My gnuradio flow graph has a custom block taking input from multiple
USRP’s and the output of the block is connected to a USRP transmitter.
applications demands a sample rate of at least 5Msps and up to 10Msps.
Inside the block around 500 (depends on the sample rate) complex samples
from each of the USRP is stored in a buffer and processed.Without the
transmitter connected, the flow graph runs smoothly and there is no
overflow message in the grc. But with the transmitter USRP, I see a lot
underruns in the grc and the spectrum in signal analyzer shows
discontinuity.Is there a way to overcome the underrun issue within the
- Also, GRC produces the following warning,
gr_buffer::allocate_buffer: warning: tried to allocate
16 items of size 4000. Due to alignment requirements
128 were allocated. If this isn’t OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
Is this warning something of a concern?
National University of Singapore