14 results about "Branch Metrics" patented technology

The application discloses a low-delay sequence detection device for CPO photoelectric signal reception, comprising an adaptive module and a plurality of partitioned forward-looking parallel detectors, the partitioned forward-looking parallel detectors comprising partitioned and branch metric calculation modules, trellis merging modules and decision modules connected in sequence, the partitioned and branch metric calculation modules being used for partitioning and branch metric calculation of PAM4 signals based on tap coefficients and ISI coefficients provided by the adaptive module for input signals, the trellis merging modules being used for trellis signal merging calculation of path metrics of synchronization blocks and backtracking blocks according to obtained branch metrics, and the decision modules being used for decision of input signals to obtain binary PAM4 signals according to obtained path metrics, and the adaptive module being used for adaptive update of tap coefficients and ISI coefficients. The application aims at CPO photoelectric signal reception while reducing the complexity, power consumption and delay of PAM4 signal sequence detection technology.

This invention provides a Viterbi decoding method, apparatus, electronic device, and storage medium. The method includes: calculating the distance between a received codeword and a desired codeword at the same time to obtain a branch metric value at the current time; determining a surviving path metric value at the current time based on the branch metric value, thereby determining surviving path information; setting a deletion threshold; filtering the surviving path metric value at the current time based on the deletion threshold to obtain the minimum surviving path metric value; and, when the decoding time reaches the backtracking depth, starting from the state corresponding to the minimum surviving path metric value at the current decoding time, starting backtracking based on the surviving path information to output the corresponding decoding result. Thus, the setting of the deletion threshold achieves effective filtering of surviving paths, effectively reducing the computational load in the decoding process, and simultaneously achieving high-speed, low-power efficient decoding under any signal-to-noise ratio conditions.

A sequence detection device includes a feed-forward filter, a feedback filter, a combining circuit, a decision circuit, and a sequence detection circuit. The feed-forward filter processes a received signal to generate a first equalized signal. The feedback filter processes a symbol decision signal to generate a second equalized signal. The combining circuit combines the first and second equalized signals to generate a sample signal. The decision circuit performs hard decision upon the sample signal to generate the symbol decision signal. The sequence detection circuit performs sequence detection upon the first equalized signal, and includes a region estimation circuit and a trellis selection circuit. The region estimation circuit is independent of the decision circuit, and categorizes each sample of the sample signal into one region. The trellis selection circuit selects one trellis scheme for branch metric calculation according to region estimation results output from the region estimation circuit.

The present application relates to the field of GNSS satellite communication, and particularly relates to a data storage method, system, storage medium and electronic device.The method comprises the following steps: step 1, based on the Viterbi algorithm, the soft bit information is calculated to obtain the branch metric of each soft bit information, and the soft bit information is the information data after baseband processing; step 2, based on the branch metric, the surviving path is obtained; step 3, the index relationship between the surviving path and the current storage address corresponding to the surviving path is established; step 4, based on the index relationship, the surviving path is updated to the physical position of the current storage address. The method can effectively solve the problem that a large amount of resources are occupied due to separate storage of the calculation result in the prior art by replacing the position of the storage address, in addition, the calculation result can also be saved without affecting the data of other positions by replacing the physical position, so that the integrity of the data is ensured.

The invention relates to a Viterbi incoherent demodulation method and system. The method comprises the following steps: acquiring a received symbol sequence; calculating a non-correlation branch metric of each candidate path based on a preset forgetting factor, a correlation cumulant of each candidate path in a previous moment state, and an instantaneous correlation value between a receiving symbol at a current moment and a reference symbol of each candidate path; calculating the path metric of each candidate path at the current moment based on the path metric at the previous moment, and selecting the candidate path with the maximum path metric from the plurality of candidate paths at the current moment state as a surviving path at the current moment state; based on the forgetting factor, the correlation cumulant of the previous moment state corresponding to the selected surviving path and the instantaneous correlation value of the surviving path, updating the correlation cumulant of the current moment state reached by the surviving path; processing the received symbols hourly; and finally, selecting the state corresponding to the maximum value from the path metrics of all the states as a backtracking starting point at the moment, and carrying out step-by-step backtracking to obtain a demodulation data sequence.

The invention discloses a CPO photoelectric signal receiving-oriented low-delay sequence detection device, which comprises an adaptive module and a plurality of partition look-ahead parallel detectors, and is characterized in that each partition look-ahead parallel detector comprises a partition and branch metric calculation module, a grid merging module and a judgment module which are connected in sequence; the partitioning and branch metric calculation module is used for performing partitioning and branch metric calculation on the PAM4 signal on the basis of a tap coefficient and an ISI coefficient provided by the adaptive module for the input signal; the grid merging module is used for performing grid signal merging according to the obtained branch metrics to calculate path metrics of the synchronization block and the backtracking block; the judgment module is used for judging an input signal according to the obtained path metric to obtain a binary PAM4 signal; and the adaptive module is used for adaptively updating a tap coefficient and an ISI coefficient. The invention aims at receiving CPO photoelectric signals and reducing the complexity, the power consumption and the delay of a PAM4 signal sequence detection technology at the same time.

