1080results about "Error correction/detection using convolutional codes" patented technology

Embodiments are directed to transmitting L1 pre-signaling information with predetermined modulation and code rate such that L1 pre-signaling information can be received without preliminary knowledge on the network. L1 pre-signaling information makes it possible to receive the L1 signaling information, data link layer information, and notification data that may have configurable code rates and modulation. Therefore, L1 pre-signaling information can be thought of as signaling metadata (i.e., information about other signaling information). L1 signaling is divided into pre-signaling and signaling parts. The pre-signaling part includes parameters used for receiving the L1 signaling information. L1 pre-signaling signaling enables the receiver to receive the signaling itself (L1 signaling and data link layer information) by informing the receiver about the type of modulation, coding, and the like, used to transmit the L1 signaling, data link layer, and notification information.

Apparatus and methods store error recovery data in different dimensions of a memory array. For example, in one dimension, block error correction codes (ECC) are used, and in another dimension, supplemental error correction codes, such as convolutional codes, are used. By using separate dimensions, the likelihood that a defect affects both error recovery techniques is lessened, thereby increasing the probability that error recovery can be performed successfully. In one example, block error correction codes are used for data stored along rows, and this data is stored in one level of multiple-level cells of the array. Supplemental error correction codes are used for data stored along columns, such as along the cells of a string, and the supplemental error correction codes are stored in a different level than the error correction codes.

A wireless communication network includes a base station and a relay station. The relay station is configured to relay communications between the base station and at least one subscriber station. The base station is configured to communicate with the subscriber station via the relay station. The base station further is configured to transmit, in a subframe, a plurality of transport blocks for a plurality of Hybrid Automatic Repeat Request (HARQ) processes to the relay station. Each transport block corresponds to a different HARQ process.

An apparatus for transmitting information comprises a bitstream source for providing a bitstream representing the information, a redundancy adding encoder for generating an encoded bitstream, which is arranged to output, for a first number of input bits, a second number of output bits, the second number of output bits having at least twice as many output bits as the first number of input bits, wherein the second number of output bits includes two portions of output bits, each portion of output bits individually allowing the retrieval of information represented by the first number of input bits, and the first portion of output bits being coded based on the bitstream in a different way with respect to the second portion of output bits. The apparatus further comprises a partitioner for partitioning the second number of output bits into the two portions of output bits and a transmitter for transmitting the output bits of the first portion via a first channel and the output bits of the second portion via a second channel, the second channel being spatially different from the first channel. An inventive receiving apparatus combines the signals received via the first and second channels and uses both channel signals for channel decoding by removing redundancy. Thus, the transmitting receiving system is suitable for providing time and / or space diversity and, in the optimal case, provides a C / N value which is greater than 4.3 dB with respect to a two-channel system comprising a duplicator in the transmitter and a channel-controlled switch in the receiver.

PCT No. PCT / FR97 / 00607 Sec. 371 Date Apr. 19, 1999 Sec. 102(e) Date Apr. 19, 1999 PCT Filed Apr. 3, 1997 PCT Pub. No. WO97 / 38495 PCT Pub. Date Oct. 16, 1997Disclosed are a method and a device for the convolutive encoding of blocks each formed by a predetermined number N of source data elements, wherein each of said source data elements is introduced twice into one and the same convolutive encoder implementing a generating polynomial with a period L in an order such that the two instances of introduction of one and same source data element di are separated by the introduction of (pi.L)-1 other source data elements, pi being a non-zero integer. Also disclosed are a corresponding decoding method and device that can be applied, in particular, to the transmission of short messages, for example in radiotelephony, for satellite communications or gain computer telecommunications (Internet for example). FIG. 2.

A system and method is provided for decoding a set of bits using a plurality of hypotheses, for example, each independently tested on-the-fly. Initial bit states and associated reliability metrics may be received for the set of bits. A current hypothesis may be decoded for correcting the set of bits, wherein the current hypothesis defines different bit states and associated reliability metrics for the set of bits. If decoding the current hypothesis is not successful, a subsequently ordered hypothesis may be decoded, wherein the hypotheses are ordered such that their associated reliability metric is a monotonically non-decreasing sequence. Decoding may proceed iteratively until the current hypothesis is successful.

A computing system retrieves securely stored encrypted and encoded data from a dispersed data storage system. The computing system includes a processing module and a plurality of storage units. The processing module includes an error decoder and a decryptor and to decode and decrypt the encrypted and encoded data retrieved from the dispersed data storage system utilizing a read command to the storage units. The storage units retrieve the encrypted and encoded data and send the encrypted and encoded data to the processing module when receiving the read command.

