49results about How to "Improve bit error resistance performance" patented technology

This invention relates to earth digital television broadcast coding method in digital information transmission technique field, which comprises the following steps: diving transmission flow into 752 bit set and adding 261 zeros to get 1013 bit for BCH coding and removing front 261 bit to get BCH(762,752); forming one set of BCH(762,752) with certain number to generate matrix of LDPC(7493,3048),LDPC(7493,4572) or LDPC(7493,6096); deleting output 7493 bit front five correction bit to get final 7488 output bit.

The invention provides a streaming media transmission method and system. The streaming media transmission method comprises the steps of, by a transmitting terminal, determining a coding parameter of acurrent frame based on a communication bandwidth of a current network, and performing SVC video coding on video source data based on the coding parameter to obtain video coding frame data; by the transmitting terminal, performing RTP packaging on the video coding frame data to obtain a RTP media package and copying the RTP media package to a media package buffering queue; by the transmitting terminal, judging whether transmission of an FEC error correction package is needed; if so, performing FEC coding on the RTP media package in the media package buffering queue to generate an FEC error correction package and sending the FEC error correction package to a receiving terminal by the transmitting terminal; judging whether a package loss condition occurs based on the received RTP media package; and if so, performing lost package recovery on the lost RTP media package based on the FEC error correction package which corresponds to the lost RTP media package. The system provides execution modules for the method. By adoption of the invention, the risk that the subsequent video frame cannot be decoded caused by reference frame data loss can be reduced, and a video playing fluency is improved.

The invention relates to a fiber channel sectionalized cyclic redundancy check (CRC) method for longitudinal protection. The method comprises that: when data is transmitted, a transmitter divides data information to be transmitted into a plurality of data sections, wherein a CRC code with a bit length equal to that of an information code is appended in each data section; and after receiving the data, a receiver performs conversion check on each data section according to the CRC code, discards data sections with errors when detecting the errors, and continues using data without any error. By the sectionalized CRC method, the CRC code and the information code have the equal bit length, so error codes of any form can be detected and an error detection rate is 100 percent. The transmission can be ensured to be absolutely reliable, so longitudinal fiber distance protection and remote tripping protection can act after a frame of signal is received, and the acting speed of the protection is further increased. Simultaneously, due to the adoption of the sectionalized CRC method, when a certain data section has the errors, the usage of the other data sections is not influenced, so the error resilience of a fiber channel can be greatly improved, and the acting speed of the protection can be increased.

A parameter channel error code resisting method of vocoder line spectrum includes carrying out odd-even calibration on parameter and writing calibration bit into most non-important parameter bit of vocoder at coding end, picking light voiced sound parameters and integrating said parameters with maximum post verification probability algorithm to carry out recovery estimation for raising parameter recovery accuracy by line spectrum then picking line spectrum to make relevant odd-even calibration on parameters at decoding end.

The invention discloses a totally blind recognition method for a coding parameter of a convolutional code, which mainly solves the problems of incapability of realizing totally blind recognition and high calculation complexity existing in the prior art. The technical scheme provided by the invention is that: (1) the code length n, the input information bit length k and the register length m are solved according to the mutual check relationship between a convolutional code coder and an information code word; (2) when the code rate k/n is 1/n, two adjacent bits of the code word in the convolutional code bit stream are taken in sequence to construct an analysis matrix C, and fast Walsh-Hadamard transformation is used for the analysis matrix C to solve a generator matrix G; and (3) when the code rate k/n is (n-1)/n, the first to (n+1)th bits of the code word in the convolutional code bit stream are taken to construct an analysis matrix C, and fast Walsh-Hadamard transformation is used for the analysis matrix G to solve a basic check matrix H; and thus, the totally blind recognition for the coding parameter of the convolutional code is finished. According to the totally blind recognition method, the problem of totally blind recognition for the coding parameter of the convolutional code under the conditions of knowing no priori knowledge and containing an error code are solved well, and the operation complexity is simplified; and the totally blind recognition method can be used for multi-cast communication and intelligent communication.

The invention belongs to the technical field of coding parameter identification and discloses a punctured Turbo code blind identification method under an error code condition. Lower triangular transformation is carried out for a matrix at a galois field GF2; compared with a traditional matrix rank-solving method, the punctured Turbo code blind identification method under the error code condition can remove influences from the error codes to the identification of the code length and the interlacing length to a great extent. Confidence coefficient evaluation is carried out for a verification relationship obtained through Hadamard Transform when punctured Turbo code blind identification method is used for identifying the start point of a group and the length of a register, the identification rate of the start point of the group and the length of the register is increased greatly. The provided method of identifying an interlaced mapping relationship has strong anti-error-code performance as identification is carried out after removal of the error code; and the solving method for the interlacing relationship has the characteristics of low complexity and easy implementation.

The invention discloses a method for encoding a wavelet image. The method comprises the following steps of: classifying corresponding wavelet coefficients, which are obtained by wavelet decomposition, of each subband by using a pyramid structure; performing corresponding encoding operation on the classified wavelet coefficients to acquire a compressed code stream of each subband; according to a rate distortion characteristic of the compressed code stream of each subband, optimally allocating a target code rate between the compressed code streams of each subband; and according to the allocatedcode rate of each subband, cutting off the code stream of each subband to acquire the code stream for encoding the wavelet image. The invention also discloses a device for encoding the wavelet image.By the method and the device, the error-code-resisting capability of the code stream acquired by encoding can be enhanced and the code stream is decoded to obtain images of multiple spatial resolutions.

