OFDM transmitter receiver

GNU Radio
1

Hi
I used the ofdm transmitter receiver blocks to create a simple system as
shown in the attachment. I used the system parameters as those used in
the example transmitter and receiver grcs. Now I get error that
‘Detected a packet larger than max frame size (80 symbols)’. I would
like to know how the max frame size is set and should I add more
information to the grc.

My transmitter- receiver parameters

fft length= 64
cyclic prefix = 16
packet length = 96
no. of occupied carriers = 48
no. of pilot carriers = 4

2

What’s your kernel.shmmax value? (run sysctl kernel.shmmax)

M

3

Try and not kill the context in a mailing list thread; these are also
archived and are used by others for referral.

Max frame size depends on max_output_buffer(). 80 symbols at a 64-sized
FFT would be ~40kB… that doesn’t seem unreasonable. Not sure if
there’s a problem here. I suggest you have a look at the buffer sizes to
track down this problem.

M