75 results about "Raptor code" patented technology

A video encoder system includes a base layer and an enhancement layer for encoding video data. The base layer encodes a reduced quality version of the video data to obtain base layer data. The enhancement layer encodes the video data using energy-concentrating transform operations, nested scalar quantization, and Raptor encoders. The base layer data and enhancement layer data are transmitted through a channel to a video decoder system. The decoder system decodes the base layer data to recover an estimate of the reduced quality video and decodes the enhancement layer data (using the reduced quality video as side information) to obtain blocks of coset indices. The decoder system then operates on the blocks of coset indices to generate estimates of the original video data.

Significant improvement in Raptor codes and punctured LDPC codes are obtainable by use of the invention. In both a transmission scheme for Raptor-encoded or LDPC-encoded information, a dynamic adjustment approach is employed. A fraction of a codeword or information frame is transmitted. A feedback signal is sent from the receiver to the transmitter indicating either 1) successful decoding, or 2) failure to decode and / or a feedback signal indicative of a statistical measure of transmission channel quality. If decoding fails, a further portion of the codeword or frame is sent. The intensity and / or size of the fraction is adjusted based on the feedback signal. In one embodiment, a specific range for probabilities employed in the encoding process for Raptor codes provides the ability to increase transmission throughput. Further it has been found that the advantageous Raptor codes are useful in noise conditions where even the improved punctured LDPC codes of the invention begin to degrade.

A system and method for encoding symbols in a wireless communication is provided. The system and method includes a transmitter configured to encode data transmissions. The transmitter includes a raptor encoder configured to perform a coding operation. The raptor encoder generates intermediate symbols without using a half-code such that the intermediate symbols consist of precoded symbols and parity symbols. Thereafter, the intermediate symbols are encoded using a Luby Transform to produce and output encoded symbols. The transmitter further is configured to transmit one or more of the source symbols, parity symbols or encoded symbols.

A method and system use capacity-approaching rateless code to communicate multimedia data even with very short codewords, such as 64 bits or less, via erasure and noise channels. The method provides a way to design the edge degree distribution of rateless codes for any arbitrary channel. Based on an equivalent metric of decoding behavior in any channels, the degree distribution of a rateless code such as Luby-transform codes and raptor codes is optimized based on in-process status of decoding. A regularized least-squares optimization is used to avoid erroneous decoding. Multiple feedbacks can further improve the performance.

Methods and apparatus are provided for encoding and decoding via authenticated error correcting codes, such as secure LT codes, secure Raptor codes, block codes and / or rateless codes. Encoded symbols are generated via an authenticated error correcting code by applying a Luby Transform (LT) code to a plurality of message symbols to produce one or more intermediate symbols using a pseudo random number generator (PRNG) to select the plurality of message symbols to combine to produce the intermediate symbols; encrypting the intermediate symbols to produce encrypted symbols; computing an authentication value, such as a message authentication code (MAC), over one or more of the one or more encrypted symbols; and appending the authentication value to the corresponding encrypted symbols to form the encoded symbols. Block scalable and random scalable constructions are also provided, as well as decoding techniques for all of the constructions.

The invention discloses a Raptor Codes encoding / decoding method suitable for medium / short code lengths of an additive white Gaussian noise channel. According to the method disclosed by the invention, the degree distribution of the inner codes, i.e. LT (Linear-Time) Codes, of the Raptor Codes which are more suitable for the medium / short code lengths is proposed; and the improved PEG (Progressive Edge-Growth) algorithm is used for encoding the inner codes, i.e. the LT codes, of the Raptor Codes, wherein the encoding manner consists of two PEG encoding manners, i.e. independently carrying out PEG composition on the LT Codes and carrying out the PEG composition on the LT Codes through combining with outer codes, i.e. LDPC (Low Density Parity Check) Codes, thus the problem that excessive shortloops appear in a Tanner graph, caused by randomly selecting information packets in an LT encoding stage, is solved. With the adoption of the method disclosed by the invention, the effectiveness for the transfer of soft information when the BP (Background Processing) iterative decoding is carried out is therefore enhanced, the performance better than that of a random composition manner is obtained, and the more reliable transmission for the rateless codes with the medium / short code lengths is realized.

A system and method for recovering erased symbols in a wireless communication is provided. The system and method includes a receiver configured to receive encoded data transmissions. The receiver includes a single stage decoder configured to perform a decoding operation. The single stage decoder also is configured to determine a symbol erasure rate, the symbol erasure rate defined by a number of erased symbols. The single stage decoder further is configured to generate a recovery matrix based on the symbol erasure rate and invert the recovery matrix. Thereafter, the single stage decoder recovers the erased symbols based on a function of the inverted recovery matrix.

