Description: 信号与系统基础知识包括连续信号与模型、离散信号与模型；常用信号变换包括Z变换、Chirp Z变换、FFT变换、DCT变换和Hilbert变换等；离散系统结构包括IIR、FIR和Lattice结构；IIR滤波器设计包括模拟和数字低通、高通、带通与带阻滤波器设计，以及基于冲激响应不变法和双线性Z变换法的IlR滤波器设计等；FIR滤波器设计包括基于窗函数、频率抽样法和切比雪大逼近法的FIR滤波器设计；平稳信号分析包括经典功率谱估计、基于参数模型的功率谱估计和基于非参数模型的功率谱估计；非平稳信号分析包括STFT变换、Gabor展开、Wigner-Ville分布与Choi-Williams分布；非高斯信号分析包括基于非参数法的双谱估计、基于参数模型的双谱估计，以及双谱估计的应用；信号处理的GUI实现包括滤波器设计与分析的FDATool工具和滤波器设计与信号分析的SPTool工具。-signals and systems based on knowledge, including continuous signal with the model, discrete signal and model; Common signals include transform Z transform, chirp Z-transform, FFT transform. DCT and Hilbert transform; Discrete system architecture including IIR, FIR and Lattice structure; IIR filter design, including analog and digital low-pass, high-pass, band-pass and band stop filter design, Based on the impulse response of the same law and bilinear Z transform the IlR filter design; FIR filter design including on the basis of the window function, frequency sampling and snow all over the big approximation of FIR filter design; stationary signal analysis include classical power spectrum estimation, Based on the model parameters of the power spectrum estimation and non - parametric model b Platform: |
Size: 101182 |
Author:james |
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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. Platform: |
Size: 1265450 |
Author:吴大亨 |
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Description: 信号与系统基础知识包括连续信号与模型、离散信号与模型；常用信号变换包括Z变换、Chirp Z变换、FFT变换、DCT变换和Hilbert变换等；离散系统结构包括IIR、FIR和Lattice结构；IIR滤波器设计包括模拟和数字低通、高通、带通与带阻滤波器设计，以及基于冲激响应不变法和双线性Z变换法的IlR滤波器设计等；FIR滤波器设计包括基于窗函数、频率抽样法和切比雪大逼近法的FIR滤波器设计；平稳信号分析包括经典功率谱估计、基于参数模型的功率谱估计和基于非参数模型的功率谱估计；非平稳信号分析包括STFT变换、Gabor展开、Wigner-Ville分布与Choi-Williams分布；非高斯信号分析包括基于非参数法的双谱估计、基于参数模型的双谱估计，以及双谱估计的应用；信号处理的GUI实现包括滤波器设计与分析的FDATool工具和滤波器设计与信号分析的SPTool工具。-signals and systems based on knowledge, including continuous signal with the model, discrete signal and model; Common signals include transform Z transform, chirp Z-transform, FFT transform. DCT and Hilbert transform; Discrete system architecture including IIR, FIR and Lattice structure; IIR filter design, including analog and digital low-pass, high-pass, band-pass and band stop filter design, Based on the impulse response of the same law and bilinear Z transform the IlR filter design; FIR filter design including on the basis of the window function, frequency sampling and snow all over the big approximation of FIR filter design; stationary signal analysis include classical power spectrum estimation, Based on the model parameters of the power spectrum estimation and non- parametric model b Platform: |
Size: 101376 |
Author:james |
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Description: 对低频段的带通信号进行高精度的时延估计，有详细说明。-Of low-frequency band signal for high-precision time-delay estimation, has a detailed description. Platform: |
Size: 3072 |
Author:郑耀 |
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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. Platform: |
Size: 1265664 |
Author:吴大亨 |
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Description: 为解决直接序列扩频系统的数字收发机中初始频率的捕获问题，提出了一种通过DFT变换，在频域
上进行抛物插值运算的频偏估计的算法。该算法可适应低信噪比、宽频率偏移范围的恶劣通信环境和突发的通信
模式，且算法复杂度较低。该算法已在FPGA 中实现。-To address the direct sequence spread spectrum system, the number of transceivers in the initial frequency of the capture problem, a transformation through the DFT, in the frequency domain for parabolic interpolation computing frequency offset estimation algorithms. The algorithm can be adapted to low signal to noise ratio, broadband rates offset the scope of bad communications environment and unexpected modes of communication, and the algorithm complexity low. The algorithm has been realized in the FPGA. Platform: |
Size: 63488 |
Author:赵平 |
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Description: 瞬时谱估计，用于检测低频油气特性，有助于地层油气识别。-Instantaneous spectrum estimation for detecting low-frequency oil and gas properties, help to identify the formation of oil and gas. Platform: |
Size: 924672 |
Author:ljc |
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Description: The Yin algorithm was developed by Alain de Cheveigné of IRCAM-CNRS and Hideki Kawahara of Wakayama University. It allows for real-time continuous (for each sample) fundamental frequency estimation.
