter noise-immune code, such as adaptive noise-immune concatenated code.

SUBSTANCE: newly introduced in system on sending end are transmitting-part code parameter register, transmitting part control signal distributor, and transmitting-part switching unit; control input of system transmitting part is connected to input of transmitting-part code parameter register whose first output is connected to control input of external code encoder and second output, to first data input of transmitting-part switching unit; transmitting-part synchronization input of system is connected to input of transmitting-part control signal distributor whose first output functions as control input of sync pulse train generator; newly introduced on receiving end are receiving-part switching unit, internal-code syndrome computing circuit, internal-code syndrome decoder, and code parameter computing unit; synchronization input of system receiving part is connected to input of control signal distributor whose control input is connected to output of frame synchronization device and output, to syndrome decoder input.

EFFECT: enhanced digital data transfer speed, data reception noise immunity, and reliability in transmission of noise-immune code parameters.

1 cl, 3 dwg

FIELD: electrical communications; decoding noise-immune concatenated code in digital information transmission systems.

SUBSTANCE: proposed method includes formation of either short or long concatenated code on transmitting end which is decoded on receiving end starting from decoding internal code of long concatenation and determination of s number of internal code words in concatenation received in place of internal code words of concatenation which are not transmitted for short concatenated code. If s exceeds threshold value s1, decision is taken to receive long concatenated code, in which case external code of long concatenation is decoded. Otherwise, if s does not exceed threshold value s1, decision is taken to receive short concatenated code, and external code of short concatenation is decoded. Then number s2 of internal-code words of concatenation received in place of internal-code words of concatenation is determined using results of decoding internal code of concatenation which are transferred both for long concatenated code and for short one; communication channel quality is estimated, and threshold value s1 is varied depending on communication channel quality. Communication channel quality is estimated in this case by mean probability of receiving internal-code words of concatenation.

EFFECT: enhanced noise immunity.

1 cl

FIELD: engineering of data encoding systems.

SUBSTANCE: in accordance to method, signal is originally encoded for production of a flow of encoded data, while in the flow of encoded data information about importance of source is included, containing recommended speeds of protection of appropriate parts of flow of encoded data, while channel encoded may receive information about importance of source from the flow of encoded data, providing an advantage in case of presence of intermediate network levels, while a flow of encoded data contains appropriate packets, and information about importance of source is included in appropriate headers, connected to appropriate packets, given header pointing out recommended speeds of protected for appropriate portions (pin) of linked packet, to provide for easy detection of information about importance of source, first header is positioned at the beginning of flow of encoded data, alternatively, first header is provided with identifier.

EFFECT: creation of encoding method with consideration of importance of information from source.

8 cl, 9 dwg

FIELD: electrical communications; digital data transfer systems for decoding noise-immune variable-length concatenated code.

SUBSTANCE: proposed decoding device for noise-immune variable-length concatenated code has buffer memory and frame synchronization unit; their inputs are integrated to function as information input of device; outputs of buffer memory and frame synchronization unit are connected to internal-code decoder whose output is connected to external-code decoder; output of the latter functions as information output of device; newly introduced in device are time interval shaper, code word counter, and analysis unit; synchronization input of device is connected to input of time interval shaper whose control input is connected to output of frame synchronization unit; output of time interval shaper is coupled with inputs of code word counter and analysis unit whose other input is connected to output of code word counter whose synchronization input is coupled with internal-code decoder; output of analysis unit is connected to external-code decoder.

EFFECT: enhanced noise immunity of decoding device.

1 cl, 1 dwg

FIELD: information technology.

SUBSTANCE: proposal is given of a device for transmitting data bits after coding data bits using a LDPC, with unequal values of error probability in a mobile communications system, carries out channel coding and transmits the data bits. The device consists of: a LDPC coder for converting high data bits to low variable nodes and low data bits to high variable nodes. The high data bits have higher priority, and low data bits have low priority. Low variable nodes are variable nodes with low error probability values, and high variable nodes are variable nodes with high error probability values on the graph of coefficients of LDPC codes.

