• Title/Summary/Keyword: Additive Algorithm

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Impulse Noise Cancellation Using Adaptive Threshold Algorithm (적응 문턱치 알고리즘을 이용한 충격잡음 제거)

  • Lee, Jin;Park, Jong-Hwan;Kim, Se-Dong;Lee, Young-Suk;Kim, Sung-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.8
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    • pp.26-34
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    • 2000
  • This paper presents a new adaptive impulse noise cancelling technique based on the adaptive nonlinear suppressing function. The proposed "adaptive threshold algorithm (ATA)" is controlled by the normalized power prior input data term, and this adaptive threshold makes the cancelling system highly robust against additive impulse noise. For the performance evaluation, we have tested the proposed algorithm with the observed signals simulated in various impulsive noise environments and real EMG signals. As a result the proposed algorithm shows superior performance of 51.7% to the available techniques in the points of SNR and MSE.

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A Study on TCM Decoder Performance for 8 PSK, 8 PAM, 16 QAM in the Communication Channel With additive Gaussian and Impulsive Noise (가우스성 잡음과 임펄스성 잡음이 혼재하는 통신 채널 상에서 8 PSK, 8PAM, 16 QAM 에 대한 TCM 복호기 성능에 관한 연구)

  • 정지원;김경신;원동호
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.9
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    • pp.18-25
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    • 1994
  • Previously. TCM decoder has been using the Viterbi algorithm that was complex. In order to reduce the complexity of decoder. we proposed the “modified decoding algorithm using the path back method” and the modified decoding algorithm which extends the previous decoding algorithm to be able to applied to TCM decoder in this paper. On the gaussian and impulsive noise channel. Monte-Carlo simulation is used for analyzing the TCM performance and proving the efficiency of proposed decoding algorithm.

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FPGA Implementation of Recursive DFT based Phase Measurement Algorithm (DFT 연산 FPGA 모들에 기반한 위상 측정 앨고리즘의 구현)

  • Ahn Byoung-Sun;Kim Byoung-Il;Chang Tae-Gyu
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.3
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    • pp.191-193
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    • 2005
  • This paper proposes a phase measurement algorithm which is based on the recursive implementation of sliding-DFT. The proposed algorithm is designed to have a robust behavior against the erroneous factors of frequency drift, additive noise, and twiddle factor approximation. Four channel power-line phase measurement system is also designed and implemented based on the time-multiplexed sharing architecture of the proposed algorithm. The proposed algorithm's features of phase measurement accuracy and its robustness against the finite wordlength effects can provide a significant impact especially for the ASIC or microprocessor based embedded system applications where the enhanced processing speed and implementation simplicity are crucial design considerations.

Modified Gaussian Filter based on Fuzzy Membership Function for AWGN Removal in Digital Images

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of information and communication convergence engineering
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    • v.19 no.1
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    • pp.54-60
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    • 2021
  • Various digital devices were supplied throughout the Fourth Industrial Revolution. Accordingly, the importance of data processing has increased. Data processing significantly affects equipment reliability. Thus, the importance of data processing has increased, and various studies have been conducted on this topic. This study proposes a modified Gaussian filter algorithm based on a fuzzy membership function. The proposed algorithm calculates the Gaussian filter weight considering the standard deviation of the filtering mask and computes an estimate according to the fuzzy membership function. The final output is calculated by adding or subtracting the Gaussian filter output and estimate. To evaluate the proposed algorithm, simulations were conducted using existing additive white Gaussian noise removal algorithms. The proposed algorithm was then analyzed by comparing the peak signal-to-noise ratio and differential image. The simulation results show that the proposed algorithm has superior noise reduction performance and improved performance compared to the existing method.

Adaptive Clustering based Sparse Representation for Image Denoising (적응 군집화 기반 희소 부호화에 의한 영상 잡음 제거)

  • Kim, Seehyun
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.910-916
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    • 2019
  • Non-local similarity of natural images is one of highly exploited features in various applications dealing with images. Unique edges, texture, and pattern of the images are frequently repeated over the entire image. Once the similar image blocks are classified into a cluster, representative features of the image blocks can be extracted from the cluster. The bigger the size of the cluster is the better the additive white noise can be separated. Denoising is one of major research topics in the image processing field suppressing the additive noise. In this paper, a denoising algorithm is proposed which first clusters the noisy image blocks based on similarity, extracts the feature of the cluster, and finally recovers the original image. Performance experiments with several images under various noise strengths show that the proposed algorithm recovers the details of the image such as edges, texture, and patterns while outperforming the previous methods in terms of PSNR in removing the additive Gaussian noise.

