• 한국정보전자통신기술학회논문지
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• 제9권2호
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• pp.190-195
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• 2016

본 연구에서는 균일 선형 배열 안테나 시스템에서 입사신호의 방향을 추정하기 위한 기존의 방법과 제안방법의 성능에 대해서 비교한다. 본 논문에서 제안한 방법은 최대 사후 확률 추정기를 적용하여 신호의 도래방향 추정 오차확률을 감소하고자 한다. 신호 추정 방향 확률 오차를 감소시키면 안테나에 입사하는 신호의 방향을 정확히 추정할 수 있다. 모의실험을 이용하여 본 연구에서 제안한 방법과 기존의 방법을 비교 분석하였으며 또한 배열 안테나 개수를 증가시키면서 신호 추정 오차 확률을 비교 분석하였다. 본 연구에서 제안한 방법이 기존의 방법보다 약 8%의 신호 추정 오차 확률을 감소시켜 도래방향 신호 추정 능력이 우수함을 입증하였다.

• 한국정보전자통신기술학회논문지
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• 제9권3호
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• pp.291-297
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• 2016

본 논문에서는 상관성 신호 시스템에서 원하는 목표물의 도래방향을 추정하기 위한 기존 MUSIC알고리즘과 제안 알고리즘에 대한 성능을 비교 분석한다. 본 논문에서 제안한 알고리즘은 가중치 갱신을 위해서 선형 구속 최소 분산 방법과 도래 방향 오차 확률을 최적으로 감소시키기 위해서 베이스 방법과 최대 사후 확률에 MUSIC알고리즘 적용하여 목표물 도래 방향 추정 오차 확률을 감소하고자 한다. 모의실험을 이용하여 본 연구에서 제안한 알고리즘과 기존의 MUSIC알고리즘의 성능을 비교 분석하였다. 신호대 잡음비가 10dB이고 안테나 배열 개수가 9개와 12일 때, 본 논문에서 제안한 알고리즘이 기존의 MUSIC알고리즘보다 각각 약 11%와 13%의 도래 방향 추정 오차를 감소시켜 본 연구에서 제안한 알고리즘이 우수함을 확인하였다.

• 전자공학회논문지B
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• 제30B권12호
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• pp.1-11
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• 1993

This paper concentrates on models useful for analyzing the error performance of ML(Maximum Likelihood) estimators of a single unknown signal parameter: that is the error intensity model. We first develop the point process representation for the estimation error and the conditional distribution of the estimator as well as the distribution of error candidate point process. Then the error intensity function is defined as the probability dessity of the estimate and the general form of the error intensity function is derived. We then develop several intensity models depending on the way we choose the candidate error locations. For each case, we compute the explicit form of the intensity function and discuss the trade-off among models as well as the extendability to the case of multiple parameter estimation.

• 전자공학회논문지B
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• 제32B권1호
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• pp.85-95
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• 1995

The error intensity models for the ML estimation of a signal parameter have been developed in a companion paper [1]. While the methods described in [1] are applicable to any estimation problem with continuous parameters, our main application in this paper is the time delay estimation, and comparisons among the models derived in [1] (i.e. LC, LM, and ALM models)have been made. We first consider the case where only additive Gaussian noise is involved, and then the shot noise environment where coherent impulsive noise is also involved in addition to the Gaussian noise. We compare the models in terms of the probability of error, MSE(Mean Squared Error), and the computational complexity, which are the most important performance criteria in the analysis of parameter estimation. In conclusion, the ALM model turned out to be the most adequate model of all from the viewpoints of the criteria mentioned above.

• 한국통신학회논문지
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• 제41권11호
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• pp.1406-1409
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• 2016

본 논문에서는 송수신단 간 변조기법 및 채널 상태 값이 약속되지 않은 완벽한 블라인드 통신 상황에서 송신측의 변조방식을 알아내기 위해 성좌도 회전 및 확률밀도함수(probability density function : pdf)를 이용한 새로운 자율 변조 구분(Automatic modulation classification : AMC)기법과 경험적 신호 그룹화 알고리즘을 통해 채널 상태 값을 추정하는 방법을 제안한다. 평균제곱근 편차(Root mean square error : RMSE) 및 심볼 오류율(Symbol error rate : SER) 등의 모의실험을 통해 제안된 기법과 기존의 다른 기법간의 채널 상태와 변조 추정 능력을 비교 평가한다.

• Journal of information and communication convergence engineering
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• 제10권3호
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• pp.269-275
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• 2012

In this paper, we proposed a novel location estimation algorithm based on the concept of space-time signature matching in a moving target environment. In contrast to previous fingerprint-based approaches that rely on received signal strength (RSS) information only, the proposed algorithm uses angle, delay, and RSS information from the received signal to form a signature, which in turn is utilized for location estimation. We evaluated the performance of the proposed algorithm in terms of the average probability of error and the average error distance as a function of target movement. Simulation results confirmed the effectiveness of the proposed algorithm for location estimation even in moving target environment.

