112results 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 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.

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.

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.

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 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.

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 method for transmitting a codeword in a wireless communication system is disclosed. The method includes generating a codeword by encoding an input signal based on a polar code, acquiring a Hamming weight from a bit sequence of at least a part of the codeword, generating Hamming weight information based on the Hamming weight, and transmitting the Hamming weight information and the codeword to a receiver. The Hamming weight information includes a range indicator indicating a range to which the Hamming weight belongs, among a plurality of ranges.

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.