997results about How to "Improve decoding performance" patented technology

The invention discloses a density evolution based polarization code constructing method and polarization code coding and decoding system. According to the invention, the code length N and the information bit length K of an information code to be processed are obtained, an expectation value set of a log-likelihood ratio probability density function of N bit channels, K bit channels are selected as the information bit channels according to the expectation value set and information bit information index vector quantity is generated; an information bit sequence and a fixed bit sequence are mixed and the mixed bit vector quantity is multiplied by a polarization code for generating a matrix so as to output an encoding sequence; the encoding sequence is modulated and input into a transmission channel and the sequence output by the transmission channel is subjected to decoding operation by adopting a polarization code decoding algorithm, bit error probability and frame error rate of the decoded code are calculated and a design signal to noise ratio is changed, the above operation is repeated until the bit error probability and frame error rate become the minimum. The method and system provided by the invention are suitable for general binary system memoryless channels, the bit error probability and frame error rate are low, the calculation complexity is low and the communication performance of a communication system is improved.

The invention provides a decoding method and a decoding device for polar codes concatenated with a cyclic redundancy check (CRC). The decoding method includes the following steps: SC-list decoding is carried out on the polar codes according to the number, which is L, of survival paths to obtain the L survival paths, wherein the L is a positive integer; each of the L survival paths is subjected to the CRC; and when none of the L survival paths passes the CRC, the number of the survival paths is increased, and decoding results of the polar codes are obtained according to the number, which is increased, of the survival paths. According to the decoding method and the decoding device for the polar codes concatenated with the CRC, the path number of the survival paths is adjusted according to the result of the CRC, and therefore the paths which can pass the CRC can be output as far as possible, and the decoding performance is improved.

An iterative message passing decoder, e.g., an LDPC decoder, operating in conjunction with a soft input-soft output signal processing unit, e.g., an ISI detector, has an error floor performance region influenced by the decoder's sub-optimal message passing nature. Error floor reduction is achieved by a simple message re-initialization mechanism. Decoder edge states, e.g., constraint to variable node messages in decoder memory, are reinitialized, e.g., for an iteration, during the decoding after soft values provided by signal processing unit have improved. During the message re-initialization and for some subsequent amount of iterative decoder processing, extrinsic information fed back from the decoder to the signal processing unit and / or soft values delivered to the decoder from the signal processing unit, in an outer communications loop, is temporarily frozen, e.g., using a switch and a buffer. Then, the outer communications loop is restored as the decoding continues, achieving improved decoding performance.

The present invention relates to a Vestigial Side Band (VSB) Digital Television (DTV) in agreement with the DTV standards (A / 53) of the Advanced Television System Committee (ATSC), and to a method thereof. More particularly, it provides 4-VSB DTV transceiver that improves reception performance of a receiver by transmitting and receiving dual streams formed of normal data and robust data without increasing average power, regardless of a mixing rate of the normal and robust data. The 4-VSB DTV transceiver of the present research includes an encoding unit for encoding the robust data to be mapped to one of two groups having 4 levels {−5, −3, 1, 7} and {−7, −1, 3, 5}.

Provided is a Vestigial Side Band Digital Television (DTV) transmitter / receiver based on Advanced Television System Committee A / 53. The invention provides DTV transmitter / receiver having a dual stream structure through generation of robust data which has a transmission rate a fourth as fast as that of normal data, and a method thereof. The DTV transmitter includes: input means for receiving digital video data stream including normal and robust data; encoding means for performing ¼ rate coding on the digital video data stream so that one bit can be transmitted through two symbols; and transmitting means for modulating / transmitting output signals of the encoding means. This invention can reduce SNR and satisfy TOV of robust data by performing additional FEC on robust data, transmitting / receiving ¼ rate coded robust data, which are capable of transmitting one-bit data for two symbols, and improving decoding ability of an equalizer and a trellis decoder of a DTV receiver.

