• Title/Summary/Keyword: Multiple Signal Processing

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Efficiency Evaluation of the Unconditional Maximum Likelihood Estimator for Near-Field DOA Estimation

  • Arceo-Olague, J.G.;Covarrubias-Rosales, D.H.;Luna-Rivera, J.M.
    • ETRI Journal
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    • v.28 no.6
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    • pp.761-769
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    • 2006
  • In this paper, we address the problem of closely spaced source localization using sensor array processing. In particular, the performance efficiency (measured in terms of the root mean square error) of the unconditional maximum likelihood (UML) algorithm for estimating the direction of arrival (DOA) of near-field sources is evaluated. Four parameters are considered in this evaluation: angular separation among sources, signal-to-noise ratio (SNR), number of snapshots, and number of sources (multiple sources). Simulations are conducted to illustrate the UML performance to compute the DOA of sources in the near-field. Finally, results are also presented that compare the performance of the UML DOA estimator with the existing multiple signal classification approach. The results show the capability of the UML estimator for estimating the DOA when the angular separation is taken into account as a critical parameter. These results are consistent in both low SNR and multiple-source scenarios.

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A Study on the Digital Signal Processing for the Pattern fiecognition of Weld Flaws (용접결함의 패턴인식을 위한 디지털 신호처리에 관한 연구)

  • 김재열;송찬일;김병현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.393-396
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    • 1995
  • In this syudy, the researches classifying the artificial and natural flaws in welding parts are performed using the smart pattern recognition technology. For this purpose the smart signal pattern recognition package including the user defined function was developed and the total procedure including the digital signal processing,feature extraction , feature selection and classifier selection is treated by bulk. Specially it is composed with and discussed using the statistical classifier such as the linear disciminant function classifier, the empirical Bayesian classifier. Also, the smart pattern recognition technology is applied to classification problem of natural flaw(i.e multiple classification problem-crack,lack of penetration,lack of fusion,porosity,and slag inclusion, the planar and volumetric flaw classification problem). According to this results, if appropriately learned the neural network classifier is better than ststistical classifier in the classification problem of natural flaw. And it is possible to acquire the recognition rate of 80% above through it is different a little according to domain extracting the feature and the classifier.

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Signal Processing of the Continuous-Wave Radar for Approach and Retreat of Targets Using I and Q Channels (I/Q 채널을 이용한 연속파 레이다의 표적 접근/후퇴 신호처리)

  • Cho, Choon Sik
    • Journal of Satellite, Information and Communications
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    • v.12 no.1
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    • pp.34-37
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    • 2017
  • This letter presents the signal processing of a CW radar (Continuous Wave or Doppler radar) sensor which enables the radar to detect the multiple targets' approaching and retreating using both I and Q channels. The proposed algorithm utilizes the phase change of the Quadrature signal, which occurs when targets move back and forth from the radar. The verification is carried out with the board containing a commercially available MMIC chip and an MCU by analyzing the received data from MMIC. Also the proposed algorithm is downloaded to MCU and the approaching and retreating movement is confirmed. The CW frequency is 24.125 GHz and the transmitter output power used is 7.2 dBm. Detectable distance is about 12 m.

Parallel Structure of Viterbi Decoder for High Performance of PRML Signal (PRML신호용 고성능 Viterbi Decoder의 병렬구조)

  • Seo, Beom-Soo;Kim, Jong-Man;Kim, Hyong-Suk
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.623-626
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    • 2009
  • In this paper, we applied new analog viterbi decoder to decode PR(1,2,2,1) signal for DVD and analyze the specific and signal characteristics. We implemented the parallel analog viterbi decoder and the convolution digital viterbi decoder(the digital PRML) utilizing the technology of analog parallel processing circuits. The proposed analog viterbi decoder can replace the conventional digital viterbi decoder by a new one. Our circuits design the low distortion and the high accuracy over the previous implementation. Through the parallel structure of the proposed viterbi decoder, we got the achievement of the decoding speed by the multiple times.

An Implementation of High Speed Rendering to Process Touch Screen Multiple Inputs based on FPGA (FPGA 기반의 터치스크린 다중입력처리를 위한 고속 렌더링 구현)

  • Yoon, Junhan;Kim, Jin Heon
    • Journal of Korea Multimedia Society
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    • v.20 no.11
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    • pp.1803-1810
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    • 2017
  • A large amount of processing time is required if the process of detecting the touch position on the touch screen and displaying it on the display panel is performed only by software. In this paper, we propose a method to output information touched on the screen using H/W method in order to improve the response speed delay. In the FPGA module designed for the HDMI signal output to the display module, the touch information is input to the serial data signal including touch coordinate information, point size, and color information. Then the module render the image using HDMI signal input to the module and the touch information. This method has a pipeline structure so it has effect of reducing the delay time that occurs in outputting the touch information compared with the conventional software processing method.

