System overrun after short time

GNU Radio
1

Hi Lists,

I wrote a program in C + + use gnuradio library to demodulate some
signals. The
program works well with the low data rate signal (below 20
Ksymbols/s). With higher
data rate signal: 200 Ksymbols/s, the program works well for a few
minutes
then the console window will appear the letters ‘O’ continuously and
data
after demodulation was wrong. With 1 Msymbols/s signal, the system can
operate well over 1 minute.

Could you help me to solve the problem, please?

Thank you.

Best regards,

Phong.

2

On 07/23/2012 03:08 AM, Luong Tan P. wrote:

Could you help me to solve the problem, please?

It sounds like you found the tripping point where the rate of data
flowing into the buffers exceeds the rate of data being removed.

http://files.ettus.com/uhd_docs/manual/html/general.html#overflow-underflow-notes

I admit, that is a rather low rate. Perhaps you have a filter with an
unexpectedly large number of taps? Or you max consider benchmarking the
performance of your demodulator code, or try to isolate which processing
block is slow, etc

-josh