A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes: an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding; an interleaver configured to interleave the LDPC codeword; and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver includes a block interleaver formed of a plurality of columns each comprising a plurality of rows, and the block interleaver is configured to divide the plurality of columns into at least two parts and interleave the LDPC codeword.

The present invention relates to a Vestigial Side Band (VSB) Digital Television (DTV) in agreement with the DTV standards (A / 53) of the Advanced Television System Committee (ATSC), and to a method thereof. More particularly, it provides 4-VSB DTV transceiver that improves reception performance of a receiver by transmitting and receiving dual streams formed of normal data and robust data without increasing average power, regardless of a mixing ratio of the normal and robust data. The 4-VSB DTV transceiver of the present research includes an encoding unit for encoding the robust data to be mapped to one of two groups having 4 levels {−5, −3, 1, 7} and {−7, −1, 3, 5}.

Memory devices and / or error control codes (ECC) decoding methods may be provided. A memory device may include a memory cell array, and a decoder to perform hard decision decoding of first data read from the memory cell array by a first read scheme, and to generate output data and error information of the output data. The memory device may also include and a control unit to determine an error rate of the output data based on the error information, and to determine whether to transmit an additional read command for soft decision decoding to the memory cell array based on the error rate. An ECC decoding time may be reduced through such a memory device.

A decoding method for block-based digital encoded picture is disclosed. The method including the steps of reconstructing a zeroth reference picture list and a first reference picture list for a current picture based on a predetermined digital picture coding protocol; establishing a lookup table which includes a parameter field for storing a distance scalar, the distance scalar being derived from the time sequence characteristic values of the current picture, the co-located picture and a predetermined reference picture; determining a derived motion vector of a direct mode bi-predictive block according to the distance scalar and a predetermined motion vector of a co-located block with respect to the predetermined reference picture. An apparatus for implementing the method is also disclosed.

A method of video decoding is provided that includes receiving a data stream comprising a sequence of syntax elements that were compressed using context-adaptive binary arithmetic coding (CABAC), such that the encoding of each bin of a bin string representative of a syntax element was performed by arithmetic encoding. Two consecutive bins of a syntax element are decoded in parallel. Speculative computation and prefetching is used to reduce the critical path and thereby improve processing speed.

A method for transmitting control signals in a multi-carrier system. A method for arranging pilots in a transmitting side which transmits and receives data using a plurality of sub-carriers includes acquiring transmission data to be transmitted to a receiving side, processing data of a specific region among the transmission data in accordance with hidden pilots for channel estimation of the receiving side, allocating specific radio resources exclusively for the transmission data and dedicated pilots for channel estimation of the receiving side.

There is provided a wireless communication device capable of improving a decoding performance by using an optimal selection criterion for a start address and a read direction in a circular buffer. An interlacer (13) writes an interleaved and interlaced bit sequence into a circular buffer (14). An RV decision unit (109) decides the read start address and read direction of the circular buffer (14) based on the number of non-transmitted systematic bits, the number of non-transmitted important parity bits, and / or the number of non-transmitted unimportant parity bits. A read control unit (110) controls the read start address and read end address of the circular buffer (14). A read unit (15) is controlled by the read control unit (110) to continuously read encoded bits from the circular buffer (14).

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 iterative message passing decoder, e.g., an LDPC decoder, operating in conjunction with a soft input-soft output signal processing unit, e.g., an ISI detector, has an error floor performance region influenced by the decoder's sub-optimal message passing nature. Error floor reduction is achieved by a simple message re-initialization mechanism. Decoder edge states, e.g., constraint to variable node messages in decoder memory, are reinitialized, e.g., for an iteration, during the decoding after soft values provided by signal processing unit have improved. During the message re-initialization and for some subsequent amount of iterative decoder processing, extrinsic information fed back from the decoder to the signal processing unit and / or soft values delivered to the decoder from the signal processing unit, in an outer communications loop, is temporarily frozen, e.g., using a switch and a buffer. Then, the outer communications loop is restored as the decoding continues, achieving improved decoding performance.

