192results about How to "The estimate is accurate" patented technology

The invention discloses a co-channel full-duplex system based on MPPSK modulation. After the system isolates receiving and sending signals at the radio-frequency head normally, cancellation conducted on leakage self-interference signals is finished on a digital baseband; the cancellation method is conducted after conducting shock filter on MPPSK receiving and sending aliasing signals, extracting and multiplying by coherent carrier, band-pass filtering and digitizing, the result of initial channels of all self-interference channels between the output end of a modulator and a receiver ADC is estimated before formal communication, self-interference offset signals are rebuilt by the adoption of the estimated result, further residual errors are filtered out with the combination of methods of coding rate filtering and double matched filtering of a method of shock filtering-multiplying by the coherent carrier-band-pass filtering-coherent demodulation, and MPPSK receiving signals are demodulated reliably. The co-channel full-duplex system based on MPPSK modulation is free of radio-frequency self-interference cancellation, has low requirements for the dynamic range and sampling rate of the ADC, has high isolation degree for the self-interference signals, and is simple in structure, low in complexity, high in spectrum efficiency and good in demodulation performance.

The invention discloses a self-adaptive channel estimation method based on compressed sensing and large-scale MIMO and belongs to the technical field of wireless communication. The self-adaptive channel estimation method includes the steps that decomposition values Ur and Ut of a channel matrix in an angle domain are obtained, and a corresponding measurement matrix phi and a corresponding perceptual measurement value Y are calculated; iterative computation is conducted on a shared channel parameter estimation value (shown in the description) based on an index set Gamma n-1 at a previous moment of a system, the measurement matrix phi and the perceptual measurement value Y; a sparse signal estimation value (shown in the description) is calculated through iteration of the shared channel parameter estimation value (shown in the description), the phi and the Y; finally, a channel matrix estimation value (shown in the description) is obtained according to a formula (shown in the description) based on the number M of transmitting antennas, the signal-to-noise ratio P of the transmitting antennas and the pilot frequency length T of the transmitting antennas. The self-adaptive channel estimation method does not need knowing shared channel information for channel estimation, utilizes the index set at the previous moment in a self-adaptive mode and produces smaller errors compared with a traditional subspace tracking algorithm.

The invention relates to the wireless communication field, discloses a channel estimation method based on orthogonal frequency division multiplexing system and device thereof, which improves channel estimating precision and channel estimated performance. The method includes: selecting a plurality of pilot symbols form OFDM pilot symbols transmitted by a pilot frequency subcarrier to be measured, wherein, each pilot symbol is in corresponding to a channel coefficient of the pilot frequency subcarrier to be measured, obtained by preliminary estimating of the pilot symbol; filtering these channel coefficients obtained by preliminary estimating to obtain accurate channel coefficients of the pilot frequency subcarrier to be measured; performing frequency domain estimation according to the accurate channel coefficients, to obtain channel coefficients of non-pilot-frequency subcarrier to be measured. The selected pilot symbols are pilot symbols whose correlation coefficient is larger or equal to the prearranged threshold, in the received N pilot symbols, thereby correlation in time-domain is ensured by controlling the correlation degree of the selected pilot symbols.

The invention relates to a face identification based living body detection method and apparatus. The method comprises the steps of: carrying out identity authentication on a to-be-detected user in a to-be-detected crowd through face identification; obtaining a training eye image of the to-be-detected user watching a training sight point, and further extracting training sightline features; obtaining a to-be-detected eye image of the to-be-detected user watching a system random point, and further extracting to-be-detected sightline features; for the to-be-detected user passing the identity authentication, carrying out primary sight point position estimation by adopting an adaptive linear regression algorithm by utilizing a training sight point sequence, the training sightline features and the to-be-detected sightline features; adding the system random point, meeting the predetermined conditions, in the sight point position obtained by primary sight point position estimation into the training sight point sequence to form a new sight point sequence, and carrying out incremental sight point position estimation; and estimating the estimated sight point position according to the incremental sight point position, and carrying out living body judgment by utilizing KL divergence.

