The present invention discloses a coding and decoding method, apparatus, and system for forward error correction, and pertains to the field of communications. The method includes: determining check matrix parameters of time-varying periodic LDPC convolutional code according to performance a transmission system, complexity of the transmission system, and a synchronization manner for code word alignment, constructing a QC-LDPC check matrix according to the determined check matrix parameters, and obtaining a check matrix H_c of the time-varying periodic LDPC convolutional code according to the QC-LDPC check matrix; de-blocking, according to requirements of the H_c, data to be coded, and coding data of each sub-block according to the H_c, so as to obtain multiple code words of the LDPC convolutional code; and adding the multiple code words of the LDPC convolutional code in a data frame and sending the data frame. In the present invention, forward error correction is performed by using time-varying periodic LDPC convolutional code with a QC-LDPC structure. The check characteristics of the QC-LDPC may decrease the complexity of the check; furthermore, the performance of LDPC convolutional code is better than that of LDPC block codes, and the performance of time-varying LDPC convolutional code is better than that of time-invariant LDPC convolutional code. Therefore, the present invention may be applicable to the high-speed optical transmission system and meet the requirements of high-gain performance and high throughput.

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.

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.

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 communication apparatus (120) comprises a redundancy encoder (200) for encoding an input information signal to obtain an encoded output sequence of information units, including information of the input signal and redundant information. Furthermore, the communication apparatus (120) comprises an encrypter (202) for encrypting the encoded output sequence to obtain an encrypted output sequence of information units, the encrypter (202) comprising a sequence manipulator (204) for manipulating the encoded output sequence which includes an interleaver (306) having an interleaving rule controllable with a secret encryption key, and a puncturer (308) for applying a puncturing pattern controllable with the secret encryption key, which is only known to an intended recipient of the input information signal.

A radio telecommunications system is provided operative to communicate digital data symbols with multilevel-coded modulation using higher than quadrature phase shift keying (QPSK) in a multiple-input multiple-output (MIMO) transmit environment. The system comprises a transmitter (1) and a receiver (2).

The transmitter (1) contains a means to split the data into a first block of more significant bits of symbols and a second block of less significant bits of symbols which are then separately encoded (a,b) and interleaved (c,c') for modulation by a modulator (d). This transmitter performs multilevel-coded modulation to provide a layered encoding scheme that enables unequal error protection for the transmitted bits.

The receiver (2) is operative to receive the multilevel-coded modulated signal via multiple-transmit antennas by iterative determination of soft estimates of bits followed by a hard decision as to what bit was intended. The receiver (2) comprises a first processor (3) operative to provide first soft estimates of bits of the received signal, and a second processor (13) operative to decode the first soft estimates and to provide second soft estimates of the bits. The receiver (2) also comprises a first combiner (11') operative to provide adapted first soft estimates to the second processor (13), the adapted first soft estimates of each bit being dependent upon the respective first soft estimate and a respective previous first soft estimate. The receiver (2) also comprises a second combiner (17) operative to provide third soft estimates back to the first processor for subsequent further decoding, the third soft estimates of each bit being dependent upon the respective second soft estimate and a respective previous second soft estimate.

Erläutert wird ein Verfahren zum Bearbeiten von durch einen Empfänger (16) empfangenen Daten. Die empfangenen Daten werden mit Hilfe eines Metrikinkremente verwendenden Maximum-Aposteriori-Wahrscheinlichkeitsalgorithmus bearbeitet. Zum Berechnen der Metrikinkremente werden Zuverlässigkeitswerte (L(u_k,l)) verwendet, die unter Verwendung eines Kalman-Filters in einer Schätzeinheit (20) ermittelt wurden.

A partir de la séquence des bits d'information à transmettre, le codeur forme une seconde séquence (T2) de bits c_n, qui inclut un sous-ensemble redondant. Un codage différentiel de la forme d_n=c_n⊕d_f(n) avec f(n)<n produit une troisième séquence (T3) de bits d_n. Le signal émis représente les bits de la troisième séquence (T3) dans un ordre déterminé. Ayant obtenu des données de vraisemblance r_n associées aux bits d_n, le récepteur calcule des estimations des bits c_n du sous-ensemble redondant en fonction du signe de r_n.r_f(n). En exploitant la redondance, le récepteur peut détecter les bits c_n dudit sous-ensemble ayant des estimations erronées, et rectifier le signe de la moins fiable des deux données de vraisemblance r_n et r_f(n) associées. Les autres bits c_n, de la seconde séquence (T2) bénéficient alors d'une protection supplémentaire s'il y a au moins un bit c_n du sous-ensemble redondant tel que n'=f(n) ou f(n')=n ou f(n).