An Improved Echo Cancellation Algorithm with Low Computational Complexity

2013 ◽  
Vol 303-306 ◽  
pp. 2042-2045
Author(s):  
Ya Ting Wu ◽  
Y.Y. Zhao ◽  
Fei Yu
Keyword(s):  
Return Loss ◽  
Linear Prediction ◽  
Low Complexity ◽  
Echo Cancellation ◽  
Echo Canceller ◽  
Convergence Process ◽  
Speed Up ◽  
Echo Return Loss Enhancement ◽  
Active Detection ◽  
The Voice

A low-complexity echo canceller integrated with vocoder is proposed in this paper to speed up the convergence process. By making full use of the linear prediction parameters retrieved from decoder and the voice active detection feature of the vocoder, the new echo canceller avoids the need to calculate decorrelation filter coefficients and prewhiten the received signal separately. Simulation results show performance improvement of the proposed algorithm in terms of convergence rate and echo return loss enhancement.

Performance enhancement of Echo Cancellation Using a Combination of Partial Update ( PU) Methods and New Variable Length LMS (NVLLMS) Algorithm

2018 ◽  
Vol 24 (5) ◽  
pp. 66
Author(s):  
Thamer M. Jamel ◽  
Faez Fawzi Hammood
Keyword(s):  
Mean Square Error ◽  
Return Loss ◽  
Performance Enhancement ◽  
Variable Length ◽  
Echo Cancellation ◽  
Convergence Time ◽  
Length Variation ◽  
Mean Square ◽  
Step Size ◽  
Echo Return Loss Enhancement

In this paper, several combination algorithms between Partial Update LMS (PU LMS) methods and previously proposed algorithm (New Variable Length LMS (NVLLMS)) have been developed. Then, the new sets of proposed algorithms were applied to an Acoustic Echo Cancellation system (AEC) in order to decrease the filter coefficients, decrease the convergence time, and enhance its performance in terms of Mean Square Error (MSE) and Echo Return Loss Enhancement (ERLE). These proposed algorithms will use the Echo Return Loss Enhancement (ERLE) to control the operation of filter's coefficient length variation. In addition, the time-varying step size is used.The total number of coefficients required was reduced by about 18% , 10% , 6%, and 16% using Periodic, Sequential, Stochastic, and M-max PU NVLLMS algorithms respectively, compared to that used by a full update method which  is very important, especially in the application of mobile communication since the power consumption must be considered. In addition, the average ERLE and average Mean Square Error (MSE) for M-max PU NVLLMS are better than other proposed algorithms.  

scholarly journals Acoustic Echo Cancellation Embedded in Smart Transcoding Algorithm between 3GPP AMR-NB Modes

2010 ◽  
Vol 2010 ◽  
pp. 1-5
Author(s):  
Emmanuel Rossignol Thepie Fapi ◽  
Dominique Pastor ◽  
Christophe Beaugeant ◽  
Hervé Taddei
Keyword(s):  
Mobile Communications ◽  
Linear Prediction ◽  
Voice Quality ◽  
Echo Cancellation ◽  
Acoustic Echo Cancellation ◽  
New Approach ◽  
Acoustic Coupling ◽  
Low Bit Rate ◽  
Acoustic Echo ◽  
Echo Return Loss Enhancement

Acoustic Echo Cancellation (AEC) is a necessary feature for mobile devices when the acoustic coupling between the microphone and the loudspeaker affects the communication quality and intelligibility. When implemented inside the network, decoding is required to access the corrupted signal. The AEC performance is strongly degraded by nonlinearity introduced by speech codecs. The Echo Return Loss Enhancement (ERLE) can be less than 10 dB for low bit rate speech codecs. We propose in this paper a coded domain AEC integrated in a smart transcoding strategy which directly modifies the Code Excited Linear Prediction (CELP) parameters. The proposed system addresses simultaneously problems due to network interoperability and network voice quality enhancement. The ERLE performance of this new approach during transcoding between Adaptive Multirate-NarrowBand (AMR-NB) modes is above 45 dB as required in Global System for Mobile Communications (GSM) specifications.

The Dynamic LMS for Line Echo Cancellation

2013 ◽  
Vol 284-287 ◽  
pp. 2941-2945
Author(s):  
Ning Yun Ku ◽  
Shaw Hwa Hwang ◽  
Shun Chieh Chang ◽  
Cheng Yu Yeh
Keyword(s):  
Impulse Response ◽  
Return Loss ◽  
Experimental Results ◽  
Echo Cancellation ◽  
Mean Square ◽  
Least Mean Square ◽  
Excellent Performance ◽  
Pure Delay ◽  
Echo Return Loss Enhancement ◽  
Computation Load

To the best of our knowledge, this study represents the proposal using the dynamic least mean square (DLMS) algorithm to reduce the computation load of LMS. Moreover, three regions of impulse response of line echo path are also proposed to analyze the redundant coefficients. Using the DLMS method, redundant coefficients can be detected and grouped, thereby automatically reducing computation. We employed line echo cancellation (LEC) to evaluate the performance of DLMS. The pure-delay and overlong regions of impulse response of line echo path are grouped and the associated computation load is reduced. The experimental results confirm the excellent performance of DLMS achieving a 35% savings in computation. Moreover, the quality echo return loss enhancement (ERLE) of DLMS also maintains at a level nearly equal to LMS.

