共查询到18条相似文献,搜索用时 125 毫秒
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针对最小频移键控(MSK)信号的循环平稳特性,分析其循环谱密度,将渐进最优x2分布应用到该种信号的盲检测中,提出了一种基于信号频域循环平稳特征的检测方案。根据其循环谱截面的特点,提出了对信号载频和码元速率进行估计的方法,该方法避免了多维搜索,而且不需要知道信号的频率参数等先验信息。仿真结果证明了在低信噪比下本文所提出检测和参数估计方法的有效性。 相似文献
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文中在研究信号循环平稳特性的基础上给出了一种2FSK信号参数估计方法。基于2FSK信号频域上的单个谱峰与2ASK信号谱的相似性,首先在频谱上将2FSK信号的两个谱峰分离,然后根据2ASK信号的循环谱特征对单个谱峰做参数估计,最后将上述估计值做加权平均得到原2FSK信号的参数估计值。仿真结果表明该算法在信噪比(SNR)高于0dB时,信号参数估计MSE低于10^-4。 相似文献
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线性调频连续波信号检测与参数估计算法 总被引:1,自引:0,他引:1
针对长时间积累的方法较难在线性调频连续波信号的检测和参数估计中应用的问题,该文基于归一化变窗长相干平均法,提出一种联合帧间相关法与循环平稳法的线性调频连续波信号检测与参数估计算法。该方法首先利用归一化变窗长相干平均法实现噪声方差的一致性,然后在此基础上利用帧间相关法实现周期的精确估计,最后利用循环平稳法估计信号的相位参数。该算法以较低的计算复杂度实现信号的长时间积累,在低信噪比条件下具有较好的估计性能。仿真结果验证了该方法的有效性。 相似文献
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Two computationally efficient algorithms for digital cyclic spectral analysis, the FFT accumulation method (FAM) and the strip spectral correlation algorithm (SSCA), are developed from a series of modifications on a simple time smoothing algorithm. The signal processing, computational, and structural attributes of time smoothing algorithms are presented with emphasis on the FAM and SSCA. As a vehicle for examining the algorithms the problem of estimating the cyclic cross spectrum of two complex-valued sequences is considered. Simplifications of the resulting expressions to special cases of the cross cyclic spectrum of two complex-valued sequences, such as the cyclic spectrum of a single real-valued sequence, are easily found. Computational and structural simplifications arising from the specialization are described 相似文献
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根据直接序列扩频(DS-SS)信号的特点,将其建立为循环平稳模型。利用循环谱分析的方法估计了低信噪比下DS-SS信号的载波频率。利用时域平滑循环周期图估计了循环谱密度函数,在循环谱密度函数的数字实现过程中,研究了有限采集数据条件下数据截短点数对循环谱的时域平滑周期图估计性能的影响,分析了经过时域平滑后的DS-SS信号载频估计精度。最后,仿真实验验证了算法的有效性。 相似文献
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一种基于循环谱的直扩信号参数估计方法 总被引:1,自引:1,他引:0
分析BPSK调制的直扩信号循环谱密度函数特征,提出一种直扩信号参数估计方法。从循环谱物理意义入手,计算谱密度,通过时域预处理,可以减少DFT要求的数据量,提高运算效率,使循环谱实时处理成为可能,同时可以准确分辨出循环频率方向和谱频率方向的谱峰;在非零循环频率上搜索特征谱线,可以在较低信噪比环境下完成直扩信号载波频率和PN码速率的估计,并通过仿真确定了该方法的信噪比容限。 相似文献
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提出一种基于循环平稳差异的直扩信号盲提取抗干扰方法.针对源信号在统计域上的近似独立性,构建直扩通信盲源分离抗干扰模型,基于源信号的循环平稳差异,利用循环自相关函数的典型极值点定义一个用于区分直扩信号和干扰的二阶循环差异度特征参数,通过比较该特征参数的大小进行模式识别,提取出直扩信号而抑制掉干扰,达到抗干扰的目的.仿真结果表明:当信干比(SJR)为-40dB、归一化信噪比(NSNR)为9dB时,直接解扩/解调信号的误比特率约为IE-0.3,而本文所提抗干扰算法误比特率(BER)低至IE-3,可从强干扰中有效分离并提取出直扩信号. 相似文献
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The large computation amount of multiple signal classification (MUSIC) spectrum function seriously affects the timeliness of direction finding system using MUSIC algorithm, especially in the two-dimensional directions of arrival (DOA) estimation of azimuth and elevation with a large antenna array. This paper proposes a fast computation method for MUSIC spectrum. It is suitable for any circular array. First, the circular array is transformed into a virtual uniform circular array, in the process of calculating MUSIC spectrum, for the cyclic characteristics of steering vector, the inner product in the calculation of spatial spectrum is realised by cyclic convolution. The computational amount of MUSIC spectrum is obviously less than that of the conventional method. It is a very practical way for MUSIC spectrum computation in circular arrays. 相似文献
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在非协作通信领域,传统的基于循环自相关的OFDM(Orthogonal Frequency Division Multiplexing,正交频分复用)时间参数盲估计算法常分析的是无导频OFDM信号,不适用于实际应用场景中含导频OFDM信号的参数盲估计。本文分析了不同导频图案的OFDM信号循环自相关谱特性,针对谱特征变化改进了OFDM信号参数估计算法。改进算法既适用于无导频OFDM信号,也适用于不同导频图案的OFDM信号。仿真结果表明,对于无导频OFDM信号,改进算法比传统算法的时间参数估计误差可降低一个数量级;同时改进算法有效避免了导频引入的二阶周期性谱峰对OFDM时间参数估计的影响,可精确估计含导频OFDM信号的时间参数,具有很好的鲁棒性和应用价值。 相似文献
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Sara Mihandoost Mehdi Chehel Amirani 《Multidimensional Systems and Signal Processing》2018,29(3):1119-1134
This paper presents a new affective scheme to estimate the two-dimensional cyclic spectral function of a texture as a two-dimensional signal. Recently, considering textures as cyclostationary signals, several algorithms have been introduced to utilize the more discriminant features of hidden periodicity for texture analysis, such as one-dimensional strip spectral correlation analysis (1D-SSCA), one-dimensional FFT-accumulated method, and direct frequency smoothing method. Although the reported results of these algorithms are proper, all of them suffer a drawback: they sweep texture images row by row and column by column and analyze them as one-dimensional signals, and hence lose the relationships between neighboring pixels. In this paper a new efficient extended algorithm namely two-dimensional SSCA is proposed to estimate the two-dimensional cyclic spectral function for two-dimensional signals. This algorithm is fast respect to other cyclic spectral function estimators and is based on 1D-SSCA algorithm. The effectiveness of the proposed algorithm is evaluated on three well-known databases. The experimental results illustrate that the proposed scheme is computationally efficient, generates flexible features and improves correct classification rate, in comparison with other studies in this field. 相似文献