printf("Setting USRP RX gain to %f\n",openair0_cfg[0].rx_gain[0]-openair0_cfg[0].rx_gain_offset[0]);
printf("Setting USRP RX gain to %f (rx_gain %f,gain_range.stop() %f)\n",openair0_cfg[0].rx_gain[0]-openair0_cfg[0].rx_gain_offset[0],openair0_cfg[0].rx_gain[0],gain_range.stop());