249results about How to "Reduce decoding complexity" patented technology

The invention discloses a segmented cyclic redundancy check method for polarization codes mainly in order to solve the problems of high decoding complexity and high block error rate in the prior art. According to the technical scheme, the method comprises the steps as follows: first, the correct probability of the estimated value of each bit channel is calculated, and a channel for transmitting non-fixed bits is selected according to the probability; then, according to the correct probability of the estimated value of the channel for transmitting non-fixed bits, an information bit sequence is divided into sub information bit sequences, and segmented CRC check is carried out; next, polarization coding is carried out on the bit sequence joining in the segmented CRC check; and finally, the coded sequence is transmitted in the channel. Compared with the prior art, the method has the advantage that the method reduces the decoding complexity, improves the block error rate of decoding, and can be used to reduce the transmission error probability in the process of wireless communication.

A method for data transmission. The method including the steps of generating at least one resource tree, mapping a plurality of resource elements into respective leaf nodes in the at least one resource tree according to a certain mapping scheme, with each node in the at least one resource tree representing a resource allocation scheme for data transmission, and transmitting data using a resource allocation scheme selected from among the plurality of resource allocation schemes represented by respective nodes in the at least one resource tree. In response to reception of the data, a receiver decodes the data by recursively applying the plurality of resource allocation schemes represented by respective nodes in the at least one resource tree until the data is decoded.

The invention discloses a list successive cancellation decoding method for polar codes, belonging to the technical field of wireless channel coding. In searching of a code tree, a candidate path list is updated as follows: each candidate path in a previous layer of candidate path list is expanded, and a reliable measurement value of each expanded path is computed; then, expanded paths, the reliable measurement values of which are less than the reliable measurement threshold of the current layer, are eliminated, it is determined whether the quantity of left expanded paths is greater than a preset maximum list length lmax, if yes, expanded paths among the left expanded paths, the reliable measurement values of which are the minimum, are eliminated, and the quantity of the last remaining expanded paths is not greater than lmax; and finally, the paths are selected adaptively. Loose ranking of the measurement values of the paths is combined with existing self-adaption polar decoder, so that the apparatus is guaranteed to have the same detection performance as conventional decoders, and decoding complexity is greatly lowered.

The invention provides a polarized code simplifying and decoding method.The polarized code simplifying and decoding method includes the following steps that step S1, a tree graph model is established for received polarized codes; step S2, nodes in a tree graph are divided into information nodes, fixed value nodes and mixed nodes; step S3, the tree graph is pruned, sub-trees between the fixed value nodes and the information nodes are cut off, and the fixed value nodes and the information nodes connected with the mixed nodes are left; step S4, a decoding tree graph after pruning is subjected to decoding operation.The polarized code simplifying and decoding method can achieve the purposes of reducing decoding complex and improving the decoding efficiency on the premise that the decoding performance is not affected and finally performs simulation verification, and the decoding complexity of SC decoding and BP decoding after simplification are reduced by 36%-65% and 41%-67% respectively compared with an original algorithm.

The invention discloses an adaptive error control method for source channel coding combined optimization, which is characterized in that the source coding output code streams are classified to the following three grades according to the significance: significance, secondary significance and non-significance; and during the channel coding process, the source code streams of the three graders undergo the adaptive unequal error protection by means of variable-velocity forward error control / hybrid automatic repeat request (FEC / HARQ), so as to allow the transmission rate and the channel coding rate of the source code streams to be adjusted adaptively according to the time-varying fading characteristics of the wireless channel, thereby optimizing the transmission quality of the source code streams and improving the transmission efficiency and the channel utilization rate of the whole system. The method comprises the six steps, overcomes the problems of contradiction and resource waste caused by the independent coding of the source and the channel in the prior communication system, achieves the effect of adaptive combined optimization of the source code stream transmission rate and the channel coding rate based on the time-varying fading characteristics of channel, and has good application prospects.

The invention discloses a quasi-cyclic low density odd-even check code belief propagation decoding method based on oscillation. In the initial iteration, a mean value is used for obtaining normalizing factors alpha and beta, under different signal-to-noise ratios, an extrinsic information value of a check node is dynamically corrected to reduce fluctuation of the extrinsic information value of the check node, the quasi-cyclic low density odd-even check code belief propagation decoding method unites a bit flip method in hard decision decoding to reduce occurrences of the oscillation, decoding performance of transmission data can be improved, and decoding complexity can be reduced. Decoding methods of soft decision and hard decision are combined to obtain big decoding gains. Balancing states of complexity and decoding efficiency of a decoder are achieved due to the facts that combination of low density odd-even check code hard decision decoding and low density odd-even check code soft decision decoding and excellent coding gains of a soft decision belief propagation algorithm are utilized, and a hard decision decoding method is fully applied to reduce influences of accumulated error code words.

