Adaptive filter application in echo cancellation system and implementation using FPGA
In telephony system, the received signal by the loudspeaker, is reverberated through the environment and picked up by the microphone. It is called an echo signal. Which is in the form of time delayed and attenuated image of original speech signal, and causes a reduction in the quality of the communi...
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Published in | al-Rafidain Engineering Journal : Regional Referred Scientific Journal. Vol. 16; no. 5 |
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Main Author | |
Format | Journal Article |
Language | Arabic English |
Published |
Mosul, Iraq
University of Mosul, College of Engineering
2008
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Subjects | |
Online Access | Get full text |
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Summary: | In telephony system, the received signal by the loudspeaker, is
reverberated through the environment and picked up by the microphone. It is
called an echo signal. Which is in the form of time delayed and attenuated
image of original speech signal, and causes a reduction in the quality of the
communication. Adaptive filters are a class of filters that iteratively alter their
parameters in order to minimize a difference between a desired output and their
output. In the case of acoustic echo, the optimal output is an echoed signal that
accurately emulates the unwanted echo signal. This is then used to negate the
echo in the return signal. The better the adaptive filter simulates this echo, the
more successful the cancellation will be. This paper examines LMS algorithm of
adaptive filtering and the application in acoustic echo cancellation system.
Employing a discrete signal processing in Matlab for simulation with real
acoustic signals. Also a hardware implementation of an adaptive filter have been
developed using XC3S500E Xilinx FPGA chip, and VHDL language on RTL
abstraction level.
إن الإشارات المستلمة في نظام الهاتف يعاد التقاطها كإشارات صدى و هذا يؤثر على جودة الاتصال. لذا استخدمت المرشحات المتكيفة و التي تعتبر أساس نظام إلغاء الصدى لقابليتها على محاكاة إشارة الصدى المتولدة في البيئة المحيطة و إلغائها. في هذا البحث تم محاكاة المرشح المتكيف و الذي يعمل بخوارزمية LMS و محاكاة نظام إلغاء الصدى المعتمد على المرشح المتكيف في البيئة البرمجية Matlab باستخدام إشارات حقيقية. ثم تم تنفيذ البنية المادية للمرشح المتكيف باستخدام شريحة البوابات المبرمجة حقليا FPGA نوع XC3S500E Xilinx باستخدام لغة وصف الكيان المادي VHDL، و على مستوى التصميمي RTL. |
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ISSN: | 1813-0526 2220-1729 |