50results about How to "Achieving Joint Estimation" patented technology

The invention relates to a symbol synchronization and Doppler compensation method for a mobile orthogonal frequency division multiplexing (OFDM) underwater sound communication signal. The method comprises the following steps of: obtaining rough estimation of a first OFMD symbol start position according to a frame header signal, extracting a symbol, then obtaining Doppler expansion rough estimation of the symbol according to a frequency measurement simple-frequency signal in the symbol, converting the symbol to a frequency domain according to Chirp-z conversion, searching a precise start moment and a Doppler expansion amount of the symbol by taking a pilot of the frequency domain and a relevant value of a local pilot as cost functions, presuming the start position of the next symbol according to the start position of the current symbol, extracting the next symbol, and repeating the operations till the end of a frame of signal. According to the Doppler measurement and compensation method, based on the Chirp-z conversion, the measurement and compensation precision is high; the Chirp-z conversion is implemented according to fast Fourier transformation (FFT); the practicability is high; according to the Doppler expansion search method which is in a manner that large step length is superior to small step length, so that the search efficiency is high; a Doppler measurement range is not limited; and the method can be used for constant-speed motion and variable-speed motion.

The invention provides a method for estimating the parameters of an underwater constant-speed vehicle based on a vertical vector array. According to the technical scheme of the invention, on a vertical array-based underwater vehicle noise measurement platform or an underwater vehicle detection platform, a Doppler frequency shift difference is generated according to different spatial information of each array element, and then the accurate Doppler frequency shift of each array element is obtained through the polynomial frequency-modulation wavelet transformation process. In combination with the pitch angle information of each vector sensor, the weighted nonlinear least squares of a joint multi-objective function is optimized and solved. Therefore, the joint estimation on the speed of an underwater vehicle, the depth of the underwater vehicle, the horizontal proximal distance of the underwater vehicle and the abeam distance thereof to different array elements is realized. The above method is simpler in implementation and higher in estimation accuracy. Based on the method, the parameter estimation robustness and the estimation speed are significantly increased.

The invention relates to the technical field of battery state-of-charge estimation of an electric vehicle power battery system, in particular to an algorithm based on SOC and SOH joint estimation of apower battery. The method optimizes parameters of an RF algorithm through a TSBSO algorithm so as to optimize an algorithm pruning threshold, the number of pre-test samples and the number of decisiontrees, and the optimized algorithm can quickly find a globally optimal solution and improve the algorithm efficiency. The SOH of the power battery is estimated through the RBM, the RBM is optimized through the WOA, and model parameters are prevented from falling into local optimum and thus the purposes of correcting the maximum available capacity of the battery and improving the SOC estimation precision of the power battery under the full-time working condition are achieved; the SOC of the power battery is estimated through the combination of a TSBSO-RF H-infinity calculation method and filtering, the advantages of the two algorithms are exerted by adopting a linear fusion algorithm, the defects of the two algorithms are avoided and the SOC estimation precision of the power battery is higher.

The invention discloses a circumference SAR multi-target tracking method based on a random finite set and relates to a circumference SAR multi-target tracking method. The invention aims to solve the problem that the traditional multi-target tracking method based on data association is complex in calculation. The method comprises the following steps: 1, performing initial detection on a moving target based on a DPCA-CFAR method to acquire a measuring value of the moving target; 2, according to the measuring value of the moving target, establishing a state vector set and a measuring vector set of multiple moving targets; 3, correcting the acquired measuring vector to acquire a measuring vector after compensation; 4, according to the measuring vector after compensation, establishing a targetstate model and a measuring model; 5, according to the given target state model and the measuring model, performing target tracking based on a GMPHD filter. The method is applied to the fields of a microwave remote sensing technology and radar data processing.

The invention discloses a novel target parameter estimation based on a wideband ambiguity function, which belongs to the technical field of electronic communication. A WBAF-MUSIC algorithm and a WBAF-ESPRIT algorithm are provided, the WBAF-MUSIC algorithm realizes estimation of an acceptance angle, and the WBAF-ESPRIT algorithm realizes estimation of a phase angle. According to the novel target parameter estimation based on the wideband ambiguity function provided by the invention, in a dual-base station MIMO (multiple input multiple output) radar, linear frequency modulation signals are selected as transmission signals, the characteristic of a large time-bandwidth product is used, and a better low-interception probability characteristic is thus acquired. Joint estimation of a Doppler frequency shift factor and time delay is realized through searching a wideband ambiguity function peak point firstly.

