Fang Ye

A Complex Mixing Matrix Estimation Algorithm Based on Single Source Points

This paper considers the complex mixing matrix estimation in the under-determined blind source separation. An effective estimation algorithm through detecting single source points contributed by only one source is proposed. First, the single source points are detected by utilizing the real and the imaginary components of the time–frequency coefficients of mixed signals. The algorithm is suitable for the case in which the mixing matrix is complex, while traditional algorithms usually estimate the real mixing matrix. Then, through modeling and calculating, the mixing matrix of mixed signals can be estimated. Finally, the clustering process is improved in order to get more accurate results. The algorithm can estimate the complex mixing matrix when the number of sensors is less than that of sources. The experimental results validate the efficiency of the estimation algorithm.

A Fetal Electrocardiogram Signal Extraction Algorithm Based on the Temporal Structure and the Non-Gaussianity

Fetal electrocardiogram (FECG) extraction is an important issue in biomedical signal processing. In this paper, we develop an objective function for extraction of FECG. The objective function is based on the non-Gaussianity and the temporal structure of source signals. Maximizing the objective function, we can extract the desired FECG. Combining with the solution vector obtained by maximizing the objective function, we further improve the accuracy of the extracted FECG. In addition, the feasibility of the innovative methods is analyzed by mathematical derivation theoretically and the efficiency of the proposed approaches is illustrated with the computer simulations experimentally.

A Mixing Matrix Estimation Algorithm for Underdetermined Blind Source Separation

This paper considers mixing matrix estimation for underdetermined blind source separation. First, we propose an effective detection algorithm to identify single source points where only one source occurs. The detection algorithm finds single source points by utilizing the time–frequency coefficients of mixed signals and the complex conjugates of the coefficients. Then, a method based on probability density is proposed in order to find more reliable single source points and cluster them. Finally, the mixing matrix is obtained through re-selecting and clustering single source points. The experimental results indicate that the algorithm can accurately estimate the mixing matrix when there are fewer sensors than sources.

Performance Enhancement of a USV INS/CNS/DVL Integration Navigation System Based on an Adaptive Information Sharing Factor Federated Filter

To improve the ability of autonomous navigation for Unmanned Surface Vehicles (USVs), multi-sensor integrated navigation based on Inertial Navigation System (INS), Celestial Navigation System (CNS) and Doppler Velocity Log (DVL) is proposed. The CNS position and the DVL velocity are introduced as the reference information to correct the INS divergence error. The autonomy of the integrated system based on INS/CNS/DVL is much better compared with the integration based on INS/GNSS alone. However, the accuracy of DVL velocity and CNS position are decreased by the measurement noise of DVL and bad weather, respectively. Hence, the INS divergence error cannot be estimated and corrected by the reference information. To resolve the problem, the Adaptive Information Sharing Factor Federated Filter (AISFF) is introduced to fuse data. The information sharing factor of the Federated Filter is adaptively adjusted to maintaining multiple component solutions usable as back-ups, which can improve the reliability of overall system. The effectiveness of this approach is demonstrated by simulation and experiment, the results show that for the INS/CNS/DVL integrated system, when the DVL velocity accuracy is decreased and the CNS cannot work under bad weather conditions, the INS/CNS/DVL integrated system can operate stably based on the AISFF method.

A Pulse Signal Characteristic Recognition Algorithm Based on Multifractal Dimension

In low SNR condition, it is difficult to identify the radio transient characteristics of the signals. To solve this problem, a new recognition algorithm based on multifractal dimension characteristics is proposed. In fractal theory, multifractal dimension is the most sophisticated characterize that can describe the similar characteristics of the signals. Therefore, multifractal dimension is used in this paper to extract the nsubtle features of different impulse noise signals, in order to achieve the purpose of the classification and identification of the radiation source.

A Mixing Matrix Estimation Algorithm for the Time-Delayed Mixing Model of the Underdetermined Blind Source Separation Problem

Considering the time-delayed mixing model of the underdetermined blind source separation problem, we propose a novel mixing matrix estimation algorithm in this paper. First, we introduce the short-time Fourier transform (STFT) to transform the mixed signals from the time domain to the time–frequency domain. Second, a neoteric transformation matrix is addressed to construct the linear clustering property of STFT coefficients. Then, a preeminent detection algorithm is raised to identify the single source points. After eliminating the low-energy points and outliers in the time–frequency domain, a potential function of clustering approach is put forward to cluster the single source points and obtain the clustering centers. Finally, the mixing matrix can be estimated through the derivation and calculation. The experimental results validate that the proposed algorithm not only accurately estimates the mixing matrix for the time-delayed mixing model of the underdetermined blind source separation problem but also has certain universality for different array structures. Therefore, both the effectiveness and superiority of the proposed algorithm have been verified.

A complex mixing matrix estimation algorithm in under-determined blind source separation problems

This paper considers the complex mixing matrix estimation in under-determined blind source separation problems. The proposed estimation algorithm is based on single source points contributed by only one source. First, the problem of complex matrix estimation is transformed to that of real matrix estimation to lay the foundation for detecting single source points. Secondly, a detection algorithm is adopted to detect single source points. Then, a potential function clustering method is proposed to process single source points in order to get better performance. Finally, we can get the complex mixing matrix after derivation and calculation. The algorithm can estimate the complex mixing matrix when the number of sources is more than that of sensors, which proves it can solve the problem of under-determined blind source separation. The experimental results validate the efficiency of the proposed algorithm.