查询词典 correlation function

Through data processing arrangement and cross correlation function calculation designed on PC,flight time spectra of 252Cf Source fission neutron and gamma ray can be obtained.

实验结果表明，该系统可以获得252Cf自发裂变中子源的中子、γ射线飞行时间谱，与经典的飞行时间谱测量方法相比较，其图谱表达及数值结果有着很高的吻合度。

And the cross correlation function is approximately zero, which makes them suppress the disturbances due to the other users. After describing some basic knowledge of chaotic theory in chapter 2, we interview and classify the applications of chaos in communications including chaos secure communication, chaotic spreading codes for multi-user access in spreading spectrum system and chaotic modulation and demodulation in chapter 3. FM-DCSK system with non-coherent demodulation offers the best performance in chaotic modulation schemes.

在混沌调制方案中， FM-DCSK调制是一种极具竞争力的混沌调制方式，它克服了CSK、COOK、DCSK解调中存在的估计问题的缺点，在无线信道的传输过程中，可以很好的抑制噪声干扰与多径衰落，并且能获得非常优越的解调性能，加上混沌信号本身优越的保密性能，该调制方式在未来的无线通信领域存在着巨大的潜在优势。

A frequency domain poly reference modal identification method under operational conditions was presented on the basis of the cross correlation function of measured responses to solve the only output problem.

针对工程实际情况，从实测响应间的互相关函数入手，推导出适用于工作状态下的频域多参考点模态识别法，然后采用一飞机模型对该方法进行了试验验证。

In this study, we use LabVIEW programming language of PC-Based to carry out the reduction of actively noise with theoretical equations of acoustic feedback cancellation and incorporate Filtered-X LMS algorithm. Furthermore, it was to verify that the reliable of simulation and analysis for the processed of signal by the concept of cross correlation function.

而本研究中采用PC-Based作为控制处理器，透过LabVIEW图控程式实现消除声场回授的理论方程式，并且加入到Filtered-X LMS演算法则，当作控制器的输入讯号进行实验测试，以实现主动式噪音的消除，并且也同时验证本文中使用交互相关函数概念，辨识是否使用转移函数分离法之讯号模拟分析的可靠性。

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

The time correlation function of concentration fluctuation for PSt-DVB having wave vector q is proved to have the form of an exponential decay.

该微粒的浓度涨落时间相关函数在波矢为q时，有指数衰减形式，其衰减速率г=q2Dt。

based on the introduction of the merit and shortcoming and the analysis of the generate methods of the main random sequences,we propose a new method which is based on the substitution and recurrence structure,and the method is implemented by fpga.the generated sequences by this method not only can pass the test of the fips 140-2 standard,but also have high performance:long period,high linear complexity,good correlation function value and high generation speed,it can be used widely in information security system and so on.

摘 要：在介绍了现有随机序列的优缺点以及分析随机序列主要产生方法的基础上，提出了一种基于循环替换原理的伪随机序列产生方法，并用fpga加以实现。该方法产生的伪随机序列完全符合fips140-2标准，并具有周期长、线性复杂度高、相关性好以及产生时间短的特性，能广泛应用于信息安全等系统中。

This technique is based on the auto-correlation function of fractional Gauss noise.

该方法基于分数高斯噪声的自相关函数。

The proposed approach extends the basic theory of FBM to the discrete case and investigates characteristics of auto-correlation function based on fractional Gauss noise.

提出了一种基于分数高斯噪声增量及其自相关函数的分形维数估计的新方法。

Because the definition of the correlation function approximates Gauss distribution and it has a character of the single peak.

在工业测量中像素级的测量精度是远远不够，必须把测量精细到亚像素级。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。