排序方式: 共有25条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
In this paper, a Maximum Likelihood (ML) approach, implemented by Expec-tation-Maximization (EM) algorithm, is pro-posed to blind separation of convolutively mixed discrete sources. In order to carry out the expectation procedure of the EM algorithm with a less computational load, the algorithm named Iterative Maximum Likelihood algorithm (IML) is proposed to calculate the likelihood and recover the source signals. An important feature of the ML approach is that it has robust performance in noise environments by treating the covariance matrix of the additive Gaussian noise as a parameter. Another striking feature of the ML approach is that it is possible to separate more sources than sensors by exploiting the finite alphabet property of the sources. Simulation results show that the proposed ML approach works well either in determined mixtures or underdetermined mixtures. Furthermore, the performance of the proposed ML algorithm is close to the performance with perfect knowledge of the channel filters. 相似文献
9.
体感诱发EEG的混沌时间序列分析 总被引:1,自引:1,他引:0
电刺激左腿足三里穴,采用单极导联法记录,C3、CA、F3、F4、13、T4的脑电图信号,在对原始脑电信号进行去噪处理后,进行混沌时间序列分析.使用小数据量法和G-P算法分别计算EEG时间序列的最大Lyapunov指数和关联维数.结果显示各个状态下脑电时间序列的最大Lyapunov指数均大于零,说明脑电信号可能是混沌的.比较刺激前、刺激时以及刺激后的脑电时间序列的关联维变化,可以发现刺激左腿足三里穴可以引起大脑右侧脑电信号的关联维数显著增加,尤其是额叶和颞叶部分,说明该脑区在刺激时出现比较明显的激活,为大脑认知功能研究提供了理论依据. 相似文献
10.