The present invention discloses a combined tracking method for timing deviation and sampling frequency offset, which is suitable for a digital mobile multimedia broadcasting system. The method comprises the steps of: according to channel impulse response information obtained by estimation, firstly estimating timing deviation for OFDM symbols and determining timing adjusting information for the next time slot; and then estimating sampling frequency offset according to the position information of the strongest path in the channel impulse response and the timing adjusting information for the last time slot, thereby realizing the combined adjusting of the timing deviation and the sampling frequency offset. The combined tracking method of the invention can not only track a symbol timing error brought by multipath distribution characteristic of a transmission channel, but also track and correct the sampling frequency offset brought by the inconsistency between two local oscillators for transmitting and receiving terminals; stable operation can also be realized even in the time division working mode of a receiver and the receiver can stably work by flexibly changing the estimation size of the sampling frequency offset according to the length of the time division working time of the receiver.

The invention discloses an external radiation source radar same-frequency interference time delay and energy rapid estimation system and method. The method comprises the following steps that the reference antenna obtains reference signals directly reached by the same-frequency interference base stations through beam forming; the echo antenna receives echo signals containing same-frequency interference and target echoes; a pilot cross-correlation algorithm is usedto obtain coarse time delay parameters of reference signals and same-frequency interference signals, clustering matching processing is performed on the reference signals and the same-frequency interference of each base station, then a same-frequency interference signal matrix is constructed, and a subspace projection method is utilized to obtain two-dimensional accurate estimation of same-frequency interference time delay and energy. The method can achieve the precise estimation of the same-frequency interference time delay andenergy from different radiation sources under the condition of the same-frequency interference of a plurality of radiation sources of the mobile communication external radiation source radar, and further achieves effective inhibition. The invention also discloses an external radiation source radar same-frequency interference time delay and energy rapid estimation system. The system is low in costand convenient in networking.

The invention is applicable to the technical field of signal processing, and provides a two-dimensional direction of arrival estimation method, which comprises the steps of acquiring snapshot data output by an antenna array; processing the snapshot data based on a constructed filter self-adaptive to a weighted least square method, and obtaining the estimation of an incident signal repeated amplitude; based on the estimation of the incident signal repeated amplitude, carrying out iterative computation to obtain an energy matrix of an incident signal in a specified two-dimensional space; carrying out two-dimensional spectrum peak searching on the energy matrix, and obtaining a two-dimensional direction of arrival of the incident signal. According to the two-dimensional direction of arrival estimation method provided by the invention, the problem that in the prior art, the two-dimensional direction of arrival estimation cannot be estimated under the short snapshot condition is solved, andthe combined estimation of an azimuth angle and a pitch angle of a far-field narrow-band signal can be realized by utilizing less snapshots.

The invention discloses a moving target positioning method under clock skew and clock drift conditions, and the method comprises the steps: constructing a WLS problem which comprises four unknown quantities: the position and speed of a source node, the clock skew and the clock drift; converting a non-convex weighted least square (WLS) problem into a convex positive semidefinite programming problem by adopting a positive semidefinite relaxation method, and solving the convex positive semidefinite programming problem by utilizing an interior point method to obtain a globally optimal solution. The method has the advantages that under the condition that the clock skew and the clock drift coexist and are unknown, from the perspective of the weighted least square estimation model estimation theory and the convex optimization theory, joint estimation of the clock skew and the clock drift is achieved while position and speed estimation of a source node is achieved, the positioning precision is high, and the calculation complexity is low. The method is suitable for complex deployment environments.