An efficient telecommunications receiver system for accurately decoding a received composite signal having a data signal component and a pilot signal component. The receiver system includes a first circuit for receiving the composite signal and extracting a pilot signal and a data signal from received composite signal. A second circuit calculates a log-likelihood ratio as a function of a channel estimate based on the pilot signal. A third circuit scales the log-likelihood ratio by a predetermined log-likelihood ratio scaling factor and provides an accurate log-likelihood value in response thereto. A fourth circuit decodes the received composite signal based on the accurate log-likelihood value and the data signal. In a specific embodiment, the pilot signal and the data signal comprise pilot samples and data samples, respectively. The third circuit includes a carrier signal-to-interference ratio circuit for computing a first signal-to-interference ratio and a second signal-to-interference ratio based partly on the pilot signal. The first signal-to-interference ratio is based on the data samples, and the second signal-to-interference ratio is based on the pilot samples. The first signal-to-noise ratio and the second signal-to-noise ratio provide input to a circuit for computing the predetermined log-likelihood ratio scaling factor that is included in the third circuit. In a more specific embodiment, the first circuit includes a despreader for despreading the received composite signal in accordance with a predetermined spreading function and providing a despread signal in response thereto. The spreading function is a pseudo noise sequence or a Walsh function. The first circuit further includes a decovering circuit that extracts the pilot signal and the data signal from the despread signal. In the illustrative embodiment, the accurate receiver system further includes a circuit for generating a rate and / or power control message and transmitting the rate and / or power control message to an external transceiver in communication with the efficient receiver system.

A system and method for using a cyclic redundancy check (CRC) to evaluate error corrections. A set of data and initial CRC values associated therewith may be received. The set of data by changing a sub-set of the data may be corrected. Intermediate CRC values may be computed for the entire uncorrected set of data in parallel with said correcting. Supplemental CRC values may be computed for only the sub-set of changed data after said correcting. The intermediate and supplemental CRC values may be combined to generate CRC values for the entire corrected set of data. The validity of the corrected set of data may be evaluated by comparing the combined CRC values with the initial CRC values.

A method begins by a router receiving data for storage and interpreting the data to determine whether the data is to be forwarded or error encoded. The method continues with the router obtaining a routing table when the data is to be error encoded. Next, the method continues with the router selecting a routing option from the plurality of routing options and determining error coding dispersal storage function parameters based on the routing option. Next, the method continues with the router encoding the data based on the error coding dispersal storage function parameters to produce a plurality of sets of encoded data slices. Next, the method continues with the router outputting at least some of the encoded data slices of a set of the plurality of sets of encoded data slices to an entry point of the routing option.

A method and system of wireless communication is provided which involves inputting information bits, wherein certain bits have higher importance level than other bits, and applying unequal protection to the bits at different importance levels. As such, important bits are provided with more protection for transmission and error recovery. Applying unequal protection involves using skewed constellations such that more important bits are provided with more error recovery protection.

An automatic retransmission request control system in OFDM-MIMO communication system. In this system, an ACK / NACK output part (320) of a receiver transmits, to a transmitter, a feedback information of positive or negative response based on the result of a cyclic redundancy check. An error data stream decision part (310) of the transmitter determines, based on the feedback information, a data stream that need be retransmitted, and a retransmission mode selection part (312) selects a retransmission mode from among (a) a mode in which to transmit the data, which are to be retransmitted, via the same antenna as in the previous transmission, while transmitting, at the same time, new data by use of an antenna via which no data retransmission is requested; (b) a mode in which to transmit the data, which are to be retransmitted, via an antenna via which no retransmission is requested, while transmitting new data via another antenna at the same time; (c) a mode in which to use STBC to retransmit the data via an antenna via which no retransmission is requested; and (d) a mode in which to use STBC to retransmit the data via all the available antennas.