The invention discloses a method for preventing tampering of electric power internet of things sensing data of cascaded codes, and belongs to the field of data processing. According to the method, the characteristic advantages of cascade connection of the RS codes and the convolutional codes are fused, the grading strategy of triggering the RS codes on demand is adopted, the optimized convolutional decoding algorithm is matched, and on the premise that calculation and transmission expenses are not remarkably increased, the requirement of an electric power internet-of-things scene for real-time transmission and the core target of data reliability are considered. Meanwhile, the improved Viterbi algorithm is used, values of other branch metrics are rapidly calculated through symmetry and a logic relation, and therefore the convolutional code decoding efficiency is improved. Besides, an optimized search algorithm is used, and based on path measurement characteristics of Viterbi decoding, error positions are subjected to probability sorting and a search sequence is optimized, so that the efficiency of RS code decoding error correction is improved.

Disclosed are a decoding method, apparatus, device, medium and product, the method comprising: in response to a decoding request for target data, dividing the target data into at least one sub-block according to a preset length, the target data comprising system sequence soft information, verification sequence soft information and prior information; performing multi-channel parallel computing on the target data according to a pre-stored state transition table, and respectively determining current branch metric information of each sub-block, current forward state metric information of the target data and current backward state metric information of the target data; determining a posterior probability log-likelihood ratio and extrinsic information of each sub-block according to the current branch metric information, the current forward state metric information and the current backward state metric information; and determining a decoding result for target data according to each posterior probability log-likelihood ratio. According to the technical characteristics, the decoding complexity is reduced, the calculation time delay is reduced, and the decoding efficiency is improved.

An apparatus configured to:receive an input dataset indicative of radar signals, reflected from targets, received at an antenna;determine an objective function for evaluation over a plurality of points of a search space representing possible direction-of-arrival angles;evaluate the objective function for a first candidate number of targets;perform a first evaluation of a branch metric function based on a second candidate number of targets, wherein the branch metric function is indicative of a change in the objective function; andif the branch metric function is greater than a predetermined threshold, then evaluate the objective function for the second candidate number of targets;if the branch metric function is less than the predetermined threshold, then evaluate the objective function for the first candidate number of targets, wherein the evaluation is based on at least one of the first candidate number of targets having a different, second candidate direction-of-arrival angle.

The invention relates to the technical field of wireless communication, and discloses a convolutional code encoding and decoding method and device, computer equipment and a storage medium. The method comprises the following steps: acquiring a convolutional code corresponding to an encoder and a generator polynomial corresponding to the convolutional code, grouping each state corresponding to the encoder based on the generator polynomial to obtain a plurality of similar state groups, calculating a branch metric value corresponding to each similar state group, screening out a target path based on the branch metric value, and when the backtracking depth of the target path is greater than a preset value, outputting a decoding result corresponding to the target path. According to the method, multiple similar states are divided into one similar state group according to the special structure of the generator polynomial, and each similar state group only needs to calculate the branch metric value once, so that the number of calculation times and hardware resources required by calculation are reduced, and meanwhile, the effectiveness and reliability of communication are ensured.

The invention provides an SOQPSK-A signal incoherent demodulation method, device and equipment and a medium, and the method comprises the steps: receiving a signal, and carrying out the differential phase detection of an original signal after matched filtering through the relative phase difference between two adjacent modulation symbols; the method comprises the following steps: constructing an extended state transition grid in a differential phase space through a 3-bit differential Viterbi algorithm, calculating a branch metric according to the extended state transition grid, and recursively updating a path metric value according to the branch metric of a current state and a path metric of a state at a previous moment so as to determine a surviving path, an optimal path is obtained through Viterbi path search; and carrying out segmented backtracking demodulation on the optimal path through an overlapping window backtracking mechanism to output a demodulation result. According to the method, the problem of inconsistent path directions caused by phase ambiguity of the window boundary in the backtracking process is reduced, and low-delay and high-performance SOQPSK-A signal real-time demodulation can be realized.

A sequence detection device includes a feed-forward filter and a sequence detection circuit. The feed-forward filter processes a received signal to generate an equalized signal. The sequence detection circuit performs sequence detection upon the equalized signal to generate and output a symbol sequence. The sequence detection circuit includes a region estimation circuit and a trellis selection circuit. The region estimation circuit categorizes each of samples included in the equalized signal into one of regions. The trellis selection circuit selects one of trellis schemes for branch metric calculation according to region estimation results of two of the samples output from the region estimation circuit.

Provided is a soft decision device that performs a soft decision on an (n+1)th symbol of a transmission signal with a symbol multilevel degree of m, the soft decision device including: a control unit that estimates a branch metric, which is a distance that is obtained by a Viterbi algorithm, is in a distance function, and indicates a likelihood of transition from an nth symbol of the transmission signal to each candidate for the (n+1)th symbol, based on a received signal and an estimated transfer function that is an estimation result of a transfer function of a transmission line, estimates a path metric, which is a sum of a distance that is obtained by the Viterbi algorithm, is in a distance function, and indicates a likelihood that each candidate for the (n+1)th symbol of the transmission signal is a symbol of the transmission signal and a distance of a predetermined remaining path of the transmission signal, based on a result of the branch metric estimation process, and estimates a likelihood that a kth bit in the (n+1)th symbol of the transmission signal is a predetermined bit by using the path metric of each candidate for the (n+1)th symbol of the transmission signal.

A sequence detection device includes a feed-forward filter and a sequence detection circuit. The feed-forward filter processes a received signal to generate an equalized signal. The sequence detection circuit performs sequence detection upon the equalized signal to generate and output a symbol sequence. The sequence detection circuit includes a region estimation circuit and a trellis selection circuit. The region estimation circuit categorizes each of samples included in the equalized signal into one of regions. The trellis selection circuit selects one of trellis schemes for branch metric calculation according to region estimation results of two of the samples output from the region estimation circuit.