The invention relates to a path parameter extraction method for a millimeter wave 3D MIMO channel, and belongs to the field of communication channel parameter extraction. The method comprises the following steps: S1, acquiring wireless channel measurement data, and integrating the wireless channel measurement data into a channel matrix; S2, adding a vertical dimension of a steering vector in the channel matrix in the step S1, and dividing to-be-estimated path parameters into three parameter subsets, namely propagation time delay, horizontal and vertical angles of a transmitting end and horizontal and vertical angles of a receiving end; S3, performing iterative operation on the channel parameters of each path by adopting a combined search strategy of time delay and three-dimensional space angles, and updating the channel parameters in the current to-be-estimated parameter subset; and S4, based on an extraction result in the step S3, performing multipath clustering characteristic analysis to obtain intra-cluster time delay extension and angle extension characteristics. The method is suitable for millimeter wave 3D MIMO wireless channel parameter extraction, and the accuracy and resolution of sparse multipath channel parameter extraction can be ensured.

The invention relates to a positioning system and method based on multi-frequency-point joint measurement of a wireless local area network. The system is composed of a joint estimation unit, user equipment and a plurality of wireless access points. All wireless access points receive signals emitted by the user equipment at a plurality of frequency points by changing an antenna angle and process the received signals, estimate arrival angles and propagation time of the signals based on time-offset compensation and signal reconstruction, estimate locations of the user equipment relative to the wireless access points, and returns relative location information to the joint estimation unit; and the joint estimation unit estimates the precise geographic position of the user equipment by combining pre-stored information and updates the geographic position of the user timely. Therefore, on the premise that no extra wireless access point deployment cost increases, joint measurement at multiple frequency points by multiple wireless access points is carried out to solve a problem that precise positioning can not be realized by the traditional positioning method is solved; and the good foundation is laid for other applications based on user locations in a wireless local area network.

The invention provides a combined spectrum sensing and authorized user position estimating scheme for solving the problem of mobile authorized user spectrum sensing and mobile authorized user geographic position information estimating. A self-adaptation view expanding method is provided for the first time, the negative effect caused by the nondeterminacy and silence state of the authorized user position is effectively solved, and the spectrum sensing performance is improved. A brand new dynamic state-space model is established based on Bernoulli random finite sets and a Bayes sequential estimation frame, a three-section type Bernoulli smoothing mechanism is designed, the mobile authorized user geographic position is estimated while the authorized user working state is detected, and accordingly the spectrum sensing performance is obviously improved. Meanwhile, spectrum multiplexing of time, frequency and space is achieved, and accordingly the following spectrum resource allocation is further optimized.

The invention discloses an online estimation method and device for the state of charge and the state of health of a power battery and a storage medium. The online estimation method comprises the steps of 1, collecting the current, the voltage and the temperature of a single battery in real time in the charging and discharging process of the power battery, 2, in the discharging process, identifying parameters of each single battery on line through a recursive least square method with a forgetting factor, 3, estimating the terminal voltage of each single battery by using a Thevenin equivalent circuit model in the charging and discharging process, 4, estimating the SOC of each single battery by using a self-adaptive extended Kalman filtering algorithm, 5, calculating the capacity of each single battery in a charging process, and 6, calculating the battery pack charge state, the battery pack capacity and the battery pack health state, and 7, applying the calculated capacity of each single battery to the capacity parameter of each single battery in the Thevenin equivalent circuit model to realize joint estimation of the state of charge and the state of health of the battery subjected to online closed-loop feedback correction. The method can be used for accurately evaluating the inconsistency state between the battery pack monomers, and provides a basis for formulating a power battery equalization control strategy.

The invention discloses a channel estimation method based on a minimum mean square error for a quantized millimeter-wave multi-antenna channel. According to the scheme, the channel estimation based onthe minimum mean square error is realized under the condition that a receiving signal on a receiving end is quantized, and the estimation method utilizes an EM algorithm at the same time, so that a channel estimation algorithm does not depend on the statistical information of an accurate known channel. According to the method, the influence of the quantization operation of the receiving end on channel estimation is fully considered, and mathematical modeling is carried out on the quantized signal. Only a probability model obeyed by the known channel is needed, and joint estimation of the channel and the parameters of the probability model can be simultaneously realized by utilizing the proposed iterative algorithm. The method has the advantages that the statistical information of the channel does not need to be known accurately, only the obeyed probability distribution type needs to be known, and then the joint estimation of the probability distribution parameters and the channel is realized through the EM algorithm, so that the channel estimation scheme provided by the invention has a wide application scene and strong robustness, and thus the stability of a wireless communicationsystem is guaranteed.