Adaptive Echo Cancellation Combined with Delay Estimation

2013 ◽  
Vol 303-306 ◽  
pp. 2072-2075
Author(s):  
Zhi Ping Zhang ◽  
Xi Hong Wu
Keyword(s):  
Adaptive Filters ◽  
Signal To Noise Ratio ◽  
Low Complexity ◽  
The Other ◽  
Echo Cancellation ◽  
Delay Estimation ◽  
Delay Compensation ◽  
Echo Canceller ◽  
Signal To Noise ◽  
Echo Delay

This paper proposed an echo canceller to reduce the computational complexity of the long delay echo cancellation. Two adaptive filters were used for constructing this echo canceller. One was designed as a delay estimator, which used down-sampled sub-band signals to estimate the echo delay time. The other was designed as a short-tap filter to subtract the echo from the recorded signal with delay compensation. Experimental results showed that the output signal-to-noise ratio from the proposed canceller with low complexity is similar to that from the conventional canceller based on a long-tap filter.

scholarly journals Low-Complexity Network Echo Cancellation Approach for Systems Equipped With External Memory

2011 ◽  
Vol 19 (8) ◽  
pp. 2506-2515 ◽  
Author(s):  
Magnus Berggren ◽  
Markus Borgh ◽  
Christian Schuldt ◽  
Fredric Lindstrom ◽  
Ingvar Claesson
Keyword(s):  
Low Complexity ◽  
Echo Cancellation ◽  
External Memory

A New Echo Cancellation Algorithm without Double-Talk Detection Based on Correlation Function

2011 ◽  
Vol 225-226 ◽  
pp. 996-999
Author(s):  
Li Jun Sun ◽  
Shou Yong Zhang ◽  
Wei Sheng Wang ◽  
Xiao Ning Zhang
Keyword(s):  
Computer Simulation ◽  
Correlation Function ◽  
Adaptive Filter ◽  
Detection Algorithm ◽  
Echo Cancellation ◽  
Acoustic Echo Cancellation ◽  
Error Signal ◽  
Echo Canceller ◽  
Filter Performance ◽  
Simulation Results

In an adaptive echo canceller, the detection algorithm able to distinguish echo path change (EPC) from double-talk (DT) is vital to ensure that adaptive filter tap coefficients are updated in case of EPC and frozen during the DT period. The paper presents a new echo cancel algorithm, which can protect the adaptive filter performance during double-talk in acoustic echo cancellation of teleconference without setting a detector. A judgment value can be directly used in the iteration formula to control the iteration speed of the filter, which composed of the correlation of the far-end signal and near-end received signal, the pre-correlation of the error signal. The computer simulation results verify that the mentioned algorithm has the good double talk protection performance, and it is very useful and efficient in distinguishing EPC from DT but with less computational complexity contrast to the congener algorithm.

Differential Evolution Algorithm with Triangular Adaptive Control Parameter for SHEPWM Switching Pattern Optimization

2017 ◽  
Vol 8 (3) ◽  
pp. 1381
Author(s):  
Ismail Yusuf ◽  
Ayong Hiendro ◽  
F. Trias Pontia Wigyarianto ◽  
Kho Hie Khwee
Keyword(s):  
Adaptive Control ◽  
Differential Evolution ◽  
Control Parameter ◽  
Pulse Width Modulation ◽  
Differential Evolution Algorithm ◽  
De Algorithm ◽  
Harmonic Elimination ◽  
Switching Patterns ◽  
Convergence Process ◽  
Speed Up

Differential evolution (DE) algorithm has been applied as a powerful tool to find optimum switching angles for selective harmonic elimination pulse width modulation (SHEPWM) inverters. However, the DE’s performace is very dependent on its control parameters. Conventional DE generally uses either trial and error mechanism or tuning technique to determine appropriate values of the control paramaters. The disadvantage of this process is that it is very time comsuming. In this paper, an adaptive control parameter is proposed in order to speed up the DE algorithm in optimizing SHEPWM switching angles precisely. The proposed adaptive control parameter is proven to enhance the convergence process of the DE algorithm without requiring initial guesses. The results for both negative and positive modulation index (<em>M</em>) also indicate that the proposed adaptive DE is superior to the conventional DE in generating SHEPWM switching patterns

Low-Complexity Multiplication Using Complement and Signed-Digit Recoding Methods

2014 ◽  
Vol 619 ◽  
pp. 342-346
Author(s):  
Te Jen Chang ◽  
Ping Sheng Huang ◽  
Shan Jen Cheng ◽  
Ching Yin Chen ◽  
I Hui Pan
Keyword(s):  
Computational Complexity ◽  
Low Complexity ◽  
Fast Multiplication ◽  
Speed Up ◽  
Overall Performance ◽  
Representation Method ◽  
Computing Method

In this paper, a fast multiplication computing method utilizing the complement representation method and canonical recoding technique is proposed. By performing complements and canonical recoding technique, the number of partial products can be reduced. Based on these techniques, we propose algorithm provides an efficient multiplication method. On average, our proposed algorithm to reduce the number of k-bit additions from (0.25k+logk/k+2.5) to (k/6 +logk/k+2.5), where k is the bit-length of the multiplicand A and multiplier B. We can therefore efficiently speed up the overall performance of the multiplication. Moreover, if we use the new proposes to compute common-multiplicand multiplication, the computational complexity can be reduced from (0.5 k+2 logk/k+5) to (k/3+2 logk/k+5) k-bit additions.

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