130results about How to "High coding gain" patented technology

A space-time code has a codeword matrix. The codeword matrix is a square matrix with dimension equal to the number of the transmit antennas, wherein a row of the codeword matrix represents combined signals transmitted by each transmit antenna and a column of the codeword matrix represents timeslots of the number of the transmit antennas. Signals are transmitted through the rows of the number of spatial multiplexing rate, in each column of the matrix. Further, the symbols of the number of the transmit antennas are combined by way of utilizing complex weights, in each row of the matrix. With this space-time code, a delay is minimized, so that change of channels can be managed efficiently. Also, the space-time code has minimum number of data symbols, and thus its complexity is minimized.

The invention discloses a design scheme of LDPC cascaded code, which is an LDPC-SPC product code which takes LDPC code as horizontal code and SPC code as vertical code, and each bit of an SPC code word is acquired by the even parity check of the bits in corresponding positions of n LDPC code words. The scheme can solve the flat bed of error codes of the LDPC code and has higher flexibility and greater encoding gain than the cascaded methods of BCH code. The invention simultaneously provides an encoding method of the LDPC-SPC product code and two decoding methods (a hard decision method and a soft decision iteration method), and provides corresponding decoders. The LDPC-SPC product code provided by the invention can acquire greater encoding gain with very small redundancy cost and is a signal channel encoding scheme which is applicable to delay-insensitive businesses.

The invention provides a method for sensing an optical fiber in long distance based on self-correlation characteristics of a Hadamard matrix. The method comprises the following steps that row vectors of matrixes are used as code words for detecting pulse codes; the row vectors of a matrix A and a matrix B are respectively used as train pulse of the code words to be inputted into the optical fiber, and a returned Brillouin signal is correlated with continuous light outputted by a laser; coherent signals are acquired by a spectroanalyzer so as to acquire signal power distribution under a frequency point, and acquired results are subtracted; the row vector Hi of the Hadamard matrix is correlated with a corresponding scattered signal, and then, after the correlated results are summed, the correlated results are divided by n to acquire scattered light power acquired when equivalent individual pulse is inputted into the optical fiber; the steps are repeated on each required frequency point; Brillouin power spectrum consisting of the scattered points corresponding to each moment is acquired; and the method performs sensing by a corresponding relation of center frequency, peak power and full width at half maximum of the power spectrum and temperature and stress.

The present invention discloses a coding block dividing method. The device comprises a coding block dividing unit, a code modulation processing unit, a mapping unit, a first calculating unit and a second calculating unit. The method comprises the following steps: setting to divide the burst to k coding blocks in total; if the burst length n<=cascade connection number j of physical resource block of the maximum coding block, then taking the whole burst as a coding block with length for n; otherwise if the n is integer times of j, dividing the burst to k coding blocks with length for j; if the n is not integer times of j, dividing the burst to k1 coding blocks with length for m1 and k2 coding blocks with length for m2; and at last mapping the divided coding blocks to the physical resource blocks with a corresponding number after procession. The coding device according to the invention can reasonably divide the burst and guarantees that the smallest coding block generated by dividing is as large as possible thereby obtaining the purpose of guaranteeing the burst capability and obtaining larger coding gain and interweaving gain.

The invention discloses a cooperation diversity method based on a constellation rotation quasi-orthogonal space-time group code, which mainly solves the problem that the transmission rate of a cooperation method of an orthogonal space-time group code is low. The cooperation transmission procedure comprises: during the broadcasting phase, a source node sends broadcast signals to a relay node and a destination node, the relay node performs the coding and the cyclic redundancy check to the received signals, if the cyclic redundancy check is right, the received signals are involved in the cooperation transmission in the space-time cooperation phase, or else the received signals are not involved in the cooperation transmission; during the space-time cooperation phase, the source node and the relay node calibrated right divide transmitted information into two groups for the constellation mapping, respective transmitted information is generated according to the coding matrix of the quasi-orthogonal space-time group code, and is sent to the destination node; the destination node performs the joint maximum likelihood decoding for received signals in the broadcasting phase and the space-time cooperation phase, and divides the decoding result into two groups for the demodulation. The invention has higher space diversity gain under the condition of same spectrum effectiveness and transmission power compared with the cooperation diversity method of the orthogonal space-time group code.

