115 research outputs found
Study of L0-norm constraint normalized subband adaptive filtering algorithm
Limited by fixed step-size and sparsity penalty factor, the conventional
sparsity-aware normalized subband adaptive filtering (NSAF) type algorithms
suffer from trade-off requirements of high filtering accurateness and quicker
convergence behavior. To deal with this problem, this paper proposes variable
step-size L0-norm constraint NSAF algorithms (VSS-L0-NSAFs) for sparse system
identification. We first analyze mean-square-deviation (MSD) statistics
behavior of the L0-NSAF algorithm innovatively in according to a novel
recursion form and arrive at corresponding expressions for the cases that
background noise variance is available and unavailable, where correlation
degree of system input is indicated by scaling parameter r. Based on
derivations, we develop an effective variable step-size scheme through
minimizing the upper bounds of the MSD under some reasonable assumptions and
lemma. To realize performance improvement, an effective reset strategy is
incorporated into presented algorithms to tackle with non-stationary
situations. Finally, numerical simulations corroborate that the proposed
algorithms achieve better performance in terms of estimation accurateness and
tracking capability in comparison with existing related algorithms in sparse
system identification and adaptive echo cancellation circumstances.Comment: 15 pages,15 figure
multi-band acoustic echo canceller
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 68-69).by Mingxi Fan.S.B.and M.Eng
Residual echo signal in critically sampled subband acoustic echo cancellers based on IIR and FIR filter banks
Published versio
On the spectral factor ambiguity of FIR energy compaction filter banks
This paper focuses on the design of signal-adapted finite-impulse response (FIR) paraunitary (PU) filter banks optimized for energy compaction (EC). The design of such filter banks has been shown in the literature to consist of the design of an optimal FIR compaction filter followed by an appropriate Karhunen-Loe/spl grave/ve transform (KLT). Despite this elegant construction, EC optimal filter banks have been shown to perform worse than common nonadapted filter banks for coding gain, contrary to intuition. Here, it is shown that this phenomenon is most likely due to the nonuniqueness of the compaction filter in terms of its spectral factors. This nonuniqueness results in a finite set of EC optimal filter banks. By choosing the spectral factor yielding the largest coding gain, it is shown that the resulting filter bank behaves more and more like the infinite-order principal components filter bank (PCFB) in terms of numerous objectives such as coding gain, multiresolution, noise reduction with zeroth-order Wiener filters in the subbands, and power minimization for discrete multitone (DMT)-type nonredundant transmultiplexers
Robust Total Least Mean M-Estimate normalized subband filter Adaptive Algorithm for impulse noises and noisy inputs
When the input signal is correlated input signals, and the input and output
signal is contaminated by Gaussian noise, the total least squares normalized
subband adaptive filter (TLS-NSAF) algorithm shows good performance. However,
when it is disturbed by impulse noise, the TLS-NSAF algorithm shows the rapidly
deteriorating convergence performance. To solve this problem, this paper
proposed the robust total minimum mean M-estimator normalized subband filter
(TLMM-NSAF) algorithm. In addition, this paper also conducts a detailed
theoretical performance analysis of the TLMM-NSAF algorithm and obtains the
stable step size range and theoretical steady-state mean squared deviation
(MSD) of the algorithm. To further improve the performance of the algorithm, we
also propose a new variable step size (VSS) method of the algorithm. Finally,
the robustness of our proposed algorithm and the consistency of theoretical and
simulated values are verified by computer simulations of system identification
and echo cancellation under different noise models
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