On the FIR Inversion of an Acoustical Convolutive Mixing System: Properties and Limitations
نویسنده
چکیده
In this paper we address the problem of Least-Squares (LS) optimal FIR inverse-filtering of an convolutive mixing system, given by a set of acoustic impulse responses (AIRs). The optimal filter is given by the LS-solution of a block-Toeplitz matrix equation, or equivalently by the time-domain Multi-Channel Wiener Filter. A condition for the minimum FIR filter length can be derived, depending on the number of sensors and sources and the AIR length, such that an exact FIR inverse exists, which perfectly separates and deconvolves all sources. In the general case, where an exact FIR solution does not exist, we discuss how SDR, SIR and SNR gains can be traded against each other. Results are shown for a set of AIRs, measured in an typical office room. Furthermore we present a method, which allows a time-domain shaping of the envelope of the global transfer function, reducing pre-echoes and reverberation.
منابع مشابه
Optimal linear separation and deconvolution of acoustical convolutive mixtures
This thesis addresses the problem of the optimal inversion of a linear acoustical convolutive mixing process by means of multichannel linear filtering. In most real-world acoustical scenarios, a number of sound emitting sources are encountered, which may be simultaneously active. When perceiving the sound of these sources by direct listening or from microphone recordings, the original undistort...
متن کاملAn iterative inversion approach to blind source separation
In this paper we present an iterative inversion (II) approach to blind source separation (BSS). It consists of a quasi-Newton method for the resolution of an estimating equation obtained from the implicit inversion of a robust estimate of the mixing system. The resulting learning rule includes several existing algorithms for BSS as particular cases giving them a novel and unified interpretation...
متن کاملAn extended ACDC algorithm for the blind estimation of convolutive mixing systems
This paper presents an extension of the ACDC algorithm introduced by Yeredor for the instantaneous mixing problem to the more general convolutive mixing problem with non-white sources. Further assumptions made on the source signals are their mutual statistical independence, nonstationarity and smoothness of their power spectra. The algorithm iterates the estimation of the mixing system (AC step...
متن کاملUnderdetermined blind separation of sparse sources with instantaneous and convolutive mixtures
We consider the underdetermined blind source separation problem with linear instantaneous and convolutive mixtures when the input signals are sparse, or have been rendered sparse. In the underdetermined case the problem requires solving three subproblems: detecting the number of sources, estimating the mixing matrix, and finding an adequate inversion strategy to obtain the sources. This paper s...
متن کاملBlind signal separation for convolutive mixing environments using spatial-temporal processing
In this paper we extend the infomax technique [1] for blind signal separation from the instantaneous mixing case to the convolutive mixing case. Separation in the convolutive case requires an unmixing system which uses present and past values of the observation vector, when the mixing system is causal. Thus, in developing an infomax process, both temporal and spatial dependence of the observati...
متن کامل