04-23-2018 09:13 AM
Hello
i am trying to make 2x2 MIMO OFDM system using two USRP 2922 as transmitter and one USRP 2943.
when i run my program for transmitter for IQ Rate 500k, its running smoothly but when i change the IQ rate for 20M, occured error like this picture.
what should i do to fix this error because i need my program to rum with bandwidth up to 20MHz so i need IQ rate 20M?
thank you
04-24-2018 09:17 AM
Hey chandra.ha,
Your rate equals bandwidth*1.25, so you should specify an IQ rate of 25MS/s to achieve your 20MHz bandwidth.
Underflow means the USRP hardware is attempting to transmit samples that haven;t been written to its buffer from software yet. There could be a couple reasons for this. Another forum post discusses a few approaches you can take to address the underflow.
-Will
05-01-2018 11:32 PM
thank you for your reply
But i still don't know waht should i do to fix underflow error
i have tried changing
1.this ** HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\AFD\Parameters\, I don't see any "FastSendDatagramThreshold". but its still error underflow
2. change write rate by increase my data but i got this error
3. i don't know how to set samples write
if you have solution please share