• Title/Summary/Keyword: 적응빔형성 알고리즘

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A Feedback and Noise Cancellation Algorithm of Hearing Aids Using Adaptive Beamforming Method (적응 빔형성기법을 이용한 보청기의 궤환 및 잡음제거 알고리즘)

  • Lee, Haeng-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1C
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    • pp.96-102
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    • 2010
  • This paper proposes a new adaptive algorithm to cancel the acoustic feedback and noise signals in the digital hearing aids. The proposed algorithm improves its convergence performances by canceling the speech signal from the residual signal using two microphones. The feedback canceller firstly cancels the feedback signal among the mic signal, and then it is reduced the noise using the beamforming method. To verify the performances of the proposed algorithm, the simulations were carried out for some cases. As the results of simulations, it was proved that the feedback canceller and the noise canceller advance about 14.43 dB for SFR, 10.19 dB for SNR respectively during speech, in the case of using the new algorithm.

Multichannel Adaptive IIR Beamforming Algorithm of Output Error Method (출력오차방법의 다채널 IIR 적응 빔 형성 알고리즘)

  • 김달수;박의열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.4
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    • pp.530-536
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    • 1993
  • In adaptive antenna, recently Gooch suggested a new adaptive system using equation error method, but the system demands inverse model about the pole part and thus does not guarantee stability. In this paper, algorithm is proposed that has a basis on Popov's extra-stability theory. And system is developed of output error method. In addition, the result obtained by applying proposed algorithm to system of output error method is compared with that of Gooch model.

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A Study on Adaptive Pattern Null Synthesis for Active Phased Array Antenna (능동위상배열안테나의 적응형 패턴 널 형성에 관한 연구)

  • Jung, Jin-Woo;Park, Sung-Il
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.3
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    • pp.407-416
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    • 2021
  • An active phased array antennas can not only electrically steer the beam by controlling the weighting of the excitation signal, but can also form a pattern null in the direction of the interference source. The weight of the excitation signal to steer the main beam can be easily calculated based on the position of the radiating element. In addition, the weight of the excited signal for pattern null formation can also be calculated by setting the required radiation pattern and using WLSM(Weighted Least Squares Method). However, in a general wireless communication network environment, the location of the interference source is unknown. Therefore, an adaptive pattern null synthesis is needed. In this paper, it was confirmed that pattern null synthesis according to the required radiation characteristic was possible. And based on this, adaptive pattern null synthesis into the direction of an interference source was studied using a binary search algorithm based on observation area. As a result of conducting a simulation based on the presented technique, it was confirmed that adaptive pattern null forming into the direction of an interference is possible in efficient way.

An Adaptive Microphone Array with Linear Phase Response (선형 위상 특성을 갖는 적응 마이크로폰 어레이)

  • Kang, Hong-Gu;Youn, Dae-Hui;Cha, Il-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.11 no.3
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    • pp.53-60
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    • 1992
  • Many adaptive beamforming methods have been studied for interference cancellation and speech signal enhancement in telephone conference and auditorium. Main aspect of adaptive beamforming methods for speech signal processing is different from radar, sonar and seismic signal processing because desire output signal should be apt to the human ear. Considering that phase of speech is quite insensible to the human ear, Sondhi proposed a nonlinear constrained optimization technique whose constraint was on the magnitude transfer function from the source to the output. In real environment the phase response of the speech signal affects the human auditorium system. So it is desirable to design linear phase system. In this paper, linear phase beamformer is proposed and sample processing algorithm is also proposed for real time consideration Simulation results show that the proposed algorithm yields more consistent beam patterns and deep nulls to the noise direction than Sondhi's.

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Adaptive Beamforming System Based on Combined Array Antenna (혼합 배열 안테나 기반의 적응 빔형성 시스템)

  • Kim, Tae-Yun;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.9-18
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    • 2021
  • The 5G communication system employs the millimeter wave with the extremely high frequency. Since the high frequency signal has the strong straightness, the beamforming technology based on the multiple base stations is required for services covering wide range. The beamformer needs the angle-of-arrival(AOA) information of the signal incident to the antenna, and it is generally estimated through the high resolution AOA estimation algorithm such as Multiple Signal Classification (MUSIC) or Estimation of Signal Parameters via Rotational Invariacne Technique (ESPRIT). Although various antenna array shapes can be employed for the beamformer, a single shape (square, circle, or hexagonal) is typically utilized. In this paper, we introduce a transmitting/receiving beamforming system based on the combined array antenna with square and circular shapes, which is proper to various frequency signals, and evaluate its performance. For evaluating the performance of the proposed beamforming system based on the combined array antenna, we implement the computer simulation employing various scenarios.

