查询词典 signal noise ratio

It is proved that these methods are valid and time domain filtering and noise estimation can reduce the ambient noise, and increase the signal-to-noise ratio.

结果表明：时域滤波和噪声估计方法能够较好的压制背景噪声，提高处理结果的信噪比。

Initial growths of disturbances are measured by means of hot-wire anemometry. Due to the detected signals with low signal to noise ratio, the coherence function is used to eliminate background noise during data reduction.

在扰动增长的初始阶段，信号的信噪比非常地低，根据相关谱分析方法，应用相干函数，将扰动信号有效地提取出来，测量了初始扰动的增长。

Two new functions based on the property of bubble wavelet are proposed. An approximate 2nd derivative of an analytical signal can be obtained by applying n times of the wavelet transform to the signal, the signal-to-noise ratio can be enhanced greatly.

根据小波的定义和墨西哥帽小波的一些特点提出了两种简单的窗口函数，利用它们对模拟高斯信号求2n阶近似导数的同时滤除了噪声，同时还可分离重叠峰，并讨论了尺度因子对变换结果的影响。

Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.

在此基础上，(1)结合连续小波变换的特点和卷积的微分性质，提出了使用Gaussian函数的一阶和二阶导数，Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法，与其他导数计算方法(包括数字微分法，多项式滤波法，Fourier变换法和离散小波变换法)相比，本法简单便捷，计算速度快，对于噪声含量较高的信号(S/N为5)，只要适当调节尺度即可获得比较满意的结果。

By means of analyzing the noise error, it is proposed to use an algorithm of singular value decomposition total least squares to conduct the interharmonics estimation, namely taking the noise interference at both sides of the matrix equation into account simultaneously and solving the minimum norm problem by least square method under such condition. In the proposed algorithm by means of singular value decomposition of a new augmented matrix and by use of a simple and practical method to determine the number of principal singular value related to signal to noise ratio, the storage calculation of right singular matrix is performed, thus a more accurate frequency estimation of interharmonics can be obtained.

通过分析噪声误差，提出采用奇异值总体最小二乘(singular value decomposition total least squares，SVDTLS)算法进行间谐波频率估计，即同时考虑矩阵方程两边的噪声干扰，采用SVDTLS算法求解该情况下的最小范数解，通过对增广矩阵进行奇异值分解(singular value decomposition，SVD)，采用简单实用的与信噪比相关的主奇异值个数确定方法对分解的右奇异矩阵进行存储计算，得到了较精确的间谐波频率估计结果。

It is shown that the new MMSE-based method outperforms zero forcing equalizer. It can mitigate the intersymbol interference and depress the noise amplification effect simultaneously, and subsequently maximizes the signal to noise ratio of the system at the receiver.

该均衡算法的性能要明显好于基于ZF准则的方法，并且在消除ISI的同时可以抑制噪声的影响，从而使系统的输出信噪比达到最优，而增加的复杂度很有限。

What is the channel capacity for a teleprinter channel with a 300-Hz bandwidth and a signal-to-noise ratio of 3 dB, where the noise is white thermal noise?

一个电传打印机的带宽是300Hz，信道内所传信号的平均功率与白热噪声功率的比值为3分贝，问其信道容量是多少？

In order to advance the capability of correlation signal detection method, a new method for LFM signal detection,based on the technology for ambiguity resolution of stagger repeated frequency, is proposed. Using the method, the signal in low signal-to-noise ratio can be detected very well and its parameters can be estimated more precisely too.

本文提出基于重频参差解模糊技术的信号参数估计方法，通过相位解模糊，实现了在低信噪比条件下对信号参数更有效地侦取，并对处于白噪声环境下的窄带和超宽带LFM信号进行了仿真，验证其有效性。

In comparison with the current version, in which the signal-to-noise ratio accuracy of the noisy signal produced is heavily influenced by 'clean' signal itself, the proposed approach has removed this unfavorable impact by choosing another factor to rescale the signal.

在目前广泛使用的加噪信号方法中，产生的信噪比精度受无噪信号的影响很大，与之相比，新方法通过选择新的因子对信号进行归一化，剔除了无噪信号对产生的加噪信号的信噪比影响。

Secondly, making use of the good time frequency characteristics of the wavelet analysis in the signal processing, the wavelet softthreshold filtering of the swing CO2 welding voltage signal under the arc discharge sense was carried out, showing the possibility of removing the peak current of the shortcircuit transition and improving the signal-to-noise ratio.

二是利用小波分析在信号处理上良好时域、频域局域性，对电弧传感方式下的摆动焊接电流进行了软阈值滤波，取得了良好的效果，消除了短路过渡所造成的峰值电流，提高了信噪比。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。