<< Chapter < Page Chapter >> Page >

The outputs of the command are n = filter length - 1 , and the vectors fo , mo , and w which are intermediate filter parameters.

Once the filter length, n , is obtained, the Matlab command for designing a Parks-McClellan filteris b = firpm(n,fo,mo,w) . The inputs n , fo , mo , and w are the corresponding outputs of firpmord , and the output b is a vector of FIR filter coefficients such that

H ( z ) = b ( 1 ) + b ( 2 ) z - 1 + + b ( n + 1 ) z - n

(What is the impulse response of this filter?)

For further information, read the help document on using Matlab to implement the Parks-McClellan algorithm.

Now design a symmetric FIR filter using firpmord and firpm in Matlab to meet the design specifications given in the "Filter Design Using the Kaiser Window" section. Compute the DTFT of the filter's response for at least 512 points,and use this result to compute the passband and stopband ripple of the filter that was designed.Adjust the filter length until the minimum order which meets the design constraints is found.Plot the magnitude of the DTFT in dB of the final filter design.

Inlab report

Do the following:
  1. Submit the final measured values of filter length, passband ripple, and stopband ripple.How accurate was the filter order computation using Matlab's firpmord ? How does the length of this filter compare to the filterdesigned using a Kaiser window?
  2. Submit the plot of the filter's DTFT. How does the frequency response of the Parks-McClellan filtercompare to the filter designed using the Kaiser window? Comment on the shape of both the passband and stopband.

Use the filter you have designed to remove the noise from the signal nspeech2.mat . Play the noisy and filtered speech signals back using sound and listen to them carefully. Compute theDTFT of 400 samples of the filtered signal starting at time n = 20 , 001 (i.e. 20001:20400 ).Plot the magnitude of the DTFT in decibels versus frequency in radians for | ω | < π . Compare this with the spectrum of the noisy speech signal shownin [link] , and also with the magnitude of the DTFT of the Kaiser filtered signal.

Submit the plot of the DTFT magnitude for the filtered signal. Comment on how the audio qualityof the signal changes after filtering. Also comment on any differences in audio quality between the Parks-McClellan filteredspeech and the Kaiser filtered speech.

Design of discrete-time iir filters using numerical optimization

In this section, we consider the design of discrete-time IIR filters through the direct search of filter parametersthat will minimize a specific design criterion. Such “brute force” approaches to filter design have becomeincreasingly more popular due to the wide availability of high speed computers and robust numerical optimization methods.

Typically, numerical approaches to filter design have two parts. First, they design a cost , or error criterion. This criterion is a measure of the difference betweenthe ideal filter response and the response of the computed or “approximate” filter. The goal is to findthe approximate filter with the lowest cost (error). Mean square error isa popular cost criterion. The second part is to minimize the cost with respect to the filter parameters.We will perform the required numerical optimization with the fminsearch function in Matlab's Optimization Toolbox .

Questions & Answers

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
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
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





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?

Ask