Performance Analysis of Turbo Encoded Parallel Interference Canceller on Rayleigh Fading Channel (Rayleigh 페이딩 채널에서 터보부호화 병렬간섭제거기의 성능분석)

  • 박재오;이정재
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.4
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    • pp.65-70
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    • 2001
  • In this paper a new scheme combining the turbo coder with parallel interference canceller, which effectively mitigates the effects of multiple access interferences and Ralyeigh fades in the DS-CDAM mobile communication systems is proposed Using the Monte-Carlo simulation, the performance of this scheme in terms of the number of users and signal to noise ration under AWGN and Ralyeigh fading environment is analyzed. The results of simulations show that the proposed scheme outperforms conventional CDMA receiver systems over Rayleigh fading as well as AWGN.

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Performance Analysis of Turbo Encoded Parallel Interference Canceller over Rayleigh Fading Channel (Rayleigh 페이딩 채널에서 터보부호화 병렬간섭제거기의 성능 분석)

  • 박재오;이정재
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2000.12a
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    • pp.21-24
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    • 2000
  • In this paper a new scheme combining the turbo coder with parallel interference canceller, which effectively mitigates the effects of multiple access interferences and Rayleigh fades in the BS-CDMA mobile communication systems, is proposed. Using the Monte-Carlo simulation, the performance of this scheme in terms of the number of users and signal to noise ratio under AWGN and Rayleigh fading environment is analyzed.

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Implementation of Adaptive Shading Correction System Supporting Multi-Resolution for Camera

  • Ha, Joo-Young;Song, Jin-Geun;Im, Jeong-Uk;Min, Kyoung-Joong;Kang, Bong-Soon
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2006.06a
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    • pp.25-28
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    • 2006
  • In this paper, we say the shading correction system supporting multi-resolution for camera. The shading effect is caused by non-uniform illumination, non-uniform camera sensitivity, or even dirt and dust on glass (lens) surfaces. In general this shading effect is undesirable [1]. Eliminating it is frequently necessary for subsequent processing and especially when quantitative microscopy is the fine goal. The proposed system is available on thirty nine kinds of image resolutions scanned by interlaced and progressive type. Moreover, the system is using various continuous quadratic equations instead of using the piece-wise linear curve which is composed of multiple line segments. Finally, the system could correct the correct effect without discontinuity in any image resolution. The proposed system is also experimentally demonstrated with Xilinx Virtex FPGA XCV2000E- 6BG5560 and the TV set.

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Highly Efficient and Precise DOA Estimation Algorithm

  • Yang, Xiaobo
    • Journal of Information Processing Systems
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    • v.18 no.3
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    • pp.293-301
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    • 2022
  • Direction of arrival (DOA) estimation of space signals is a basic problem in array signal processing. DOA estimation based on the multiple signal classification (MUSIC) algorithm can theoretically overcome the Rayleigh limit and achieve super resolution. However, owing to its inadequate real-time performance and accuracy in practical engineering applications, its applications are limited. To address this problem, in this study, a DOA estimation algorithm with high parallelism and precision based on an analysis of the characteristics of complex matrix eigenvalue decomposition and the coordinate rotation digital computer (CORDIC) algorithm is proposed. For parallel and single precision, floating-point numbers are used to construct an orthogonal identity matrix. Thus, the efficiency and accuracy of the algorithm are guaranteed. Furthermore, the accuracy and computation of the fixed-point algorithm, double-precision floating-point algorithm, and proposed algorithm are compared. Without increasing complexity, the proposed algorithm can achieve remarkably higher accuracy and efficiency than the fixed-point algorithm and double-precision floating-point calculations, respectively.

Multiple Mixed Modes: Single-Channel Blind Image Separation

  • Tiantian Yin;Yina Guo;Ningning Zhang
    • Journal of Information Processing Systems
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    • v.19 no.6
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    • pp.858-869
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    • 2023
  • As one of the pivotal techniques of image restoration, single-channel blind source separation (SCBSS) is capable of converting a visual-only image into multi-source images. However, image degradation often results from multiple mixing methods. Therefore, this paper introduces an innovative SCBSS algorithm to effectively separate source images from a composite image in various mixed modes. The cornerstone of this approach is a novel triple generative adversarial network (TriGAN), designed based on dual learning principles. The TriGAN redefines the discriminator's function to optimize the separation process. Extensive experiments have demonstrated the algorithm's capability to distinctly separate source images from a composite image in diverse mixed modes and to facilitate effective image restoration. The effectiveness of the proposed method is quantitatively supported by achieving an average peak signal-to-noise ratio exceeding 30 dB, and the average structural similarity index surpassing 0.95 across multiple datasets.