Scilab/C4/Digital-Signal-Processing/English-timed

Time	Narration
00:01	Dear Friends,Welcome to the spoken tutorial on “Signal Processing using Scilab”
00:07	In this tutorial, using Scilab, I will show you how to Generate different kinds of signals , and Perform different operations to analyse signals.
00:19	To record this tutorial, I am using Ubuntu 11.04 as the operating system with Scilab 5.3.3 version
00:30	Before practicing this tutorial, a learner should have a basic knowledge of Scilab.
00:35	To know the basics of Scilab, please refer to the series of basic level of spoken tutorials in Scilab
00:42	which is available on our website www.spoken-tutorial.org
00:45	In this tutorial, I will describe about 3 basic Signals.Plotting continuous and discrete sine wave.Plotting step function. Plotting ramp function.
00:58	Let me start with “Plotting continuous and discrete sine wave”
01:02	Let us switch to the Scilab Console Window.
01:06	Here type: t equal to zero colon zero point one colon two multiplied by precentage pi semicolon.
01:17	Then x equal to sin of t semicolon then plot 2D into bracket t comma xand press Enter key on your keyboard.
01:33	This is a continous sine wave
01:36	Let us discuss the discrete sine wave.
01:39	On the console window type: plot two d3 within bracket invertes comma gnn comma t comma x and press Enter.
01:54	This is discrete sine wave.
01:57	Let us now discuss about Plotting step function and plotting ramp function.
02:04	I have already written the code to generate step and ramp signal in the file called signals.sce.
02:14	Let us open this file signal.sce using scilab editor.Let us execute this code.Click on the “Execute” button in the Menu bar
02:27	Step and Ramp signal is displayed in this plot.
02:32	Now let us learn how to perform different operations to analyse signals.Let us see how to perform Convolution between two signals.
02:43	Let us switch to the Scilab Console window and typex equals to within square bracket one comma two comma three comma four
02:55	Then type h equals to within square bracket one comma one comma one
03:04	Now let us apply the convolution by typing convol opening bracket x comma h closing bracket and press Enter on your keyboard.
03:17	An output can be seen here.
03:20	Now let us learn Discrete fourier transform for a discrete sequence by using the inbuilt command dft().
03:30	On the console window here type x equals to within square bracket one comma two comma three comma four
03:41	ThenType within square bracket xf equals to dft into bracket x comma minus 1Where x is the input vector and flag value is -1 for DFT.
03:59	Let us press Enter
04:01	The output appears as this 10. - 2. + 2.i - 2. - 9.797D-16i - 2. - 2.i
04:05	Now I will show you how to calculate inverse discrete fourier transform. This can be done by using the same inbuilt command dft().
04:15	On the Scilab console window type: squareBracket x equals to dft within bracket xf comma 1Here the flag value is 1 for idft.
04:31	This is the output + 5.551D-17i - 1.225D-16i - 5.551D-16i
04:34	Let us calculate discrete fourier transform using fft()
04:39	On the console window, type x= square [1,2,3,4]x equals to square bracket one comma two comma three comma four
04:49	Press Enter and type y = fft(x,-1) y equals to fft within bracket x comma minus one
04:59	Press Enter and you can see the output as these:-10. - 2. + 2.i - 2. - 2. - 2.i
05:05	Let us now see how to calculate inverse discrete fourier transform by using fft().
05:12	On the Scilab console window type y equals to within square bracket ten comma minus two plus two into percentage i comma minus two comma minus two minus two into percentage i.
05:33	and Press EnterType x fft(y,1) x equals to fft within bracket y comma 1 and Press Enter
05:45	The output will be displayed as x =1. 2. 3. 4.
05:49	Let us now find out the correlation between two vectors.
05:53	To do this on the Scilab console window,
05:56	Type x one equals to within square bracket one comma two comma three comma fourand press Enter
06:08	Type x2 equals to within square braccket one comma three comma one comma five and press Enter
06:20	Type R x one x two equals to corr within bracket x one comma x two comma four and press Enter
06:34	The output will be displayed as Rx1x2=1.25 0.3125 0.25 - 0.9375
06:38	Let us learn how to sample the given signal
06:42	Let me open sampling.sce where I have already written the code in sampling.sce .Here click on the “Execute”button.
06:52	A plot is displayed.
06:56	Let us summarise.
06:58	In this tutorial we have learnt How to Plot sine, step and ramp signal.
07:04	To perform Linear convolution by convol().To perform DFT and IDFT by dft().
07:12	To perform FFT by fft().To find out the Correlation by corr().To do sampling
07:20	Watch the video available atthis URL http://spoken-tutorial.org/What is a Spoken Tutorial
07:23	It summarises the Spoken TutorialprojectIf you do not have goodbandwidth, you can also download and watch it
07:30	The Spoken Tutorial Project Team Conducts workshops using spokentutorials. Gives certificates to those who pass an online test Please contact us contact@spoken-tutorial.org
07:42	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education throughICT, MHRD, Government of India
07:51	This script has been contributed by Manas and this is Sheetal Prabhu signing off. Thank you for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble