1999 Fiscal Year Final Research Report Summary
Design of Adaptive Beam Former Using 2 Dimensional Lattice Filters and Its Performance Verfication
Project/Area Number |
10650377
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
情報通信工学
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Research Institution | Keio University |
Principal Investigator |
HAMADA Nozomu Keio University, Faculty of Science and Engineering, 理工学部, 教授 (80051902)
|
Co-Investigator(Kenkyū-buntansha) |
YAMASHITA Katsumi University of Ryukyus Department of Engineering, 工学部, 教授 (60158152)
|
Project Period (FY) |
1998 – 1999
|
Keywords | Array signal processing / Adaptive Filter / Beam Forming / Direction-of-Arrival Estimation / Circular Array / Equalizer / Adaptive Algorithm / Echo Canceller |
Research Abstract |
(1) A new method of adaptive beam forming which is robust against signal model errors and reduces computational load is established. In order to reduce the affection of the model errors, we deduce both blocking matrix and passing matrix based on the method of eigenvector constrained calibrated Generalized Sidelobe canceller in the time domain. (2) The microphone array system to estimate direction-of-arrival of speaker is proposed. It utilizes harmonic component such as vowel sound. It is effective under a directional noise and sensor noise. (3) A receiver using GMA adaptive array combined with Tapped Delay Line is proposed for frequency selective fading and co-channel interference suppression in DS/CDMA systems. We investigate the convergence behavior of the constrained CMA with three waves model. Based on analytical results, we propose a novel criterion to select a modulus factor of capturing desired signal successfully. (4) An estimation method of direction-of-arrival using Hopfield network with linear array is proposed. The proposed method is robust for sensor error. Additionally, the method is useful to estimate DOA of distributed source. These methods can give proper direction even the low SNR condition. (5) It is proposed that a digital channel equalizer using radial basis function (RBF) network which has identical structure to the optimal Bayesian symbol-detection. A clustering algorithm has been proposed to find the correct center of RBF. The simulation results show its better convergence and less calculation than the conventional algorithm. (6) A new algorithm for tap adaptation to search gradient by input correlation functions is proposed. This algorithm is used for echo cancellation in teleconference systems.
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Research Products
(27 results)