The invention relates to encoding-decoding technique, and discloses a method and a device for decoding fountain codes, wherein the method for decoding fountain codes comprises the following steps of: receiving L Raptor code packets; decoding the L Raptor code packets by a BP algorithm; and if the L Raptor code packets are failed to be decoded by the BP algorithm, decoding the Raptor code packets which are failed to be decoded by the BP algorithm by a GE algorithm. By adopting the technical scheme provided by the invention, the success ratio of decoding the Raptor code packets is improved.

Significant improvement in Raptor codes and punctured LDPC codes are obtainable by use of the invention. In both a transmission scheme for Raptor-encoded or LDPC-encoded information, a dynamic adjustment approach is employed. A fraction of a codeword or information frame is transmitted. A feedback signal is sent from the receiver to the transmitter indicating either 1) successful decoding, or 2) failure to decode and / or a feedback signal indicative of a statistical measure of transmission channel quality. If decoding fails, a further portion of the codeword or frame is sent. The intensity and / or size of the fraction is adjusted based on the feedback signal. In one embodiment, a specific range for probabilities employed in the encoding process for Raptor codes provides the ability to increase transmission throughput. Further it has been found that the advantageous Raptor codes are useful in noise conditions where even the improved punctured LDPC codes of the invention begin to degrade.

The invention discloses a Raptor code (with non-regular codes as precoding) optimized coding method; when the Raptor code using non-regular LDPC code as precoding is coded, different probabilities areselected for intermediate codons of different columns for LT coding, and the selection probability of the intermediate codon with the big column is properly lowered, thus relatively uniforming the total number of degrees of the intermediate codons in a Tanner graph of the Raptor code, and improving the decoding success rate.

The invention discloses a power control method applicable to Raptor Codes under an additive white Gaussian noise channel. In the power control method, by utilizing the self-adaptive link fitting characteristic of the Raptor Codes, on the premise of constant total transmitting energy, if a transmitting end reduces the transmitting power and increases the code length, the difference value between the capacity C and code rate R of the channel can be increased, so that the performance of the Raptor Codes is obviously improved. By utilizing the characteristic of the Raptor Codes, the transmitting power can be controlled by the transmitting end so as to meet the requirement of the current channel. For channels with higher requirements for the transmission time, the transmitting power can be increased as high as possible on the premise of meeting the total transmitting energy so as to reduce the transmission time; and for channels with higher requirements for the transmission energy consumption, the transmitting power can be reduced as low as possible on the premise of meeting the maximum transmission time so as to reduce the total transmission energy.

The invention discloses a DNA information storage method based on Raptor codes and quaternion RS codes. The method comprises a DNA information storage process based on Raptor codes. The DNA information storage process comprises the following steps: 1, converting an information file needing to be stored into a binary code stream; 2, encoding the binary code stream into a base sequence containing A,T, C and G by using Raptor codes; and 3, adding a quaternary RS error correction mechanism to the base sequences to ensure the correctness of information storage, then adding primer segments requiredfor synthesizing DNA to the two ends of the base sequences, and synthesizing the base sequences into DNA chains by using a biotechnology to complete information storage; compared with the prior art,the DNA storage technology realized by the invention has the beneficial effects of good ductility, high encoding and decoding efficiency, low complexity and the like.

The invention discloses a Raptor code method of system unequal error protection. The Raptor code method of the system unequal error protection solves the problems that an existing Raptor code method of the system unequal error protection either modifies degree distribution and structure of standard system Raptor codes and damages code word performance, or uses a standard system Raptor encoder to distribute different amounts of redundancy (code rate) for different important data and causes difficulty and waste of redundancy data distribution. According to the Raptor code method of the system unequal error protection, coding is performed based on a standard system Raptor coding algorithm, an algorithm similar to window extension is used for a middle symbol, the unequal error protection for a source symbol is achieved, decoding is performed by only slightly modifying a generation matrix, and a standard system Raptor decoder is still used. The Raptor code method of the system unequal error protection has the advantages of being achieved completely through standard system Raptor code stepping coding and decoding, especially performing the increment decoding according to the classification of the protected degree of the source symbol, and simultaneously maintaining the advantages of original degree distribution, high efficiency of coding and decoding and the like of the standard system Raptor encoder and the standard system Raptor decoder, and achieving the high efficiency unequal error protection.

The invention relates to a fountain encoding and decoding method for forward error correction of a binary erasure channel, and the encoding method does not need to calculate intermediate nodes while maintaining output which is the same with the traditional Raptor Codes encoding algorithm and directly calculates check nodes through a generator matrix, thereby being high efficient and simple. The decoding method does not need to calculate the intermediate nodes while maintaining redundancy rate which is the same with the traditional Raptor Codes, and the size of a matrix Z'N'*k which is constituted by carrying out degree reduction on repair nodes is only linearly correlated with the product of the packet loss rate of the binary erasure channel and the number of source nodes, thereby being more efficient and simple in comparison of the matrix ZN*K with the size which is linearly correlated with data of the source nodes, and the matrix ZN*K needs to be processed during the traditional Raptor Codes decoding.