The invention discloses a method and a device for forward error correction encoding, a method and a device for forward error correction decoding, and a communication device and system, which belong to the technical field of communication. The encoding method comprises: to-be-transmitted data of the ith row are obtained, wherein the i is an arbitrary value; interleaving processing of the encoded to-be-transmitted data of the (i - 1)th to (i - h)th row is carried out, and interleaved data of the ith row are obtained, wherein the h is no less than 2 and is an integer; the to-be-transmitted data and the interleaved data of the ith row are joined and merged, and to-be-encoded data of the ith row are obtained; BCH encoding is conducted on the to-be-encoded data of the ith row, and encoded data corresponding to the to-be-encoded data of the ith row are obtained; and the encoded data are used to fill an expense portion of the to-be-transmitted data of the ith row, and the encoded to-be-transmitted data of the ith row are obtained and transmitted. The method is good in error correction capability, short in processing time delay and low in implementation cost. The method can satisfy the requirements of data frames in need of high speed transmission.

A mutually-operated emitting and receiving system of microwave is prepared as forming emission system by randomization module, channel coding module, interlacing module, modulation module, setting-frame module, IFFT conversion module, adding circulation prefix module, parallel/series conversion module, etc; forming receiving system by sampling-positioning module, A/D conversion module, symbol synchronization module, de-circulation prefix module, FFT conversion module, de-framing module, channel estimation module, balance module, decoding module, derandomization module, etc.

The invention provides a data retransmission method based on network coding (NC), wherein the method has high NC efficiency. The method comprises the following steps: a statistics step, to be more specific, a source node sends data packets and then reception and statistics are carried out on all data packets' reception situations feedbacked by receiving nodes and a determination step is entered, wherein the data packets are original data packets or encoded data packets; the determination step, to be more specific, the source node determines whether it is necessary to retransmit the data packets; if so, a encoding step is entered; if not, retransmission is finished; the encoding step, to be more specific, the source node gives priority to NC of the data packet with the poorest reception situation according to an encoding rule so as to obtain a latest encoding data packet that is retransmitted this time as well as a sending step is entered; and the sending step, to be more specific, the source node broadcasts the data packet that is needed to be retransmitted this time to all the receiving nodes and the statistics step is returned to. According to the invention, a data packet with the poorest reception situation is used in preference to carry out NC, so that an encoding gain can be increased; and the larger the encoding gain is, the smaller the transmission frequency is.

The invention discloses a mixed modified weighted bit-flipping LDPC decoding algorithm. The mixed modified weighted bit-flipping LDPC decoding algorithm comprises a first step of initializing a decoder and measuring and calculating parameters, a second step of calculating syndromes of a check matrix, wherein if all syndromes are zero, the decoding is successfully achieved and then the process is finished and if not all syndromes are zero, a third step is carried out, the third step of calculating the judgment standard value En1 of a main algorithm and the judgment standard value En2 of an auxiliary algorithm according to the parameters of the first step and a verifying result of the second step, a fourth step of defining a bit corresponding to the position p as an error bit according to the judgment standard value En1 of the main algorithm and defining a bit corresponding to the position q as an error bit according to the judgment standard value En2 of the auxiliary algorithm, a fifth step of rectifying the bit corresponding to the position p and the bit corresponding to the position q at the same time or only rectifying the bit corresponding to the position p, and a sixth step of repeating the second step to the fifth step, wherein when the decoding is successfully achieved or a maximum number of iterations is reached, the iteration is stopped, and a decoding sequence is output. The mixed modified weighted bit-flipping LDPC decoding algorithm has the advantages that the decoding property is good, computation complexity is low, and hardware is easy to achieve.

The invention discloses a Raptor code (with non-regular codes as precoding) optimized coding method; when the Raptor code using non-regular LDPC code as precoding is coded, different probabilities areselected for intermediate codons of different columns for LT coding, and the selection probability of the intermediate codon with the big column is properly lowered, thus relatively uniforming the total number of degrees of the intermediate codons in a Tanner graph of the Raptor code, and improving the decoding success rate.