The invention discloses a hybrid spread spectrum communication system based on low density parity code (LDPC) encoding and a method thereof. The problems of leakage capture, high leakage capture probability, slow convergence of a phase-locked loop and low decoding performance of the existing synchronous capture method are mainly solved. The system comprises a transmitting part and a receiving part, wherein the transmitting part is used for carrying out pretreatment on original information; the pretreatment data are subjected to frequency hopping treatment and transmitted after being modulated and filtered by a base band; the receiving part is used for obtaining a synchronization point position and a frequency offset value in the received signal through synchronous capture, and intercepting useful data to carry out de-hopping according to the synchronization point position; the base band demodulates and filters; the filtering data are subjected to frequency offset compensation according to the frequency offset value; the data after frequency offset compensation are subjected to dispreading and frequency offset rectification; the frequency offset rectification data are decoded and the decoding result is output. The hybrid spread spectrum communication system has the advantages of being strong in burst error resisting ability, high in real-time synchronization capture speed, high in capture accuracy, high in convergence speed of the phase-locked loop, and good in decoding performance, and can be applied to reliable communication under the condition of very low powder spectral density.

The invention discloses a video frequency decoding method comprising: identifying critical image and non-critical image from code stream to be decoded according to preset method; decoding the critical image, acquiring reconstruction image of critical image; according to first preset sampling fraction, decoding for pixel sampling for non-critical image, acquiring reconstruction image of non-critical image; according to display sequence, sequencing the reconstruction image of critical image and reconstruction image of the non-critical image, sampling processing for reconstruction image of the critical image according to display image resolution corresponding to display format. In addition, the invention also discloses a video frequency decoding device. The inventive technical scheme can reduce complexity of decoding.

The invention provides a method for improving BP (belief propagation) decoding by use of a polarisation code based on early termination of the iterative strategy. According to the method, the convergence condition of the likelihood ratio of the information bit of the polarisation code is used as the criterion for stopping iteration in the BP decoding algorithm, the iteration number is reduced, and the purpose of reducing the complexity of the BP decoding algorithm can be achieved; simulation results show that the strategy can greatly reduce the decoding iterations, when the maximum iteration number is 60 and the signal-to-noise ratio is 3.5dB, the average iteration number is reduced by 80% compared with the original BP decoding algorithm, and the method is better than the existing early termination method of the iterative strategy.

The invention belongs to the field of digital communication and digital storage, and especially relates to a recursive block Markov superimposed encoding method. The method is characterized by comprising the following steps: taking a short code of which the code length is n and the information bit length is k as a basic code, and encoding an information sequence FORMULA of which the length K is equal to kBL to a code word FORMULA of which the length N is equal to nB(L+T), wherein the encoding method includes the following steps: firstly, dividing the information sequence FORMULA of which the length K is equal to kBL into L equal-length blocks FORMULA, ensuring that the length of each block is kB, and aiming at t that is equal to -1, -2, ..., -(m-1), -m, initializing a sequence FORMULA of which the length is nB to an all-zero sequence; and then, at the time of t that is equal to 0, 1, ..., L-1, sending a sequence FORMULA of which the length is kB to a basic code encoder C for encoding to obtain an encoded sequence FORMULA of which the length is nB, and combining the fed-back FORMULA to calculate the t(th) sub-sequence FORMULA of the code word FORMULA. The recursive block Markov superimposed encoding method disclosed by the invention has the advantages of approaching the channel capacity, achieving simple encoding and flexible structure, and the like. Compared with a non-recursive block Markov superimposed encoding method, the method disclosed by the invention has lower decoding delay and decoding complexity, and has a very low error floor in decoding performance.

The invention provides a method for improving end-to-end wireless transmission control protocol (TCP) linear network coding. Particularly, the method comprises the following steps of: (1) optimizing a network coding head frame design on a network coding layer, so that required parameters of coding and decoding are comprehensively considered, the length of a network coding head is shortened, and the complexity of the network coding head is reduced; (2) according to the condition of wireless network packet loss, designing reasonable sliding windows and coding windows, and optimizing so that the sizes of the sliding windows and the coding windows are equal; (3) determining piggyback information content to be network coding message sequence expected to be received next time; and (4) amending a message loss retransmission mechanism, and starting retransmission when the accumulated packet loss number of coding messages achieves the number of sliding windows. Through the operation, the complexity of network coding can be reduced, and the network coding efficiency and the TCP throughput of an end-to-end system are improved.

