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Approach to blind estimation of the PN sequence in DS-SS signals with residual carrier 被引量:8
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作者 Tianqi Zhang Shaosheng Dai +2 位作者 Guoning Ma Wei Zhang Pu Miao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期1-8,共8页
This paper presents an approach of singular value de- composition plus digital phase lock loop to solve the difficult problem of blind pseudo-noise (PN) sequence estimation in low signal to noise ratios (SNR) dire... This paper presents an approach of singular value de- composition plus digital phase lock loop to solve the difficult problem of blind pseudo-noise (PN) sequence estimation in low signal to noise ratios (SNR) direct sequence spread spectrum (DS-SS) signals with residual carrier. This approach needs some given parameters, such as the period and code rate of PN sequence. The received signal is firstly sampled and divided into non-overlapping signal vectors according to a temporal window, whose duration is two periods of PN sequence. An autocorrelation matrix is then computed and accumulated by those signal vectors one by one. The PN sequence with residual carrier can be estimated by the principal eigenvector of the autocorrelation matrix. Further more, a digital phase lock loop is used to process the estimated PN sequence, it estimates and tracks the residual carrier and removes the residual carrier in the end. Theory analysis and computer simulation results show that this approach can effectively realize the PN sequence blind estimation from the input DS-SS signals with residual carrier in lower SNR. 展开更多
关键词 direct sequence spread spectrum (DS-SS) signal pseudo-noise (PN) sequence blind estimation singular value de-composition digital phase lock loop residual carrier.
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Analysis of an improved acquisition method for high-dynamic BOC signal 被引量:6
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作者 Yi Pan Tianqi Zhang +1 位作者 Gang Zhang Zhongtao Luo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第6期1158-1167,共10页
To reach a compromise between short acquisition time and excellent detection probability for the high-dynamic binary offset carrier (BOC) signal, an overall algorithm based on discrete polynomial-phase transform (DPT)... To reach a compromise between short acquisition time and excellent detection probability for the high-dynamic binary offset carrier (BOC) signal, an overall algorithm based on discrete polynomial-phase transform (DPT) and partial matching filter (PMF)-fast Fourier transform (FFT) algorithm is given. The high order items of received signals are removed by the method of DPT, and the PMF-FFT algorithm is redesigned for the BOC signal. The simulation experiments and theoretical analyses verify that the improved algorithm has attained improvement in acquisition performance. © 2016 Beijing Institute of Aerospace Information. 展开更多
关键词 Bins Mergers and acquisitions TITRATION
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Super-resolution reconstruction of images based on uncontrollable microscanning and genetic algorithm 被引量:3
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作者 代少升 刘劲松 +2 位作者 向海燕 杜智慧 刘琴 《Optoelectronics Letters》 EI 2014年第4期313-316,共4页
Aiming at these disadvantages like lack of details, poor contrast and blurry edges of infrared images reconstructed by traditional controllable microscanning super-resolution reconstruction(SRR), this paper proposes a... Aiming at these disadvantages like lack of details, poor contrast and blurry edges of infrared images reconstructed by traditional controllable microscanning super-resolution reconstruction(SRR), this paper proposes a novel algorithm, which samples multiple low-resolution images(LRIs) by uncontrollable microscanning, and then uses LRIs as chromosomes of genetic algorithm(GA). After several generations of evolution, optimal LRIs are got to reconstruct the high-resolution image(HRI). The experimental results show that the average gradient of the image reconstructed by the proposed algorithm is increased to 1.5 times of that of the traditional SRR algorithm, and the amounts of information, the contrast and the visual effect of the reconstructed image are improved. 展开更多
关键词 遗传算法 红外图像 超分辨率 微扫描 不可控 高分辨率图像 边缘模糊 低分辨率
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A separation method of singing and accompaniment combining discriminative training deep neural network 被引量:2
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作者 ZHANG Tianqi XIONG Mei +1 位作者 ZHANG Ting YANG Qiang 《Chinese Journal of Acoustics》 CSCD 2019年第2期227-239,共13页
For the difficulty of separation between singing and accompaniment in the musical signals,an improved music separation method of based on discriminative training depth neural network(DNN) was proposed.Firstly,based on... For the difficulty of separation between singing and accompaniment in the musical signals,an improved music separation method of based on discriminative training depth neural network(DNN) was proposed.Firstly,based on the DNN model,considering the reconstruction errors and discrimination information between singing and accompaniment,an improved objective function was presented to discriminate the training;Then,an additional layer was added to DNN model,introducing the time-frequency masking to optimize the estimated accompaniment of the song,and the corresponding time-domain signal was obtained by inverse Fourier transform;Finally,the influence of different parameters on the separation performance was verified,and compared it with the existing music separation methods.The experimental results showed that the improved objective function and the introduction of time-frequency masking significantly improved the separation performance of the DNN,and the separation performance was improved about 4 dB compared with other existing music separation methods,thus verifying that the proposed method was an effective music separation algorithm. 展开更多
