Masayuki Kawamata

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This paper proposes a new method for online secondary path modeling in active noise control systems. The existing methods for active noise control systems with online secondary path modeling consist of three adaptive filters. The main feature of the proposed method is that it uses only two adaptive filters. In the proposed method, the modified-FxLMS(More)
This paper proposes a new method for online secondary path modeling in active noise control (ANC) systems. The proposed method is a modified version of the basic method, proposed by Eriksson et. al. The objective is to realize improved performance at a reasonable computational cost. In the proposed method, the control filter is adapted by using same error(More)
In active noise control (ANC) systems, the online secondary path modeling (OSPM) methods that use additive random noise are often applied. The additive random noise, however, contributes to the residual noise, and thus deteriorates the noise control performance of ANC systems. This paper proposes a new OSPMmethod with power scheduling of additive random(More)
This paper proposes an improved performance cross-updating active noise system with online secondarypath modeling. The existing cross-updating active noise control system comprises three adaptive filters; a noise-control filter, a secondary-path modeling filter, and an adaptive-noisecancelation filter; where FxLMS algorithm is used in adaptation of the(More)
This paper proposes a two-channel adaptive microphone array with target tracking to reduce external noise in hands-free speech communications. The proposed microphone array has two processings, one of which is beamforming and the other is target tracking. The Frequency Domain Generalized Sidelobe Canceller (FDGSC), which is the frequency domain adaptive(More)
In this paper, we propose a novel bicubic method for digital image interpolation. Since the conventional bicubic method does not consider image local features, the interpolated images obtained by the conventional bicubic method often have a blurring problem. In this paper, the proposed bicubic method adopts both the local asymmetry features and the local(More)
This paper proposes a novel approach to L2sensitivity minimization problem of state-space digital filters subject to L2-scaling constraints. The proposed approach reduces the constrained optimization problem to an unconstrained optimization problem by appropriate variable transformation. As a result, iterative algorithms for the L2-sensitivity minimization(More)
The presence of strong acoustic feedback degrades the convergence speed of the active noise control (ANC) filter, and in the worst case the ANC system may become unstable. A fixed feedback neutralization filter, obtained offline, can be used to neutralize the acoustic feedback. The feedback path, however, may be time varying, and we may need continual(More)
This letter proposes a method for active noise control (ANC) systems with online acoustic feedback neutralization. The proposed method is a modified version of authors’ previous work, and the objective here is to reduce the computational complexity. This is achieved by combining the role of feedback path modeling and neutralization filters. The computer(More)
This paper proposes a simple method of realization of center-frequency adaptive filters for high-accuracy detection of band-pass signals immersed in a broadband signal. Our method extends the conventional method proposed by Kumar and Pal. While the conventional center-frequency adaptive filters were mathematically difficult to describe in the case of high(More)