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Description: 可对噪声处理后的心电数据进行评价，既噪声的估计，用信噪比来评价的-noise can be dealt with right after the ECG data for evaluation, we estimate the noise used to evaluate the SNR
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Author: 唐娜 |
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Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers.
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Size: 1265450 |
Author: 吴大亨 |
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Description: 可对噪声处理后的心电数据进行评价，既噪声的估计，用信噪比来评价的-noise can be dealt with right after the ECG data for evaluation, we estimate the noise used to evaluate the SNR
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Size: 1024 |
Author: 唐娜 |
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Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers.
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Size: 1265664 |
Author: 吴大亨 |
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Description: 摘要:为了提高图像复原算法的性能 ,提出了一种改进的奇异值分解法估计图像的点扩散函数。从图像的退化离散模型
出发 ,对图像进行逐层分块奇异值分解 ,并自动选取奇异值重组阶数以减少噪声对估计的影响。利用理想图像奇异值向
量平均能谱指数模型 ,估计点扩散函数奇异值向量的频谱 ,再反傅里叶变换得到其时域结果。实验结果表明 ,该方法能
在不同信噪比情况下估计成像系统的点扩散函数 ,估计结果比原有估计方法有所提高 ,有望为图像复原算法的预处理提
供一种有效的手段。-Abstract : To improve the performance of image restoration algorithms , a modified Singular Value De2
[ ] [ ]
composition SVD method was proposed to estimate the Point Spread Function PSF of an imaging
system. Using the discrete image degradation model , a block2based SVD filter scheme was applied for
the image denoising with an automatically determined singular value rank. After the spectra of PSF
singular vectors were estimated under an exponential model for the averaged spectra of un2degraded
image singular vectors , the IFFT was used to get the time2domain estimation of the PSF. The experi2
mental results show that this proposed method can be applied to estimate the PSF of the imaging sys2
tem under a wide SNR range and its performance is better than the original method. It may be used as
an effective method for the image preprocessing in image restoration problems.
[ ]
Key words: image restoration Point Spread Function PSF block2based Singular Value Decomposi2
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Size: 476160 |
Author: zy |
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Description: cdma function used to estimate snr vesus diffrent parametrs like fading and no of users
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Size: 61440 |
Author: ahmed |
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Description: to estimate snr in MRI
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Size: 3220480 |
Author: waza |
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Description: 通过MATLAB软件；通过仿真得出性能曲线；从而比较bpsk的性能-The bit-error rate (BER) of binary phase-shift keying
in Rayleigh fading, using the Alamouti transmission scheme and
receiver selection diversity in the presence of channel-estimation
error, is studied. Closed-form expressions for the BER of log-likelihood
ratio selection, signal-to-noise ratio (SNR) selection, switchand-
stay combining selection, and maximum ratio combining are
derived in terms of the SNR and the cross-correlation coefficient
of the channel gain and its corrupted estimate. Two new selection
schemes, space–time sum-of-squares combining selection diversity
and space–time sum-of-magnitudes selection diversity, are
proposed and proven to provide almost the same performance as
SNR selection, but with much simpler implementations. The effects
of channel-
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Author: 刘小洋 |
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Description: duction techniques proposed in the art are expressed as a spectral
gain depending on the a priori SNR. In the well-known decision-
directed approach, the a priori SNR depends on the speech spec-
trum estimation in the previous frame. As a consequence the gain
function matches the previous frame rather than the current one
which degrades the noise reduction performance. We propose a
new method called Two-Step Noise Reduction (TSNR) technique
which solves this problem while maintaining the benefi ts of the
decision-directed approach. This method is analyzed and results
in voice communication and speech recognition context are given.-noise estimate
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Author: leon |
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Description: estimate offset time for pulse that modulate in bpsk and compare pe to snr with without offset . we assume offset is between 0 to 4
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Size: 2048 |
Author: ss |
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Description: 该程序用盖氏圆盘方法（GDE）计算均匀直线阵（ULA）中信号源个数估计性能随SNR的变化情况,采用Monte-Carlo模拟。
-estimate the number of source using GDE criterion
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Size: 1024 |
Author: 朱全江 |
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Description: 这是一篇很好的有关信道估计的文章，
可以用来快速的了解信道估计的基本内容-In this paper, a method for fast blind estimation
of DS-SS signal is proposed which aims at the
Direct-Sequence Spread- Spectrum (DS-SS) signals
with parameters unknown. Considering the
characteristic that Pseudo-Random noise (PN)
sequence modulates the information symbol, we
make use of the method based on the second-order
cyclic-cumulant to estimate the period of PN
sequence, and then the method of segmented
cross-correlation to estimate the synchronous start
bit between the information symbols and the PN
codes. On base of this, a method of multiple
subsection cross-correlation average is used to
estimate the PN sequence. Computer simulations
show that the method can work well on signals at
low signal noise ratio (SNR).