The embodiment of the invention provides a method, a device and a system for encoding and decoding and relates to the field of communication. The invention aims to improve the decoding performance and improve the accuracy of a survivor path. The method comprises the following steps: first, encoding information bits according to a first-stage encoding method to obtain a first-stage encoded codeword; acquiring the sorting data volume of each check bit of the first-stage encoded codeword, and adjusting each check bit to a corresponding position according to the sorting data volume of the check bit, wherein the sorting data volume is the value of S when the check bit is related to the first S information bits among the information bits in the first-stage encoded codeword, and S is a non-zero integer; and carrying out second-stage encoding on the first-stage encoded codeword of which the positions of the check bits are adjusted according to a second-stage encoding method to obtain a second-stage encoded codeword. The method, the device and the system for encoding and decoding are applicable to various communication systems.

A network side equipment, a user equipment, and a method for soft buffer processing are provided. The method includes allocating, by a base station, transmission resource for a User Equipment (UE), and processing a soft buffer according to at least one parameter of the soft buffer, when uplink and downlink configurations of a plurality of cells of the UE Carrier Aggregation (CA) are different, sending, by the base station, data to the UE by a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH), wherein the at least one parameter of soft buffer is determined by at least one of a Primary cell (Pcell) and a Secondary cell (Scell) uplink and downlink configurations of the UE, and wherein rate matching is performed on the PDSCH.

A unequal protection hybrid automatic retransfer request method based on equality and un-equality constellation diagram mapping, it is used in MQAM communication system with which the stage numbers is M and M=2, the modulation mapping of sending end and the resolving mapping of receiving end adopt constellation diagrams that have same distribution, in the first transmission and anterior m / 2-1 time retransmission, adopts equality constellation diagram, at the m / 2 time and the latter retransmission adopts un-equality constellation diagram, provides higher error protection for two most significant bit in the modification symbol; the bits un-equality protection in the modification symbol of sending end reset; uses m / 2 reset and opposite reset rules, at different retransmission time adopts circularly in turn, achieves alternative protecting the bits in modulation symbol; the bits in modulation symbol of receiving end reset oppositely. Reset oppositely the bits according to the reset rules of sending end, recover it into bits sequence soft value before sending end bits resetting. It promotes the signals S / N of combining soft value after demodulating and resolving mapping at receiving end, reduces efficiently grouping retransmission time, makes the output of system maximum.

In a Maximum A posteriori Probability decoding (MAP decoding), a correlation and a deviation of noises for past and future states which depend on input signal patterns in past N bits and future Q bits are calculated by training by a noise correlation arithmetic operating unit 84 and they are stored. Upon reproduction, in a white noise arithmetic operating unit 91, white noise values for the past and future states in which colored noises are converted into white noises are obtained by using the stored correlation and deviation of the noises. In an input signal arithmetic operating unit 92, an input signal (channel information) Λc(yk|Smk) of the MAP decoding is calculated from the white noise values and the deviation for the past and future states. A likelihood in the MAP decoding is obtained from the input signal.

A data transfer method via a packet oriented channel and a continuous channel in parallel between a mobile station and a base stations, where the transfer via the continuous channel is interrupted whereby at least one transfer gap is formed.

Methods and systems for transmitting and receiving data include reverse concatenated encoding and decoding. Reverse concatenated decoding includes inner decoding the encoded stream with an inner decoder that uses a low-complexity linear-block code to produce an inner-decoder output stream, outer decoding the inner-decoder output stream with an outer decoder that uses a low-density parity-check code to produce an information stream, and iterating extrinsic bit reliabilities from the outer decoding for use in subsequent inner decoding to improve decoding performance.

