hallo list, i'd like to setup an OFDM System using 2 USRP2. while this i getting two Questions. ( currently there is no external 10MHz generator connected. however, hope it will be working)
1. To achieve my goal,first i want to compensate the freq.offset and figure out (with usrp2_fft.py) a ~40kHz difference. Now i want to set this in my GRC workspace but it is not working.Using the GRC USRP2 wrapper and modified the LO Offset option with 40e3 and generate, i can't see any response. Does "set_lo_offset" work, i'm sure? What is the problem? 2. Second, to figure out the offset i transmit a simple 1k sinus with amp 0.8, decimation 200 and TX/RX Gain 0. On RX Side i see a main peak(~-44dB) with freq.offset and some additional small peaks(~-68dB) while noise is ~98dB. reducing the sinus amp to 0.1, only the main peak with ~-60dB exist. When i raise the RX Gain(amp=0.1) the same effect occurs by around 15dB, peak is ~-51dB. Is this a normal behavior or is something wrong with my Daugherboard/USRP2 amplifiers. My Setup: 2xUSRP2(hw=0x0400) with RFX2400 , Gnuradio is latest from tom branch dig_ofdm thanks for any hints lars -- View this message in context: http://old.nabble.com/USPR2-set-freq.Offset-tp33399521p33399521.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
