The sound recognition is considered as an effective tool to improve the performance of man-machine interaction. However, because of the non-ideal effect during the propagation and the extensive variation range of soun...
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ISBN:
(纸本)9781849199940
The sound recognition is considered as an effective tool to improve the performance of man-machine interaction. However, because of the non-ideal effect during the propagation and the extensive variation range of sound signal, it is quite difficult to achieve high accuracy target sound recognition for conventional sound recognition methods. In order to improve the performance of sound recognition, a robust sound recognition method based on human auditory bionic processing is proposed in this paper. In the proposed method, by analyzing the major function of human auditory system, the mathematical model of human auditory system is firstly developed to simulate the sound propagation in human auditory physiological processing. Then by extracting the muti-dimensional eigenvectors of the auditory spectrum, the feature of target sound signal is obtained. Afterwards, the recognition and classification of sound signal is achieved by the back-propagation (BP) neural network method. Based on the simulation of actual sound signal, it is verified that the proposed method can effectively simulate the sound propagation and achieve desirable sound recognition performance under noise condition.
For ground penetrating radar (GPR), clutter suppression effect has an important role on target detection. Approaches based on minimal entropy, the signal to clutter ratio (SCR) and image contrast are widely used for a...
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ISBN:
(纸本)9781849199940
For ground penetrating radar (GPR), clutter suppression effect has an important role on target detection. Approaches based on minimal entropy, the signal to clutter ratio (SCR) and image contrast are widely used for assessment. These traditional approaches have inevitable defects. Such as, minimum entropy and image contrast methods lead to inaccurate image evaluation under the cases of heavy clutter. SCR method will be influenced by subjective feeling. This paper presents an adaptive SCR evaluation method. This method can evaluate clutter cancellation effect quantitatively without being influenced by subjective factors.
A wideband PAR (Phased Array Radar) implementation framework based on wide band digital intermediate frequency is proposed for aperture full time problem. A method compensating the aperture full time by digital stretc...
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ISBN:
(纸本)9781849199940
A wideband PAR (Phased Array Radar) implementation framework based on wide band digital intermediate frequency is proposed for aperture full time problem. A method compensating the aperture full time by digital stretch processing for chirp signal is presented. A compensation approach for RF channels phase consistency using phase adjustment of digital oscillator is also given. Experiment results based on hardware system indicate that the method is effective and engineering realizable.
Phase autofocus is a key step of translational motion compensation (TMC) in inverse synthetic aperture radar (ISAR). In this paper, a modified phase autofocus algorithm is proposed for ISAR to improve the computationa...
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The performance of the conventional Gram-Schmidt orthogonalization of covariance matrix (RGS) beamforming method will decrease significantly when non-ideal factors exists such as the appearances of fast moving interfe...
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ISBN:
(纸本)9781849199940
The performance of the conventional Gram-Schmidt orthogonalization of covariance matrix (RGS) beamforming method will decrease significantly when non-ideal factors exists such as the appearances of fast moving interferences, array platform movement. In order to improve the robustness of interference suppression, a derivative constrained Gram-Schmidt orthogonalization of covariance matrix (CRGS) beamforming method with widened nulls is proposed in this paper. In the proposed method, the number of interference P is initially estimated and the first subspace is reconstructed by Gram-Schmidt orthogonalization of the first P columns of sample covariance matrix. Afterwards, the derivative constrained vectors and the second subspace spanned of these vectors are constructed. At last the adaptive weight vector is obtained by orthogonally projecting the quiescent weight vector onto the interference subspace made up of the first subspace and the second subspace. Based on the numeral simulation results, it is verified that the proposed method can form widened nulls and effectively improve the robustness of interference suppression.
Slow-time MIMO radar is investigated to deal with some cost sensitive applications like UAVs detection to avoid the use of arbitrary waveform generators and digital receivers. But this method suffers from the deterior...
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Orthogonal projection (OP) adaptive beamforming is widely applied in practical scenarios because of strong robustness. However, the performance of traditional OP adaptive beamforming would degrade severely when OP ada...
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ISBN:
(纸本)9781849199940
Orthogonal projection (OP) adaptive beamforming is widely applied in practical scenarios because of strong robustness. However, the performance of traditional OP adaptive beamforming would degrade severely when OP adaptive beamforming is applied at subarray level, especially in asymmetrical subarray configuration. To overcome this problem, the improved orthogonal projection (IOP) adaptive beamforming based on normalization at subarray level is proposed. In the proposed method, the covariance matrix is firstly modified by normalizing the noise power at subarray level. Subsequently, the interference subspace is estimated by eigenvalue decomposition, and then the adaptive weight is calculated by using OP adaptive beamforming. Numeral simulation results show that the proposed method at subarray level outperforms the traditional OP adaptive beamforming and the output signal-to-interference-plus-noise ratio (SINR) is close to the optimum value. The proposed method can be significantly effective in practical applications.
This paper proposed a genetic algorithm based on division position coding to solve the optimization of subarray partition in monopulse application, which aims at finding the best compromise between sum and difference ...
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ISBN:
(纸本)9781849199940
This paper proposed a genetic algorithm based on division position coding to solve the optimization of subarray partition in monopulse application, which aims at finding the best compromise between sum and difference patterns. In the proposed method, the division position is encoded as a chromosome gene, then the initial population is randomly generated by a series of non-repeated integers, and the fitness calculation and genetic operation are subtly designed to improve the convergence and stability. Various numeral simulation results are presented to verify the effectiveness of the proposed method.
Beam pattern synthesis is of great interest for colocated MIMO radar with larger aperture. Sever gating lobes and high sidelobe level would cause great performance loss when the transmitting array is sparse. In order ...
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Conventional Space-time adaptive processing (STAP) requires large numbers of independent and identically distributed (i.i.d.) training samples to ensure the clutter suppression performance, which is hard to be achieve...
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ISBN:
(纸本)9781849199940
Conventional Space-time adaptive processing (STAP) requires large numbers of independent and identically distributed (i.i.d.) training samples to ensure the clutter suppression performance, which is hard to be achieved in nonhomogeneous environment. In order to obtain improved clutter suppression with small training support, an iterative sparse recovery STAP algorithm is proposed in this paper. In the proposed method, the clutter spectrum sparse recovery and the calibration of space-time overcomplete dictionary are implemented iteratively, modified focal underdetermined system solution (FOCUSS) with recursive calculation is used to alleviate the recovery error and reduce the computational cost, meanwhile the mismatch of space-time overcomplete dictionary is calibrated by minimized the cost function. Based on the simulated and the actual data, it is verified that the proposed method can not only converge with much smaller training samples compared with conventional STAP methods, but also provide improved performance compared with existing sparsity-based STAP methods.
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