High-end ultrasound imaging system always requires high-speed data acquisition and processing system, which often leads to high-cost issues of ultrasound hardware. Fortunately, the compressed sensing theory offers a p...
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High-end ultrasound imaging system always requires high-speed data acquisition and processing system, which often leads to high-cost issues of ultrasound hardware. Fortunately, the compressed sensing theory offers a perspective of reducing the data sampling rate. To obtain better-reconstructed ultrasound imaging quality at a low sampling rate, this paper explores coding technology with compressed sensing and proposes a kind of Orthogonal Sparse Dictionary based on Chirp echo (OSD). The simulation experiments of scattering point targets, cyst phantoms, and geabr_0 data were conducted, and a series of performance index parameters about reconstructed image quality were calculated and analyzed. The simulation results indicate that the image quality reconstructed by the proposed OSD is superior to traditional sparse dictionaries with the same reconstruction algorithm and sampling rate. By applying the proposed OSD, there is no obvious distortion about the image quality at 30% sampling rate. (C) 2019 Elsevier Ltd. All rights reserved.
The performance of a partial response maximum likelihood (PRML) system in perpendicular magnetic recording that uses double-layered media perpendicular to the MR head is evaluated. The codes of (1,7) RLL and 16/17 (0,...
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The performance of a partial response maximum likelihood (PRML) system in perpendicular magnetic recording that uses double-layered media perpendicular to the MR head is evaluated. The codes of (1,7) RLL and 16/17 (0,6/6), which are commonly used in modern hard disk equipment, are used as the recording codes. The relationship between the normalized linear density and the desired 4 SNR at the reading point for a bit error rate of 10(-4) is determined from a computer simulation, assuming equalization by a transversal filter, and a comparative study is performed. It is shown that a (1,7) RLL coded PRML system has better performance when the recording density is comparatively low. For high recording density, a 16/17 (0,6/6) coded PRML system has shown better performance. (C) 2002 Wiley Periodicals, Inc.
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