Sparse dictionary compressed sensing ultrasonic imaging method based on Chirp code

Abstract

The invention relates to a sparse dictionary compressed sensing ultrasonic imaging method based on Chirp codes, and belongs to the technical field of ultrasonic imaging. The method comprises the following steps: adopting a Chirp code excitation signal subjected to windowing function processing in an ultrasonic emission signal; carrying out amplification processing and A / D conversion on the received ultrasonic echo signal; constructing a sparse dictionary for sparse representation of ultrasonic echoes in combination with the echo signals; carrying out non-uniform compression sampling on the sparse signal by using a measurement matrix to obtain a measurement signal, and carrying out data transmission; at a receiving end, solving an optimization problem through a reconstruction algorithm to obtain a coefficient vector of the ultrasonic signal; and recovering an ultrasonic signal by using the coefficient vector so as to carry out ultrasonic beam forming and imaging. According to the method, the high-precision ultrasonic signal can be reconstructed at a higher compression rate, so that the storage space of an ultrasonic system and the complexity of hardware implementation are reduced.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic imaging, and relates to a sparse dictionary compressive sensing ultrasonic imaging method based on Chirp codes. Background technique [0002] With the improvement of the quality requirements of ultrasonic imaging, a higher sampling frequency is required, so the amount of echo data to be stored is very large, which increases the complexity of hardware implementation. Compressed sensing theory (CS) is a method proposed for high-speed data acquisition and large-capacity data storage in recent years. The theory believes that when the signal itself or in a certain transform domain is sparse, it can be much lower than the Naiqui The rate of Stern compresses the signal while sampling and transmits the data. At the receiving end, through the reconstruction algorithm, the original signal can be reconstructed from a small amount of sampled data with extremely high precision, reducing the amount of data t...

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Problems solved by technology

[0005] In view of this, the object of the present invention is to provide a sparse dictionary compressive sensing ultrasonic imaging method based on Chirp codes, constructing a sparse dictionary based on Chirp codes to perform sparse representation of ultrasonic signals, which can effectively overcome the lack of sparse capabilities of traditional sparse dictionaries for ultrasonic signals defects, and can reconstruct the ultrasonic signal with extremely high precision at a low sampling rate, thus ensuring the quality of ultrasonic imaging

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