Public-address system has been widely used in many applications to amplify speech and music signals. In such environments, an acoustic feedback from a loudspeaker to a microphone usually exists and it may causes howling which explosively increases a certain frequency amplitude. The howling is a persistent and an annoying problem in many acoustic enviroments. To solve this problem, we have previ...

In this paper, a new multi-path adaptive interpolated FIR (AIFIR)-based echo canceller is presented to perform the echo cancellation in full-duplex digital transmission over digital subscriber loop (DSL). This new approach inherits the concept of conventional AIFIR-based echo canceller, where the long tail portion is modeled by an adaptive sparse FIR filter. We then propose a multi-path structu...

This paper describes a new technique for implementing an echo canceller for full-duplex data transmission (such as in digital subscriber loops and voiceband data sets). The canceller can operate in spite of time-invariant nonlinearities in the echo channel or in the implementation of the echo canceller itself (such as in the D/A converters). The basic structure of the linear echo canceller is n...

In this article, we propose a new weak maneuvering target detection method in sea environment with Radon-fractional Fourier transform (RFrFT) canceller, which can efficiently suppress the clutter and detect targets low computations. To accomplish suppression, design canceller based on RFrFT process, utilizes different representations of clutter. A nonuniform searching strategy interval fraction...

In this paper, as a key technology for improvement of speech recognition system in car environments, we propose an acoustic echo canceller for selecting an optimum cancellation result based on the echo estimation with maximum likelihood using transfer characteristics measured prospectively. The results of experiments conducted to speech superimposed on music show that the proposed canceller can...

This paper presents a microphone array technique aimed at enhancing speech quality in a reverberant environment. This technique is based on the central idea of single-input-multiple-output equivalent source inverse filtering (SIMO-ESIF). The inverse filters required by the time-domain processing in the technique serve two purposes: de-reverberation and noise reduction. The proposed approach cou...

Abstract This paper presents a study on the side-lobe level (SLL) reduction with transmission type metasurface (MTS) using concept of non-uniform array technique and transmit antenna. According to antenna technique, SLL can be controlled by controlling amplitude phase distribution simultaneously. Initially, is used design MTS. The radiation characteristics MTS are analyzed exciting rectangular ...

In this paper the Discrete Frequency Coded Waveforms (DFCWs) with good correlation properties are numerically designed utilizing Accelerated Particle Swarm Optimization Algorithm for MIMO Radar. To achieve this object the cost function was intended based on Peak Side lobe level Ratio (PSLR) and Integrated Side lobe Level Ratio (ISLR). The simulation results show that the DFCWs signal utilized i...

BACKGROUND In the ultrasound B-mode (Brightness-mode) imaging, high side-lobe level reduces contrast to noise ratio (CNR). A linear apodization scheme by using the window function can suppress the side-lobe level while the main-lobe width is increased resulting in degraded lateral resolution. In order to reduce the side-lobe level without sacrificing the main-lobe width, a non-linear apodizatio...