BER and OFDM

Hello guys,

I’m getting some problems to use the error rate on a ofdm system, i used
the
example ofdm_loopback as base and add the error rate and number sink but
there’s not any response, it doesn’t bring me any error but the results
are
clearly wrong…

There’s a picture of the circuit

Sorry about the bad English, not my main language

http://gnuradio.4.n7.nabble.com/file/n47428/ofdm2.png


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On 04/07/2014 06:09 PM, MegaDuzera wrote:

Hello guys,

I’m getting some problems to use the error rate on a ofdm system, i used the
example ofdm_loopback as base and add the error rate and number sink but
there’s not any response, it doesn’t bring me any error but the results are
clearly wrong…

MegaDuzera,

what exactly is wrong? Also, you could try the new OFDM blocks (OFDM
Transmitter / Receiver).

Martin

Dear user,
I think this is not the way to implement OFDM simulation. It requires
multiply const block before channel model. You may get variation in BER
value when you use USRP boards. I will execute the same flow-graph and
let
me inform you results in soon.


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On 04/09/2014 05:43 AM, bsivakumar wrote:

Dear user,
I think this is not the way to implement OFDM simulation. It requires
multiply const block before channel model. You may get variation in BER
value when you use USRP boards. I will execute the same flow-graph and let
me inform you results in soon.

Not in this case: I assume the EbN0 drives the SNR of the channel model.
A noise voltage above 2 will definitely cause dropped packets.

M

On 04/08/2014 02:43 PM, MegaDuzera wrote:

I already tried the new blocks…

The BER results are wrong, it gives me a value of “0.00000 Units” always

With an Eb/N0 of 30 dB, that’s what I’d expect. For other cases, I don’t
think your setup works, because of the packet-based nature of the OFDM
transceiver (what happens if the demod doesn’t find a packet?).

Martin

Hi,
Some time ago I also tested this ofdm_loopback file and i figure out
that
is good to use additional noise source (simulate the channel but also
add
AWGN).
I don’t know if this is a proper way of simulating OFDM Tx/Rx but it can
be
some hint.

Best regards,
Piotr Potocki

2014-04-09 9:52 GMT+02:00 Martin B. [email protected]:

I already tried the new blocks…

The BER results are wrong, it gives me a value of “0.00000 Units” always


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