4 three new fast algorithms of higher order cumulant ( hoc ) based adaptive dynamic spectrum enhancer are presented . based on the advantage of the sign algorithm , a fast algorithm of foc diagonal slice sign iterative adaptive dynamic line enhancer is proposed 4提出了三种自适应动态谱线增强快速算法?利用极性迭代算法可减小计算量的优点，提出了基于四阶累积量对角切片极性迭代的自适应动态谱线增强快速算法。
Because the detector based on the fourth - order cumulant 2 - d slice , which has better ability to suppress gaussian noise , possesses both characters of square detector and correlation detector , it can estimate not only the carrier frequency , but also the symbol period 其中，基于四阶累积量2 - d切片的检测方法能够很好地抑制高斯噪声，并且兼顾了时域相关检测和平方倍频检测两种方法的特点，能够同时估计出载波频率和扩频码周期两个参数。
The emphasis of the research of the method of time difference measurement is how to suppress noise and interference effectively . the second part is to discuss the capacity for anti - interference of generalized cross correlation ( gcc ) algorithm . the algorithm based on high order cumulant is introduced to solve the problem , which is bad performance to suppress noise of gcc 基于广义平稳信号的模型,论文第二部分讨论了广义互相关( gcc )时差测量算法的抗加性噪声干扰能力,针对其相关噪声抑制能力差的问题,提出了基于高阶累积量的时差测量算法,对算法的适用范围、计算复杂度等方面进行了分析。
Take the hoc based blind modulation detection algorithm as an example , the relationship between the blind modulation detection algorithm and synchronization is investigated . an unproved detection algorithm robust to frequency offset is proposed which solves the problem caused by the error in carrier synchronization . how to synchronize a received signal with unknown modulation type is studied and a blind algorithm to estimate symbol timing of the signals with unknown modulation type is presented 研究了载波同步和码元定时同步与调制方式盲检测算法的关系；以自适应单载波中高阶累积量调制方式盲检测算法为例，对于载波同步误差引起的频偏问题，提出一种基于频偏稳健的mdpsk信号调制方式盲检测算法；对于未知调制方式信号的定时同步问题，提出一种盲定时估计算法，该算法可以估计mdpsk和mqam信号的定时同步信息，实现数字信号的同步分类；提出了一种基于调制方式盲检测的自适应接收机结构，把调制方式盲检测，信噪比估计和同步解调联合起来进行，实现调制方式随信道质量而自适应变化的信号的正确接收。
In the aspect of blind - identification , the mutual power spectrumx time - frequency distribution product of two delay signals are used as the features of classification . the cluster analysis and cumulant invariants of mpsk signals are used to automatically classify communication signals 在信号识别中，选取信号的互功率谱、时频分布、 mpsk信号的延迟相乘信号作为分类特征，利用模式识别中的聚类分析以及mpsk信号的基于高阶累积量构成的分类特征不变量实现了信号调制类型的自动分类。
In order to decrease the computational complexity of higher - order statistics ( hos ) , novel approximate estimation theorems of the foc and the fifth order cumulants are created and proved in theory . the simulation result shows that employing the estimation theorems to optimize the calculation of higher order statistics is an effective method 理论分析与仿真表明：按估计定理对高阶统计量的计算进行优化，不仅计算量能大幅度地减小，而且保证了通过估计得到的高阶累积量有抑制高斯噪声的优越性能，这为高阶统计量的工程应用创造了一条捷径。
Then , the definition of high order cumulants and the value of digital modulation signals ’ high order cumulants are presented . according to calculate the value of base band signals ’ high order cumulants , 4ask , 2fsk , 4fsk , bpsk , qpsk , 16qam can be distinguished . this method is demonstrated by simulation data and sampled data 接着,本文介绍了高阶累积量的定义和多种数字调制信号高阶累积量的值,通过计算基带信号的高阶累积量,可以对4ask 、 2fsk 、 4fsk 、 bpsk 、 qpsk 、 16qam六种信号进行分类,利用仿真信号和实际采样信号对该方法进行了论证,该方法可以在低信噪比条件下实施。