The invention discloses a pulse-encoded distributed optical fiber raman temperature sensing method and device. An any-order encoding matrix is provided, all of principal diagonal elements are 0 and all of the remaining elements are 1; each row of the matrix is sequentially injected into the distributed optical fiber raman temperature sensing device; the device comprises a semiconductor laser, a driving module, an FPGA (Field Programmable Gate Array) code modulator including an SOA (Semiconductor Optical Amplifier), an optical fiber amplifier, an optical fiber circulator, an optical fiber wavelength division multiplexer, a thermotank, a sensing optical fiber, a detector module, an A/D (Analog to Digital) module and an industrial computer. In combination with a pulse encoding principle and an optical fiber rayleigh scattering assisted demodulation raman scattering principle, the dynamic range of a sensing system is improved without changing a spatial resolution, the measurement length and measurement precision are enhanced; and the pulse-encoded distributed optical fiber raman temperature sensing method and device are suitable for measurement and disaster warning of water, oil and gas pipelines, a tunnel and a large-scale civil project in a large range.

The invention discloses a loop-break based mixed weighted bit-flipping LDPC decoding method. The method comprises the following steps of: initializing a decoder and calculating parameters; calculating a check matrix syndrome; calculating a main algorithm decision criterion En1 and flipping a bit z1 most likely wrong; if one bit is flipped repeatedly, calculating an auxiliary algorithm decision criterion En2 again for code words after a hard decision and flipping a bit z2 most likely wrong, and if not, continuing iteration; if one bit is flipped repeatedly again, continuously calculating the main algorithm decision criterion En1 for code word sequences after the processing and flipping the bit z1 most likely wrong, and if not, continuing iteration; and repeating the above steps, and stopping iteration when decoding is successful or a maximum iteration number is reached, and outputting decoded sequences or outputting decoding failure information. The LDPC decoding method provided by the invention has the advantages that the decoding performance is good, the convergence speed of iteration is high, the calculation complexity is low, the realization mode is relatively easy, etc.

The invention discloses a high throughput network coding method in a wireless network. The high throughput network coding method in the wireless network comprises the steps of a selecting step, a combining step and a coding step, wherein in the selecting step, data streams which are involved in coding are selected according to the sizes of packages, reachable transmission speed and the number of catch packages; in the combining step, for each data stream which is selected to be involved in the coding, the number of data packages which are combined in each data stream is determined, and combination is conducted on the date packages; and in the coding step, the operation of network coding is conducted on a combined package of the selected data streams or a plain text package, and a coding package of the sending is obtained. The high throughput network coding method in the wireless network can reduce the frequency of transmission of original data packages on network nodes in the wireless network, largely improves the network throughput and has good practical value.

The invention discloses a wireless optical communication pulse position modulation (PPM) detection and demodulation method based on least posterior error probability. The detection and the demodulation of the PPM are realized through the steps of dividing modulation position sets, calculating receiving bit posterior probability, calculating likelihood measure and performing binary judgment estimation. In a wireless optical communication system not using error correction encoding, the method is more effective than a threshold detection and demodulation method and has the performance equivalentto that of a maximum detection and demodulation method; in a system using soft iterative error correction encoding, the bit likelihood measure acquired by the method is used for iterative encoding, so that the method is superior to the situation of combination of the maximum detection and demodulation method as well as the threshold detection and demodulation method and the soft iterative error correction encoding; and therefore, the error performance of the atmospheric wireless optical communication system is effectively improved.

The invention discloses a pulse coding-combined distributed optical fiber vibration sensing method and device. For a random-order coding matrix, the main diagonal elements are all "0", and the rest elements are all "1", and each row of the matrix is sequentially injected into the distributed optical fiber vibration sensing device, wherein the device comprises a narrow-line-width laser, a driving module, an FPGA coding modulator containing an SOA (semiconductor optical amplifier), an optical fiber circulator, a sensing optical fiber, an APD detector module, an A/D module and an industrial personal computer. A pulse coding principle and an optical fiber rayleigh scattering phase change demodulation vibration principle are combined, so that the dynamic range of the sensing system is enlargedunder the condition that the spatial resolution is not changed, and the measuring length and the measuring precision are increased. The device can be suitable for monitoring of leakage of water, oil,gas pipelines within a relatively large range and monitoring of large-scale civil engineering security and protection.

