波谱学杂志 ›› 2006, Vol. 23 ›› Issue (2): 217-223.

• 4 • 上一篇    下一篇

扩展基于AD9874数字接收机谱宽的二次抽取算法

  

  1. 华东师范大学光谱学与波谱学教育部重点实验室, 华东师范大学 物理系,上海 200062
  • 收稿日期:2005-10-21 修回日期:2005-12-26 出版日期:2006-06-05 发布日期:2006-06-05

An Second Decimation Algorithm for Widening the Range of Sweep Width of the AD9874 Based Digital Receiver

  1. Key Laboratory for Optical and Magnetic Resonance Spectroscopy, East China Normal University Department of Physics,  East China Normal University, Shanghai 200062 China
  • Received:2005-10-21 Revised:2005-12-26 Online:2006-06-05 Published:2006-06-05

摘要:

针对基于AD9874芯片的数字接收机的最小谱宽和谱宽允许设置的数目均不能满足常规临床用磁共振成像技术的要求,本文从软件角度提出了一种扩展数字接收机谱宽的二次抽取算法. 该算法具体实现过程主要包括两个步骤:(1) 自适应过采样倍率和自动谱宽调整;(2) 数字滤波和抽取. 为了验证这个二次抽取算法的有效性,本文分别用单脉冲实验和磁共振成像实验加以了验证.

关键词: 磁共振成像, 数字接收机, 数字滤波, 二次抽取

Abstract:

Here we propose a second decimation algorithm for widening the range of sweep width in the AD9874 based digital receiver to meet the sweep width requirement set by the clinic imaging pulse sequences. The algorithm is implemented using a two-step approach. First, the best over-sampling number is found adaptively and adjusted automatically to the sweep width of the digital receiver. Secondly, digital filtering and decimation processing are employed. The performance of the proposed second decimation algorithm was tested on a 0.3 T imaging system using a single pulse experiment and an imaging experiment.

Key words: magnetic resonance imaging, digital receiver, digital filter, second decimation

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