It features a very low error rate and few tuning parameters.
This implementation is a C++ template, with EMM support for faster processing. Developped in Visual C++ 6.0, but should compile with other compilers.-The Yin algorithm was developed by Alain de Cheveigné of IRCAM-CNRS and Hideki Kawahara of Wakayama University. It allows for real-time continuous (for each sample) fundamental frequency estimation.
It features a very low error rate and few tuning parameters.
This implementation is a C++ template, with EMM support for faster processing. Developped in Visual C++ 6.0, but should compile with other compilers. Platform: |
Size: 12288 |
Author:_tika_ |
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Description: A paper about band width estimation in Electronic circuit . It will be use full for handy estimation(without any software) of band width (low frequency and high frequency) Platform: |
Size: 492544 |
Author:pooya |
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Description: 主要讲解的低噪比下跳频信号的调速估计问题，可以作为一定的参考-The main explanation of the low-noise ratio of the speed estimation of frequency hopping signals, can be used as a reference Platform: |
Size: 230400 |
Author:徐鹏 |
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Description: 提出一种新的低复杂度的迭代turbo信道估计技术，用一种迭代的方式充分利用前导、导频和软译码信息，在时频选择衰落信道中提高系统性能，同时保持系统的吞吐量，数值和分析的结果显示了相比于已存在的信道估计方法，所提出的技术可以在具有较少前导和导频符号时，达到具有理想CSI的系统性能。-A new low complexity iterative turbo channel estimation, an iterative approach with the full use of leading, pilot and soft decoding information, select the time-frequency fading channel to improve system performance, while keeping the system throughput, numerical and analytical results show compared to the existing channel estimation method, the proposed technology and leading in a few pilot symbols to achieve the system performance with ideal CSI. Platform: |
Size: 1498112 |
Author:雨儿 |
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Description: 频域不同导频密度的信道估计在被研究，并且在高低时延信道其信道估计被固定了导频分配时域。频域信道估计是基于插补，多项式的广义线性模型（或最小二乘法）和维纳滤波（或线性最小均方误差法）的方法。时域的信道估计是用线性插补完成的。我们通过测量在基于克拉克散射模型的瑞利衰落信道上并带有QPSK调制的粗误码率，已经比较了所有这些方案的结果。-Different pilot density in frequency domain channel estimate to research, and its high and low delay channel estimation channel was fixed allocation of time-domain pilot. Frequency domain channel estimation is based on interpolation, polynomial generalized linear model (or least squares) and the Wiener filter (or linear minimum mean square error method) method. Time domain channel estimation is done using linear interpolation. We are by measuring the scattering model based on Clark and Rayleigh fading channels with QPSK modulation bit error rate of crude, has compared the results of all these programs. Platform: |
Size: 2505728 |
Author:雨儿 |
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Description: 分析了噪声背景下实谐波过程ARMA模型系数之间的对称性,并以此为约束条件加入ARMA谱估计方法的求解过程中,从而提出了一种改进的正弦信号频率估计方法.理论分析与计算机仿真表明,对于低信噪比条件下的正弦信号参量估计,这一算法的精度与稳定性都优于仅使用总体最小二乘法(SVD-TLS)的ARMA谱估计方法.-Analysis of real harmonic process noise background symmetry between ARMA model coefficients, and as a constraint to join ARMA spectral estimation method solving process, and thus an improved method of sinusoidal frequency estimation. Theoretical analysis and Computer simulations show that under conditions of low SNR for sinusoidal signal parameter estimation, precision and stability of this algorithm are superior to only using total least squares method (SVD-TLS) for ARMA spectrum estimation methods. Platform: |
Size: 37888 |
Author:wangling |
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Description: Abstract—In this paper, we study the joint estimation of inphase