The invention is applied to the audio and video playing field, and provides a method and a terminal for playing video on a low-side embedded product. The method comprises the following steps of: obtaining audio data and video code stream, and adopting a digital-to-analog convertor to convert the audio data from a digital signal to an analog signal; confirming an audio timestamp of the audio data according to audio parameter of the digital-to-analog convertor; confirming a video timestamp of the video code stream according to frame rate of the obtained video code stream; and decoding the video code stream according to the audio timestamp and the video timestamp and playing the decoded video code stream. According to the embodiment of the invention, only when an absolute value of the difference between the audio timestamp and the video timestamp is less than a preset time threshold, can the video code stream coded by adopting an MJPED coding mode with lower complexity be decoded, so that the audio and the video can be played synchronously.

The present invention discloses a postprocessing decoding method of LDPC (Low Density Parity-Check) codes based on CRC (Cyclic Redundancy Check) check codes. The method comprises the following steps: 1) executing a LBP (Layered Belief-Propagation) decoding method; 2) performing CRC verification; 3) performing LLR (Log-Likelihood Ratio) value sorting; 4) selecting target node; 5) performing node overturning; and 6) performing CRC verification again: a decoding decision result is subjected to CRC verification again at a postprocessing phase, if the verification is successful, the decoding is successful and is finished, or else, the process jumps to the step 5) to go on overturning. The method provided by the invention can perform overturning of error bits in order at the subsequent processing phase of error frames to damage a potential trapping set and improve the error floor while ensuring low decoding complexity.

The invention relates to a mixed iterative decoding method for an LDPC-RS two-dimensional product code in the technical field of communication system channel decoding. According to a received LDPC-RS product code block, log-SPA soft-decision decoding is conducted on LDPC codons of each row, bit soft value information after the decoding and soft value information corresponding to the edge of a bipartite graph are stored; improved WBF decoding is conducted on LDPC rows failed in the log-SPA soft-decision decoding and estimated bit error patterns of the rows failed in decoding can be returned through an improved WBF algorithm; when the estimated error patterns can be corrected by following RS, LDPC hard-decision decoding, RS+LDPC hard-decision decoding is converted; if all errors can not be corrected after one time of iteration is finished, bit soft values corresponding to the rows which is confirmed to be right after the hard-decision decoding are corrected and iteration of the next round is conducted. According to the mixed iterative decoding method for the LDPC-RS two-dimensional product code, the problem that when LDPC-RS is decoded through an SISO decoding structure, an RS soft-decision decoder is high in complexity. Meanwhile, compared with simple LDPC+RS cascading decoding, the mixed iterative decoding method for the LDPC-RS two-dimensional product code improves codon correction performance.

The invention relates to the technical field of digital information transmission, in particular to a constellation mapping and demapping method, and a coding, modulating, decoding and demodulating system. In a sign-amplitude independent modulation constellation mapping method, constellation mapping order M equals to 2m, and the constellation mapping dimension is D. The constellation mapping method includes that S11, each m input bits are divided into a group according to the constellation mapping order M; S12, when a transmission signal S equaling to [s1,s2,...,sD] is a D-dimensional real-number vector, plus-minus of each dimension is determined by D input bits in each group of input bits, and rest input bits with number of subtracting D from m determine absolute values of each-dimensional range of to-be-transmitted signals. The absolute values refer to Iota s1 Iota, Iota s2 Iota,..., Iota sD Iota . The method and the system with the method have low decoding complexity, and design and implementation of coding and modulating schemes are facilitated.

The invention discloses a high-throughput and low-complexity hierarchy decoder suitable for a non-binary LDPC code and a decoding method of the decoder. The decoder comprises a relative addressing unit, a caching unit and a computing unit, wherein the relative addressing unit prestores an input address for each of the computing unit and the caching unit so that a redundant clock period is inexistent between tiers; the depth of the caching unit is 1 so that the delay is maximally lowered; the computing unit comprises 2p-1 basic computing units capable of accomplishing the updating of one tire in a clock unit and optimizing a key path of each module so as to improve the clock frequency. Furthermore, the decoding method disclosed by the invention is a hard decoding method based on majority logic so as to take a compromise on the decoding performance and the complexity; a most reliable message and a secondary reliable message are selected in the method, symbols and confidences thereof are input and output in a bit way, 2p messages are converted into the transmission of P messages, and the storage space is greatly lowered.

