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//
// Copyright 2010 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
#include "usrp_cal_utils.hpp"
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/utils/paths.hpp>
#include <uhd/utils/algorithm.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <boost/program_options.hpp>
#include <boost/format.hpp>
#include <boost/thread/thread.hpp>
#include <boost/math/special_functions/round.hpp>
#include <iostream>
#include <complex>
#include <cmath>
#include <ctime>
namespace po = boost::program_options;
/***********************************************************************
* Transmit thread
**********************************************************************/
static void tx_thread(uhd::usrp::multi_usrp::sptr usrp, const double tx_wave_ampl){
uhd::set_thread_priority_safe();
//create a transmit streamer
uhd::stream_args_t stream_args("fc32"); //complex floats
uhd::tx_streamer::sptr tx_stream = usrp->get_tx_stream(stream_args);
//setup variables and allocate buffer
uhd::tx_metadata_t md;
md.has_time_spec = false;
std::vector<samp_type> buff(tx_stream->get_max_num_samps()*10);
//fill buff and send until interrupted
while (not boost::this_thread::interruption_requested()){
for (size_t i = 0; i < buff.size(); i++){
buff[i] = float(tx_wave_ampl);
}
tx_stream->send(&buff.front(), buff.size(), md);
}
//send a mini EOB packet
md.end_of_burst = true;
tx_stream->send("", 0, md);
}
/***********************************************************************
* Tune RX and TX routine
**********************************************************************/
static double tune_rx_and_tx(uhd::usrp::multi_usrp::sptr usrp, const double rx_lo_freq, const double tx_offset){
//tune the receiver with no cordic
uhd::tune_request_t rx_tune_req(rx_lo_freq);
rx_tune_req.dsp_freq_policy = uhd::tune_request_t::POLICY_MANUAL;
rx_tune_req.dsp_freq = 0;
usrp->set_rx_freq(rx_tune_req);
//tune the transmitter with no cordic
uhd::tune_request_t tx_tune_req(usrp->get_rx_freq() - tx_offset);
tx_tune_req.dsp_freq_policy = uhd::tune_request_t::POLICY_MANUAL;
tx_tune_req.dsp_freq = 0;
usrp->set_tx_freq(tx_tune_req);
//wait for the LOs to become locked
boost::this_thread::sleep(boost::posix_time::milliseconds(50));
boost::system_time start = boost::get_system_time();
while (not usrp->get_tx_sensor("lo_locked").to_bool() or not usrp->get_rx_sensor("lo_locked").to_bool()){
if (boost::get_system_time() > start + boost::posix_time::milliseconds(100)){
throw std::runtime_error("timed out waiting for TX and/or RX LO to lock");
}
}
return usrp->get_rx_freq();
}
/***********************************************************************
* Main
**********************************************************************/
int UHD_SAFE_MAIN(int argc, char *argv[]){
std::string args;
double tx_wave_ampl, tx_offset;
double freq_start, freq_stop, freq_step;
size_t nsamps;
po::options_description desc("Allowed options");
desc.add_options()
("help", "help message")
("verbose", "enable some verbose")
("args", po::value<std::string>(&args)->default_value(""), "device address args [default = \"\"]")
("tx_wave_ampl", po::value<double>(&tx_wave_ampl)->default_value(0.7), "Transmit wave amplitude in counts")
("tx_offset", po::value<double>(&tx_offset)->default_value(.9344e6), "TX LO offset from the RX LO in Hz")
("freq_start", po::value<double>(&freq_start), "Frequency start in Hz (do not specify for default)")
("freq_stop", po::value<double>(&freq_stop), "Frequency stop in Hz (do not specify for default)")
("freq_step", po::value<double>(&freq_step)->default_value(default_freq_step), "Step size for LO sweep in Hz")
("nsamps", po::value<size_t>(&nsamps)->default_value(default_num_samps), "Samples per data capture")
;
po::variables_map vm;
po::store(po::parse_command_line(argc, argv, desc), vm);
po::notify(vm);
//print the help message
if (vm.count("help")){
std::cout << boost::format("USRP Generate RX IQ Balance Calibration Table %s") % desc << std::endl;
std::cout <<
"This application measures leakage between RX and TX on an XCVR daughterboard to self-calibrate.\n"
<< std::endl;
return ~0;