The invention relates to an estimation method of scattered point cloud data differential geometric senses, which comprises the following three parts of: estimating an initial normal vector for each point in point cloud data according to the position distributing situation of points in an adjacent field, and carrying out unitization on the initial normal vector of each point; carrying out normal fitting on the initial normal vectors, and computing the normal partial derivative of scattered point cloud at each point; and computing the second-order differential quantities such as the maximum principal curvature, the minimum principal curvature, the principal direction, the Gaussian curvature, the mean curvature and the like of the scattered point cloud at each point through the unitized initial normal vectors and the normal partial derivative. Aiming at the scattered point cloud data with strong noise, the invention can accurately estimate various differential geometric senses of each point and has important application value in computer graphics and computer visual adjacent fields.

The invention provides a traffic capacity estimation method and device of a congestion region and data processing equipment. The method comprises the steps of acquiring historical travelling track data of a plurality of vehicles on a target road; acquiring a road speed distribution matrix according to the historical travelling track data; identifying a bottleneck generation position and bottleneckgeneration time of a traffic bottleneck from the road speed distribution matrix; determining a critical travelling speed and a congestion propagation speed of the congestion region caused by the traffic bottleneck according to the bottleneck generation position and the bottleneck generation time; and performing forecast calculation on a traffic flow basic map according to the critical travellingspeed, the congestion propagation speed, preset congestion vehicle density and a preset smooth travelling speed, and outputting corresponding vehicle flow as traffic capacity of the congestion region.Therefore, the track data which is low in cost and is capable of completely and continuously reflecting a road traffic state is used for estimating the traffic capacity of the congestion region, an estimation result can be more accurate, and reliable reference data is provided for traffic control.

The invention relates to a lithium battery state-of-health estimation method, which comprises the following steps of: selecting battery capacity as a state variable, and extracting a plurality of characteristics as input and output data of a subsequent model according to correlation analysis so as to simulate an aging process of a lithium battery; dividing the sample data into a training set and atest set, establishing a regression model based on a gradient boosting decision tree, performing parameter optimization on the regression model, and performing sample training to obtain a mixed algorithm regression training model; and estimating the state-of-health of the lithium battery under the test set by using the mixed algorithm regression training model. The lithium battery state-of-health estimation method has the advantages of high precision, high generalization ability and the like, and can precisely and effectively estimate the state-of-health of the lithium battery.

The invention discloses a multi-source self-adaptive fault-tolerant federated filtering integrated navigation system and a navigation method. The system comprises a strapdown inertial navigation system, a satellite navigation system, a Doppler velocity measurement system, a celestial navigation system, and a main filter and three sub-filters that are in information connection with the systems respectively; the three sub-filters are all in information connection with the strapdown inertial navigation system, and are connected to the main filter through a fault detection and isolation module, the strapdown inertial navigation system is connected to the fault detection and isolation module through a state transmitter, and an output result of the fault detection and isolation module passes through an information sharing factor calculation module, then the calculation result is input into the main filter; and the main filter outputs the fused information and synchronizes a fusion result tothe three sub-filters and the state transmitter. According to the system and the method disclosed by the invention, the state of each sub-filter can be tracked more accurately, and a more precise fusion result can be obtained.

A low frequency oscillation on-line analysis and early warning method of an electric power system includes the steps of acquiring and preprocessing a frequency signal, estimating frequency and a damping ratio of an oscillation mode, determining a dominant mode, and performing early warning of a dominant modal state. The method is based on self-adaption detrend processing of empirical mode decomposition, steady state and nonlinear components of system response under stimulating of disturbance in different strengths can be eliminated, and dynamic oscillation characteristics of the system response can be kept; an expanding stage Yule-Walker method is combined to estimate the system oscillation mode, energy of the oscillation mode is calculated, and the dominant mode of the system is determined; according to the strength of damping, safety, alert or emergency information of system oscillation is sent. The method can be applied to distribution network frequency signals, practical value is high, an estimated result is accurate, free response to the system and random response to the system can be performed uniformly, the method is applicable to on-line analysis of low frequency oscillation modes of a large-scale electric power system, and the method provides oscillation early warning information to a control center timely.

The invention discloses an inverse synthetic aperture radar (ISAR) image distance unit selecting and cross-range scaling method and mainly solves the problem that estimated errors of frequency modulation rates are large due to the fact that appropriate distance units are not selected by means of existing methods. The achievement process of the method includes reading radar pulse echo, subjecting radar echo data to motion compensation, selecting distance units where targets are located according to amplitude, selecting a required distance unit from the distance units where the targets are located according to various criterions, subjecting the selected distance unit to frequency modulation rate estimation by using local polynomial Fourier transform, performing secondary selection of a distance unit according to an area normalization criterion, and using a least square method for obtaining average for a plurality of times to obtain an angular speed estimation value so as to finish cross-range scaling of ISAR images by means of angular speeds. According to the ISAR image distance unit selecting and cross-range scaling method, accuracy of frequency modulation rate estimation is improved, and the method can be used for the cross-range scaling of the ISAR images.