The invention discloses a block verification and acknowledgement-based satellite network TCP (Transmission Control Protocol) performance enhancement method, and relates to a TCP performance enhancement technology in a satellite communication field. According to the block verification and acknowledgement-based satellite network TCP performance enhancement method, the transmission performance of a TCP in a high error code environment is improved on the premise of not obviously increasing the cost of a TCP by utilizing expansion options of the TCP and introducing a new mechanism of data block verification and block acknowledgement based on ideas of combined transmission and block retransmission on the basis of the compatibility of basic mechanisms, such as TCP flow control, error control and congestion control. The method disclosed by the invention has the advantages of standard TCP compatibility, high error code resistance and low information verification cost, and is particularly suitable for a satellite communication system which performs data transmission by utilizing the TCP.

The invention discloses a method for detecting a bit error rate of a channel which comprises: the filling data of an audio and video signal is obtained; the filling data and the prescient filling data are compared and the bit error rate of the current channel is confirmed according to a comparing result. The invention also discloses a device for detecting the bit error rate of the channel; besides, the invention also discloses a method and device for treating an audio and video signal based on the method and the device. The invention can be utilized to confirm the bit error rate of the current channel by calculating the bit error rate of the filling data; thereby being able to adjust the coding parameter of the audio and video signal to be transmitted according to the bit error rate situation of the current channel so as to lead the capacity of anti-bit error rate of the audio and video signal to be improved, thus avoiding the situation of serious mosaics on an image from appearing.

The invention discloses an anti-error method based on cyclic redundancy check and erasure correction coding, which belongs to the technical field of wireless link digital measurement and control communication with random or burst errors. Add the fast cyclic redundancy check to the length of the code stream, and add the error correction supervision code to the cyclic redundancy check code, and then perform fast Vandermonde erasure coding on the bytes of a certain length by column, and finally send the encoded data to the The input channel is transmitted, and the decoding end decodes and restores the original data in a corresponding manner. The method can be applied to fields such as high compression ratio video code streams that are particularly sensitive to channel code errors, important data protection transmitted in wireless channels with high code error rates, and the like. The invention enables the decoding end to quickly and timely discover and correct data that generates bit errors, has the advantages of large coding gain, small delay, and low algorithm complexity, and provides a real-time processing basis for further reducing the impact of bit errors on video image quality.

The invention discloses a lossless compression method for a large-format remote sensing image, and belongs to the field of image processing. The method comprises the following steps: dividing a large-format remote sensing image into independent coding regions which are not overlapped with each other; identifying the dynamic range of the pixel of each independent coding area, and determining the quantized bit number of the pixel; calculating a lossless compression parameter of each independent coding region according to the quantization bit number of each independent coding region; and according to the lossless compression parameter of each independent coding region, carrying out lossless compression on the independent coding region until lossless compression of the large-format remote sensing image is completed. According to the invention, a large-format remote sensing image is divided into a plurality of independent coding areas which are not overlapped with one another; the dynamic range of each independent coding area is identified as the local dynamic range of the large-format remote sensing image, the characteristic that the local dynamic range of the large-format remote sensing image is lower than the fixed dynamic range of the camera is effectively used, the overall lossless compression ratio is increased, compression parameters can be adjusted according to the local dynamic range, and lossless compression of the large-format remote sensing image is achieved.

The invention discloses a hyperspectral image distributed compression method and system based on compressed sensing. The hyperspectral image distributed compression method comprises the steps of conducting spectral compression sampling on an original hyperspectral image; carrying out distributed encoding processing on the sampled data; dividing each waveband into at least one coding block with thesame number, taking the first waveband as a starting waveband, carrying out linear prediction on the current coding block by utilizing the corresponding coding block in the adjacent previous wavebandfor any coding block in any of the rest wavebands, and determining the number r of LSBs needing to be transmitted by the current coding block according to the prediction residual error; and transmitting the data after spatial lossless compression of each coding block in the first waveband, the first r LSBs of each coding block in other wavebands and the prediction coefficient to a receiving end for compressed sensing reconstruction of the hyperspectral image. The compression method provided by the invention has relatively low complexity, good compression performance and error code resistance.With a coding block as a basic unit, an error code is controlled in the coding block and cannot be transmitted to other blocks.

A gradation-inequality protective method of irregular LDPC code to MPEG-2TS includes address protective processing circuit at emitting end of communication system for storing node adding with high irregular LDPC code degree to let MPEG-2TS code stream packet head and adaptive domain map on node with high irregular LDPC code degree , adding protective counter processing circuit at receiving end of communication system for storing MPEG-2TS stream packet head and adaptive domain address to utilize this address to restore normal order of MPEG-2TS code stream.

The invention discloses a CORS data coding transmission system applicable to long-distance communication. The system comprises a mobile big dipper CORS vehicle used for receiving data through a big dipper receiver on the vehicle and sending the data to a CORS service system; a CORS service system used for grouping difference data information in CORS data; a coding module used for performing anti-interference coding on high broadcasting frequency information and low broadcasting frequency information; a high-power ultra-shortwave radio station used for receiving the data coded by the CORS service system through an ultra-shortwave interface, sending the coded data to a long distance receiving end radio station, and accomplishing data transmission; and a decoding module used for decoding the code received by the receiving end radio station, sending the decoded CORS data to a background server, and accomplishing transmission of the CORS data. According to the system, by employing the big dipper CORS vehicle and the high-power ultra-shortwave radio station, long-distance credible transmission of the CORS data is realized through extraction and coding of the CORS difference data, the error rate of long-distance communication of the CORS data is reduced, and the communication quality is improved.