• Title/Summary/Keyword: DOA 추정

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Root-assisted MUSIC algorithm for the efficient DOA estimation in Multi-Jammer Environments (다중 재머 환경에서 DOA 추정 성능 개선을 위한 Root-assisted MUSIC 알고리즘)

  • Lee, Ju Hyun;Choi, Heon Ho;Choi, Yun Sub;Lim, Deok Won;Park, Chansik;Lee, Sang Jeong
    • Journal of Advanced Navigation Technology
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    • v.17 no.4
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    • pp.386-395
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    • 2013
  • This paper proposes a root-assisted MUSIC algorithm which uses a combination of the MUSIC and the root-MUSIC algorithm. This algorithm consists of two steps. Firstly, a coarse DOA is computed by the root-MUSIC algorithm. Secondly, a precise DOA estimation is carried out by the MUSIC algorithm in the reduced searching range. This paper analyzes the accuracy and the resolution performance of the proposed DOA estimation method using a software simulation platform.

Performance analysis of DOA estimation and beamforming in 3-dimensional array antenna for GPS receiver (GPS 수신기를 위한 3 차원 배열 안테나의 도래각 추정 및 빔 형성 성능 분석)

  • Lee, Chong-Hyun;Kim, Suk-Joong;Lim, Seung-Gag
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.4
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    • pp.88-94
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    • 2007
  • This paper deals with the performance analysis of 3-dimensional array antenna by DOA estimation and beamforming in GPS receiver for performance improvement by interference elimination. The array antenna in GPS receiver can improve the system performance by estimating DOA of arriving signal direction, making the main beam for desired direction and elimate the jammer signal by nulling while keeping the GPS signal direction by spatial filtering. In this paper, we propose five types of 3-dimensional array antenna and analyze the estimation error via MUSIC algorithm which is used for the estimation of DOA of arrived signal and beamforming performance. In analyzing DOA performance, we measure DOA estimation error, while in analyzing beamformig performance, we measure BER. In beamforming performance analyzing, we use various jammer power and the existence of GPS signal and angle spread. By performing through the computer simulation, Curved (B) 7-element antenna in proposed 3-dimensional array antenna exhibits the superior performance in the DOA estimation, estimation error, BER characteristic and angle spread compared to the rest four array antenna types.

A Study of DOA estimation based on TDOA/AOA for jammer localization (전파위협원 위치결정을 위한 TDOA/AOA 기반의 DOA 추정 기법 연구)

  • Choi, Heon-Ho;Jin, Mi-Hyun;Lim, Deok-Won;Nam, Gi-Wook;Park, Chan-Sik;Lee, Sang-Jeong
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.962-969
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    • 2011
  • This paper proposes the DOA estimation method based on TDOA/AOA for jammer localization method in GBAS environment. The proposed method can effectively estimate DOA of jamming signal as the range for DOA estimation is reduced remarkably by using DOP and 1st approximate solution using TDOA measurements only. Through the proposed method, more precise DOA can be obtained and the performance of jammer localization is increased simultaneously. Also, the effectiveness of proposed method will be confirmed through the simulated results.

Estimation Technique of Direction of Arrival for Location Service in the next Generation Mobile Communication System (차세대 이동통신시스템에서 Location Service를 위한 신호도착방향 추정기법)

  • 이성로;최명수;김철희;안동순;김종화
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5A
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    • pp.284-293
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    • 2003
  • Location service is usually provided by the GPS method using satellites. In the next generation mobile communication systems which use smart antennas, location service can be accomplished using direction of arrival (DOA) estimation techniques. In this paper, we propose a DOA estimation technique for the location service of the next generation mobile communication systems and investigate the validity of the proposed technique through computer simulation. First, DOA estimation problems of distributed sources are considered using vortical and horizontal array processors which are orthogonal to each other. The DOA of the elevation angle is estimated by the vertical array processor and then that of the azimuth angle is estimated by the horizontal array processor. Finally, the procedures of the location service for specific signal sources using three smart antennas are exhibited by computer simulation to show that the proposed DOA estimation technique can be used for the location service in the next generation mobile communication systems.

Fast DOA Estimation Algorithm using Pseudo Covariance Matrix (근사 공분산 행렬을 이용한 빠른 입사각 추정 알고리듬)

  • 김정태;문성훈;한동석;조명제;김정구
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.1
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    • pp.15-23
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    • 2003
  • This paper proposes a fast direction of arrival (DOA) estimation algorithm that can rapidly estimate incidence angles of incoming signals using a pseudo covariance matrix. The conventional subspace DOA estimation methods such as MUSIC (multiple signal classification) algorithms need many sample signals to acquire covariance matrix of input signals. Thus, it is difficult to estimate the DOAs of signals because they cannot perform DOA estimation during receiving sample signals. Also if the D0As of signals are changing rapidly, conventional algorithms cannot estimate incidence angles of signals exactly. The proposed algorithm obtains bearing response and directional spectrum after acquiring pseudo covariance matrix of each snapshot. The incidence angles can be exactly estimated by using the bearing response and directional spectrum. The proposed DOA estimation algorithm uses only concurrent snapshot so as to obtain covariance matrix. Compared to conventional DOA estimation methods. The proposed algorithm has an advantage that can estimate DOA of signal rapidly.

