• Title/Summary/Keyword: Adaptive Array Algorithm

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A Study on Applying the ${\mu}$-LMS Algorithm to the Adaptive Antenna Systems (${\mu}$-LMS 알고리즘의 적응 안테나 시스템에의 응용에 관한 연구)

  • Shin, Yoon-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.2
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    • pp.170-177
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    • 1986
  • The adaptive array antenna with the LMS algorithm has the advantage in that it can perform train't because of its slower convergencerate. In this paper, the \ulcornerLMS algorithm is applied to the adaptive array so that the convergence rate can be improved, and the performance of he adaptive array by the \ulcornerLMS algorithm is compared to, that of the LMS adaptive array. It is shown that the adaptive array by the \ulcornerLMS algorithm is superior to the LMS adaptive array in the narrow frequency band.

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Performance Analysis of Spatial Adaptive Null Pattern Control Algorithm for 5 Elements Array Antenna (5소자 배열안테나의 공간 적응 널패턴 제어 알고리즘 성능분석)

  • Ahn, Seung-Gwan;Lee, Sang-Jeong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.2
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    • pp.313-319
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    • 2010
  • GNSS receiver which uses the weak satellite signal is very vulnerable to the intentional jamming or non-intentional electromagnetic interference. One of the best method to overcome this disadvantage is to use an adaptive array antenna which has the capability of beamforming or nulling to the certain direction. In this paper, the performance of spatial adaptive null pattern control algorithm of 5 element array antenna is analyzed. A control algorithm which is designed in the 5 element array antenna is OPM(Output Power Minimization) which is eliminating the correlation characteristics between a reference antenna and the others. This algorithm can be applied effectively to the satellite navigation's CRPA because the satellite direction is not considered and GNSS signal power is below the thermal noise. The feature of the OPM algorithm is analyzed and the performance is compared with other null pattern control algorithm.

General Linearly Constrained Broadband Adaptive Arrays in the Eigenvector Space

  • Chang, Byong Kun
    • Journal of information and communication convergence engineering
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    • v.15 no.2
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    • pp.73-78
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    • 2017
  • A general linearly constrained broadband adaptive array is examined in the eigenvector space with respect to the optimal weight vector and the adaptive algorithm. The optimal weight vector and the general adaptive algorithm in the eigenvector space are obtained by eigenvector matrix transformation. Their operations are shown to be the same as in the standard coordinate system except for the relevant transformed vectors and matrices. The nulling performance of the general linearly constrained broadband adaptive array depends on the gain factor such that the constraint plane is shifted perpendicularly to the origin by an increase in the gain factor. The general linearly constrained broadband adaptive array is observed to perform better than a conventional linearly constrained adaptive array in a coherent signal environment, while the former performs similarly to the latter in a non-coherent signal environment.

Design of an adaptive tracking algorithm for a phased array radar (위상배열 레이다를 위한 적응 추적 알고리즘의 설계)

  • Son, Keon;Hong, Sun-Mog
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.541-547
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    • 1992
  • The phased array antenna has the ability to perform adaptive sampling by directing the radar beam without inertia in any direction. The adaptive sampling capability of the phased array antenna allows each sampling time interval to be varied for each target, depending on the acceleration of each target at any time. In this paper we design a three-dimensional adaptive tracking algorithm for the phased array radar system with a given set of measurement parameters. The tracking algorithm avoids taking unnecessarily frequent samples, while keeping the angular prediction error within a fraction of antenna beamwidth so that the probability of detection will not be degraded during a track update illuminations. In our algorithm, the target model and the sampling rate are selected depending on the target range and the target maneuver status which is determined by a maneuver detector. A detailed simulation is conducted to test the validity of our tracking algorithm for encounter geometries under various conditions of maneuver.

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Adaptive Nulling Algorithm for Null Synthesis on the Moving Jammer Environment (이동형 재밍환경에서 널 합성을 위한 적응형 널링 알고리즘)

  • Seo, Jongwoo;Park, Dongchul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.8
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    • pp.676-683
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    • 2016
  • In this paper, an adaptive nulling algorithm which can be used to form nulls in the direction of jammer or interference signals in array antennas of single port system is proposed. The proposed adaptive algorithm does not require a priori knowledge of the incoming signal direction and can be applied to the partially adaptive arrays. This algorithm is the combination of the PSO(Particle Swam Optimization) algorithm and the gradient-based perturbation adaptive algorithm, which shows stable nulling performance adaptively even on the moving jammer environment where the incident direction of the interference signal is changing with time.

