Need Help for OFDM upsamplin and Downsampling

Need Help for OFDM upsamplin and Downsampling
Dear AOa;

Need your HELP i am using raspberry Pi As OFDM modulator and Demodulator. I have made a model. It is working fine when it is in Baseband as i am Upsampling it by factor of 20 and Downsampling it by a factor of 20.then at receiver i am receiving errors upto BER 0.5. in simulink model. kindly help.

I am generating data using Bernoulli generator with following Specs.
a.sample time= 1/1800
b.Sample per frame=48

I am using PAM for modulation

Using 64 carrier in IFFT
48 Data symbol
15 Gaurd carrier
1 DC carrier

Then I am Upsampling it by factor of 2 and then 10 total 20 and using FIR filter for Interpolation

at Reciever

I am Downsampling it by a factor of 2 10 and then 2 and using FIR filter for decimation

.But at receiveing error.

I have tried to introduce a delay but it is not working using Delay block

It is a bit hard to follow your description. You need to explain the error that you see. Are you looking at the FFT in the receiver?

I would take a look at the frequency domain in the different stages and first check that you get the carriers at all to the base band in the receiver.

Notice also that in OFDM you might have different delays in different carriers and one single delay block might not suffice.

Dear;

i am check BER between transmitted bits before symbol modulation and Received bit after symbol demodulation.

if i am not upsampling/Downsampling my Baseband OFDM signal i am recieving all bits correctly no errors.
but if i am Upsamling/downsampling and using FIR filters then i am receiving ber OF 0.5 HALF BIT GETS CORUPPTED.
IF I AM JUST UPSAMPLING/downsampling without filter no errors.
if i am using Idel filter after upsamling no erros

So the issues are your filters... I would inspect the signals in each stage and see what's corrupting them. Are you sure the filters themselves are correctly implemented?