Back projection radio-frequency chromatography imaging method of dual space and apparatus thereof, and back projection radio-frequency chromatography positioning method of dual space and apparatus thereof

Abstract

The invention provides a back projection radio-frequency chromatography imaging method of dual space and an apparatus thereof, and a back projection radio-frequency chromatography positioning method of dual space and an apparatus thereof. The back projection radio-frequency chromatography imaging method comprises the following steps: step A1, establishing a positioning system; step A2, measuring areceived signal strength (RSS) value of a radio-frequency link without a target and an RSS value of the radio-frequency link with a target and carrying out subtraction on the RSS values to obtain anobserved value y; step A3, mapping a fading image vector x of original space to dual space based on a formula x=phi z and expressing a result value as a vector z; step A4, on the basis of a measuringequation y=(phi x)+n and the mapping relationship, obtaining a measuring equation y, being expresses by a formula: y=(psi z)+n, of the dual space; step A5, carrying out reconstruction in the dual space by combining the observed value y obtained at the step A2 and the measuring equation y=(psi z)+n obtained at the step A4, thereby obtaining a signal z; step A6, carrying out back projection of the reconstruction result z to original signal space based on a mapping equation x=phi<T>z to obtain a fading image factor x; and step A7, transforming the fading image vector x into a corresponding two-dimensional image matrix. At the step A4, the psi meets a formula: psi=phi phi<T>. With the method provided by the invention, the original space signal dimension is reduced; redundant and invalid linksare removed; and the calculation efficiency is improved.

Description

Technical field [0001] The present invention relates to the field of hands-free target positioning, in particular to a dual-space back-projection radio frequency tomography imaging method. The present invention also includes a method for realizing positioning using the imaging and a device applying the above method. Background technique [0002] Narrowband radio frequency tomography is an environmental perception method that uses radio frequency signals to achieve projection measurement, reconstructs environmental shadow fading images from radio frequency link shadow fading information, and realizes target hands-free positioning and through-wall perspective imaging. With the help of the non-intrusive sensing mode provided by radio frequency signals that is not affected by light changes and obstructions, radio frequency tomography has other sensing technologies that cannot be used in the detection, positioning and tracking of indoor or hidden objects of interest. The advantage of ...

AI Technical Summary

Problems solved by technology

However, the reconstruction directly in the original signal space faces some problems

First of all, due to the relatively high dimensionality of the original signal space x, the calculation amount is relatively large when using regularization method, greedy algorithm, convex optimization method, Bayesian compressed sensing method, dictionary learning and other methods to reconstruct the fading image vector; secondly, From the perspective of sparse Bayesian learning, the original signal space robust loss function can only deal with abnormal data, and the data of redundant and invalid links needs additional link selection strategies

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