Hello Experts,
I am brand new to USRP.
I have connected analog signal generator's sine wave output (999.999 MHz, -30dBm) to the USRP2 (ant #2.).
A Rb 10 MHz freq. standard provides reference signal to the signal generator as well as to the USRP2.
I have set the carrier frequency of the radio at 1GHz.
I am trying to see the output of rx_stream. I expected a 1kHz sine wave signal, but I just get a flat line. I have no idea how to fix or debug this program.
Here are the values I have set:
//setup the program options
po::options_description desc("Allowed options");
("args", po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
("type", po::value<std::string>(&type)->default_value("short"), "sample type: double, float, or short")
("nsamps", po::value<size_t>(&total_num_samps)->default_value(0), "total number of samples to receive")
("duration", po::value<double>(&total_time)->default_value(0), "total number of seconds to receive")
("spb", po::value<size_t>(&spb)->default_value(10000), "samples per buffer")
("rate", po::value<double>(&rate)->default_value(10e6), "rate of incoming samples")
("freq", po::value<double>(&freq)->default_value(1e9), "RF center frequency in Hz")
("gain", po::value<double>(&gain), "gain for the RF chain")
("ant", po::value<std::string>(&ant)->default_value("RX2"), "antenna selection")
("subdev", po::value<std::string>(&subdev), "subdevice specification")
("bw", po::value<double>(&bw), "analog frontend filter bandwidth in Hz")
("ref", po::value<std::string>(&ref)->default_value("external"), "reference source (internal, external, mimo)")
("wirefmt", po::value<std::string>(&wirefmt)->default_value("sc16"), "wire format (sc8 or sc16)
("setup", po::value<double>(&setup_time)->default_value(1.0), "seconds of setup time")
("progress", "periodically display short-term bandwidth")
("stats", "show average bandwidth on exit")
("sizemap", "track packet size and display breakdown on exit")
("null", "run without writing to file")
("continue", "don't abort on a bad packet")
("skip-lo", "skip checking LO lock status")
("int-n", "tune USRP with integer-N tuning")
;When I set reference source to "internal", I *do* get a desired output, a nice looking sine wave.
What should I be doing to get a sine wave while using an external ref.?
Any pointers would be highly appreciated.
Thank you.
