• Title/Summary/Keyword: 충격잡음 환경

Search Result 45, Processing Time 0.031 seconds

Optimum Solutions of Minimum Error Entropy Algorithm (최소 오차 엔트로피 알고리듬의 최적해)

  • Kim, Namyong;Lee, Gyoo-yeong
    • Journal of Internet Computing and Services
    • /
    • v.17 no.3
    • /
    • pp.19-24
    • /
    • 2016
  • The minimum error entropy (MEE) algorithm is known to be superior in impulsive noise environment. In this paper, the optimum solutions and properties of the MEE algorithm are studied in regard to the robustness against impulsive noise. From the analysis of the behavior of optimum weight and factors related with mitigation of influence from large errors, it is revealed that the magnitude controlled input entropy plays the main role of keeping optimum weight of MEE undisturbed from impulsive noise. In the simulation, the optimum weight of MEE is shown to be the same as that of MSE criterion.

Decision Feedback Algorithms using Recursive Estimation of Error Distribution Distance (오차분포거리의 반복적 계산에 의한 결정궤환 알고리듬)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.5
    • /
    • pp.3434-3439
    • /
    • 2015
  • As a criterion of information theoretic learning, the Euclidean distance (ED) of two error probability distribution functions (minimum ED of error, MEDE) has been adopted in nonlinear (decision feedback, DF) supervised equalizer algorithms and has shown significantly improved performance in severe channel distortion and impulsive noise environments. However, the MEDE-DF algorithm has the problem of heavy computational complexity. In this paper, the recursive ED for MEDE-DF algorithm is derived first, and then the feed-forward and feedback section gradients for weight update are estimated recursively. To prove the effectiveness of the recursive gradient estimation for the MEDE-DF algorithm, the number of multiplications are compared and MSE performance in impulsive noise and underwater communication environments is compared through computer simulation. The ratio of the number of multiplications between the proposed DF and the conventional MEDE-DF algorithm is revealed to be $2(9N+4):2(3N^2+3N)$ for the sample size N with the same MSE learning performance in the impulsive noise and underwater channel environment.

Biased Zero-Error Probability for Adaptive Systems under Non-Gaussian Noise (비-가우시안 잡음하의 적응 시스템을 위한 바이어스된 영-오차확률)

  • Kim, Namyong
    • Journal of Internet Computing and Services
    • /
    • v.14 no.1
    • /
    • pp.9-14
    • /
    • 2013
  • The criterion of zero-error probability provides a limitation on error probability functions being used for adaptive systems when the error samples are shifted by the influence of DC-bias noise. In this paper, we employ a bias term in the error distribution and propose a new criterion of the biased zero-error probability with error being zero. Also, by maximizing the proposed criterion on expanded filter structures, a supervised adaptive algorithm has been derived. From the simulation results of supervised equalization, the algorithm based on the proposed criterion yielded zero-centered and highly concentrated error samples without disturbance in the environments of strong impulsive and DC-bias noise.

The Effect of Phase Noise from PLL Frequency Synthesizer (PLL 주파수 합성기에서 발생하는 위상잡음의 영향)

  • 조형래;최정수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.6
    • /
    • pp.865-870
    • /
    • 2001
  • In this paper, we analyse the effect of phase noise from PLL frequency synthesizer on 64 QAM when detecting corrupted signals. To predict the phase noise of an oscillator very accurately, we assume that the oscillator is linearly time-varying when the input impulsive current to the oscillator is small. The performance of the detector which detects the corrupted signal by oscillator phase noise is compared with that when the detector is only affected by AWGN and then analyse how much the phase noise degrades the system performance for 64 QAM.