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Size: 103424 |
Author: renkill |
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Description: 正弦信号进行傅里叶变换，估计其在不同信噪比下的均值方差，并画出图形-Some interpolated Discrete Fourier Transform (DFT) methods are analyzed and estimate the different frequency under the vary SNR.
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Size: 75776 |
Author: 路静 |
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Description: This is a matlab program using the most-likelihood method to estimate the frequency of a sinusoid wave. Also, a basic filter is provided to check the benefit from using that. The result show that ML method reacches CRB at normal SNR.
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Size: 1024 |
Author: LionTheGreat |
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Description: This is a matlab program using the most liklihood method to estimate the SNR of a sinusoid wave. The experiment shows that it works well at normal SNR, while the noise is Gausian.
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Size: 1024 |
Author: LionTheGreat |
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Description: 利用FFT估计正弦信号的频率,要估计一个叠加了高斯白噪声的正弦信号 的频率 ，可以通过对x(n)做傅里叶变换，得到频谱图，找出幅度的最大值对应的频率值 ，进行多次变换，求出均方误差 。改变信噪比SNR，通过仿真可以得出随着信噪比增加，均方误差减小。-Sinusoidal signal using FFT frequency estimation, to estimate a Gaussian white noise superimposed on the frequency of sinusoidal signals, can be achieved by x (n) be the Fourier transform to get spectrum to identify the magnitude of the frequency value corresponding to the maximum , several transformations, find the mean square error. Change the signal to noise ratio SNR, the simulation can be drawn as the SNR increases, the mean square error decreases.
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Size: 1024 |
Author: 云卷云舒 |
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Description: 对于给定信噪比的通信系统，估计差错概率,数据调制采用GMSK-Estimate error probability for a given SNR communications system,the data modulation method is GMSK
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Size: 2048 |
Author: jieli |
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Description: 针对多径效应的影响，提出了一种基于矩阵束的MIMO 雷达低仰角快速估计方法。该方法同时考虑了发射多径信号和接收多径信号，采用单样本数信号矢量构造了一个前后向矩阵束，并利用两个酉矩阵对该矩阵束进行降维处理，最后采用广义特征值分解的总体最小二乘法来估计目标角度。算法不需要估计数据协方差矩阵，可在低
信噪比和单样本数情况下，有效地克服多径效应，实现同时多目标低仰角估计，相比最大似然算法，避免了谱峰搜索，计算量小。仿真结果验证了该算法的有效性。-To overcome the multipath effect, a fast algorithm for low elevation estimation for MIMO radar via matrix pencil is proposed. The signals both in transmit multipath and receive multipath are considered. Firstly, a forward-backward matrix pencil is formed based on the single-sampled vector. Secondly, the reduced-dimensional processing is applied to the matrix pencil via two unitary matrices. Finally, the generalized eigen-decomposition is employed to estimate the low elevation in multipath environments directly. Without the covariance matrix estimation, the proposed method can overcome multipath effect effectively in case of low SNR and estimate multi-target simultaneously. Compared with Maximum Likelihood (ML) method, it avoids spectrum peak searching and reduces the computational burden. Numerical results verify the effectiveness of this method
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Description: 本程序给出了OFDM信道的仿真，直接运行主函数OFDM_test即可，给出了信道BER随SNR的关系。-This procedure gives a simulation of OFDM channel and run directly the main function OFDM_test can, given the relationship between the channel BER with SNR.
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Size: 1091584 |
Author: 王文集 |
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Description: 语音增强系统，包括信噪比估计和传递函数，分段函数和重建函数-speech enhancement project, including Prior SNR estimate, noise PSD estimate, gain function, framing and over-lap add
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Size: 60416 |
Author: hz |
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