Accuracy Improvement Scheme for Location Awareness based on UWB system (UWB 기반 위치인식 정확도 향상 기법)

  • Choi, Young-Hoon;Bae, Jung-Nam;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.2
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    • pp.231-236
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    • 2011
  • In recent years, LBS(Location Based Service) is applied in many different fields. Therefore, various location-aware schemes have been studied. In the location awareness system using time dependent algorithm, TOA(Time of Arrival) or TDOA(Time Difference of Arrival) algorithm, distortion of a signal by AWGN(Additive White Gaussian Noise) and multi-path effects cause the degradation of location awareness performance. In this paper, the unexpected noise is eliminated by averaging multiple pulses in order to overcome the degradation of performance. Also, we research the technique for improving the performance of the location awareness by detecting direct-path signal with adjusting threshold.

A Study on Image Restoration Filter in AWGN Environments (AWGN 환경에서 영상복원 필터에 관한 연구)

  • Xu, Long;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.4
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    • pp.949-956
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    • 2014
  • Recently, with the development of hardware and software technology related with image information delivery, the demand for various multimedia service has increased. But, the process of treating, sending, and storing image signals generates image degradation by various external causes. The main cause of image degradation is noise. image is mostly damaged by AWGN (additive white Gaussian noise). Therefore, there have been active researches on noise elimination. This paper, to reduce the effects of AWGN added to the image, suggests a noise-eliminating algorithm which is excellent in low-frequency and high-frequency characteristics in space. And, this paper, through simulation techniques, compared the result of the suggested algorithm with those of the existing methods. And, to evaluate the performance of it, PSNR (peak signal to noise ratio) was used.

Decision Feedback Doppler Adaptive Band-Limit Algorithm for Maximum Doppler frequency Estimation (속도 추정 시 부가 잡음의 영향을 억제하기 위한 결정 궤환 적응형 대역 제한 방법에 대한 연구)

  • 박구현;한상철;류탁기;홍대식;강창언
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.11C
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    • pp.1111-1117
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    • 2003
  • The maximum Doppler frequency, or equivalently, the mobile speed is very useful information to optimize the performance of many wireless communication systems. However, the performance of a maximum Doppler frequency estimator is limited since it requires an estimate of the signal-to-noise ratio (SNR) of the channel environment. In this paper, the improved method for the maximum Doppler frequency estimations based on the decision feedback Doppler adaptive band-limit (DF-DABL) method is proposed. To reduce the effect of additive noise, the proposed algorithm uses a novel Doppler adaptive band-limit (DABL) technique. The distortion due to the additive noise is drastically removed by the proposed DF-DABL method. Especially, the DF-DABL method does not need any other channel information such as SNR.

Watermark Detection Algorithm Using Statistical Decision Theory (통계적 판단 이론을 이용한 워터마크 검출 알고리즘)

  • 권성근;김병주;이석환;권기구;권기용;이건일
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.1
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    • pp.39-49
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    • 2003
  • Watermark detection has a crucial role in copyright protection of and authentication for multimedia and has classically been tackled by means of correlation-based algorithms. Nevertheless, when watermark embedding does not obey an additive rule, correlation-based detection is not the optimum choice. So a new detection algorithm is proposed which is optimum for non-additive watermark embedding. By relying on statistical decision theory, the proposed method is derived according to the Bayes decision theory, Neyman-Pearson criterion, and distribution of wavelet coefficients, thus permitting to minimize the missed detection probability subject to a given false detection probability. The superiority of the proposed method has been tested from a robustness perspective. The results confirm the superiority of the proposed technique over classical correlation- based method.

An Improved Weighted Filter for AWGN Removal (AWGN 제거를 위한 개선된 가중치 필터)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.5
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    • pp.1227-1232
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    • 2013
  • Recently, the expectation of quality about images over the increasing demand of digital devices is increasing with the development of the technology of the digital. But the images are degraded by a variety of causes, and the main reason is the noises. Therefore, the necessity of denoising comes to the fore, and the research for denoising is progressing dynamically. The images are mainly degraded by AWGN(additive white Gaussian noise), and the characteristics of denoising of existing methods such as mean filter are insufficient. In this paper, an algorithm combined by the spatial weighted filter and the modified adaptive weighted filter is proposed in order to effectively remove the AWGN. In the simulation result, the proposed algorithm showed excellent denoising capabilities.