The existed coding/decoding method with low density odd-even check code cannot reduce the small circulation existing in the checking matrix. The said small circulation depresses the coding feature. The technical scheme of the invention finds out the weak bit in the related signal original bit group in the given check matrix. When the coding end groups the signal source bits to be set, the scheme obtains corresponding code words after inserting appointing bit info promised by both sending and receiving ends into weak bit of each group. According to the appointed bit info, the decode end initializes the probability info related to the weak bit node into a value close to infinity. Thus the scheme raises the accuracy of probability info transferred between the bit node and the checking node during the iterative progress. The invention also corrects the error info of adjacent nodes. These raises decoding feature and obtains an obvious coding gain.

The embodiment of the present invention provides the method and device for sending and receiving feedback information, and relates to the communication field. The method for sending the feedback information comprises the steps of receiving the uplink data sent by a user equipment (UE); determining a first load length, wherein the first load length is one of at least two load lengths in a load length set; determining the position index of the feedback information corresponding to the uplink data in a feedback information set, wherein the length of the feedback information set is the first load length; according to the position index, mapping the feedback information corresponding to the uplink data to the feedback information set; according to the first load length, carrying out the jointed coding on the feedback information set; and sending the coded feedback information set. According to the present invention, the coding cost can be reduced, and the coding gain can be improved.

The invention relates to the communication technology, in particular to a multicast retransmission method and device based on a D2D cluster under high packet loss probability. The multicast retransmission method includes the steps that (1) before a multicast service is started, a terminal with a multicast service requirement is built into the D2D cluster, and after the cluster is built, a eNB broadcasts a data packet to the D2D cluster in a multicast mode; (2) after a cluster head and cluster members receive the multicast data packet, the cluster head forms the feedbacks of the cluster members into a feedback table, and a sliding window is built and initialized; (3) in the sliding window, the cluster head detects the feedback table and executes the corresponding operation; (4) in the sliding window, the cluster head retransmits and collects a data packet which is not decoded correctly through intra-cluster cooperation; (5) the cluster head carries out network encoding on the retransmitted data packet after collecting the lost data packet, broadcasts the network encoded packet to the cluster members in a multicast mode, updates the feedback table and the sliding window and executes the steps from (3) to (5) again. The multicast retransmission device is provided with a multicast sending module, a receiving module, a feedback module, an intra-cluster cooperation retransmission module, a network encoding module and an updating module.

The invention provides an image filtering method, device and equipment, and a readable storage medium, and solves the problem of low coding gain of an existing frame image. The method comprises the steps that after inverse transformation and dequantization processing are carried out on a current frame, filtering processing is carried out on the current frame through a first loop filtering technology and a target loop filtering technology, and the current frame is a current coded frame or a current decoded frame, wherein the target loop filtering technology comprises at least one of the following technologies: a deblocking effect filtering technology; a sample point adaptive compensation technology; an adaptive loop filtering technology; the first loop filtering technology is a technology for filtering the current frame based on first filtering information, and the first loop filtering information is obtained by classifying all pixels of the current frame, so that the coding gain of a frame image can be improved.

The invention relates to the field of photoelectric communication, and discloses a data transmission method and a data transmission system for a digital video optical transceiver system. According to the data transmission method and the data transmission system, coding redundancy is adjusted according to the error rate, whether or not a forward error correction coding mode is needed and which forward error correction decoding mode of the coding redundancy is adopted are determined dynamically, and accordingly, forward error correction coding/decoding technology based adaptive error detection and correction are achieved. The data transmission method includes receiving video data and information representing the coding redundancy of the video data through an optical fiber; selecting the corresponding forward error correction decoding mode to decode the video data according to the information representing the coding redundancy; calculating the error rate of the decoded video data; adjusting the coding redundancy according to the error rate; according to the adjusted coding redundancy, selecting the corresponding forward error correction coding mode to code the to-be-sent video data; sending the video data and the information representing the coding redundancy through the optical fiber.