115results about "Joint error correction" patented technology

Disclosed is an adaptable / variable type modulation / demodulation apparatus. A physical layer transmission apparatus for adaptable / variable type modulation, the transmission apparatus including a classification unit to classify a bit stream according to a standard that is determined in advance after receiving the bit stream, an uncoded bit group unit to group the bit stream not to be LDPC-coded by a predetermined number of bits, an LDPC encoder to perform LDPC-coding of the bit stream, a coded bit group unit to group the coded bit stream by the predetermined number of bits, a quadrature amplitude modulation (QAM) unit to select a symbol coset using the coded bit groups; and a convolutional interleaver to perform convolutional interleaving of the symbol.

A data modulating device includes: an LDPC encoding unit configured to execute LDPC encoding; and a balance encoding unit configured to input a data string subjected to encoding by the LDPC encoding unit as data to be encoded, and convert k bits of this data to be encoded into balance code made up of m-bit block data; with the balance encoding unit executing balance encoding of said data to be encoded using a data conversion table subjected to mapping so that a set of the k-bit data patterns of which the Hamming distance is 1 corresponds to a set of block data of which the Hamming distance is 2.

A multiple access scheme is described. One or more encoders are configured to encode a plurality of bit streams using Low Density Parity Check (LDPC) coding. The bit streams correspond to a respective plurality of terminals. The plurality of bit streams are converted to provide a multiple access scheme for the terminals.

Systems and methods for jointly performing encryption and error-correction coding offer advantages, especially in the presence of noise. According to one embodiment, a method for encryption and transmission of information includes: inserting at least one encryption key element into source data elements that are to be communicated, yielding an extended information sequence; encoding the extended information sequence using an error-correcting code, yielding an extended codeword; removing at least one element of the extended codeword, leaving a punctured extended codeword; and transmitting the punctured extended codeword across a medium. According to another embodiment, a system for decrypting information includes: means for receiving input data that includes error-correction code with missing elements and with errors, the missing elements being based on a key, the key already known on the receiving side of said transmission; and means for automatically decoding said input data based on the key to recover a message despite the errors.

A data modulating device includes: an LDPC encoding unit configured to execute LDPC encoding; and a balance encoding unit configured to input a data string subjected to encoding by the LDPC encoding unit as data to be encoded, and convert k bits of this data to be encoded into balance code made up of m-bit block data; with the balance encoding unit executing balance encoding of said data to be encoded using a data conversion table subjected to mapping so that a set of the k-bit data patterns of which the Hamming distance is 1 corresponds to a set of block data of which the Hamming distance is 2.

An error correction decoding (ECC) processing scheme is disclosed that reduces computational complexity normally associated with multiuser detection (e.g., TurboMUD) solutions, without causing degradation in quality of service or decreasing the total throughput. Error correction decoding algorithms are applied only to portions of the estimates that were affected by the immediately previous MUD update process. Even though the MUD and / or ECC updating is targeted so as to reduce complexity of each iteration, all of the estimates are maintained and remain candidates for future updates. As such, there is no negative impact real-time or future performance. This targeting approach can be used in conjunction with many variations of MUD, including full-complexity or reduced complexity, and may include MUD with confidence ordering or voting, and other techniques for facilitating efficient and effective MUD processing.

A disk drive using a read / write channel including an iteration decoder for performing iterative decoding processing is disclosed. The iteration decoder has an RLL error detector for detecting a burst error portion from an LLR group output from the channel decoder, and an LLR adjuster. The LLR adjuster makes adjustment by reducing the value of the LLR group corresponding to the detected burst error portion.

Systems and methods are provided for implementing various aspects of a Reed-Solomon (RS) error-correction system. A detector can provide a decision-codeword from a channel and can also provide soft-information for the decision-codeword. If the decision-codeword corresponds to an inner code and an RS code is the outer code, a soft-information map can process the soft-information for the decision-codeword to produce soft-information for a RS decision-codeword. A RS decoder can employ the Berlekamp-Massey algorithm (BMA), list decoding, and a Chien search, and can include a pipelined architecture. A threshold-based control circuit can be used to predict whether list decoding will be needed and can suspend the list decoding operation if it predicts that list decoding is not needed.

