Inlämning av Examensarbete / Submission of Thesis

Mamun Ahmed , pp. 52. ING/School of Engineering, 2012.

The work

Författare / Author: Mamun Ahmed
Mamun, Ahmed/mamuncse99cuet@yahoo.com
Titel / Title: Adaptive Sub band GSC Beam forming using Linear Microphone-Array for Noise Reduction/Speech Enhancement.
Översatt titel / Translated title: Adaptive Sub band GSC Beam forming using Linear Microphone-Array for Noise Reduction/Speech Enhancement.
Abstrakt Abstract:

This project presents the description, design and the implementation of a 4-channel microphone array that is an adaptive sub-band generalized side lobe canceller (GSC) beam former uses for video conferencing, hands-free telephony etc, in a noisy environment for speech enhancement as well as noise suppression. The side lobe canceller evaluated with both Least Mean Square (LMS) and Normalized Least Mean Square (NLMS) adaptation.

A testing structure is presented; which involves a linear 4-microphone array connected to collect the data. Tests were done using one target signal source and one noise source. In each microphone’s, data were collected via fractional time delay filtering then it is divided into sub-bands and applied GSC to each of the subsequent sub-bands. The overall Signal to Noise Ratio (SNR) improvement is determined from the main signal and noise input and output powers, with signal-only and noise-only as the input to the GSC. The NLMS algorithm significantly improves the speech quality with noise suppression levels up to 13 dB while LMS algorithm is giving up to 10 dB.

All of the processing for this thesis is implemented on a computer using MATLAB and validated by considering different SNR measure under various types of blocking matrix, different step sizes, different noise locations and variable SNR with noise.

Ämnesord / Subject: Signalbehandling - Signal Processing
Telekommunikation - Telecommunications
Datavetenskap - Computer Science\Networks and Communications
Nyckelord / Keywords: Generalized Side lobe Canceller (GSC), Blocking matrix, Microphone array, Sub band, SNR.

Publication info

Dokument id / Document id: houn-8sksvl
Program:/ Programme Magisterprogram i Elektroteknik / Master of Science in Electrical Engineering
Registreringsdatum / Date of registration: 03/20/2012
Uppsatstyp / Type of thesis: Masterarbete/Master's Thesis (120 credits)

Context

Handledare / Supervisor: Dr. Nedelko Grbic
nedelko.grbic@bth.se
Examinator / Examiner: Dr. Benny Sällberg
Organisation / Organisation: Blekinge Institute of Technology
Institution / School: ING/School of Engineering

+46 455 38 50 00
I samarbete med / In co-operation with: +46 455 38 50 00
Anmärkningar / Comments:

Mamun Ahmed
E-mail: mamuncse99cuet@yahoo.com

Files & Access

Bifogad uppsats fil(er) / Files attached: bth2012ahmed.pdf (1260 kB, öppnas i nytt fönster)