Hybrid LMS–LMF algorithm for adaptive echo cancellation (original) (raw)
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A hybrid LMS-LMF scheme for echo cancellation
1997 IEEE International Conference on Acoustics, Speech, and Signal Processing
The coecients of an echo canceller with a nearend section and a far-end section are usually updated with the same updating scheme, such as the LMS algorithm. In this paper we propose a novel scheme for echo cancellation that is based on the minimization of two dierent cost functions, i.e., one for the near-end section and a dierent one for the far-end section. Two approaches are addressed and only one of them lead to a substantial improvement in performance over the LMS algorithm when it is applied to both sections of the echo canceller. The proposed scheme is also shown to be robust to noise variations, which is not the case for the LMS algorithm.
Adaptive Echo Canceller Using a Modified LMS Algorithm
2005 2nd International Conference on Electrical and Electronics Engineering, 2005
In this paper, an echo canceller is presented, using an adaptive filter with a modified LMS (Least Mean Square) algorithm, where this modification is achieved coding error on conventional LMS algorithm. Simulation results, show a better convergence speed than conventional LMS algorithm, furthermore, Coded Error algorithm presents less complexity for digital adaptive filters design, due to reduction of floating point operations.
Performance comparison of adaptive algorithms applied to acoustic echo cancelling
2003 IEEE International Symposium on Industrial Electronics ( Cat. No.03TH8692), 2003
In this paper, the convergence behaviors of fulliiand and sub-band LMS algorithms are compared for the acoustic echo canceling application. Post-filtering techniques for the reduction of the residual echo and noise are also described. Experimental results with measured speech signals are presented. hidex Ternshands-free telephony, adaptive filtering, filter banks, acoustic echo cancellation, noise reduction. ' This work was partially supported by CNF'q/UFRJ, Brazil.
Computationally-Efficient DNLMS-Based Adaptive Algorithms for Echo Cancellation Application
Journal of Communications, 2006
This paper investigates the application of the delayed normalized least mean square (DNLMS) algorithm to echo cancellation. In order to reduce the amount of computations, DNLMS is modified by using computationallyefficient techniques including the M-Max algorithm, a Stopand-go (SAG) algorithm, and Power-of-two (POT) quantization. For the SAG algorithm, a new stopping criterion related to the regressor energy is presented. Cumulatively, these modifications lead to reductions in power and/or area. Simulation results and comparisons with the normalized least mean square (NLMS) algorithm are included to show the advantages of the computationally-efficient algorithms.
Adaptive echo cancellation using least mean mixed-norm algorithm
IEEE Transactions on Signal Processing, 1997
A novel algorithm for echo cancellation is presented in this work. The algorithm consists of simultaneously applying the least mean square (LMS) algorithm to the near-end section of the echo canceller and the least mean fourth (LMF) algorithm to the far-end section. This new scheme results in a substantial performance improvement over the LMS algorithm and other algorithms.
The Conventional acoustic echo canceller encounters problems like slow convergence rate (especially for speech signal) and high computational complexity as the identification of the echo path requires filter with more than a thousand taps, non-stationary speech input, slowly timevarying systems to be identified. The demand for fast convergence and less MSE level cannot be met by conventional adaptive filtering algorithms. There is a need to be computationally efficient and rapidly converging algorithm.
Echo cancelling using adaptive algorithms
2009 15th International Symposium for Design and Technology of Electronics Packages (SIITME), 2009
In the paper, an echo canceller based on a system identification scheme with adaptive algorithms is presented. The algorithms consider FIR filters with the taps chosen to minimize an error signal derived from the system according to a stochastic gradient-based method. The following adaptive filters are discussed and simulated in Matlab: classical LMS and its variants: NLMS, VSLMS, VSNLMS and RLS. The echo was simulated by adding several delayed and attenuated replica to a vocal input. The comparison between the algorithms was made taking into account the mean-square error (MSE) and average attenuation (AV), as well as the required number of multiplications.
The problem of acoustic echo is well defined in case of hands-free communication.The presence of large acoustic coupling between the loudspeaker and microphone would produce an echo that causes a reduction in the quality of the communication.The solution to this problem is the elimination of the echo with an echo canceller which increases the speech quality and improves listening experience. In this paper, many prominent work done in relation to acoustic echo cancellation (AEC) is discussed and analysed. The existing AEC algorithms are analysed and compared based on their merits and demerits in a time varying echoed environment. It covers the basic algorithms like least mean square (LMS) , normalized least mean square (NLMS) and recursive least square algorithm as well as their modified versions like variable step size NLMS, fractional LMS, Filtered-x LMS, variable tap-length LMS algorithm, multiple sub-filter (MSF) based algorithms, variable tap-length MSF structures etc. Finally, a judicious comparison is presented towards the end of the paper in order to judge the best AEC algorithm in the present time.
IJERT-A Review of Adaptive Algorithms for Acoustic Echo Cancellation
International Journal of Engineering Research and Technology (IJERT), 2018
https://www.ijert.org/a-review-of-adaptive-algorithms-for-acoustic-echo-cancellation https://www.ijert.org/research/a-review-of-adaptive-algorithms-for-acoustic-echo-cancellation-IJERTCONV6IS13037.pdf Acoustic echo is the major issue involved in telecommunication system, which is actually a delayed and distorted version of sound reflected back to the source. Cancellation of echoes involves the use of acoustic echo cancellers. Echo cancellation is done by using adaptive filters by making use of adaptive filter algorithms. In this review paper, we have studied and discussed few of the previous work done on these algorithms in relation to acoustic echo cancellation. This paper contains the basic review of all such existing algorithms of the acoustic echo cancellation like LMS, LLMS, NLMS, RLS, AAF, and APA. Finally, comparison of above algorithm is given in order to conclude the discussion.