A method and apparatus for encoding and decoding a channel in a communication system using a Low-Density Parity-Check (LDPC) code. The encoding method includes determining a modulation scheme for transmitting a symbol; determining a shortening pattern in consideration of the determined modulation scheme; grouping columns corresponding to an information word in a parity-check matrix of the LDPC code into a plurality of column groups; ordering the column groups; determining a range of a resulting information word desired to be obtained by shortening the information word; based on the range of the resulting information word, performing column group-by-column group shortening on the ordered column groups of the information word, according to the determined shortening pattern; and LDPC-encoding the shortened information word.

An apparatus and method for receiving a message stream on a channel. A message is received on the channel. Information regarding the bits of a successfully decoded message is added to a message attributes list if the message is successfully decoded. An attempt is made to decode a subsequent message based on the information in the message attributes list.

A multiple access scheme is described. One or more encoders are configured to encode a plurality of bit streams using Low Density Parity Check (LDPC) coding. The bit streams correspond to a respective plurality of terminals. The plurality of bit streams are converted to provide a multiple access scheme for the terminals.

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 forward error correction encoding, decoding method, an apparatus and a system and belongs to the communication field. The method comprises: determining check matrix parameters of LDPC recurrent code of a time varying period according to transmission system performance, complexity and codon synchronization alignmental, constructing a QC-LDPC check matrix according to determined check matrix parameters and obtaining the check matrix HC of time variant LDPC recurrent code according to the QC-LDPC check matrix; blocking to-be-encoded data according to HC requirement, encoding every blocking data based on HC and obtaining a plurality of codens of LDPC recurrent code; adding the plurality of codens of LDPC recurrent code to data frames and sending the codens of LDPC recurrent code. The invention carries out forward error correction by adopting time variant LDPC recurrent code and LDPC recurrent code has a QC-LDPC structure. Because QC-LDPC checking characters can reduce checking complexity, the performance of LDPC recurrent code is superior to the performance of LDPC block code and the performance of time variant LDPC recurrent code is superior to the performance of time invariant LDPC recurrent code, the invention can be appropriate for a high-speed optical transmission system and satisfy requirements of high gain performance and high throughput.

A multi-user turbo decoder combining multi-user detection and forward error correction decoding is disclosed in which randomly ordered indices are assigned to interfering users before a decoding tree is constructed in the multi-user decoder for each symbol interval for every iteration and for each new block of data. By building the decoding tree in this manner for each symbol interval, a reduced complexity search is more likely to include paths (and nodes) in the tree containing the correct value for the channel symbols. All users thus share in the benefit of root level placement in the decoding tree. In an alternative embodiment of the invention only one decoding pass is accomplished and there is no re-construction of the decoding tree based on further random index ordering for iterative decoding. No modification to the transmitted signaling method is needed.

A communication apparatus includes a plurality of descramblers for subjecting a second header portion of a received frame to descrambling processing using pseudo-random sequences that differ from one another; a plurality of syndrome arithmetic units for performing a syndrome calculation, which is in accordance with a cyclic redundancy check code, with respect to headers descrambled by respective ones of the plurality of descramblers, and an error correction unit for selecting a header that has been descrambled by one descrambler among the plurality of descramblers as a receive header, in accordance with syndrome values calculated by respective ones of the plurality of syndrome arithmetic units.

Systems and methods are provided for implementing list decoding in a Reed-Solomon (RS) error-correction system. A detector can provide a decision-codeword from a channel and can also provide soft-information for the decision-codeword. The soft-information can be organized into an order of combinations of error events for list decoding. An RS decoder can employ a list decoder that uses a pipelined list decoder architecture. The list decoder can include one or more syndrome modification circuits that can compute syndromes in parallel. A long division circuit can include multiple units that operate to compute multiple quotient polynomial coefficients in parallel. The list decoder can employ iterative decoding and a validity test to generate error indicators. The iterative decoding and validity test can use the lower syndromes.