The invention provides a post data-based rotary guided projectile quick air alignment method. The alignment position and the speed in the method are provided by a satellite navigation system, and a course angle and a pitching angle at the corresponding moment are calculated according to a speed signal output by satellite navigation; a coefficient matrix of a transverse roll angle observation equation is determined according to the pitching angle from the set moment T to the alignment moment T1, the change rate of the coarse angle, the change rate of the pitching angle and the gyro output angle speed in INS data, and is solved by the least square method, thus realizing precise calculation of the inertial navigation initial position, the speed and the attitude angle, namely realizing quick air alignment of a rotary guided projectile; therefore, the falling precision of the rotary guided projectile is greatly improved. The alignment algorithm is simple, and the precision is high; meanwhile, the alignment time is short, the alignment speed is high, and important implying in improving the falling precision of the rotary guided projectile and shortening the striking time is made.

The invention relates to the technical field of communication, particularly relates to a self-interference reconstruction device and method, and self-interference elimination equipment and method, and aims at solving a problem of inaccuracy of self-interference after reconstruction if multinomial coefficients used in reconstruction of self-interference in self-interference elimination are inaccurate. The self-interference reconstruction device provided by the embodiment of the invention comprises a multinomial coefficient updating decision circuit, a multinomial coefficient generating circuit which is connected with the multinomial coefficient updating decision circuit, and a nonlinear term generating circuit which is connected with the multinomial coefficient generating circuit. Whether the multinomial coefficient generating circuit needs to update coefficients of all orders of non-linear terms in multiple orders of nonlinear terms is judged by the multinomial coefficient updating decision circuit so that an opportunity suitable for updating the multinomial coefficients is confirmed, and the problem of inaccuracy of the multinomial coefficients after updating caused by the fact that the multinomial coefficients are updated at an inappropriate opportunity is avoided.

The invention relates to a method for predicting the fatigue life of a material based on wavelet packet analysis. The method comprises the following steps: establishing a sample piece model of the material and calculating stress powder spectrum density of a dangerous part in the sample piece model; according to the stress power spectrum density, obtaining time sequence under different frequency bands and the corresponding relation between each time sequence and the stress according to a wavelet packet analysis method; selecting the time sequence, with the maximal transient stress, in the time sequences under different frequency bands, and calculating by combining an S-N curve of the material to obtain the fatigue life of the material. Compared with the prior art, the method has the advantages of accurate prediction result, high practical performance, convenience in implementation and the like.

The invention discloses a nonlinear self-healing control method for a multi-sensor fault of a hypersonic flight vehicle, and the method comprises the steps: obtaining a longitudinal affine nonlinear system of the hypersonic flight vehicle through employing an input and output feedback linearization technology for a longitudinal nonlinear model of a cruise stage of the hypersonic flight vehicle; establishing a sliding mode surface for the obtained system, and designing a sliding mode controller under a fault-free condition; and injecting a multi-sensor constant deviation fault into an originalhealth system, and designing a fault estimation scheme. Specifically, a nonlinear adaptive observer is designed for a speed channel; aiming at a height channel, a backstepping sliding mode observer isdesigned to estimate a state quantity and a sensor fault; and after a fault estimation result of the height sensor and the speed sensor is obtained, a fault-tolerant controller is designed to compensate output signals of the height sensor and the speed sensor. The method can solve the problem of fault-tolerant control under the condition that the longitudinal system of the hypersonic aircraft suffers from speed and angle channel multi-sensor faults, and the self-healing capacity of the system is improved.

The invention discloses a moving target detection and parameter estimation method based on a reconstructed signal and 1-norm. The method comprises the first step of performing clutter rejection on total echo data received by an airborne radar to obtain data after the clutter rejection, the second step of reconstructing one target signal with a speed value as a variable, the third step of constructing a cost function by utilizing the reconstructed signal obtained from the second step and the 1-norm of the data, after the clutter rejection, obtained from the first step, and the fourth step of searching for speeds so as to allow the speed value when the cost function achieves the minimum value to be an estimation result. In the method, the target signal is reconstructed according to a moving target space-time data model, and then the cost function is constructed by utilizing the reconstructed signal and the 1-norm of the data after the clutter rejection, so that parameter estimation of a moving target is completed. According to a simulation experiment, it is proved that accurate moving target parameter estimation results can be obtained through the method under the condition that the number of pulses transmitted by the airborne radar is limited.