Array Resolution Improving Methods for Beamforming Algorithm (빔형성방법에서의 분해능 향상 기법에 관한 연구)

  • Hwang, Seon-Gil;Rhee, Wook;Choi, Jong-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.164-169
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    • 2005
  • Microphone array techniques are being used widely in wind tunnel measurements for identification of the distributed aerodynamic noise sources on the model being tested. Depending on the frequencies and sound levels, conventional beamforming algorithm has limitation in separating two adjacent sources. Several modifications to the classical beamforming have been developed to enhance way resolution and reduce sidelobe levels. In this Paper the robust adaptive beamforming and the CLEAN algorithm are used to compare to the result of conventional beamforming method. It is found that the CLEAN algorithm is capable of pin-pointing locations of multiple sources nearby, while these sources are unidentifiable with robust adaptive or conventional beamforming techniques.

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Study on Pattern Synthesis of Conformal Array Antenna Using Enhanced Adaptive Genetic Algorithm (향상된 적응형 유전 알고리즘을 이용한 컨포멀 배열 안테나의 빔 합성 연구)

  • Seong, Cheol-Min;Lee, Jae-Duk;Han, In-Hee;Ryu, Hong-Kyun;Lee, Kyu-Song;Park, Dong-Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.5
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    • pp.592-600
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    • 2014
  • This paper proposes an enhanced adaptive genetic algorithm(EAGA) dedicated to pattern synthesis of array antenna which conforms to a curved surface of rotation with quadratic function. EAGA combines adaptive genetic algorithm(AGA) with invasive weed optimization(IWO) for the faster convergence and the lower cost value of the cost function. The amplitude and phase of each excited weighting factor are optimized to meet the required goals using EAGA. The EAGA results indicate that the proposed algorithm is superior to AGA when applied to the problem of conformal array antenna pattern synthesis.

A Study on the Target Position Estimation Algorithm to Radar System (레이더 시스템에서 목표물 위치추정 알고리즘에 대한 연구)

  • Lee, Kwan-Houng;Song, Woo-Young
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.5
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    • pp.111-116
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    • 2008
  • Radar system must estimate exactly quickness and target in interference channel. Because interference of radio channel is multipath channel by artificial structure and nature structure. signal estimation is difficult. As long as, get rid of interference signal have been study digital beamforming, adaptive array antenna and so on. In this paper, proposed SPT-SALCMV beamforming algorithm get rid of coherent interference algorithm and adaptive array antenna. Adaptive array forms null pattern and reduces gains for direction of interference signal. And estimate signal that want by keeping gains of beam pattern changelessly to target signal direction. In this paper, proposed SPT-SALCMV algorithm was exactly received position of target. But general SPT-LCMV algorithm resulted beam error about 30degrees. Therefore, proved that SPT-SALCMV algerian that propose in this paper is more excellent than genaral SPT-LCMV algorithm.

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Performance Analysis of AGC Applebaum Array for Multiple Narrowband Interference (다중의 협대역 간섭 신호에 대한 AGC Applebaum어레이의 성능 분석)

  • 윤동현;이규만;한동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6B
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    • pp.1092-1099
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    • 2000
  • An adaptive array system can effectively remove all received interferences by using adaptive algorithms even though the received signal condition is not known. The conventional adaptive array systems, however, cannot remove all interferences adaptively and converge very slowly when the eigenvalue spread of the input covariance matrix is large. In the paper, a new adaptive array system called an automatic gain controller (AGC) Applebaum array and its control algorithm are proposed to overcome the performance degradation of conventional Applebaum array in multiple interference conditions. The performance analysis of the proposed AGC Applebaum array is described under the condition of multiple narrowband interferences. Simulation results show the array output signal-to-noise ratio (SNR) of the AGC Applebaum array increases by 30dB compared to that of the conventional Applebaum array in the simulation condition. The gain of the AGC Applebaum array in the incident direction of a weaker interference is also shown to be lower than that of the conventional Applebaum array.

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Design of a 3-D Adaptive Sampling Rate Tracking Algorithm for a Phased Array Radar (위상배열 레이다를 위한 3차원 적응 표본화 빈도 추적 알고리듬의 설계)

  • Son, Keon;Hong, Sun-Mog
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.5
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    • pp.62-72
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    • 1993
  • The phased array antenna has the ability to perform adaptive sampling by directing the radar beam without inertia in any direction. The adaptive sampling capability of the phased array antenna allows each sampling time interval to be varied for each target, depending on the acceleration of each target at any time. In this paper we design a three dimensional adaptive target tracking algorithm for the phased array radar system with a given set of measurement parameters. The tracking algorithm avoids taking unnecessarily frequent samples, while keeping the angular prediction error within a fraction of antenna beamwidth so that the probability of detection will not be degraded during a track updata illuminations. In our algorithm, the target model and the sampling rate are selected depending on the target range and the target maneuver status which is determined by a maneuver level detector. A detailed simulation is conducted to test the validity of our tracking algorithm for target trajectories under various conditions of maneuver.

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