# 0.1 Lab 1 - discrete and continuous-time signals  (Page 4/5)

 Page 4 / 5

## Processing of speech signals

For this section download the speech.au file. For instructions on how to load and play audio signals click here .

Digital signal processing is widely used in speech processing for applications ranging from speech compression and transmission,to speech recognition and speaker identification. This exercise will introduce the process of reading and manipulatinga speech signal.

First download the speech audio file speech.au , and then do the following:

1. Use the auread command to load the file speech.au into Matlab.
2. Plot the signal on the screen as if it were a continuous-time signal (i.e. use the plot command).
3. Play the signal via the digital-to-analog converter in your workstation with the Matlab sound function.
Submit your plot of the speech signal.

## Attributes of continuous-time signals

For this section download the signal1.p function.

In this section you will practice writing .m-files to calculate the basic attributes of continuous-time signals.Download the function signal1.p . This is a pre-parsed pseudo-code file (P-file), which isa “pre-compiled” form of the Matlab function signal1.m . To evaluate this function,simply type y = signal1(t) where t is a vector containing values of time.Note that this Matlab function is valid for any real-valued time, t , so y = signal1(t) yields samples of a continuous-time function.

First plot the function using the plot command. Experiment with different values for the sampling periodand the starting and ending times, and choose values that yield an accurate representation of the signal.Be sure to show the corresponding times in your plot using a command similar to plot(t,y) .

Next write individual Matlab functions to compute the minimum, maximum, and approximate energy of this particular signal.Each of these functions should just accept an input vector of times, t , and should call signal1(t) within the body of the function. You may use the built-in Matlab functions min and max . Again, you will need to experiment with the sampling period,and the starting and ending times so that your computations of the min, max, and energy are accurate.

Remember the definition of the energy is

$\text{energy}={\int }_{-\infty }^{\infty }{\left|\text{signal1},\left(,t,\right)\right|}^{2}dt\phantom{\rule{4pt}{0ex}}.$
Submit a plot of the function, and the computed values of the min, max, and energy.Explain your choice of the sampling period, and the starting and ending times.Also, submit the code for your energy function.

## Special functions

Plot the following two continuous-time functions over the specified intervals. Write separate script files if you prefer.Use the subplot command to put both plots in a single figure, and be sure to label the time axes.

• $\text{sinc}\left(t\right)$ for $t$ in $\left[-10\pi ,10\pi \right]$
• $\text{rect}\left(t\right)$ for $t$ in $\left[-2,2\right]$
The function rect(t) may be computed in Matlab by using a Boolean expression.For example, if t=-10:0.1:10 , then $y=rect\text{(}t\text{)}$ may be computed using the Matlab command y=(abs(t)<=0.5) .

Write an .m-script file to stem the following discrete-time function for $a=0.8$ , $a=1.0$ and $a=1.5$ . Use the subplot command to put all three plots in a single figure.Issue the command orient('tall') just prior to printing to prevent crowding of the subplots.

#### Questions & Answers

how can chip be made from sand
Eke Reply
is this allso about nanoscale material
Almas
are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where is the latest information on a no technology how can I find it
William
currently
William
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

### Read also:

#### Get Jobilize Job Search Mobile App in your pocket Now!

Source:  OpenStax, Purdue digital signal processing labs (ece 438). OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col10593/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Purdue digital signal processing labs (ece 438)' conversation and receive update notifications?

 By OpenStax By Stephen Voron By Madison Christian By Donyea Sweets By Sarah Warren By David Corey By Brooke Delaney By OpenStax By Brooke Delaney By OpenStax