Study of Subspace Tracking Methods for Estimating DOA of Linearly Closely Spaced Time-Varying Signals (DOA 추정을 위한 Subspace Tracking 기법들 간의 성능 비교)

  • 강경훈;유경렬
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.623-626
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    • 2001
  • 센서 array 신호처리에서 DOA(direction of arrival)의 추정에 사용되고 있는 root-MUSIC, TLS-ESPRIT 등과 같은 고해상도 스펙트럼 추정 기법들은 과다한 연산량으로 인하여 실시간 구현이 어렵고, 신호들의 DOA가 근접한 경우에서는 추적 성능이 매우 불안정하게 된다. 이러한 문제점에 대한 대안으로 여러 형태의 부공간 추적 개념을 사용하는 수치기법이 제안되어 왔다 [2], [4], [6]. 본 논문에서는 이들 부공간 추정 기법들을 LS-ESPRIT 기법에 접목하여 그 성능을 비교하고, 개선 방안을 제시하였다.

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Mutual Coupling Compensation for an Antenna Array and Direction Of Arrival Estimation Using ESPRIT (ESPRIT 알고리듬을 이용한 안테나 배열의 상호결합 보상과 도래각 추정)

  • Hong, Jeong-Geun;Ahn, Woo-Hyun;Seo, Bo-Seok
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.37-42
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    • 2013
  • In this paper, we propose a compensation method of a non-ideal antenna array and a computationally efficient estimation method of the direction of arrival (DOA) for the antenna array. For DOA estimation, an antenna array is essential. By using the phase difference between the output signals of antennas, we can derive the DOA. In practice, however, mutual coupling between the elements of an antenna array change the beam pattern of each element and degrade the performance of DOA estimation. In the proposed method, we first estimate the DOA for the mid-subarray of the array, where all elements undergo relatively same coupling effect. We use the estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm to estimate the DOA. Then, we expand the array based on the estimated DOA by compensating the coupling effect. Simulation results show that the proposed method is effective when jamming to noise power ratio (JNR)is relative low.

Averaging Methods for Enhancing the Performance of DOA Estimation Under the Rotor Effect (로터 영향 하에서의 DOA 추정 성능 개선을 위한 평균화 방법)

  • Yun, Seonhui;Oh, Jongchan;Kim, Jun O;Choi, Sangwook;Ahn, Jae Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1245-1255
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    • 2012
  • There are various anti-jamming algorithms for the GNSS system which is vulnerable to jamming, and the methods using array antenna show the best performance. Among them, the DOA estimation algorithms to identify the location of the jammer is very important. However, in case of the rotorcraft, the wireless channel which amplitude and phase changes with time is generated by the rotation of the rotor and it affects the performance of existing anti-jamming algorithms. In this paper, we modeled the effect of the rotor in four scenarios according to the correlation of antennas and assured that the performance of DOA estimation algorithms are degraded and saturated regardless of JNR due to the rotor effect. When we use the averaging method to solve this problem, the performance is improved as increasing samples for estimating. And in case of using moving average method with averaging, it shows similar performance. In addition, it reduces the required memory and moderates the variation of DOA estimation.

Estimation and Analysis of Two Moving Platform Passive Emitter Location Using T/FDOA and DOA (이동 수신기 환경에서 연속된 T/FDOA와 DOA를 이용한 고정 신호원의 위치 추정 방법)

  • Park, Jin-Oh;Lee, Moon Seok;Park, Young-Mi
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.121-131
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    • 2015
  • Passive emitter localization is preferred to use a small number of receivers as possible for the efficiency of strategic management in the field of modern electronic warfare support. Accurate emitter localization can be expected when utilizing continuous measurable parameters and a appropriate combination of theirs. For this reason, we compare CRLB (Cramer-Rao lower bound) of two moving platform with various measurable parameters to choose a appropriate combination of parameters for a better localization performance. And we propose the passive emitter localization method based on Levenberg-Marquardt algorithm with combined TDOA/FDOA and DOA to achieve better accuracy of emitter localization which is located on the ground and stationary. In addition, we present a method for determining the initial emitter position for LM algorithm's input to avoid the divergence of estimation and local minimum.

DOA Estimation of Multiple Signal and Adaptive Beam-forming for Mobile Communication Environments (이동통신 환경에서 다중신호의 DOA 추정과 적응 빔성형)

  • Yang, Doo-Yeong;Lee, Min-Soo
    • The Journal of the Korea Contents Association
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    • v.10 no.12
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    • pp.34-42
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    • 2010
  • The DOA(direction of arrival), which is based on parametric and nonparametric estimation algorithm, and adaptive beamforming algorithm for mobile communication environments are researched and analyzed. In parametric estimation algorithm, eigenvalues of the signal component and the noise component are obtained from correlation matrix of received signal by array antenna and power spectrum of the received signal is discriminated from them. Otherwise, in nonparametric estimation algorithm, we minimize a regularized objective function for finding a estimate of the signal energy as a function of angle, using nonquadratic norm which leads to supper resolution and noise suppression. And then, DOA is estimated by the signal and noise spatial steering vector, and adaptive beam-forming pattern is improved by weight vectors obtained from the spatial vector. Therefore, the improved directional estimation algorithm with regularizing sparsity constraints offers super-resolution and noise suppression compared to other algorithms.