OFDM simulation

[M.Nasiriyan]

Hi.
I want to simulate an OFDM system with MATLAB6.5 that shows the
hardware specifications of the practical board. For example a
simulating program can only show the speed of the MATLAB, not of the
real boards such as VIRTEXII.
Is there any solution for this?

 

[Paul Burridge]

Hi.
I want to simulate an OFDM system with MATLAB6.5 that shows the
hardware specifications of the practical board. For example a
simulating program can only show the speed of the MATLAB, not of the
real boards such as VIRTEXII.
Is there any solution for this?

The Official Scrabble Dictionary might be of use.

 

[Winfield Hill]

Paul Burridge wrote...

The Official Scrabble Dictionary might be of use.

Paul, OFDM means Orthogonal Frequency Division Multiplexing.
It's used for digital TV transmission in Europe, Japan and
Australia, for 802.11a RF networks at 5.8GHz, and is being
promoted for ultra-wideband, http://www.multibandofdm.org/
One benefit of ODFM is resistance to multipath problems.

Thanks,
- Win

whill_at_picovolt-dot-com

 

[red rover]

OFDM is also essentially the same as DMT (discrete multi-tone),
the modulation technique used in ADSL modems.

So, are you trying to model an existing board or are you trying
to generate a specification for a board you want developed?

I assume when you say VirtexII you mean a Xilinx part?

If you have all the blocks in Matlab it should be fairly simple
to derive the specs. The main parameters would be the number
of bits used at various stages and the baud rate.

Take standard ADSL, the baud rate is 4058.824 kHz so T= 246uS.

Your specs for the board would have to complete everything
in the pipeline during that time. Partition the data onto the tones,
scramble it, run the appropriate size IFFT (256pt complex), add
a cyclic prefix, interpolation filter, pump it out to a DAC. Reverse
order for the Rx. Every step has to be completed in 246 uS or
less to satisfy the baud rate. The number of bits required at the
various stages should fall out of you simulation plus a some basic
DSP math.

Steve

 

[gwhite]

Hi.
I want to simulate an OFDM system with MATLAB6.5 that shows the
hardware specifications of the practical board. For example a
simulating program can only show the speed of the MATLAB, not of the
real boards such as VIRTEXII.
Is there any solution for this?

IQView is *written* in MATLAB. So it must not be that hard. Anyway, you should
ask in comp.soft-sys.matlab.

http://www.litepoint.net/new/IQviewbrochure.pdf

 

[red rover]

It is still not clear to me what knows the board
specs and wants to simulate them or he is trying to
generate board specs.

As for IQView being written in Matlab I cannot see
that being mentioned anywhere in the document, but
I would assume the Matlab is running on the attached
PC for the graphical interface.

IQView is *written* in MATLAB.
So it must not be that hard.

I wonder if the authors would agree ;-)

I don't see OFDM listed on their modulation schemes
but it is more complex than the schemes listed.
Significantly more for something like standard DSL.

Steve

 

[gwhite]

It is still not clear to me what knows the board
specs and wants to simulate them or he is trying to
generate board specs.

As for IQView being written in Matlab I cannot see
that being mentioned anywhere in the document, but
I would assume the Matlab is running on the attached
PC for the graphical interface.


I wonder if the authors would agree ;-)

It's all relative. There is a reason why they didn't write it in assembly or C.

I don't see OFDM listed on their modulation schemes
but it is more complex than the schemes listed.

We have a Litepoint box. IQview is written in MATLAB.

 

[red rover]

I'm still interested in more details as
to what the OP was trying to accomplish.

From the block diagram I would assume that
the laptop has a 802.11 modem in its pcmcia
slot and the IQView box has an general purpose
modem in it that can receive/transmit 802.11.
Then it sends some pre-processed data to the same
laptop via a lan port. Is that the way it works?

I would assume the laptop is running Matlab
in order to display the information (the GUI).

Or is Matlab running in the box? Or both?

Steve