The invention discloses a method for detecting and tracking a target with a discontinuous characteristic by a passive sensing system, is applied to the technical field of target detection and trackingof the passive sensing system, and aims at the problems that an existing technology is not suitable for tracking the discontinuous target and does not consider estimation of the discontinuous characteristic of a signal. The method comprises the following steps of firstly, carrying out discontinuous period division and adaptively estimating the discontinuous characteristic of the target in combination with a signal period sliding window according to latest received intermittent measurement of the sensor; secondly, synchronously determining an update moment of a target state, and deriving a variable-period filtering formula under a Bayesian framework to obtain a posterior probability density function related to the target state; and finally, estimating the target state through a minimum mean square error criterion. According to the method, joint estimation of the discontinuous target state and the discontinuous characteristic thereof can be achieved.

The invention discloses a genetic particle filter algorithm for interactive multi-model switching and parameter online identification, which comprises the following steps: step 1, state estimation: carrying out state estimation by adopting a particle filter algorithm, and replacing resampling of traditional particle filtering with a genetic algorithm selection, crossover and variation method; firstly, inputting a previous state estimation result set, and performing input interaction operation based on a battery model set; inputting the measured value of the battery terminal voltage to update the predicted value of the state estimation, and calculating a likelihood function to update and calculate the model probability; and finally, performing output interaction operation on the state estimation according to a model probability calculation result to obtain a final state estimation result; step 2, respectively estimating the SOC value and the SOH value by using the state estimation method in the step 1; and step 3, updating the SOC value and the SOH value. The algorithm provided by the invention can keep good estimation precision in a nonlinear environment, and has good robustness.

The invention discloses a power line communication system impulse noise suppression method based on recursive compressed sensing. The method comprises: selecting a part of subcarriers from numerous subcarriers to serve as pilot frequency subcarriers to be used for block weakness channel estimation; combining the channel impulse response and the asynchronous impulse noise in the received signal onthe pilot frequency subcarrier and giving a combined probability density function; solving the hyper-parameter by using an expectation maximization method through two-step alternate iteration of E-step and M-step, and performing iterative estimation on the hyper-parameter in the E-step by using a Kalman filter and a smoother, so that estimated values of channel impulse response and asynchronous impulse noise can be further obtained; and finally, subtracting the estimated value of the asynchronous impulse noise from the received frequency domain signal; obtaining a frequency domain signal obtained after asynchronous pulse noise suppression. The method has the advantages that the block weak channel and the asynchronous pulse noise in the slow time-varying channel can be jointly estimated, and the estimation accuracy is high.

The invention discloses a passive multi-array sonar detection tracking method specific to a discontinuous target, applied to the field of passive detection and aiming at solving the problems of divergent detection tracking, target recognition failure and track breakage in the prior art. The method comprises the following steps: performing modeling on a discontinuous array receiving signal, and according to the built model, obtaining measurement data of multiple array sonars; based on the obtained measurement data, building a joint likelihood function, and constructing a joint likelihood ratiofunction; and according to a value of a joint likelihood ratio and by combining the joint likelihood function, performing estimation on a state of a target and discontinuity of the target. The methoddisclosed by the invention not only can effectively recognize the discontinuity of the target but also is obviously improved in discontinuous target tracking precision.

The invention discloses a frequency offset estimation method and device. The method comprises the following steps of carrying out frequency offset estimation for a receiving signal to obtain a first frequency offset estimation result; utilizing the first frequency offset estimation result to carry out frequency offset compensation on the receiving signal and utilizing the receiving signal after frequency offset compensation to establish a likelihood function for a sending signal, a frequency offset and a channel impulse response; and completing secondary frequent offset estimation for the receiving signal through the likelihood function. According to the method and the device, the joint estimation of the frequency offset and the channel is realized, the larger range and the higher precision of the frequent offset estimation are considered, and the influence of the channel condition on the frequent offset estimation is considered.

