Hi~ I found some strange problem setting USRP transmitting signal power. The method I change the transmit power is to use a constant to multiply the signals. the problem is that I use bigger constant like 2.0, the SNR value i calculate is lower than using constant like 1.0. the transmit signal values are 0.005,-0.005. my experiment platform is USRP N210 plus motherboard RFX2400. Is there anything wrong or there are better method to setting USRP transmiting power? thanks!!! -- View this message in context: http://gnuradio.4.n7.nabble.com/Problem-setting-US... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2013-02-25 04:38
on 2013-02-25 15:48
On Sun, Feb 24, 2013 at 10:36 PM, warren4300137 <firstname.lastname@example.org> wrote: > thanks!!! The USRPs take in normalized signals, so you want to scale your signals to +/-1 at most. If you want increased power, adjust the gain of the USRP itself. The reason you're seeing a bad signal as you increase the amplitude is that you are causing nonlinearities in the hardware from a signal that's too large. So even though the USRP will take in a +1 signal, you'll want to back off some to keep the signal in the linear range of the transmitter. Tom