and quadrature-phase (I/Q) imbalance, carrier frequency
offset (CFO), and channel response for multiple-input multipleoutput
(MIMO) orthogonal frequency division multiplexing
(OFDM) systems using training sequences. A new concept called
channel residual energy (CRE) is introduced. We show that by
minimizing the CRE, we can jointly estimate the I/Q imbalance
and CFO without knowing the channel response. The proposed
method needs only one OFDM block for training and the training
symbols can be arbitrary. Moreover when the training block
consists of two repeated sequences, a low complexity two-step
approach is proposed to solve the joint estimation problem.
Simulation results show that the mean-squared error (MSE) of
the proposed method is close to the Cramer-Rao bound (CRB).
Index Terms—MIMO OFDM, CFO, I/Q imbalance, channel
estimation. Platform: |
Size: 551936 |
Author:santhu |
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Description: Abstract—In this paper, we study the joint estimation of inphase
and quadrature-phase (I/Q) imbalance, carrier frequency
offset (CFO), and channel response for multiple-input multipleoutput
(MIMO) orthogonal frequency division multiplexing
(OFDM) systems using training sequences. A new concept called
channel residual energy (CRE) is introduced. We show that by
minimizing the CRE, we can jointly estimate the I/Q imbalance
and CFO without knowing the channel response. The proposed
method needs only one OFDM block for training and the training
symbols can be arbitrary. Moreover when the training block
consists of two repeated sequences, a low complexity two-step
approach is proposed to solve the joint estimation problem.
Simulation results show that the mean-squared error (MSE) of
the proposed method is close to the Cramer-Rao bound (CRB).
Index Terms—MIMO OFDM, CFO, I/Q imbalance, channel
estimation. Platform: |
Size: 277504 |
Author:santhu |
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Description: 针对认知无线电系统中正交频分复用( OFDM )信号参数估计这一重要问题, 利用OFDM 信号的循环谱实现了符号周期的盲估计。-For cognitive radio systems, orthogonal frequency division multiplexing (OFDM) signal parameter estimation of this important issue, the cyclic spectrum of the OFDM signal to achieve the blind estimation of symbol period. Platform: |
Size: 300032 |
Author:Chaos |
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Description: 根据软件无线电的思想，提出了一种新颖的数字信号处理算法，对QPSK信号的相位进行数字化处理，从而实现对QPSK信号的解调.该算法允许收发两端载波存在频差，用数字锁相实现收发端载波的同步，在频偏较大的情况下，估算频偏的大小，自适应设置环路的带宽，实现较短的捕获时间和较好的信噪性能。整个设计基于XILINX公司的ISE开发平台，并用Virtex-II系列FPGA实现。用FPGA实现调制解调器具有体积小、功耗低、集成度高、可软件升级、扰干扰能力强的特点，符合未来通信技术发展的方向。-According to the idea of software radio, a novel digital signal processing algorithm, the phase of QPSK digital signal processing, enabling the demodulation of QPSK signals. This algorithm allows the sending and receiving ends of the carrier frequency difference exists, using digital phase-locked to achieve synchronization of sending and receiving end of the carrier, in the case of large frequency offset, frequency offset estimation of the size, adaptive set the loop bandwidth to achieve shorter acquisition time and better noise performance. The whole design is based on the company XILINX ISE development platform, and Virtex-II series with the FPGA. FPGA realization of a modem with a small size, low power consumption, high integration, software upgrades available, the characteristics of strong interference interference, in line with the future direction of ICT development. Platform: |
Size: 64512 |
Author:马文 |