This invention relates generally to a packet recovery algorithm for real-time (live) multi-media communication over packet-switched networks, such as the Internet. Such multi-media communication includes video, audio, data or any combination thereof. More specifically, the invention comprises a forward error correction (FEC) algorithm that addresses both random and burst packet loss and errors, and that can be adjusted to tradeoff the recoverability of missing packets and the latency incurred. The transmitter calculates parity packets for the rows, columns and diagonals of a block of multi-media data packets using the exclusive or (XOR) operation and communicates the parity packets along with the multi-media data packets to the receiver. The receiver uses the parity packets to recover missing multi-media data packets in the block. The FEC algorithm is designed to be able to recover long bursts of consecutive missing data packets. If some parity packets are missing, they too can be recovered using an extra single parity packet, so that they can be used to recover other missing data packets. The invention applies to both one-way real-time streaming applications and two-way real-time interactive applications, and to both wired and wireless networks. The invention retains backwards compatibility with existing standards governing FEC for professional video over IP networks.

A method and apparatus perform forward error correction in a wireless communication device in a wireless communication network. Application layer forward error correction (AL-FEC) capability information is transmitted during a capabilities exchange. A set of source packets are reshaped to k equal-sized source symbols. Systematic packets for the source symbols and at least one parity packet is encoded using a single parity check (SPC) AL-FEC code on the k source symbols. A header of each encoded packet includes a parity packet indicator. The encoded packets are processed in a media access control (MAC) layer and a physical (PHY) layer for transmission.

It is possible to provide and an LDPC-CC (Low-Density Parity-Check Convolution Codes) encoder and an LDPC-CC decoder which performs an error correction encoding and decoding while reducing the amount of a termination sequence required for encoding / decoding the LDPC-CC encoding / decoding and suppressing degradation of the transmission efficiency. The LDPC-CC encoder (400) includes a weight control unit (470) which stores a weight pattern (475) based on an LDPC-CC inspection matrix (100); and a weight pattern (476) based on a check matrix (300) obtained by deforming an LDPC-CC inspection matrix (100). The weight control unit (470) controls a weight to be multiplied onto the outputs of a plurality of shift registers (410-1 to 410-M, 430-1 to 430-M) by using the weight pattern (475) when the input bit is an information sequence, and using a weight pattern (476) which makes a weight value to be multiplied by an inspection bit v2,t to be 0 when the input bit is a termination sequence.

A digital broadcasting system and a method of processing data are disclosed. A receiving system of the digital broadcasting system may include a signal receiving unit, a demodulating unit, a demultiplexer, and an audio / video decoder. The signal receiving unit receives a broadcast signal including main service data and an RS frame including a plurality of MPH service data packets. The demodulating unit demodulates data of the RS frame. The demultiplexer identifies an MPH service data packet including an IP datagram of mobile service data with reference to an MPH header of each MPH service data packet in the RS frame, and when a stuffing data is inserted in the identified payload of MPH service data packet, removes the stuffing data from the payload and separates an audio and video data from IP datagram of the mobile service data of the payload, and outputs the separated audio and video data.

Apparatus and methods store data in a non-volatile solid state memory device according to a rate-compatible code, such as a rate-compatible convolutional code (RPCC). An example of such a memory device is a flash memory device. Data can initially be block encoded for error correction and detection. The block-coded data can be further convolutionally encoded. Convolutional-coded data can be punctured and stored in the memory device. The puncturing decreases the amount of memory used to store the data. Depending on conditions, the amount of puncturing can vary from no puncturing to a relatively high amount of puncturing to vary the amount of additional error correction provided and memory used. The punctured data can be decoded when data is to be read from the memory device.

Apparatus and methods store stream-based error recovery data for a memory array, such as a NAND flash array. Conventionally, data is block coded per industry specification and stored in the memory array. Within the limits of the block code, this technique provides for correction of errors. By applying a stream-based inner code, that is, concatenating the outer block code with an outer code, the error correction can be further enhanced, enhancing the reliability of the device. This can also permit a relatively small-geometry device to be used in a legacy application.

A system and method of relay code design and factor graph decoding using a forward and a backward decoding scheme. The backward decoding scheme exploits the idea of the analytical decode-and-forward coding protocol and hence has good performance when the relay node is located relatively close to the source node. The forward decoding scheme exploits the idea of the analytical estimate-and-forward protocol and hence has good performance when the relay node is located relatively far from the source node. The optimal decoding factor graph is first broken into partial factor graphs and then solved iteratively using either the forward or backward decoding schemes.

A method for hard-decision channel decoding of tail-biting convolutional codes includes the step of receiving from a channel an input bit stream encoded by a tail-biting convolutional channel encoder. The encoder includes a number of memory elements and a rate. The input bit stream includes a series of symbols; each symbol includes a number of bits; the number of bits is related to the rate of the encoder. The method further includes the step of assuming a probability for each possible initial state of the encoder. The method further includes the step of decoding each symbol of the input bit stream using majority logic, with reference to a trellis structure corresponding to the encoder. The trellis structure represents: a number of states related to the number of memory elements of the encoder; a plurality of transitional branches; and a number of stages related to the number of symbols in the input bit stream.

