归一化循环相关超声回波时延估计

发布时间：2018-12-21 20:17

【摘要】：传统超声回波时延估计算法是在高斯噪声背景下展开研究的,而实际工况中超声回波不仅含有高斯噪声,还含有脉冲冲击噪声(α稳定分布噪声)等,这导致传统算法失效。为了解决上述问题,本文提出了一种针对混合噪声特别是包含噪声背景下的超声回波时延估计算法:归一化循环相关时延估计算法。首先,对归一化循环相关算法理论进行了简要的介绍。接着,对归一化循环相关时延估计算法进行了理论推导分析。然后,结合仿真分析,在相同α混合噪声情况下对传统循环相关和归一化循环相关时延估计进行比较。最后,在不同信噪比下,对归一化循环相关时延估计算法的估计性能进行了分析。通过对比实验发现,在噪声特征指数趋于1时,循环相关算法已不能估计出时延,而归一化循环相关算法的误差仍能保持在0.4μs;且在-10dB信噪比下,归一化循环相关算法时延估计也能保持在10μs误差范围内。本文所提归一化循环相关算法在混合噪声特别是包含α噪声情况下能够对超声回波时延进行精确估计,具有传统算法所不能比拟的优势。
[Abstract]:The traditional ultrasonic echo time delay estimation algorithm is studied under the background of Gao Si noise. However, the ultrasonic echo in the actual working condition not only contains Gao Si noise, but also contains impulse noise (伪 stable distribution noise), which leads to the failure of the traditional algorithm. In order to solve the above problems, this paper proposes a new time delay estimation algorithm for ultrasonic echo, which is called normalized cyclic correlation time delay estimation algorithm for mixed noise, especially in the background of noise. Firstly, the theory of normalized cyclic correlation algorithm is briefly introduced. Then, the normalized cyclic correlation time delay estimation algorithm is theoretically deduced and analyzed. Then, combined with simulation analysis, the traditional cyclic correlation and normalized cyclic correlation delay estimation are compared under the same 伪 mixed noise. Finally, the performance of the normalized cyclic correlation time delay estimation algorithm is analyzed under different SNR. By comparing experiments, it is found that the cyclic correlation algorithm can not estimate the time delay when the noise characteristic index tends to be 1, but the error of the normalized cyclic correlation algorithm can still be kept at 0.4 渭 s. Moreover, the time delay estimation of normalized cyclic correlation algorithm can also be kept in the range of 10 渭 s at-10dB signal-to-noise ratio. The normalized cyclic correlation algorithm proposed in this paper can accurately estimate the ultrasonic echo delay in the case of mixed noise, especially in the case of 伪 noise, which has the advantage that the traditional algorithm can not compare.
【作者单位】：吉林大学通信工程学院;长春建筑学院电气信息学院;
【基金】：国家自然基金面上项目(No.51475198) 吉林省青年科研基金项目(No.20140520064) 中国博士后科学基金资助项目(No.2015M570270)
【分类号】：TB559

【参考文献】