39 results about "Underdetermined blind source separation" patented technology

The invention discloses an underdetermined blind source separation method based on density, mainly solving the problems that the computation complexity of the prior art is high, the prior art is easily influenced by an initial value and the number of source signals needs to be given. The method comprises the following steps: after the low energy sampling data of an observed signal is removed, projecting the observed signal onto a right half unit hypersphere; computing the density parameters of all projective points, and deleting the projective points with smaller density; utilizing an improved K-mean value clustering algorithm to cluster the surplus projective points and determining the optimal clustering number and clustering center; removing the cluster with less number of data objects, wherein the number of the surplus clusters is the estimated value of the number of source signals, and the corresponding clustering center is the estimated value of each column vector of a confusion matrix; and according to the observed signal and the estimated confusion matrix, adopting a linear programming method to recover the source signals. According to the method, the computation complexity is reduced, the influence of the initial value on the estimated performance is reduced, the confusion matrix can be estimated when the number of the source signals is unknown, and the estimating precision of the confusion matrix and the source signals can be increased.

The invention discloses a dual-channel optical three-dimensional interference method based on underdetermined blind source separation. Through the interference data collected by a CCD camera, the interference signals between the surfaces of the slide glass under test are blindly separated, and the parameters of the interference signals are solved, including : Interference signal amplitude frequency and interference signal phase frequency; based on the dual-channel optical three-dimensional Michelson interference experiment, the estimation of the mixing matrix is ​​obtained through the K-means clustering algorithm and the recovery of the source signal is realized through the L1 norm shortest path method; finally, the laser The wave number scanning accurately blindly separates the four-surface interference signals through the light intensity values ​​collected by the CCD camera, and realizes the blind separation of the four-surface interference signals; compared with the ordinary interferometric method that cannot accurately identify each peak position, the present invention uses a dual-channel Detection and sampling, through blind source separation, enables the signal to detect the location of each interference signal even in the face of relatively strong noise.

The invention relates to a mixing matrix estimation method for underdetermined blind source separation, which performs short-time Fourier transform on two received observation signals to obtain the short-time Fourier coefficients X1(t,f) of the two observation signals ) and X2(t,f) to form multiple scattered points and remove low-energy scattered points; calculate the ratio of the remaining scattered points, classify the scattered points according to the ratio, and obtain the M category with the largest number of scattered points, and calculate each Then convert the mean value into the slope angle of the straight line, and then convert it into a column vector, and obtain the rotation matrix T according to the column vectors with close directions, and perform rotation transformation to obtain a new two-way observation signal X′1( t,f) and X′2(t,f); for the two observation signals X′1(t,f) and X′2(t,f), classify the scattered points again according to the ratio of the two observation signals , get the S class with the largest number of scattered points, calculate the mean value of the ratio of scattered points in each class, and then get the similar slope angles, get the corresponding column vectors through these slope angles, and finally get the entire mixing matrix.

The invention discloses a gradient descent method and Newton method based underdetermined blind source separation source signal recovery method. The method comprises the steps of firstly, obtaining an observation signal matrix; secondly, clustering all column vectors in the observation signal matrix to obtain a hybrid matrix; thirdly, calculating to-be-recovered source signal column vectors according to the observation signal matrix and the hybrid matrix; and finally, updating the to-be-recovered source signal column vectors by utilizing a gradient descent method, a Newton method and a projection method to obtain a recovered source signal. According to the method, the defects that the source signal recovery precision is easily influenced by a noise error and the computing complexity is high in the prior art are overcome, so that the method has the advantage that the source signal can be quickly recovered while relatively high recovery precision is kept.