3 results about "Observation matrix" patented technology

The invention discloses an edge constraint based image reconstruction method under multivariate observation and mainly aims to solve the problems of the prior art of compressed sensing image reconstruction inaccuracy and low robustness. The edge constraint based image reconstruction method includes: 1) receiving an observation matrix, a low frequency wavelet decomposition coefficient and a multivariate measurement matrix; 2) acquiring a nonzero coefficient group supporting set through edge detection and relevant guides; 3) reconstructing high frequency wavelet coefficient in the nonzero coefficient group supporting set on the basis of a multivariate Gaussian model according to the observation matrix, the multivariate measurement matrix, basic covariance and residual covariance matrix in the Gibbs sampling method; 4) converting the low frequency wavelet decomposition coefficient and the reconstructed high frequency wavelet coefficient to obtain reconstruction images. Compared with OMP and BEPA method, the edge constraint based image reconstruction method has the advantages of high reconstruction image quality and good robustness, and can be reconstruction of natural images and medical images.

The invention relates to an OFDM (Orthogonal Frequency Division Multiplexing) ultra wide band system compressed sampling method based on compressed sensing, belongs to the technical field of wireless communication, and aims at providing an optimization parallel segmented compressed sensing (OPSCS) scheme based on a Hadamard matrix according to an established segmented observation model, for a high-speed sampling problem of an OFDM ultra wide band system. The method is technically characterized in that a segmented observation matrix of any dimension is established by employing the Hadamard matrix, multiple ways of orthogonal or quasiorthogonal observing sequences are obtained, and a restricted isometry property is improved; and through adoption of a simplified orthogonal matching pursuit algorithm, iterative operation is avoided. According to the method, compressed sampling of the OFDM ultra wide band system is effectively realized, moreover, the method has the advantage of high noise immunity, and the system performance superior to that realized through adoption of existing compressed sampling and even Nyquist rate sampling can be realized.