The invention discloses a raptor code based large file transmission method. According to the raptor code based large file transmission method, according to transmission characteristics of large files, the files to be transmission are subjected to partitioning processing and pre-coding by means of raptor codes, head information is re-designed, and transmission of the files with the capacity of 1000GB at the most can be supported by means of the 8-bit head information. According to the raptor code based large file transmission method, by means of a dynamic transmission redundancy generation mechanism, real-time dynamic regulation is performed according to changes of channels; the influence of channel delay and channel packet loss probability on large file transmission in a bidirectional feedback channel is eliminated, and transmission stability and efficiency of large files are improved.

The invention discloses a P2P streaming media scheduling system and method based on coupling of codes. The system comprises a server and a terminal node, wherein the server comprises a control module and an Raptor coding module, and the control module is used for controlling interactive information; the Raptor coding module is used for coding source files and generating Raptor coding packs, and the Raptor coding packs are transmitted to a network in the transmitting time slot; the terminal code comprises a control module, network coding and decoding modules and an Raptor decoding module, wherein the network coding module is used for performing NC recoding on the received coding packs, then the coding packs are transmitted to neighboring downstream nodes, or decoding is performed when enough coding packs are received, and next the coding packs are transmitted to an Raptor decoder; the Raptor decoding module is used for decoding the Raptor coding packs having been decoded by a network decoder, and original data packets are restored. According to the system and method, Raptor codes and network codes are effectively cascaded, a complex scheduling strategy of the streaming media system is simplified, and the bandwidth availability rate and the system throughput rate are improved.

The invention discloses a Raptor code part ring elimination coding method based on degree optimization. The method includes the following steps: precoding Raptor codes, obtaining degree selection optimization conditions according to the precoded codes, randomly generating a degree on the basis of a degree distribution function, determining whether ring elimination is conducted on the basis of a situation that whether the degree satisfies the degree selection optimization conditions, and finally obtaining all output coded symbols. Ring elimination is conducted through selection of the degree, so the Raptor code performance is improved to the maximum and the calculating complexity is also reduced.

The invention provides a distributed system Raptor code transmission method specific to deep space communication, comprising the steps of: S1, separately performing system Raptor coding on source end raw information having a code length of K1 and K2, and sending coding to a same relay; S2, a relay R respectively storing coded identifications from source ends in a cache region E1 and a cache region E2, employing a DSRC algorithm to process data, and then sending the processed coded identifications to a destination end; and S3, a destination end D decoding the received coded identifications. The invention designs a distributed system Raptor code transmission method specific to the occasion where a plurality of detectors transmit towards the ground through orbiters, provides a joint decoding simplified scheme, theoretically analyzes and derivates a DSRC scheme, improves performance parameters of the scheme, performs simulation comparison with the distributed no-rate erasure correcting scheme of the prior art, and obtains a 99% decoding success rate when redundancy reaches 5%.

The invention discloses a method and device for sending and receiving on-line files of an instant messaging tool. All of modules between a sending end application layer Raptor encoder and a receiving end application layer Raptor decoder are erasure channels having certain packet loss rate. A sending method comprises the steps of 1.1, packing and encapsulating file data to be sent into a plurality of data packages, performing Raptor code encoding in a sending application layer with a data package as a unit, loading a cyclic redundancy code (CRC) and transmitting the CRC to a sending end transport layer; 1.2, performing user datagram protocol (UDP) conversion in transport layer and then transmitting the CRC to a physical layer; and 1.3, performing channel coding and modulation of the data packages in the physical layer and then transmitting the CRC to a network channel. The invention further discloses a method for receiving the on-line files of the instant messaging tool and a system for receiving the on-line files of the instant messaging tool. Compared with QQ and other instant messaging tools, the method, device and system for receiving the on-line files of the instant messaging tool improves the file transmission speed by 30% or more than 30%.

The invention discloses a decoding method of a Raptor code. In the prior Raptor decoding technology, more symbolic numbers are received for ensuring the high probability for one-time decoding success and the whole decoding process requires to be restarted once the decoding is unsuccessful. The method provided by the invention can be used for starting decoding from successfully-decoded least symbols; and if the decoding is unsuccessful, one new symbol only needs to be continuously received and the decoding continues by using the failed decoding result until the decoding is successful. The invention solves the problem that the Gaussian elimination of the decoding algorithm in the prior art damages the linear relation of a matrix. The improved method has simple flow and small expenditure, enhances the decoding instantaneity and greatly enhances the practicability.

