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Select View ->Library Browser ->Signal Processing Blockset ->Filtering->Adaptive Filters.

Highlight “Adaptive Filters”. Drag-and-drop the “LMS Filter” block onto the model.

Adding an LMS Filter Block

Setting the lms filter parameters

The most critical variable in an LMS filter is the “Step size (mu)”.

If “mu” is too small, the filter has very fine resolution, but reacts too slowly to the audio signal.

If “mu” is too great, the filter reacts very quickly, but the error also remains large.

We will start with 0.005.

Setting the Parameter “Set size (mu)”

Adding a delay

From the “Signal Processing Blockset”, highlight “Signal Operations”. Drag-and-drop the “Delay” Since we are working with frames, the delay from “Discrete Components” library will not work! block onto the model.

Adding a Delay

Setting the delay parameters

Because we are working with frames of 64 samples, it is convenient configure the delay using frames. Double-click on the “Delay” block.

Change the “Delay units” to Frames.

Set the “Delay (frames)” to 1. This makes the delay 64 samples.

Setting the Delay Size

Adding a dip switch and led

So we can hear the difference without LMS denoising and with LMS noise reduction, we will use a DIP switch of the DSK6713.

Adding a Switch and LED

Select View ->Library Browser ->Embedded Target for TI C6000 DSP. Highlight “DSK6713 Board Support”.

Drag-and-drop the “Switch” block onto the model. Also drag-and-drop the “LED” block onto the model.

Dip switch settings

The DIP switch needs to be configured. Double-click on the “Switch” block.

Select all the boxes and set “Data type” to Integer. The “Sample time” should also be set to “–1”.

Setting up the DIP Switch Values

Adding a constant, switch and relational operator

We now need to setup a way to switch between straight through without noise reduction and with LMS noise reduction.

Select View ->Library Browser ->Simulink. Highlight “Commonly Used Blocks”.

Drag-and-drop a “Constant” onto the model.

Drag-and-drop a “Switch” block onto the model.

Drag-and-drop a “Relational Operator” block onto the model.

Selecting the Commonly Used Blocks

Setting the constant value

The switch values lie between 0 and 15. We will use switch values 0 and 1. Double-click on the “Constant” block. Set the “Constant value” to 1 and the “Sample time” to “inf”.

Setting the Echo Delay Gain

Setting the constant data type

Click on the “Signal Data Types” tab. Set the “Output data type mode” to “int16”. This is compatible with the DAC on the DSK6713.

Data Type Conversion to 16-bit Integer

Setting the relational operator type

Double click on the “Relational Operator” block. Change the “Relational operator” to “==”. Click on the “Signal Data Types” tab.

Changing the Relational Operator

Setting the relational operator data type

Set the “Output data type mode” to “Boolean”. Click on “OK”.

Changing the Output Data Type

Joining the blocks

Move the blocks and join them as shown in the Figure below.

Joining the Blocks

Returning to the parent system

From the Toolbar, select the “Up Arrow” icon. This returns you to the next higher level.

Returning to the Parent System

Building the model

Selecting real-time workshop

Select Tools ->Real-Time Workshop ->Build Model.

Building the Model

Frames displayed on model

When built, the single lines are replaced by double lines. This shows frames.


The completed model running on code composer studio

From the folders on the left, select the source code for the project.

The Completed Model Running in Code Composer Studio

Different settings on the dsk6713

Microphone straight through to loudspeakers

To check out the microphone and loudspeakers, set the DIP switches on the DSK6713 as follows:

Switch Position 0

The microphone is fed directly to the loudspeakers. There is no LMS noise reduction.

Switch position for lms noise reduction

To run the “LMS Noise Reduction” subsystem, set the DIP switch to 1.

Switch Position 1 for LMS Noise Reduction

Some things to try

You may wish to experiment with different settings. Here are some suggestions.

Experiment with lms filter settings

Change the value of “Step size (mu)” between 0.0001 and 0.5. This is the critical value.

Low values of mu give good resolution, but a slow reaction time.

High values of mu give less resolution, but faster reaction times.

Find the best value of mu for noise reduction on the TI DSK6713.

Configuring the LMS Filter Block Parameter

Experiment with lms filter settings

Try different value of “Filter Length”. What is the minimum value that will allow the filter to work correctly?

Change from lms filter to rls filter

Inside the “Adaptive Filters” are different LMS types. Which are suitable for LMS denoising and which are not?

Available Adaptive Filter Types

Figure 40 –

MATLAB and Simulink are registered trademarks of The MathWorks, Inc. See www.mathworks.com/trademarks for a list of additional trademarks. Other product or brand names may be trademarks or registered trademarks of their respective holders.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
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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
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what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
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for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
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what is biological synthesis of nanoparticles
Sanket Reply
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