diff options
Diffstat (limited to 'host/utils/usrp_cal_tx_dc_offset.cpp')
| -rw-r--r-- | host/utils/usrp_cal_tx_dc_offset.cpp | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/host/utils/usrp_cal_tx_dc_offset.cpp b/host/utils/usrp_cal_tx_dc_offset.cpp new file mode 100644 index 000000000..2c75242c7 --- /dev/null +++ b/host/utils/usrp_cal_tx_dc_offset.cpp @@ -0,0 +1,262 @@ +// +// 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 <ctime> + +namespace po = boost::program_options; + +/*********************************************************************** + * Transmit thread + **********************************************************************/ +static void tx_thread(uhd::usrp::multi_usrp::sptr usrp, const double tx_wave_freq, 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<std::complex<float> > buff(tx_stream->get_max_num_samps()*10); + + //values for the wave table lookup + size_t index = 0; + const double tx_rate = usrp->get_tx_rate(); + const size_t step = boost::math::iround(wave_table_len * tx_wave_freq/tx_rate); + + //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) * wave_table_lookup(index += step); + } + 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 tx_lo_freq, const double rx_offset){ + //tune the transmitter with no cordic + uhd::tune_request_t tx_tune_req(tx_lo_freq); + 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); + + //tune the receiver + usrp->set_rx_freq(usrp->get_tx_freq() - rx_offset); + + //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_tx_freq(); +} + +/*********************************************************************** + * Data capture routine + **********************************************************************/ +static void capture_samples(uhd::usrp::multi_usrp::sptr usrp, uhd::rx_streamer::sptr rx_stream, std::vector<std::complex<float> > &buff){ + uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE); + stream_cmd.num_samps = buff.size(); + stream_cmd.stream_now = true; + usrp->issue_stream_cmd(stream_cmd); + uhd::rx_metadata_t md; + const size_t num_rx_samps = rx_stream->recv(&buff.front(), buff.size(), md); + + //validate the received data + if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE){ + throw std::runtime_error(str(boost::format( + "Unexpected error code 0x%x" + ) % md.error_code)); + } + if (num_rx_samps != buff.size()){ + throw std::runtime_error("did not get all the samples requested"); + } +} + +/*********************************************************************** + * Main + **********************************************************************/ +int UHD_SAFE_MAIN(int argc, char *argv[]){ + std::string args; + double rate, tx_wave_freq, tx_wave_ampl, rx_offset, freq_step, tx_gain, rx_gain; + 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 = \"\"]") + ("rate", po::value<double>(&rate)->default_value(12.5e6), "RX and TX sample rate in Hz") + ("tx_wave_freq", po::value<double>(&tx_wave_freq)->default_value(507.123e3), "Transmit wave frequency in Hz") + ("tx_wave_ampl", po::value<double>(&tx_wave_ampl)->default_value(0.7), "Transmit wave amplitude in counts") + ("rx_offset", po::value<double>(&rx_offset)->default_value(.9344e6), "RX LO offset from the TX LO in Hz") + ("tx_gain", po::value<double>(&tx_gain)->default_value(0), "TX gain in dB") + ("rx_gain", po::value<double>(&rx_gain)->default_value(0), "RX gain in dB") + ("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 TX DC Offset 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 the sample rates + usrp->set_rx_rate(rate); + usrp->set_tx_rate(rate); + + //set midrange rx gain, default 0 tx gain + usrp->set_tx_gain(tx_gain); + usrp->set_rx_gain(rx_gain); + + //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_freq, tx_wave_ampl)); + + //re-usable buffer for samples + std::vector<std::complex<float> > buff(nsamps); + + //store the results here + std::vector<result_t> results; + + const uhd::meta_range_t freq_range = usrp->get_tx_freq_range(); + for (double tx_lo_i = freq_range.start()+50e6; tx_lo_i < freq_range.stop()-50e6; tx_lo_i += freq_step){ + const double tx_lo = tune_rx_and_tx(usrp, tx_lo_i, rx_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_dc_freq = actual_tx_freq - actual_rx_freq; + + //capture initial uncorrected value + usrp->set_tx_dc_offset(std::complex<double>(0, 0)); + capture_samples(usrp, rx_stream, buff); + const double initial_dc_dbrms = compute_tone_dbrms(buff, bb_dc_freq/actual_rx_rate); + + //bounds and results from searching + double dc_i_start = -.01, dc_i_stop = .01, dc_i_step; + double dc_q_start = -.01, dc_q_stop = .01, dc_q_step; + double lowest_offset = 0, best_dc_i = 0, best_dc_q = 0; + + for (size_t i = 0; i < num_search_iters; i++){ + + dc_i_step = (dc_i_stop - dc_i_start)/(num_search_steps-1); + dc_q_step = (dc_q_stop - dc_q_start)/(num_search_steps-1); + + for (double dc_i = dc_i_start; dc_i <= dc_i_stop + dc_i_step/2; dc_i += dc_i_step){ + for (double dc_q = dc_q_start; dc_q <= dc_q_stop + dc_q_step/2; dc_q += dc_q_step){ + + const std::complex<double> correction(dc_i, dc_q); + usrp->set_tx_dc_offset(correction); + + //receive some samples + capture_samples(usrp, rx_stream, buff); + + const double dc_dbrms = compute_tone_dbrms(buff, bb_dc_freq/actual_rx_rate); + + if (dc_dbrms < lowest_offset){ + lowest_offset = dc_dbrms; + best_dc_i = dc_i; + best_dc_q = dc_q; + } + + }} + + //std::cout << "best_dc_i " << best_dc_i << std::endl; + //std::cout << "best_dc_q " << best_dc_q << std::endl; + //std::cout << "lowest_offset " << lowest_offset << std::endl; + + dc_i_start = best_dc_i - dc_i_step; + dc_i_stop = best_dc_i + dc_i_step; + dc_q_start = best_dc_q - dc_q_step; + dc_q_stop = best_dc_q + dc_q_step; + } + + if (lowest_offset < -90){ //most likely valid, keep result + result_t result; + result.freq = tx_lo; + result.real_corr = best_dc_i; + result.imag_corr = best_dc_q; + result.best = lowest_offset; + result.delta = initial_dc_dbrms - lowest_offset; + results.push_back(result); + if (vm.count("verbose")){ + std::cout << boost::format("%f MHz: lowest offset %fdB, corrected %fdB") % (tx_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, "TX", "tx", "dc"); + + return 0; +} |