A New Multi-Beam MVDR Technique for Removing Interference Signals in Array Antenna Based GPS Receivers (GPS 수신기에서 간섭신호 제거를 위한 배열 안테나 기반 다중 빔 MVDR 기법)

  • Jeong, Eui-Rim;Won, Hyun-Hee;Yang, Gi-Jung;Ahn, Byoung-Sun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.3
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    • pp.491-498
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    • 2017
  • GPS (global positioning system) is a popular system that provides location information by measuring arrival time difference at the receiver between several GPS satellite signals. GPS is widely used in commercial area as well as military systems. Reliable GPS signal reception is more important in the military applications such as guided missiles. However, since the carrier frequencies of the GPS signals are well known and the received power is extremely low, the GPS systems are vulnerable to intentional jamming attacks. To remove jammers while maintaining GPS signals at the received signals, a popular technique is an adaptive beam steering method based on array antenna. Among adaptive beam steering techniques, this paper considers MVDR (minimum variance distortionless response) algorithm, and proposes a new adaptive technique that preserves the received signals at desired directions, but removes the unknown jamming signals adaptively. The performance of the proposed method is verified through computer simulation.

Analysis of Adaptive Side-Lobe Canceller Algorithm for Fully Digital Active Array Radar (완전 디지털 능동배열 레이다의 적응형 부엽제거 알고리즘에 관한 연구)

  • Yang, Woo-Yong;Park, Min-Kyu;Hong, Sung-Won;Kim, Chan-Hong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.5
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    • pp.375-382
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    • 2018
  • To eliminate strong jamming signals, a radar acquires a relatively weak target signal by using a side-lobe canceller (SLC) algorithm. This paper presents a novel adaptive SLC algorithm that is applicable to a fully digital active array radar. First, a covariance matrix is obtained from the SLC beam. Then, an adaptive SLC coefficient is extracted after calculating the correlation matrix between the main beam signal and the SLC beam signal. Finally, the target signal is estimated and the jamming signal is removed through the operation with the main beam signal. The application results from simulated radar signals demonstrated that the proposed algorithm is effective in an SLC system. Moreover, we analyzed various considerations and improved systematic usability.

A Study on the Beam Steering Error Modification method to Adaptive Array System (적응배열 시스템에서 빔 지향 오차 수정기법에 대한 연구)

  • Lee, Myung-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.4
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    • pp.39-44
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    • 2008
  • Wireless channel exists interference by multipath a component. Adaptation array antenna that remove this interference a component forms null point about interference signal and maximizes gains about target signal. If target signal and correlative coherent interference signal are received, there is problem that is removed from arrangement output to target signal. And, adaptation array antenna is shortcoming that is sensitive in directivity error. Therefore, in this paper, introduce each existing algorithm to solve directivity error about coherent interference, and proposed beam forming technique that minimize degree of freedom loss and damage because analyzes the problem and reduces coherent interference and directivity error.

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A Study on the Incident Angle Estimation Method of Target at Coherent Interference (상관성 간섭에서 표적의 입사각 추정 방법에 대한 연구)

  • Shin, Ho-Sub
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.5
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    • pp.75-81
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    • 2010
  • Adaptive array antenna system estimates target signal, as making a null pattern toward the interference signal. However, receiving a coherent interference signal at adaptive array antenna system, as target signal is regarded as interference signal, the performance of system rapidly decreases. The main beam does not direct an incidence direction of target signal due to sensitivity in directivity error. This paper proposes beamforming algorithm which combines high order limit condition and directivity error modify method. And it minimizes degree of freedom and decreases interference signal and directivity error using proposed algorithm. This paper compares and analyzes the performance of proposed algorithm and general algorithm using simulation. In this paper, the proposed algorithm correctly estimates an incident angle, but general algorithm occurs an error of about $0.8^{\circ}$.

Optimal Directivity Synthesis of Ultrasonic Transducers Using a Combined Algorithm (조합 알고리즘에 의한 초음파 트랜스듀서의 최적 지향성합성)

  • ;Takao Tsuchiya;Yukio Kagawa
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.1
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    • pp.25-31
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    • 2000
  • In this paper, we proposed an algorithm that used a direct method to set an initial value of Broydon-Fletcher-Goldfarb-Shanno(BFGS) method and, accordingly, conducted an experiment in optimal directivity synthesis of adaptive ultrasonic transducer by point source array. To certify the efficiency of this method, quasi-ideal beam with arbitrary beam width, rotating beam, and multi beam, all with the limited side lobe level -30dB, were chosen to check the problem of directivity synthesis that was formed by point source array in the second dimensional sound field. The numerical calculation results showed that the proposed method performed the directivity synthesis faster than the BFGS method did. In addition, the proposed method showed a good error correction for directivity synthesis, and did not demand the choice of initial value. Finally, it is also shown that the proposed method can be used for the adaptive control that was not possible with the direct method alone.

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