sine wave in matlab
TRANSCRIPT
Sine Wave in Matlab
t = [ 0 : 1 : 40 ]; % Time Samplesf = 500; % Input Signal Frequencyfs = 8000; % Sampling Frequencyx = sin(2*pi*f/fs*t); % Generate Sine Wave figure(1);stem(t,x,'r'); % View the samplesfigure(2);stem(t*1/fs*1000,x,'r'); % View the sampleshold on;plot(t*1/fs*1000,x); % Plot Sine Wave
Fourier Transform
% FFT LengthfftLength = 1024; % Signal LengthsigLength = length(x); % Rectangular Windowwin = rectwin(sigLength)'; % Find the DFTy = fft(x.*win,fftLength); % Figure LengthfigLength = fftLength/2 + 1; % Plot the Magnitude Response in Linear Scaleplot([1:figLength]*fs/(2*figLength),abs(y(1:figLength)));
% Plot the Magnitude Response in Log Scaleplot([1:figLength]*fs/(2*figLength),20*log10(abs(y(1:figLength))));
Different Types of Windows
Length = 200;% Rectangular Window win = rectwin(Length); wRect = [zeros(200,1); win;zeros(200,1)];
Different Types of Windows
Length = 200;% Hamming Window win = hamming(Length); wRect = [zeros(200,1); win;zeros(200,1)];
Windowing Effects – Rectangular Window
Windowing Effects – Hamming Window
Frequency Resolution
Rectangular Window
Hamming Window
Short Term Fourier Transform
Two sinusoids at 500 Hz and 750 Hz. One present from 0 – 125 ms and the second one from 125250 ms.
Short Term Fourier Transform
Full signal Fourier Transform does not give time information.
Short Term Fourier Transform
Narrow Band Spectrogram STFT with long analysis windows
Short Term Fourier Transform
Wide Band Spectrogram STFT with short analysis windows
Speech Signals
Male Speech – phoneme /a/
Speech Signals
Male Speech – phoneme /a/
Speech Signals
Female Speech – phoneme /a/
Speech Signals
Female Speech – phoneme /a/
Speech Signals
Child Speech – phoneme /a/
Speech Signals
Child Speech – phoneme /a/
Speech Signals
Male Speech – word beat
Speech Signals
Male Speech – word beat
Speech Signals
Male Speech – word beat