针对含噪环境下数字调制混合信号盲源分离（BSS）误码率（BER）过高的问题,提出了一种基于Robust ICA的二阶段盲源分离算法R-TSBS。该算法采用Robust ICA算法对阵列响应向量构成的混合矩阵进行估计,然后利用数字调制信号的有限符号集特...针对含噪环境下数字调制混合信号盲源分离（BSS）误码率（BER）过高的问题,提出了一种基于Robust ICA的二阶段盲源分离算法R-TSBS。该算法采用Robust ICA算法对阵列响应向量构成的混合矩阵进行估计,然后利用数字调制信号的有限符号集特征,在第二阶段用最大似然估计（MLE）方法估计各个数字调制源信号发送的符号序列,达到盲源分离的目的。实验仿真表明,传统的独立成分分析（ICA）算法如Robust ICA算法和Fast ICA算法误码率很高,在信噪比（SNR）为10 d B时,其误码率达到了3.5×10-2左右,而基于Fast ICA的二阶段盲源分离算法F-TSBS和基于Robust ICA的二阶段盲源分离算法R-TSBS的误码率则下降到了10-3,分离性能得到了明显改善;在较低的信噪比（0~4 d B）下,R-TSBS算法较F-TSBS算法约有2 d B性能提升。展开更多
A digital image watermarking algorithm based on fast curvelet transform is proposed. Firstly, the carrier image is decomposed by fast curvelet transform, and, the watermarking image is scrambled by Arnold transform. S...A digital image watermarking algorithm based on fast curvelet transform is proposed. Firstly, the carrier image is decomposed by fast curvelet transform, and, the watermarking image is scrambled by Arnold transform. Secondly, the binary watermarking image is embedded into the medium frequency coefficients according to the human visual characteristics and curvelet coefficients. Experiment results show that the proposed algorithm has good performance in both invisibility and security and also has good robustness against the noise, cropping, filtering, JPEG compression and other attacks.展开更多
文摘针对含噪环境下数字调制混合信号盲源分离（BSS）误码率（BER）过高的问题,提出了一种基于Robust ICA的二阶段盲源分离算法R-TSBS。该算法采用Robust ICA算法对阵列响应向量构成的混合矩阵进行估计,然后利用数字调制信号的有限符号集特征,在第二阶段用最大似然估计（MLE）方法估计各个数字调制源信号发送的符号序列,达到盲源分离的目的。实验仿真表明,传统的独立成分分析（ICA）算法如Robust ICA算法和Fast ICA算法误码率很高,在信噪比（SNR）为10 d B时,其误码率达到了3.5×10-2左右,而基于Fast ICA的二阶段盲源分离算法F-TSBS和基于Robust ICA的二阶段盲源分离算法R-TSBS的误码率则下降到了10-3,分离性能得到了明显改善;在较低的信噪比（0~4 d B）下,R-TSBS算法较F-TSBS算法约有2 d B性能提升。
文摘A digital image watermarking algorithm based on fast curvelet transform is proposed. Firstly, the carrier image is decomposed by fast curvelet transform, and, the watermarking image is scrambled by Arnold transform. Secondly, the binary watermarking image is embedded into the medium frequency coefficients according to the human visual characteristics and curvelet coefficients. Experiment results show that the proposed algorithm has good performance in both invisibility and security and also has good robustness against the noise, cropping, filtering, JPEG compression and other attacks.