EFFECT: design of a device and method of transmitting bits by application of various error probability values to the transmitted bits through use of unequal codes of sparse even-parity check.

36 cl, 9 dwg

FIELD: radio engineering.

SUBSTANCE: invention relates to electric communication and may be used in discrete data transmission systems. According to the invention, the method provides for generating data encoded with jam-proof short concatenated code or long concatenated code on the transmitting side. The decoding starts from the data encoded with an internal code of the long jam-proof concatenated code. In the place of internal code words that are not transmitted for the data encoded by the short jam-proof concatenated code, the blocked length of the accepted concatenated code is more precisely defined in the channel by comparing with known sequences taking into account data distortions, when phased and numbering sequences are removed during data reading from storage device. Based on the results of more qualitative words selection in the internal code, the optimal algorithm of the external code decoding is selected.

EFFECT: improved data reliability when working in real channels.

FIELD: physics, communications.

SUBSTANCE: invention relates to transmission of a media stream over an error-prone digital video broadcasting - handheld (DVB-H) channel in which media datagrams are labelled according to a priority, packed in a multiprotocol encapsulation section, unequally protected using forward error-correction codes packed into a traffic stream and transmitted into the channel using packets with time-division. A system and a method are proposed for transmitting a multiplexed service stream over a DVB-H channel. Media IP packets are priority labelled. For each packet with time division, the IP packets are grouped based upon the priority labels. Multi protocol encapsulation - forward error correction (MPE-FEC) matrices are made for different priority labels in each packet with time division. Reed-Solomon code data table (RSDT) columns are computed such that the average service bit rate does not overshoot the maximum allowed bit rate, and protection increases with priority. The application data table (ADT) and RSDT of the MPE-FEC matrices are then encapsulated into MPE-FEC sections.

EFFECT: shorter start delay during reception of an unequally protected priority service bit stream.

21 cl, 10 dwg

FIELD: information technology.

SUBSTANCE: invention relates to a multiple input multiple output (MIMO) communication system and particularly to codebook information in a MIMO communication system. The apparatus for generating a codebook includes a codebook generator. The codebook generator is configured to generate a 4-bit precoding codebook for eight transmitting antennae for use in a closed-loop single-user MIMO (SU-MIMO) scheme. According to aspects of the present invention, it is possible to generate a precoding codebook for use in systems with eight transmitting antennae.

EFFECT: high efficiency of transmitting and receiving data.

9 cl, 13 dwg

FIELD: information technology.

SUBSTANCE: asynchronous wavelet-cepstral method of selecting encoded information sent to user using packets of ultra-wideband pulses. The objective of the invention is: a) providing reliable selection of information in form of logic "zeros" and "ones" when sending messages using ultra-wideband pulses in a mode which does not require their synchronisation, with signal-to-noise ratio of not less than 2 dB; b) enabling use of ultra-wideband pulses of arbitrary shape in a code sequence of packets of ultra-wideband pulses by reducing the logarithmic nonlinearity effect in a cepstral processing algorithm.

EFFECT: high reliability of selecting received information through reverse wavelet signal recovery without coefficients which carry information on low-frequency changes in the logarithm of the energy spectrum of the received signal.

21 dwg

Optical encoder // 2471289

FIELD: physics.

SUBSTANCE: optical encoder, wherein distribution of the transmission coefficient or distribution of the reflection coefficient, provided in scale track on the displacement scale, has a first modulation period and a second modulation period in the direction of displacement of the scale; an array of photodetector elements is intended to detect a first group of signals which includes two phase signals which are antiphase with respect to each other during the first modulation period and a second group of signals which includes two phase signals which are antiphase with respect to each other during the second modulation period, wherein first positional information during the first modulation period is determined from the first group of signals, and second positional information during the second modulation period is determined from the second group of signals, the second modulation period being an odd-multiple of the first modulation period.

EFFECT: reduced error component of the detected waveform and determining positional information with high accuracy.

5 cl, 14 dwg

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