• 전기학회논문지
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• 제61권11호
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• pp.1758-1764
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• 2012

A large number of wire rope has been used in various inderstiries as Cranes and Elevators from expanding the scale of the industrial market. But now, the management of wire rope is used as manually operated by rope replacement from over time or after the accident.It is caused to major accidents as well as economic losses and personal injury. Therefore its time to need periodic fault diagnosis of wire rope or supply of real-time monitoring system. Currently, there are several methods has been reported for fault diagnosis method of the wire rope, to find out the feature point from extracting method is becoming more common compared to time wave and model-based system. This method has implemented a deterministic modeling like the observer and neural network through considering the state of the system as a deterministic signal. However, the out-put of real system has probability characteristics, and if it is used as a current method on this system, the performance will be decreased at the real time. And if the random noise is occurred from unstable measure/experiment environment in wire rope system, diagnostic criterion becomes unclear and accuracy of diagnosis becomes blurred. Thus, more sophisticated techniques are required rather than deterministic fault diagnosis algorithm. In this paper, we developed the fault diagnosis of the wire rope using probability density estimation techniques algorithm. At first, The steady-state wire rope fault signal detection is defined as the probability model through probability distribution estimate. Wire rope defects signal is detected by a hall sensor in real-time, it is estimated by proposed probability estimation algorithm. we judge whether wire rope has defection or not using the error value from comparing two probability distribution.

• 전자공학회논문지
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• 제51권8호
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• pp.126-135
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• 2014

오차 신호의 확률분포 사이의 유클리드 거리 (Euclidean distance between error probability density functions, EDEP)는 충격성 잡음 환경의 적응 신호 처리를 위한 성능 지수로 사용되었다. 이 EDEP 알고리듬의 단점 중의 하나로 각 반복 시간마다 수행하는 이중적분에 의해 과다한 계산상의 복잡성이 있다. 이 논문에서는 EDEP 와 그 기울기 계산에서 계산상의 부담을 줄일 수 있는 반복적 추정 방법을 제안하였다. 데이터 블록 크기 N에 대하여, 기존의 추정 방식에 의한 EDEP와 그 기울기 계산량은 $O(N^2)$인 반면, 제안한 방식의 계산량은 O(N)이다. 성능 시험에서 제안한 방식의 EDEP와 그 기울기는 정상상태에서 기존의 블록 처리 방식과 동일한 추정결과를 나타냈다. 이러한 시뮬레이션 결과로부터, 제안한 방식이 실제 적응신호처리 분야에서 효과적인 방식임을 알 수 있다.

• International Journal of Contents
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• 제14권1호
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• pp.18-27
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• 2018

The objective of this study was to derive approximate closed-form error rates for M-ary burst symbol transmission (MBST) of dual-hop adaptive decode-and-forward (ADF) cooperative relay systems over quasi-static Rayleigh fading channels. Within a burst, there are pilot symbols and data symbols. Pilot symbols are used for channel estimation schemes and each relay node's transmission mode selection schemes. At first, our focus was on ADF relay systems' error-events at relay nodes. Each event's occurrence probability and probability density function (PDF) were then derived. With error-event based approach, we derived a tractable form of PDF for combined signal-to-noise ratio (SNR). Averaged error rates were then derived as approximate expressions for arbitrary link SNR with different modulation orders and numbers of relays. Its accuracy was verified by comparison with simulation results.

• International Journal of Contents
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• 제11권1호
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• pp.7-14
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• 2015

In this paper, we derive the outage probability for M-ary phase shifting keying (MPSK) and M-ary quadrature amplitude modulation (MQAM) burst transmission (BT) of adaptive decode-and-forward (ADF) cooperative relay systems over quasi-static Rayleigh fading channels. Within a burst, there are pilot symbols and data symbols. Pilot symbols are used for channel estimation schemes and each relay node's transmission mode selection schemes. At first, we focus on ADF relay systems in which the probability density function (PDF) is derived on the basis of error events at relay nodes corresponding to channel estimation errors. Next, the average outage probability is derived as an approximate expression for an arbitrary link signal-to-noise ratio (SNR) for different modulation orders. Its accuracy is demonstrated by comparison with simulation results. Further, it is confirmed that BT-ADF relay systems with pilot symbol based channel estimation schemes enables to select correctly decoded relay nodes without additional signaling between relay nodes and the destination node, and it is verified that the ideal performance is achieved with small SNR loss.