Aspects of a method and system for redundancy-based decoding of voice content in a wireless local area network (WLAN) system are provided. A WLAN receiver may determine whether a decoded portion of a received packet comprises voice content and may select a redundancy-based decoder to decode a remaining portion of the packet when voice content is detected. The redundancy-based decoder may be a Viterbi decoder. The redundancy-based decoder may be selected to decode a determined number of subsequent packets or to decode subsequent packets for a determined amount of time. After decoding the remaining portion of the packet and any subsequent packets, the WLAN receiver may select a standard Viterbi decoder to decode additional received packets. The WLAN receiver may generate at least one signal to select the redundancy-based decoder and the standard Viterbi decoder.

The invention relates to a semiconductor device and a method of writing data to a semiconductor device. The semiconductor device in related art has a problem that security at the time of writing data cannot be sufficiently assured. A semiconductor device of the present invention has: a unique code generating unit generating an initial unique code which is a value unique to a device and includes an error in a random bit; a first error correcting unit correcting an error in the initial unique code to generate an intermediate unique code; a second error correcting unit correcting an error in the intermediate unique code to generate a first determinate unique code; and a decrypting unit decrypting, with the first determinate unique code, transmission data obtained by encrypting confidential information with key information generated on the basis of the intermediate unique code by an external device to generate confidential information.

A decoding method, medium, and apparatus capable of preventing error propagation and implementing parallel processing. A decoding method includes comparing encoding information with decoding information at synchronization points for detecting a transmission error, and continuing to decode the encoded data if both the encoding and decoding information match, or continuing to decode remaining data located beyond the corresponding synchronization point by limiting a transmission error region to between the corresponding synchronization point and an immediately previous synchronization point, with reference to the encoding information if the encoding and decoding information do not match. Furthermore, the encoded data of a plurality of regions are simultaneously decoded in parallel, with reference to the encoding information of a plurality of synchronization points. Therefore, it is possible to prevent error propagation by limiting the transmission error within a smallest possible length and to reduce a decoding time by using a parallel processing.

A method and apparatus is disclosed herein for a low complexity method of securing content that is coded by a rateless code whereby it is noted that it is sufficient to encrypt only a subset of the ratelessly coded packets. In one embodiment, the method comprises performing rateless coding on a first set of blocks of data to produce ratelessly encoded blocks of data and performing encryption on a subset of the ratelessly encoded blocks of data based on a degree value for each of the ratelessly encoded blocks of data.

A plurality of encrypted packets having common payload data are received, wherein each of the plurality of encrypted packets includes a corresponding parity check field, and wherein a corresponding parity check syndrome for each of the plurality of encrypted packets indicates at least one bit error. A payload portion of each of the plurality of encrypted packets is decrypted to generate a plurality of decrypted payload portions. At least one chase coding technique is used to generate a corrected decrypted payload, based on at least one candidate bit error position and further based on the corresponding parity check syndrome for at least one of the plurality of encrypted packets.

A transceiver architecture can contain an encoder and a decoder for communicating high speed transmissions. The encoder can modulate signal data for being mapped in a constellation that is generated based on concatenations of a leech lattice having binary and non-binary codes. The data can be transmitted at a high speed according to the constellation with an embedded leech lattice configuration in order to generate a coding gain. A decoder operates to decode the received input signal data with a decreased latency or a minimal latency with a high spectral efficiency.