}
//create a usrp device
std::cout << std::endl;
std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
//set the antennas to cal
if (not uhd::has(usrp->get_rx_antennas(), "CAL") or not uhd::has(usrp->get_tx_antennas(), "CAL")){
throw std::runtime_error("This board does not have the CAL antenna option, cannot self-calibrate.");
}
usrp->set_rx_antenna("CAL");
usrp->set_tx_antenna("CAL");
//set optimum defaults
set_optimum_defaults(usrp);
//create a receive streamer
uhd::stream_args_t stream_args("fc32"); //complex floats
uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);
//create a transmitter thread
boost::thread_group threads;
threads.create_thread(boost::bind(&tx_thread, usrp, tx_wave_ampl));
//re-usable buffer for samples
std::vector<samp_type> buff;
//store the results here
std::vector<result_t> results;
if (not vm.count("freq_start")) freq_start = usrp->get_rx_freq_range().start() + 50e6;
if (not vm.count("freq_stop")) freq_stop = usrp->get_rx_freq_range().stop() - 50e6;
for (double rx_lo_i = freq_start; rx_lo_i <= freq_stop; rx_lo_i += freq_step){
const double rx_lo = tune_rx_and_tx(usrp, rx_lo_i, tx_offset);
//frequency constants for this tune event
const double actual_rx_rate = usrp->get_rx_rate();
const double actual_tx_freq = usrp->get_tx_freq();
const double actual_rx_freq = usrp->get_rx_freq();
const double bb_tone_freq = actual_tx_freq - actual_rx_freq;
const double bb_imag_freq = -bb_tone_freq;
//capture initial uncorrected value
usrp->set_rx_iq_balance(std::polar<double>(1.0, 0.0));
capture_samples(usrp, rx_stream, buff, nsamps);
const double initial_suppression = compute_tone_dbrms(buff, bb_tone_freq/actual_rx_rate) - compute_tone_dbrms(buff, bb_imag_freq/actual_rx_rate);
//bounds and results from searching
std::complex<double> best_correction;
double phase_corr_start = -.3, phase_corr_stop = .3, phase_corr_step;
double ampl_corr_start = -.3, ampl_corr_stop = .3, ampl_corr_step;
double best_suppression = 0, best_phase_corr = 0, best_ampl_corr = 0;
for (size_t i = 0; i < num_search_iters; i++){
phase_corr_step = (phase_corr_stop - phase_corr_start)/(num_search_steps-1);
ampl_corr_step = (ampl_corr_stop - ampl_corr_start)/(num_search_steps-1);
for (double phase_corr = phase_corr_start; phase_corr <= phase_corr_stop + phase_corr_step/2; phase_corr += phase_corr_step){
for (double ampl_corr = ampl_corr_start; ampl_corr <= ampl_corr_stop + ampl_corr_step/2; ampl_corr += ampl_corr_step){
const std::complex<double> correction = std::polar(ampl_corr+1, phase_corr*tau);
usrp->set_rx_iq_balance(correction);
//receive some samples
capture_samples(usrp, rx_stream, buff, nsamps);
const double tone_dbrms = compute_tone_dbrms(buff, bb_tone_freq/actual_rx_rate);
const double imag_dbrms = compute_tone_dbrms(buff, bb_imag_freq/actual_rx_rate);
const double suppression = tone_dbrms - imag_dbrms;
if (suppression > best_suppression){
best_correction = correction;
best_suppression = suppression;
best_phase_corr = phase_corr;
best_ampl_corr = ampl_corr;
}
}}
//std::cout << "best_phase_corr " << best_phase_corr << std::endl;
//std::cout << "best_ampl_corr " << best_ampl_corr << std::endl;
//std::cout << "best_suppression " << best_suppression << std::endl;
phase_corr_start = best_phase_corr - phase_corr_step;
phase_corr_stop = best_phase_corr + phase_corr_step;
ampl_corr_start = best_ampl_corr - ampl_corr_step;
ampl_corr_stop = best_ampl_corr + ampl_corr_step;
}
if (best_suppression > 30){ //most likely valid, keep result
result_t result;
result.freq = rx_lo;
result.real_corr = best_correction.real();
result.imag_corr = best_correction.imag();
result.best = best_suppression;
result.delta = best_suppression - initial_suppression;
results.push_back(result);
if (vm.count("verbose")){
std::cout << boost::format("RX IQ: %f MHz: best suppression %f dB, corrected %f dB") % (rx_lo/1e6) % result.best % result.delta << std::endl;
}
else std::cout << "." << std::flush;
}
}
std::cout << std::endl;
//stop the transmitter
threads.interrupt_all();
threads.join_all();
store_results(usrp, results, "RX", "rx", "iq");
return 0;
}
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