The invention provides an error resilient coding method for high-efficiency data reading. The error resilient coding method comprises a method for coding and constructing IZSHC (Intersecting Zigzag Sets Hierarchical Codes) and a method for reading failure data under IZSHC, wherein the method for coding and constructing IZSHC refers to implementing redundant processing on to-be-read original data, i.e. coding an original document to generate redundant data blocks; the redundant data blocks are divided into original data blocks and checkout data blocks; the method for reading the failure data under IZSHC refers to reading decoding the failure data for recovery by utilizing the redundant data blocks when reading failure occurs to the original data blocks. According to the error resilient coding method, based on the IZSHC, the data reading performance in the case of node failure can be obviously improved.

The disclosed signaling message transmitting and receiving method for mobile digital multimedia broadcast physical layer comprises: adding message source coding mode information into the signaling message, modulating and sending the signaling message; demodulating the signaling message to obtain the coding mode information. Wherein, it can use single carrier wave, data sub-carrier and pilot frequency in OFDM system. This invention reduces decoding complexity.

The invention discloses a decoding device of low density parity check code (LDPC), which comprises a variable node message storage; a controller used for controlling the read and write operation of a node calculation unit to the variable node message storage and controlling the iteration process of a LDPC decoder; and a node calculation unit used for updating the messages of check nodes and variable nodes and judging the messages. The node calculation unit comprises a variable message generation unit used for calculating the variable message required by a check message calculation unit; a check message calculation unit used for updating the check message; a variable node message update unit used for updating the corresponding variable node message; a hard decision calculation unit used for calculating the hard decision message corresponding to the variable node; a parity check unit used for calculating the check bit and outputting a result to a decoding termination controller. The decoding device can meet the performance requirement and simultaneously reduce the decoding complexity of check code and reduce the iteration times.

The invention discloses a data transmission method, a sending device, a receiving device, and a communication system. The sending device is used for sending a first transmission block, the sending device acquires a coding bit segment from a first coding block, the first coding code is obtained after LDPC coding on a first code in the first transmission block according to processing capability of the receiving device, and the sending device sends the coding bit segment to the receiving device. Due to consideration of the processing capability of the receiving device, storage overhead of the sending device or the receiving device is reduced, coding or decoding complexity is lowered, and decoding success rate is improved.

The present invention discloses an SCMA system-based DMPA decoding method and decoder architecture. The method comprises four steps: initializing, resource node updating, layer node updating, and probability calculating and symbol determining. The architecture comprises an initializing unit for initializing, a resource node updating unit for resource node updating, a layer node updating unit for layer node updating, and a probability calculating unit for probability calculating and symbol determining. The SCMA system-based DMPA decoding method and decoder architecture have the beneficial effects that a DMPA algorithm is provided by using a nature of low complexity of an MPA decoding principle in a sparse system, so that the decoding complexity of the SCMA system is greatly lowered; and for a hardware architecture of the DMPA algorithm, series optimization in time sequence and resource reuse is made, so that a very simple low-complexity decoder architecture is obtained, and in a permitted processing speed range, hardware consumption is greatly reduced and hardware use efficiency is improved.

The invention relates to the technical field of mobile communication, in particular to an improved polar code serial elimination list bit flipping decoding method and system, and the method comprisesthe steps: inputting an initialized log likelihood ratio LLR into a decoder for decoder path selection, and screening out L paths for CRC verification; determining a fixed key flipping index set SCSS,and determining an improved key flipping index set ICSS according to a threshold of simulation statistics; if the bit index in the decoding process belongs to the ICSS, performing bit flipping to obtain L paths after bit flipping; performing CRC (cyclic redundancy check) on the L paths after bit flipping, and if the L paths pass the CRC, determining that decoding succeeds; and if the CRC is not passed, changing the bit flipping index, and returning to the decoding iteration process. According to the method, the number of elements in the key flipping index set is reduced in a threshold segmentation mode, and the key flipping index set is optimized.

The invention belongs to the technical field of wireless communication and specifically relates to a method for reducing multi-user detection complexity. According to the method, SCPs (Superposed Constellation Points) in an area within which the distance between receiving signals and sending signals is smaller than a Gaussian threshold are utilized and the SCPs out of the Gaussian threshold area are discarded, in this way, the complexity of an MPA (Message Passing Algorithm) can be greatly reduced, and the BER (Bit Error Rate) performance is basically not damaged. According to the method, thedecoding complexity of an SCMA (Sparse Code Multiple Access) system can be greatly reduced; through selection of the suitable Gaussian threshold, the decoding performance is basically not damaged; theEuclidean distance between receiving signal constellation pints and the sending SCPs submits to Gaussian distribution, so the threshold can be adaptively determined through full utilization of Gaussian distribution features; through selection of different thresholds, the compromise between the detection complexity and the decoding performance is achieved; and moreover, 5G communication scenes with different quality requirements can be satisfied.