The invention discloses a channel estimating device and method for same-frequency villages, comprising the steps of: 1. calculating signal strength of each village in the same-frequency villages and arranging these villages according to the signal strength; 2. in a sequence of signal strengths from strong to weak, making interference cancellation on each village in a mode of combining fast Fourier transform algorithm (FFT) with serial interference cancellation and thus completing channel estimation. And it can make accurate channel estimation for users in local and neighbouring villages in the same-frequency villages.

The invention discloses an underwater DOA estimation method based on a noncircular signal and an adjustable-included-angle array and a device thereof. According to the estimating device, an adjustable-included-angle two-dimensional array is adopted in a receiving module. The array can perform flexible measurement. Through changing the included angle between the two-dimensional arrays and performing multiple measurements, a purpose of improving estimation performance can be realized. For overcoming a problem of signal attenuation in an underwater acoustic environment, a noncircular signal is applied to underwater DOA estimation, and an NC-ESPRIT algorithm based on the noncircular signal is utilized for improving estimation performance. For eliminating an estimation error caused by sound speed influence, a one-dimensional DOA estimation expression which is unrelated with the sound speed is utilized, thereby improving underwater DOA estimation precision. In one word, the adjustable-included-angle two-dimensional uniform array is utilized, and furthermore the advantage of noncircular signal is utilized; optimization which is unrelated with the sound speed is performed according to theunderwater environment. The underwater DOA estimation method and the device thereof have advantages of high estimation precision and relatively high practicability.

The invention discloses an underwater one-dimensional DOA estimation method and device based on a non-circular signal and an L-shaped line array. The method applies the non-circular signal to underwater DOA estimation to overcome the problem of rapid signal attenuation in a hydroacoustic environment. The non-circular characteristic of the signal is fully utilized. The effect of array aperture expansion can be acquired, so that the underwater DOA estimation result is accurate. An NC-ESPRIT algorithm based on the non-circular signal is adopted to improve the estimation performance. At the same time, in order to eliminate the estimation deviation caused by the influence of sound speed, the L-shaped uniform line array whose angle can be adjusted is used in the invention. The variable of speedsound is eliminated through the angular relationship between two sub-arrays and the arrival direction angle, so that the final operation result has nothing to do with sound speed. The estimation accuracy is improved.

The invention provides an adaptive blind equalization method based on deviation compensation, and belongs to the technical field of broadband wireless digital communication blind equalization. The adaptive blind equalization method comprises noise variance estimation, blind channel identification deviation compensation, equalizer construction and blind restoration, and comprises the following steps: 1, performing over sampling on received signals at a receiving end to obtain two paths of received signal sequences; 2, estimating transmission channel properties to obtain a biased estimation value of the transmission channel properties; 3, calculating an estimation deviation of the biased estimation value of the transmission channel properties; 4, compensating the biased estimation value to obtain a compensated biased estimation value of the transmission channel properties; 5, constructing an equalizer; 6, constructing a received signal vector, and performing blind restoration on an input signal sequence; and 7, judging whether a cycle counting value reaches the maximum value, and deciding whether the method is accomplished. By adoption of the method, unknown additive noise variances can be estimated in real time, more accurate estimation of the transmission channel properties is obtained, the convergence performance is excellent, and the output precision of the blind equalizer and the anti-interference ability of the system are improved.

The invention provides a method suitable for estimating residual discharge capacity of a battery under dynamic current working conditions. The method includes the steps that the current measured value of the battery is acquired, and a time period meeting preset conditions is selected according to the measured value to serve as a recognition period; the voltage change at the battery end and the corresponding current difference accumulation electric quantity in the current recognition period are calculated, and the current dynamic voltage change ratio is obtained; the current residual discharge capacity of the battery is determined according to the dynamic voltage change ratio and the corresponding relation between the dynamic voltage change ratio and the residual discharge capacity, wherein the corresponding relation is obtained through calibration. The method is simple in calculation and high in accuracy.