The invention claims a joint error correction security method based on Raptor code. A pseudorandom number generator is set in the encoder and decoder to generate an approximate random encoding generation matrix and a deletion pattern to realize random generation and random deletion of encoded symbols. The seed of the pseudorandom number generator is the encryption and decryption key. Non-cooperative recipients are almost impossible to decode without seeds. The invention not only maintains the good error correction performance of the rate-free code, but also ensures the safety of the transmitted information, and the safety does not depend on the quality difference between the eavesdropping channel and the legal channel. In addition, the invention can also adapt the channel performance.

The invention provides a multimedia data unequal error protection method based on a Raptor code. The method includes two application modes of basic unequal error protection and reinforced unequal error protection, and unequal error protection of multimedia data packages is achieved through the steps of distortion impact evaluation, sequencing and classification, Raptor coding and transmitting and the like. The method completely utilizes the good characteristics of the Raptor code under large block length. In addition, the method is easy to use due to the fact that the standard Raptor code is used.

A receiver for decoding a Raptor code comprises a first decoder, for performing following operations: receiving a first plurality of coded symbols encoded from a message according to the Raptor code; decoding the first plurality of coded symbols into a first plurality of decoded symbols; determining whether a second plurality of coded symbols are needed for the Raptor code according to a function of the first plurality of decoded symbols; and receiving the second plurality of coded symbols and decoding the first plurality of coded symbols and the second plurality of coded symbols into the first plurality of decoded symbols, if the second plurality of coded symbols are needed; and a second decoder, coupled to the first decoder, for decoding the first plurality of decoded symbols into a second plurality of decoded symbols.

The invention discloses a screen update transmission method based on reinforcement learning and fountain codes, and the method employs a reinforcement learning algorithm SARSA to control the transmission rate of screen update, carries out the transmission behavior decision through a specified transmission target instead of a fixed rule, and improves the adaptability of the transmission method to different network conditions. A Gilbert-Elliot model is adopted to model a network packet loss behavior, reliable transmission of screen updating is ensured by means of a system Raptor code and an ARQmechanism, the number of unnecessary retransmission times is reduced by dynamically setting the size of a coding block and the number of redundant packets, and the transmission real-time performance is considered. By means of the method, efficient transmission of screen updating in the desktop service mode is achieved, and the requirement of a user for the experience quality can be better met.

The invention discloses a Raptor Code coding method, decoding method and systems based on CUDA (Compute Unified Device Architecture). According to the parallel characteristic of Raptor Code coding and decoding operation, a decomposition mode and an iterative data storage structure for a coding and decoding task in a parallel program and a specific operating process of each thread are designed. Thus, the executing speed of Raptor Code coding and decoding is improved, and the technical problems of long test cycle and low test efficiency when a Raptor Code coding and decoding algorithm is implemented at present are solved.

A video encoder system includes a base layer and an enhancement layer for encoding video data. The base layer encodes a reduced quality version of the video data to obtain base layer data. The enhancement layer encodes the video data using energy-concentrating transform operations, nested scalar quantization, and Raptor encoders. The base layer data and enhancement layer data are transmitted through a channel to a video decoder system. The decoder system decodes the base layer data to recover an estimate of the reduced quality video and decodes the enhancement layer data (using the reduced quality video as side information) to obtain blocks of coset indices. The decoder system then operates on the blocks of coset indices to generate estimates of the original video data.

The invention discloses a high-scale Raptor code encoding and decoding method with a limited code length. The method comprises the steps of performing pre-encoding on data whose original symbol number is k to obtain an intermediate symbol whose length is n, and then performing LT encoding on the intermediate symbol to obtain a Raptor code whose encoding redundancy is gamma; elements and an original symbol b in a pre-encoding generated matrix, as shown in the specification, of the whole Raptor code and an LT code generated matrix as shown in the specification all are high-scale elements in a q-element domain, a high-scale LDGM code is adopted by the pre-encoding and the generated matrixes are in a full rank; matrix construction is performed on the LT encoding generated matrix according to a degree distribution omega, and a degree value d of each row is subject to a probability distribution as shown in the specification and as shown in the specification; non-zero elements in the generated matrixes are generated randomly; and all non-zero elements in the pre-encoding and the LT encoding are generated according to a Bernoulli variable eta and an output degree distribution omega (x) in an equal probability 1 / q. According to the high-scale Raptor code encoding and decoding method, an upper limit and a lower limit of a decoding failure probability of any scale Raptor code under an ML (Maximum Likelihood) decoding algorithm are given, the performance of an actual codeword is simulated by Monte Carlo, and the accuracy of the upper and lower limits are verified.