  • PDF

멀티미디어 서비스를 위한 HDSL 과 ADSL 부호화기술

  • 임기홍;강규민;이용훈;이경국;문두영;한상길
    • Information and Communications Magazine
    • /
    • v.15 no.12
    • /
    • pp.85-96
    • /
    • 1998
  • 본 논문에서는 현재 연구 개발되고 있는 HDSL/ADSL 시스템의 동작환경과 채널(선로감쇄(propagation loss), NEXT, 충격잡음 등)에 관하여 언급한 후, 전체 시스템의 구조 및 동작 원리를 기술하였다. 연구 개발된 HDSL/ADSL 전체시스템은 64-CAP 전송방식을 기반으로 Tomlinson precoder, Trellis코드, modulo Viterbi복호기, Convolutional-interleaved R-S 부호기/복호기, Hybrid-DFE, 반향 제거기, 타이밍 복원회로 등으로 구성되어 있다. HDSL/ADSL 전송시스템의 모든 기능들은 디지털로 구현되었으며, 칩 구현을 위하여 각 기능들의 VLSI 시스템 파라메터들을 추출하고 성능시험을 실시하였다.

  • PDF

Optimum Conditions of Adaptive Equalizers Based on Zero-Error Probability (영확률에 기반한 적응 이퀄라이져의 최적조건)

  • Kim, Namyong;Lee, Gyoo-Yeong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.10
    • /
    • pp.1865-1870
    • /
    • 2015
  • In signal processing, the zero-error probability (ZEP) criterion and related algorithm (MZEP) outperforms MSE-based algorithms and yields superior and stable convergence in impulsive noise environment. In this paper, the analysis of the relationship with MSE criterion proves that ZEP criterion has equivalent optimum solution of MSE criterion. Also this work reveals that the magnitude controlled input of MZEP algorithm plays the role in keeping the optimum solution undisturbed from impulsive noise.

An Order Statistic-Based Spectrum Sensing Scheme for Cooperative Cognitive Radio Networks in Non-Gaussian Noise Environments (비정규 잡음 환경에서 협력 무선인지 네트워크를 위한 순서 기반 스펙트럼 센싱 기법)

  • Cho, Hyung-Weon;Lee, Youngpo;Yoon, Seokho;Bae, Suk-Neung;Lee, Kwang-Eog
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37A no.11
    • /
    • pp.943-951
    • /
    • 2012
  • In this paper, we propose a novel spectrum sensing scheme based on the order statistic for cooperative cognitive radio network in non-Gaussian noise environments. Specifically, we model the ambient noise as the bivariate isotropic symmetric ${\alpha}$-stable random variable, and then, propose a cooperative spectrum sensing scheme based on the order of observations and the generalized likelihood ratio test. From numerical results, it is confirmed that the proposed scheme offers a substantial performance improvement over the conventional scheme in non-Gaussian noise environments.

Development of On Board Pyro-Shock Recorder for Launch Vehicle (발사체 탑재용 파이로 충격기록장치 개발 및 시험)

  • Kim, Joo-Nyun;Jung, Hae-Seung;Lee, Jae-Deuk;Kim, Bo-Gwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.5
    • /
    • pp.65-71
    • /
    • 2005
  • Pyro-shock measurement system in launch vehicle is necessary to validate structural robustness and to prepare environmental qualification criteria for launch vehicle systems. This paper describes design, development and function test of prototype pyro-shock recorder to be employed on KSLV-I in the near future. Due to the limitation of telemetry transmission rate, pyro-shock recorder acquires and stores the shock sensor data with high sampling rate in short period and sends the data to the KSLV-I telemetry system with lower data rate. Signal conditioning in pyro-shock recorder is designed to enhance signal-to-noise ratio through proper placement of anti-aliasing filter.

Euclidean Distance of Biased Error Probability for Communication in Non-Gaussian Noise (비-가우시안 잡음하의 통신을 위한 바이어스된 오차 분포의 유클리드 거리)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.14 no.3
    • /
    • pp.1416-1421
    • /
    • 2013
  • In this paper, the Euclidean distance between the probability density functions (PDFs) for biased errors and a Dirac-delta function located at zero on the error axis is proposed as a new performance criterion for adaptive systems in non-Gaussian noise environments. Also, based on the proposed performance criterion, a supervised adaptive algorithm is derived and applied to adaptive equalization in the shallow-water communication channel distorted by severe multipath fading, impulsive and DC-bias noise. The simulation results compared with the performance of the existing MEDE algorithm show that the proposed algorithm yields over 5 dB of MSE enhancement and the capability of relocating the mean of the error PDF to zero on the error axis.