A pre-decoder applied to a turbo decoder for decoding a punctured turbo code. The turbo code consists of a data bit stream and a plurality of parity bit streams, parts of which are punctured. The pre-decoder has an arithmetic unit for calculating estimated parity bit streams by carrying out, with respect to the data bit stream, the same algorithm used by a turbo encoder to produce the parity bit streams, a comparison unit for comparing the plurality of parity bit streams with the estimated parity bit streams, and a recovery unit for substituting estimated parity symbols for corresponding punctured parts of the parity symbol streams when related non-punctured bits of the parity bit streams are identical with corresponding estimated non-punctured parity bits. The punctured parity symbols are recovered by the pre-decoder completely, or at least partially, and provided to the turbo decoder. Accordingly, the decoding performance of the turbo decoder is enhanced.

A method of transmitting digital information comprises the steps of forward error correction encoding a plurality of bits of digital information using complementary pattern-mapped convolutional codes, modulating a plurality of carrier signals with the forward error corrected bits, and transmitting the carrier signals. The modulation can include the step of independently amplitude shift keying in-phase and quadrature components of the QAM constellation using Gray code constellation points corresponding to amplitude levels. Transmitters that transmit signals in accordance with the method and receivers that receive such signals are also included.

A digital broadcasting system and a method of processing data are disclosed, which are robust to error when mobile service data are transmitted. To this end, additional encoding is performed for the mobile service data, whereby it is possible to strongly cope with fast channel change while giving robustness to the mobile service data.

A method begins by a processing module encoding data utilizing a dispersed storage error coding function to produce a set of encoded data slices, wherein the dispersed storage error coding function includes a decode threshold parameter and a pillar width parameter. The method continues with the processing module storing a number of encoded data slices of the set of encoded data slices in a local memory, wherein the number is based on the decode threshold parameter and is less than the pillar width parameter, and outputting remaining encoded data slices of the set of encoded data slices to dispersed storage network (DSN) memory.

The present invention proposes information processing method and device using time domain pilot sequence in OFDM system. The time domain pilot sequence is filled in the initial part of protecting interval of OFDM sign, and rest part of the protecting interval is filled with the circular prefix of OFDM sign, with FFT block being following the circular prefix. Or, the time domain pilot sequence is filled into the whole protecting interval of each OFDM sign, and FFT block follows the protecting interval. The time domain pilot sequence has self-correlation or periodical self-correlation characteristic, equal amplitude or nearly equal amplitude spectrum characteristic, and length of second power. For sake of system design and according to the features of TP sequence, the present invention proposes some transceiving system, time deviation estimation, carrier deviation estimation and channel estimation method and device based on TP sequence characteristic and OFDM sign structure characteristic.

Disclosed are an apparatus and a method capable of preventing performance degradation during a channel decoding process. A bit interleaving is performed with respect to parity bits among coded bits output through a channel coding unit, thereby preventing a repetition period of the parity bits from matching a puncturing period for a rate matching. A bit de-interleaving is performed with respect to the parity bits during a channel decoding process, so that the parity bits have a repetition period identical to initial parity bits. Thus, the repetition period of the parity bits is not matched with the puncturing period for the rate matching, thereby preventing performance degradation during the channel decoding process.

A digital television transmitting system includes a pre-processor, a packet generator, an RS encoder, and a trellis encoder. The pre-processor pre-processes enhanced data by coding the enhanced data for first forward error correction (FEC) and expanding the FEC-coded enhanced data. The packet generator generates first and second enhanced data packets including the pre-processed enhanced data and main data packets and multiplexes the enhanced and main data packets. The first enhanced data packet includes an adaptation field including the pre-processed enhanced data and second enhanced data packet includes a payload region including the pre-processed enhanced data. The RS encoder performs RS encoding on the multiplexed data packets for second forward error correction (FEC), and the trellis encoder performs trellis encoding on the RS-coded data packets.

A system, method, apparatus and computer code are provided for producing coherent symbols from digital RF transmitters. A receiver receives a first initialization packet containing a plurality of stuff bytes and Trellis coders are deterministically initialized using the first initialization packet.