The invention discloses an information detection method and a device of downlink high-speed shared control channels (HSSCCH), which can realize the detection of HSSCCH part1 of low false alarm probability and low false dismissal probability under any user UEID combination. The method comprises the following steps: rate de-matching is carried out on front-end detection signals of part1 of each HSSCCH channel in a terminal HSSCCH monitoring set, thus obtaining corresponding rate de-matching information; user mask code removing is carried out on the rate de-matching information of each HSSCCH monitoring channel; Viterbi decoding is carried out on each rate de-matching information, the user mask code of which is removed, thus obtaining the Viterbi decoding 0 state cumulative measurement of each HSSCCH channel in the HSSCCH monitoring set, and the absolute values of soft information of each HSSCCH monitoring channel which is obtained after the user mask code is removed are summed respectively; according to the Viterbi decoding 0 state cumulative measurement of each HSSCCH channel and the corresponding sum of the absolute values of the soft information, the judgment variable of each HSSCCH channel is obtained; and the maximum is selected from the judgment variables of the HSSCCH channels, and the maximum is compared with a set threshold, and whether an HSSCCH channel of the user is detected or not is judged.

Methods and apparatus for code-based asymmetric cryptosystem using Quasi-Cyclic Moderate-Density Parity-Check (QC-MDPC) error correcting codes. Specifically, the method and apparatus generalizes the framework of (QC-MDPC) Code-Based (CB) cryptography from the binary domain (Galois Field of two elements) to an arbitrary size of Galois Field and provides an apparatus for implementing the cryptosystem with a simplified computational complexity of key generation, encryption, and decryption components of the cryptosystems and reduced sizes of the public and private security keys.

A method of cryptographically processing a block of data, the method comprising: receiving an encoded version of the block of data, wherein the encoded version of the block of data comprises the block of data encoded, at least in part, using an error control code; and processing the encoded version of the block of data using a predetermined function to generate an output, wherein the predetermined function is arranged so that the result of processing, with the predetermined function, a quantity of data encoded, at least in part, using the error control code equals the result of encoding, at least in part, with the error control code the result of performing encryption or decryption of the quantity of data according to the Advanced Encryption Standard, AES.

A digital broadcast receiver is provided. The digital broadcast receiver includes a receiver which receives a transport stream transmitted from a digital broadcast transmitter, an additional data stream detector which determines whether the received transport stream includes an additional data stream or not, and a processor which process the additional data stream if the transport stream include the additional data stream, and the transport stream including the additional data stream is a transport stream into which a training signal is inserted by the digital broadcast transmitter which resets memories used for trellis-encoding at predetermined time. Accordingly, it is easily detected whether the transport stream includes the additional data stream or not.

An optical transport system is configured to use a modulation scheme in which a phase rotation applied to a sequence of PSK or QAM constellation symbols encoding a codeword of an FEC code produces a modified sequence of PSK or QAM constellation symbols encoding a bit-word that is not a valid codeword of that FEC code. Based on this property of the modulation scheme, an optical receiver may be configured to relatively accurately recover the absolute phase of the optical carrier wave of the received modulated optical signal by applying maximum likelihood sequence estimation processing to each portion of the signal carrying a valid codeword of the FEC code. For example, for a modulation scheme employing a 2n-PSK constellation, the optical receiver may be able to recover the absolute phase of the optical carrier wave with an accuracy that is better than 360 / 2n degrees.

Methods and apparatus are provided for detection and decoding in flash memories with selective binary and non-binary decoding. Data from a flash memory device is processed by obtaining one or more read values for a plurality of bits from one or more pages of the flash memory device; converting; the one or more read values for the plurality of bits to a non-binary log likelihood ratio based on a probability that a given data pattern was written to the plurality of bits when a particular pattern was read from the plurality of bits; and jointly decoding the plurality of bits using the non-binary log likelihood ratio, wherein the pages are encoded independently.

A disc drive using a read / write channel (5) comprising an iterative decoder (55) for performing an iterative decoding process is disclosed. The iterative decoder (55) has a RLL error detector (552) for detecting burst error parts from the LLR set output from the channel decoder (550) and LLR adjuster (551). The LLR adjuster (551) adjusts by reducing the value of the set of LLRs corresponding to the detected error portion of the burst.