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An overview of DSP optimization techniques, from the design stage, through high-level implementations, to assembly implementations.

Introduction to code optimization

Most practical DSP applications have a clock-cycle and/or memory budget. Initial implementations typically don't meet these budgets;therefore, the code must be optimized. Code development usually follows six steps:

  • Develop algorithm on paper
  • Simulate in MATLAB
  • Develop and simulate more efficient implementations
  • Implement algorithm in C
  • Use library routines when available
  • Use optimizing compiler
  • Manually write assembly routines for key routines

Develop algorithm on paper

The algorithm to be implemented should first be designed on paper. In addition to equations describing the algorithm, its design shouldinclude inputs and outputs of each routine and a flow chart of the operation of the complete program. Never design an algorithm or a program at a computer. While it may be possible to implement some basic algorithms and programs this way, compilers cannot overcome any designflaws that are likely to be introduced.

Simulate in matlab

Before any C code is written, the algorithm should be developed and simulated in MATLAB since problems with the algorithm design can befound more easily. This is done by applying the algorithm to test vectors and inspecting and/or plotting the results. Once thealgorithm is completely defined, C implementation can begin. Recall that in each of the previous labs a MATLAB simulation step was givenbefore assembly implementation.

Develop and simulate more efficient implementations

An efficient algorithm used as few multiplications and additions as possible. Applying DSP theory to "simplify" the algorithm is a commonway of doing this. The autocorrelation function is a simple example: a simple-minded way of implementing this is tocompute sums for each lag, but careful inspection of the autocorrelation function reveals that it is actually a function of the absolute value of the lag. Therefore each value at a negative lag is identical to the value at the correspondingpositive lag. Approximately half the apparent multiplications and additions aretherefore required. If the entire autocorrelation sequence is needed, the autocorrelation can be optimized even furtherif it is treated as a convolution of two sequences. An FFT and an inverse FFT can then be used to compute the autocorrelation.

C implementation

After the algorithm has been designed and optimized, an initial implentation in C is done. Tips on writing code with efficiency inmind can be found here . It is important, however, to get a working implementation ofthe algorithm in a reasonable amount of time as some optimizations cannot be anticipated by the programmer.Some of these coding techniques in the URL reference can be applied later on when it is clear which routines need the most optimization.This implementation can serve as a reference implementation to compare the correctness and speed of optimized versions.

Questions & Answers

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 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
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Digital signal processing laboratory (ece 420 55x). OpenStax CNX. Jan 18, 2010 Download for free at http://cnx.org/content/col10397/1.10
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