• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.289-292
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• 2003

이 논문은 WCDMA 와 안테나 배열 시스템에서 저 레벨 양자화와 MUSIC 알고리즘을 사용하여 신호의 방향을 추정하는 방법을 제안한다. 추가의 Power-Up Function 이 필요 없는 방향각 방법으로 이동가입자의 위치를 알아내기 위해 안테나 배열을 이용하여, WCDMA 시스템에서 역확산 코드로 다수의 신호를 분리하고, 각 신호를 저 레벨로 양자화 시켜 MUSIC 으로 신호의 방향각을 추정하였다. 이 방법을 이용하면 단말기의 안테나 출력파워가 낮더라도 기존 방법의 에러율과 비슷함을 시뮬레이션 결과로 알 수 있고, 양자화 비트를 처리하기 위해 필요한 메모리 또한 줄일 수 있어 하드웨어의 비용을 줄일 수 있을 것이다.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.155-158
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• 2001

소나나 레이더분야에서의 방위 정보 추정에 있어서 직접신호와 반사신호가 있는 경우의 연구가 많이 이루어져왔다 특히 반사 신호 성분 중에 직접신호와 상관도가 높은 성분이 있는 스펙큘러 반사 성분이 있는 경우에 대한 연구가 많이 이루어져왔다. 이런 연구들은 대부분이 Block 데이타 처리 구조를 가지고 있다 따라서 방위가 시간에 따라서 변하는 경우 이런 Block 처리 구조를 가지고 처리하는 것은 오류를 범할 가능성이 높다. 본 논문에서는 recursive 구조를 갖는 알고리즘을 스펙큘러 환경에 강하도록 수정하여 시간에 따라 방위가 변하는 환경에 적용할 수 있도록 만든 알고리즘을 제안한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.275-280
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• 2015

In this paper, we studied for modified MUSIC algorithm of direction of arrival (DOA)estimation. Modified MUSIC algorithm search optimal covariance matrix using singular value decomposition and Bayes method, and desired signals are estimated by updating weight. In order to estimation of desired signals, we used sub spatial method of MUSIC algorithm. General MUSIC algorithm can estimate a desired signal in case of non-correlation signal. But, general MUSIC algorithm in case of correlation signal can not estimate a desired signals and resolution is decreased. Though simulation in case of correlation signal, we analyze to compare proposed MUSIC algorithm with general MUSIC algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.310-317
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• 2013

In this paper an ESPRIT-based super-resolution time delay estimation algorithm is developed for real-time locating system (RTLS) and its performance is analyzed in various multipath environments. The performance of the existing correlation method for time delay estimation seriously degrades in multipath environments where the relative time delays of multipath signals are less than a PN chip. To solve the problem we shall develop a frequency domain super-resolution time delay estimation algorithm using the ESPRIT, the most representative super-resolution direction-of-arrival (DOA) estimation algorithm, and analyze its performance in various multipath environments.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.102-107
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• 2007

Since the Matrix Pencil (MP) method can be performed to estimate multiple DOAs by using only single snapshot, this method is suitable for short data length or when the environment is dynamic. As the number of array increases, the computational load increases due to complex number computation. This paper presents an approach based on a unitary matrix pencil (MP) algorithm to reduce the computational load. Unitary transformation for the MP method has been suggested and formulated successfully. The computer simulation shows that the error rate of proposed method agree with that of MP for different SNR values.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.687-690
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• 1999

Many high-resolution algorithms based on the eigen-decomposition analysis of observed covariance matrix, such as MVE, MUSIC, and EVM, have been proposed. However, the resolution of spectral estimates for these algorithms is severely degraded when Signal-to-Noise Ratio (SNR) is low and arrival angles of signal are close to each other. And EVM and MUSIC is powerful for the characteristic of SNR. But have the limitation that the number of signals presented is known. While MVE is bad the characteristic of SNR. In this study, we propose a modified MVE to enhance the resolution for Direction-Of-Arrival (DOA) estimation of underwater acoustic signal. This is to remove the limitation that existing algorithms should know the information for the number of signals. Because the algorithms founded on the eigen value estimate DOA with only the noise subspace, they have the high-resolution characteristic. And then, with the method reducing the effect of the signal subspace, we are to reduce the degradation because of complementary relationship between the signal subspace and the noise subspace. This paper, with using the simulation data, we have estimated the proposed algorithms, compared it with other high-resolution algorithms. The simulation results show that the modified MVE proposed is accurate and has a better resolution even though SNR is low, under the same condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8A
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• pp.741-747
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• 2011

Matrix Pencil method is one of the promising method to estimate DOA in non-stationary, multi-path coherent environment. Not only the Matrix Pencil Method offers better resolution than the conventional approach using covariance matrix, but also it is computationally very efficient. In this paper, we presented an effect of unbalanced data weighting in the formulation of the Matrix Pencil method. A new formulation has been suggested to mitigate the effect of unbalanced data weighting. Numerical simulation demonstrated that the proposed method can successfully eliminate the problem of unbalanced data weighting.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.60-66
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• 1997

Most research on the estimation of direction of arrival has been accomplished based on the assumption that the signal sources are point sources. In some real surroundings, signal source localization can more adequately be accomplished with distributed source models. When the signal sources are distributed over an area, we cannot directly use well-known DOA estimation methods, In this paper, we represent an source by the center angle and degree of dispersion. Then, we address the estimation of the elevation and azimuth angles of distributed sources based on the parametric distributed source modeling in the 3-dimensional space.

• The Journal of the Acoustical Society of Korea
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• v.32 no.3
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• pp.247-251
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• 2013

In this paper, near-field source localization algorithm is presented using Matrix Pencil in Uniform Linear Array(ULA). Based on the centrosymmetry of the ULA, the proposed algorithm decouples the steering vectors which allow for the bearing estimation using Matrix pencil. With estimated bearing, the range estimation of each source is consequently obtained by defining 1D MUSIC spectrum. Simulation results are presented to validate the performance of the proposed algorithm.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.3
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• pp.1-6
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• 2003

It is difficult to detect and to track the moving targets like tanks and diesel vehicles due to the variety of terrain and moving of targets. It is possible to be happened the aliasing conditions as the difficulty of antenna deployment in the complex environment like the battle fields. In this paper, we study the problem of detecting and tracking of moving targets which are emitting wideband signals under severe spatial aliasing conditions because of the sparse arrays. We developed a direction of arrival(DOA) estimation algorithm based on subband MUSIC(Multiple Signal Classification) method which produces high-resolution estimation. In this algorithm, the true bearings are invariant regardless of changes of frequency bands while the aliased false bearings vary. As a result, the proposed algorithm overcomes the aliasing effects and improves the localization performance in sparse passive arrays.