In this paper, echo cancellation is done using genetic algorithm (GA). The genetic algorithm is implemented by two kinds of crossovers; heuristic and microbial. A new procedure is proposed to estimate the coefficients of adaptive filters used in echo cancellation with combination of the GA with Least-Mean-Square (LMS) method. The results are compared for various values of LMS step size and diff...

Echo in the telephone network is a well-known phenomenon -long delays and noticeable echo may create significant or even unbearable disturbance in a telephone conversation. Echo cancellation is a technique to reduce the echo to an acceptable level. In fact, network echo canceller is considered as the single most critical element impacting overall voice quality in typical communication networks....

Echo is the time delayed version of the original signal. Acoustic echo results from a feedback path set up between the speaker and the microphone in a mobile phone, hands-free phone .Echo can degrade the quality of service in telecommunication. Therefore echo cancellation is an important part of communication systems. A new approach based on the number of coefficients in an adaptive finite impu...

With the advent of packetized audio transmission, such as voice over IP (VoIP), and Voice over WLAN (VoWLAN), echo cancellation has put forth many challenging requirements. When an adaptive filter echo cancellation algorithm is used, its performance can be greatly increased, and its complexity can be reduced if it is only applied to the active regions in which echo exists. The proposed scheme e...

The term Acoustic Echo Cancellation (AEC) refers to a process of removing echo from the received signal that contains one or more delayed signals (copies of the original signal). The primary step while cancelling an echo is to identify the transmitted signal which reappears with some delay. Once the echo is identified it is cancelled by subtracting from transmitted signal. Echo cancellation can...

In the field of acoustic echo cancellation, it is well known that the amount of cancellation attainable in real-world systems is limited. Euphemistically this limitation has been referred to in the acoustic echo cancellation community as the “20 dB rule” [1]. This rule reflects the observation that, typically, one can obtain only about 20 to 30 dB of acoustic echo cancellation in actual physica...

In this paper a generalized postfilter algorithm design issues are presented. This postfilter is used to jointly suppress late reverberation, residual echo, and background noise. When residual echo and noise are suppressed, the best result obtains by suppressing both interferences together after the Acoustic echo cancellation (AEC). The main advantage of this approach is that the residual echo ...

An urianibiguous definition of space is necessary before a n j attenipt niade to develop product or process niodels for concurrent engineering in the AEC Industry. The ambiguit;\, is the resur‘t of cliffererit and even conflicting approach to its definition in the various phases o f the buildirig life cjcle for direrent stukeholders, e.g. Architects, Eiigitieers, arid Brtii‘ditig Services Eiigi...

In this paper, joint structures for audio coding and echo cancellation are investigated, utilizing standard audio coders. Two types of audio coders are considered, coders based on cosine modulated filterbanks and coders based on the modified discrete cosine transform (MDCT). For the first coder type, two methods for combining such a coder with a subband echo canceler are proposed. The two metho...