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Description: 用多尺度卡尔曼滤波法，对信号参数进行识别估计。高频信号和低频信号识别结合起来改进了算法识别的精确度和准确度。-It is an implementation of hierarchical (a.k.a. multi-scale) Kalman filter using belief propagation. The model parameters are estimated by expectation maximization (EM) algorithm. In this implementation, we considered two time series with different frequencies. The messages between high and low frequency signals are combined to improve the estimation and prediction. Platform: |
Size: 311296 |
Author:林真天 |
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Description: 功率谱估计是利用有限长的数据估计信号的功率谱，广泛应用于各个领域。功率谱估计主要分为经典谱估计与现代谱估计。常用的经典谱估计方法有周期图法，相关法，周期图的改进法，常用的现代谱估计方法有最大熵谱估计，AR模型，MA模型，ARMA模型。经典谱估计适用于长序列的信号，其主要缺陷是描述功率谱波动的数字特征方差性能差，频率分辨率低，现代谱估计适用于短序列的信号，旨在改善谱估计的分辨率，并将其应用于实际地震资料的谱分析。
-Power spectrum estimation is the use of a finite length data to estimate the power spectrum of the signal, widely used in various fields. Power spectrum estimation is divided into classic and modern spectral estimation spectral estimation. Commonly used methods of classical periodogram spectrum estimation method, the relevant law, the cycle graph Improvement Act, commonly used in modern spectral estimation methods have maximum entropy spectral estimation, AR model, MA model, ARMA model. Classical spectral estimation applied to signal a long sequence, its main drawback is the fluctuation power spectrum describing digital signature variance performance is poor, the frequency resolution is low, modern spectral estimation applied to signal short sequences designed to improve spectral estimation resolution, and The analysis applied to real seismic data spectrum. Platform: |
Size: 3072 |
Author:裴忠林 |
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Description: Abstract—Diagonal Bell Laboratories Layered Space-Time (DBLAST)
structure offers a low complexity solution to realize the
attractive capacity of Multiple-input and multiple-output (MIMO)
systems. In this paper, we apply D-BLAST in orthogonal frequency
division multiplexing (OFDM) systems and address the issue of
channel estimation. Different other MIMO-OFDM, where
symbols at all tones are always available for decision-directed
channel estimation, in D-BLAST OFDM, we update estimated
channel parameters each time a layer is detected with a least
square (LS) approach, using a pieced combination of received signals
at previous and current OFDM blocks. The initial estimate is
further refined by a robust estimator to exploit the time correlation
of channel parameters among OFDM blocks. Computer simulation
results show the performance improvement over block-wise
channel estimation. It is also shown that D-BLAST with proposed
channel estimation is robust to fast fading of channel parameters.-Abstract—Diagonal Bell Laboratories Layered Space-Time (DBLAST)
structure offers a low complexity solution to realize the
attractive capacity of Multiple-input and multiple-output (MIMO)
systems. In this paper, we apply D-BLAST in orthogonal frequency
division multiplexing (OFDM) systems and address the issue of
channel estimation. Different other MIMO-OFDM, where
symbols at all tones are always available for decision-directed
channel estimation, in D-BLAST OFDM, we update estimated
channel parameters each time a layer is detected with a least
square (LS) approach, using a pieced combination of received signals
at previous and current OFDM blocks. The initial estimate is
further refined by a robust estimator to exploit the time correlation
of channel parameters among OFDM blocks. Computer simulation
results show the performance improvement over block-wise
channel estimation. It is also shown that D-BLAST with proposed
channel estimation is robust to fast fading of channel parameters. Platform: |
Size: 80896 |
Author:werad |
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Search - low frequency estimation