关键词 DNN A separation method of SINGING and ACCOMPANIMENT COMBINING discriminative training DEEP NEURAL network
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Reconstruction algorithm of super-resolution infrared image based on human vision processing mechanism 被引量:1
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作者 Shaosheng DAI Zhihui DU Haiyan XIANG Jinsong LIU 《Frontiers of Optoelectronics》 CSCD 2015年第2期195-202,共8页
Aiming at solving the problem of low resolu- tion and visual blur in infrared imaging, a super-resolution infrared image reconstruction method using human vision processing mechanism (HVPM) was proposed. This method... Aiming at solving the problem of low resolu- tion and visual blur in infrared imaging, a super-resolution infrared image reconstruction method using human vision processing mechanism (HVPM) was proposed. This method combined a mechanism of vision lateral inhibition with an algorithm projection onto convex sets (POCS) reconstruction, the improved vision lateral inhibition network was utilized to enhance the contrast between object and background of low-resolution image sequences, then POCS algorithm was adopted to reconstruct super- resolution image. Experimental results showed that the proposed method can significantly improve the visual effect of image, whose contrast and information entropy of reconstructed infrared images were improved by approxi- mately 5 times and 1.6 times compared with traditional POCS reconstruction algorithm, respectively. 展开更多
关键词 human vision processing mechanism(HVPM) projection onto convex sets (POCS) SUPER-RESOLUTION infrared image reconstruction algorithm
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Music/voice separation based on the multi-repeating structure of Mel cepstrum coefficient 被引量:4
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作者 ZHANG Tianqi XU Xin +1 位作者 WU Wangjun LIU Yu 《Chinese Journal of Acoustics》 CSCD 2015年第4期424-435,共12页
For the poor adaptability of the original repeating pattern, an improved music separation method of multi-repeating structure of Mel cepstrum coefficient (MFCC) is proposed. Firstly, the MFCC coefficient matrix (39... For the poor adaptability of the original repeating pattern, an improved music separation method of multi-repeating structure of Mel cepstrum coefficient (MFCC) is proposed. Firstly, the MFCC coefficient matrix (39-dimensional data) of the music signal was extracted. Then the cosine characteristic was applied to the count of similarity matrix of MFCC, and the fragments with consistent similarity are putted together. Next different repeating patterns are built for different groups. Thereby the spectrums of the background music and vocal were separated combined with ideal binary masking (IBM), and the corresponding time domain signals were obtained by inverse Fourier transform. Fnally, the improved method was tested on the music database of different types and length, and the separation results were compared with repeating method of Rafii and the non-negative matrix factorization based on flexible framework method of Ozerov. The experimental results showed that the separation performance of improved method was improved about 3 dB, and the performance of music with melody changed larger was significantly improved. Experiments verified that the improved method was an effective music separation algorithm and more stability. 展开更多
关键词 MFCC Music/voice separation based on the multi-repeating structure of Mel cepstrum coefficient Mel
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Edge preserving super-resolution infrared image reconstruction based on L1-and L2-norms 被引量:1
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作者 Shaosheng DAI Dezhou ZHANG +2 位作者 Junjie CUI Xiaoxiao ZHANG Jinsong LIU 《Frontiers of Optoelectronics》 EI CSCD 2017年第2期189-194,共6页
Super-resolution (SR) is a widely used tech- nology that increases image resolution using algorithmic methods. However, preserving the local edge structure and visual quality in infrared (IR) SR images is challeng... Super-resolution (SR) is a widely used tech- nology that increases image resolution using algorithmic methods. However, preserving the local edge structure and visual quality in infrared (IR) SR images is challenging because of their disadvantages, such as lack of detail, poor contrast, and blurry edges. Traditional and advanced methods maintain the quantitative measures, but they mostly fail to preserve edge and visual quality. This paper proposes an algorithm based on high frequency layer features. This algorithm focuses on the IR image edge texture in the reconstruction process. Experimental results show that the mean gradient of the IR image reconstructed by the proposed algorithm increased by 1.5, 1.4, and 1.2 times than that of the traditional algorithm based on L1- norm, L2-norm, and traditional mixed norm, respectively. The peak signal-to-noise ratio, structural similarity index, and visual effect of the reconstructed image also improved. 展开更多
关键词 infrared (IR) super-resolution (SR) image reconstruction high frequency layer edge texture
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