The invention discloses an iterative polarization code receiver and an iterative polarization code decoding method. The iterative polarization code receiver comprises a detector, a first adder-subtractor, a deinterleaver, an iterative polarization decoder, a second adder-subtractor, a second interleaver and an inverse mapper. According to the iterative polarization code receiver and the iterative polarization code decoding method, the bit error rate and block error rate performances of a wireless communication system can be improved on the condition of not improving the decoding complexity while coding gain is kept, and therefore the user experience is improved.

In a communication system, a signal transceiver generates an upper pre-encoding symbol stream and a lower pre-encoding symbol stream by pre-encoding an upper transmission vector and a lower transmission vector according to a pre-encoding scheme when the upper and lower transmission vectors to be transmitted are input. The signal transceiver generates a space-time mapping matrix by space-time mapping the upper and lower pre-encoding symbol streams according to a space-time mapping scheme based on the number of transmit antennas to be used in the signal transceiver. The signal transceiver generates and transmits a codeword according to whether a null transmission is present in the space-time mapping matrix.

The invention relates to a coding method of a transmission block cycle redundancy check code CRC, which is applied for a coding device comprising a CRC coder and a subsequent coder, according to the maximum coding length of the other coder, if the CRC coder judges a transmission block is larger than the maximum coding length after CRC check bits are added, the CRC coder performs segmented encoding once or for a plurality of times and obtains a plurality of CRC code blocks the lengths of which are smaller than or equal to the maximum coding length, and each CRC code block comprises at least one CRC check bit. The coding method of the invention can satisfy the false check demand of a system and reduce the computational complexity of a Turbo decoder or an LDPC (low density parity check) decoder.

The invention provides a serial decoding method for low-density even-odd check code based on serial message schedule decoding algorithm; message weighting average method is adopted to update the message schedule from variable node to check node, namely when the message schedule from variable node to check point is updated each time, the check node message in last time and the current calculated check node message are weighed and summed to be used as the latest message of the current check node. The invention reduces the influence on normal BP message schedule due to message weighting average, effectively inhibits bit LLR value oscillation and improves the decoding performance; meanwhile, the decoding algorithm has lower decoding complexity.

The invention provides a coding method for Polar codes in a communication system. The coding method is characterized by comprising constructing an input bit sequence with length of N according to an information bit index set or frozen bit index set, wherein the input bit comprises an information bit and a frozen bit; wherein the construction process comprises an information bit index set or a frozen bit index set which corresponds with other partial bits according to the information bit index set or the frozen bit index set that corresponds with partial bits in a to-be-constructed input bit sequence, thereby obtaining the information bit index set or the front bit index set of the input bit sequence with the length of N; wherein the partial bits are 1 / m of the input bit sequence, N and m are integral power of 2, and furthermore N>m; and performing coding on the Polar codes according to the constructed input bit sequence.

The invention provides a distributed relay erasure coding method for a mobile delay tolerant network based on Y-type topology adopting two information sources, a single relay and a single destination node. An IRD-DLT relay decoding and transmitting scheme adopting two information sources and a single relay is that two source nodes are coded by using WRSD distribution, and the relay combines transmitting and random network coding and effectively adapts to the characteristic that links of the mobile delay tolerant network are easily interrupted. A DRD-DLT scheme is designed by utilizing cache information of the relay based on the IRD-DLT relay decoding and transmitting scheme, and source coding redundancy required by the IRD-DLT is reduced by about 50%. Finally, an SSGE decoding algorithm is introduced for reducing decoding redundancy required by the destination node, compromise of the decoding complexity and decoding performance is achieved, and the decoding redundancy of the destination node is reduced by about 50%.

The invention provides an encoding and decoding method of an LDPC-RS (Low Density Parity Check-Reed-Solomon) two-dimensional product code with compatible code rate and belongs to the technical field of channel encoding and decoding in a communication system. The method comprises the followings: adopting LDPC code words with compatible code rate as ingredient code words; constructing LDPC-RS two-dimensional product code words with compatible code rate; realizing a function of partial decoding by combining characteristics of the compatible code rate, so that the storage complexity, receiving delay and decoding complexity of a receiving end are reduced. A corresponding decoding scheme and an initial decoding receiving code rate can be selected by a decoding framework according to estimated channel quality information on one hand; various decoding methods are skillfully combined by the decoding framework on the other hand, so that a most applicable decoding method is adopted at different stages of decoding, so as to achieve the purposes of optimizing decoding performance and reducing the computational complexity.