互相关

Therefore, the time delay estimation of a signal can be obtained based on the correlative principle of periodic series -- circular correlation.

在时延估计的广义相关法中[1 10]，滤波后的传感器输出是互相关的，并将互相关估计取峰值时的滞后取作时延的估计。

As an improved version of Mutual Information, NCC can quantitatively describe the nonlinear correlation degree between two variables using a value in the closed interval [0, 1]. Therefore, it is more intuitionistic and suitable to compare and analyze the correlation degree among images.

由于非线性相关系数是对互信息的改进，它能够以[0，1]之间的数据量化两个变量之间信息相关的程度，因此比互信息更易于对图像之间的相关程度进行比较和分析，描述更加直观。

Prepare its own direct correlation function, used to calculate the signal autocorrelation and cross correlation.

详细说明：自己编制的直接相关函数，用来计算信号的自相关和互相关。

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。

A discrete cosine transform algorithm was used to process the joint power spectrum in order to enhance the cross correlator term and eliminate the auto correlator term in the joint power spectrum and improve the discriminability of the system.

利用离散余弦变换算法对联合变换功率谱进行数字处理，增强傅里叶面的互相关项，消除自相关项，提高了系统的识别能力。采用一种新的双参数判别方法对相关信号进行判别，提高了判别的准确度。

It consists of:(1) numerical filtering of both constant and variable parameters;(2) techniques of measuring group velocities by using "moving window" and "multiple filtering";(3) cross-correlation method of measuring phase velocities.

包括：(1)参数固定的和可变的数值滤波；(2)测定群速度的"移动窗"和"多重滤波"技术；(3)测定相速度的互相关法。

Asymmetric over-introgression of the indica alleles on chromosome 7 and many specific regions on other chromosomes in the japonica genetic background is consistent with the general trend observed in the RIL and F_2 populations of the same cross, suggesting a high genetic load in the japonica gene pool, and japonica genome experienced a very severe bottleneck by artificial domestication.2 Genetic background effect on QTL expression of grain weight and its related traitsGenetic background effect on main-effect QTL and digenic epistatic QTL mapping for GWT and its related traits including GL, GW and GT was dissected by a large set of reciprocal introgression lines and recombinant inbred lines derived from Lemont and Teqing in Beijing environment.

籼粳相互导入具有不对称性，粳稻向籼稻背景的平均导入频率与期望值相仿，相反籼稻向粳稻背景的平均导入频率大大高于理论预期，位于第7染色体和一些其它染色体的特殊区段存在籼稻等位基因的超导入现象，在来自相同亲本的重组自交系和F_2群体中也观察到同样的导入趋势，表明粳稻基因组具有较大的遗传负荷，粳稻品种在人工驯化过程中曾经历过一个非常剧烈的遗传瓶颈。2水稻籽粒相关性状的主效和互作QTL表达的遗传背景效应利用Lemont和特青培育的双向导入系和重组自交系群体，在北京环境下定位影响千粒重及其相关性状如粒长、粒宽和粒厚的主效和互作QTL，分别在特青背景导入系、Lemont背景导入系和重组自交系下检测到影响千粒重及其相关性状的主效QTL分别为33个、27个和13个，互作QTL分别为4个、8个和23个，其中仅有6个主效QTL(QGwt5，QGl1，QGl3b，QGl4，QGw7和QGw8)在籼粳两个不同背景下共同表达，3个主效QTL(QGwt5，QGwt7a和QGt5)在导入系和重组自交系中共同表达，分别占检测到影响这些性状QTL总数的11.1%和4.3%，未检测到在3个背景下相同表达的互作QTL。

It is useful for selecting reasonable system parameters through it.For the data process in DIAL system, we discussed the combined effects of temporal autocorrelation and lasers cross correlation and signal averaging.

对于DIAL系统中的数据处理，本文着重讨论了信号平均技术和激光器回波信号时域自相关以及激光器互相关对CO2 DIAL系统测量灵敏度的影响。

According to the cross correlation between the PN signal and the auxiliary signals with the different phases, an exact and valid estimation of improving direction and magnitude for the local PN generator is given, by which half the mean acquisition can be reduced.

它能根据输入信号与一个特殊序列不同相位下的互相关值，相当准确、有效地估计出本地伪随机序列的改进方向和大小，成倍地缩短了捕获的时间。

The statistical properties of mobile radio channel are studied by means of computer simulation, especially in wideband channel.

应用准同步思想，构造了新的扩频码，扩频码在零相移附近具有极低的互相关值，满足准同步码分多址系统的要求。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。