A decoding apparatus and method is disclosed by which the decoder error occurrence probability is suppressed and a high decoding performance can be achieved. An ABP decoding apparatus diagonalizes a parity check matrix, updates LLR values, decodes the LLR values and then adds a decoded word obtained by the decoding to a decoded word list. The ABP decoding apparatus repeats the decoding procedure as inner repetitive decoding by a predetermined number of times. Further, as the ABP decoding apparatus successively changes initial values for priority ranks of the LLR values, it repeats the inner repetitive decoding as outer repetitive decoding by a predetermined number of times. Then, the ABP decoding apparatus selects an optimum one of the decoded words from within a decoded word list obtained by the repeated inner repetitive decoding. The invention is applied to an error correction system.

Two-dimensional Code having superior decoding property which is possible to control the level of error correcting codes, and method for encoding and decoding the two-dimensional Code is provided. The two-dimensional code includes finding pattern area comprised finding patterns for discriminating the code area from whole image, timing pattern area comprised timing patterns for checking a position of data area from the whole code and positions of each cells of the data area, and data area inputted various kinds of data and decoding information of data itself.

Methods and apparatus for enabling effective decoding of rate-compatible punctured codes are presented herein. A puncturing component can derive one or more partial puncturing patterns and corresponding decoding matrices / graphs that represent punctured code from a parity check matrix / graph of a mother code and a puncturing pattern specified for the mother code. Further, a rowcombining component can combine rows of the parity check matrix / graph based on the derived one or more partial puncture patterns. Further, the rowcombining component can create at least one decoding matrix / graph to represent the punctured code based on the combined rows. In addition, a selection component can select a decoding matrix / graph from the created at least one decoding matrix / graph that does not contain a girth-4 cycle.

A system and method for transmitting and receiving acknowledgement information are provided. A method for communications device operations includes determining a hybrid automatic repeat request (HARQ) response for each CC in a set of configured CCs, thereby producing a set of HARQ responses, generating an information vector from the set of HARQ responses, encoding the information vector, and transmitting the encoded information vector. A sub-vector of one or more bits selected from the information vector is assigned a fixed vector value independent of HARQ responses for CCs not in a set of CCs when the set of CCs is not empty, where the set of CCs comprises at least one CC whose HARQ response is equal to DTX.

A diversity transmission scheme uses a number of antennas that is greater than the limitation of two transmitting antennas in the well-known Alamouti scheme. In an embodiment comprising four antennas, the antennas transmit in pairs such that each antenna transmits a block that is used in the Alamouti scheme. This increases the transmission rate. For example, the transmission of two signals at a given time slot increases transmission rate by a factor of two. The invention not only increases the number of antennas, but also increases the transmission rate. At the receiver end, the code is decoded without matrix inversion and without much noise enhancement. Moreover, noise enhancement stability is increased by a simple, partial interference cancellation scheme, that results in improved decoding performance.

The present invention relates to a video encoding method and apparatus for setting and encoding quantization parameters, and to a video decoding method and apparatus for decoding and setting quantization parameters in a video encoding and decoding apparatus which uses blocks having various sizes and depths as encoding and decoding units.

An apparatus and method are provided for normalizing input soft metric to a channel decoder in a wireless communication system. A demapper generates soft metric using an in-phase component (Xk) and a quadrature component (Yk) of a received modulated symbol (Rk), a channel fading coefficient (gk) and a constant value (c) defined by a modulation order of the received modulated symbol. A normalizer receives the soft metric, computes a normalized log likelihood ratio (LLR) by multiplying the soft metric by a ratio of the constant value to a noise variance value, transforms the normalized LLR into a desired range and a desired number of bits, and outputs an input LLR of the channel decoder.

Techniques for encoding and decoding data are described. In an aspect, multiple code rates for a forward error correction (FEC) code may be supported, and a suitable code rate may be selected based on packet size. A transmitter may obtain at least one threshold to use for code rate selection, determine a packet size to use for data transmission, and select a code rate from among the multiple code rates based on the packet size and the at least one threshold. In another aspect, multiple FEC codes of different types (e.g., Turbo, LDPC, and convolutional codes) may be supported, and a suitable FEC code may be selected based on packet size. The transmitter may obtain at least one threshold to use for FEC code selection and may select an FEC code from among the multiple FEC codes based on the packet size and the at least one threshold.