The invention discloses a method for suppressing impulse noise in a power line communication system based on recursive compressed sensing, which selects a part of subcarriers from many subcarriers as pilot subcarriers for block fading channel estimation, and uses the received signal on the pilot subcarriers Combine the channel impulse response and asynchronous impulse noise in and give the joint probability density function, use the expected maximum method to divide E-step and M-step two steps to iteratively solve the hyperparameters, and use the Kalman filter in E-step The sum smoother iteratively estimates the hyperparameters, so as to further obtain the estimated value of the channel impulse response and the asynchronous impulse noise; finally subtract the estimated value of the asynchronous impulse noise from the received frequency domain signal; obtain the asynchronous impulse noise suppressed Frequency domain signal; the advantage is that it can jointly estimate the block fading channel and asynchronous impulse noise in the slow time-varying channel, and the estimation accuracy is high.

The invention relates to a wireless sensor network time synchronization method based on partial timestamp information, and belongs to the technical field of wireless sensor networks. According to the method, partial timestamp information and response time interval information are transmitted through the local time of a preset clock source node returning an acknowledgement frame, so that the interaction of timestamps is avoided; and aiming at Gaussian random time delay and exponential random time delay, a maximum likelihood estimation method and an optimal linear unbiased estimation method are respectively adopted to simultaneously estimate clock frequency offset and phase offset so as to realize synchronization between nodes. According to the method, the synchronization information is transmitted without depending on a special synchronization frame, the synchronization function can be embedded into the existing network data flow, and the synchronization energy consumption is effectively reduced.

The invention discloses a frequency diversity MIMO radar parameter estimation method based on a matrix pencil principle. The method comprises the following steps: firstly, deducing a receiving signal model of a frequency diversity MIMO radar, and analyzing a coupling relationship between an angle and a distance in a transmitting-receiving steering vector; secondly, an echo signal obtained after matched filtering of a receiving end is used for constructing an augmented matrix beam of the echo signal; then, matrix decomposition and transformation are carried out on the augmented matrix bundle, and diagonal phase matrixes containing angle and distance information are obtained respectively; and finally, in consideration of the coupling and matching problems of the angle and distance parameters of the target, the matching is realized by adopting the same characteristic vector, and the accurate positioning of the target is realized. A simulation result shows that compared with the prior art, the method has excellent estimation performance under the conditions of low snapshot number and low signal-to-noise ratio.

Protection for a BOC signal parameter blind estimation method based on a cyclic autocorrelation function is claimed. The invention belongs to the technical field of signal processing. First, the cyclic autocorrelation function of a BOC signal is obtained; a tangent plane where an average cyclic autocorrelation function delay time [tau] =0 is extracted and the tangent plane is searched for the largest spectrum peak, wherein a cyclic frequency corresponding to the largest spectrum peak is the carrier frequency to be estimated; a tangent plane where an average cyclic autocorrelation function delay time [tau] not equal to zero is extracted, and the tangent is searched for two spectrum peaks which have different amplitudes and are closest to a zero-frequency, and therefore estimations of pseudo code rate and subcarrier rate can be realized according to the cyclic frequencies corresponding to the two spectrum peaks. At the same time, progressive average is performed to cyclic autocorrelation functions of multiple signals. Noise reduction and accurate estimation are realized. By use of the method, the BOC signal carrier frequency, the subcarrier rate and the pseudo code rate under low signal noise ratio can be accurately estimated, and therefore the method is of great significance to follow-up treatment and fine feature analysis of the signal.

The invention discloses an FDA-MIMO radar monopulse distance angle joint estimation method. The method comprises the following steps: constructing an angle-distance dependent transmit-receive steering vector of an FDA-MIMO radar; acquiring a monopulse receiving signal vector z by using the FDA-MIMO radar aiming at echo data of a target, wherein the expression of z is constructed as z = beta1s (u, delta) + n, beta1 represents a target reflection complex coefficient, and n represents a Gaussian color noise vector; sequentially constructing a monopulse vector r, a Bayesian correction vector mu and a slope correction matrix C based on s (u, delta), z, and an initial angle u0 and an initial distance delta0 which are obtained in advance; constructing an initial distance-angle vector h0 by utilizing u0 and delta0, and obtaining a corrected distance-angle vector hAMP by utilizing h0, r, mu and C; and projecting the hAMP to a predetermined value domain space about u and delta value ranges to obtain an estimated distance-angle vector containing a distance estimated value and an angle estimated value of the target. According to the method, the limitation on the number of snapshots is broken through, the robustness of parameter estimation is relatively high, the operation complexity is small, and the engineering practicability is relatively high.