uhd: first stab at calibration app

2 files changed, 244 insertions, 0 deletions

diff --git a/host/utils/CMakeLists.txt b/host/utils/CMakeLists.txt
index 1a0396ad3..796fdf96f 100644
--- a/host/utils/CMakeLists.txt
+++ b/host/utils/CMakeLists.txt
@@ -37,6 +37,7 @@ ENDFOREACH(util_source)
 SET(util_share_sources
     usrp_burn_db_eeprom.cpp
     usrp_burn_mb_eeprom.cpp
+    usrp_gen_db_cal_table.cpp
 )
 
 IF(ENABLE_USB)
diff --git a/host/utils/usrp_gen_db_cal_table.cpp b/host/utils/usrp_gen_db_cal_table.cpp
new file mode 100644
index 000000000..8fb3be020
--- /dev/null
+++ b/host/utils/usrp_gen_db_cal_table.cpp
@@ -0,0 +1,243 @@
+//
+// 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 <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/safe_main.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 <fstream>
+#include <complex>
+#include <cmath>
+
+namespace po = boost::program_options;
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+static const double e = 2.71828183;
+static const double tau = 6.28318531;
+static const double alpha = 0.0001; //very tight iir filter
+static const size_t wave_table_len = 8192;
+static const float ampl = 0.7; //transmitted wave amplitude
+static const double tx_wave_freq = 507.123e3; //freq of tx sine wave in Hz
+
+/***********************************************************************
+ * Sinusoid wave table
+ **********************************************************************/
+static std::vector<std::complex<float> > gen_table(void){
+    std::vector<std::complex<float> > wave_table(wave_table_len);
+    std::vector<double> real_wave_table(wave_table_len);
+    for (size_t i = 0; i < wave_table_len; i++)
+        real_wave_table[i] = std::sin((tau*i)/wave_table_len);
+
+    //compute i and q pairs with 90% offset and scale to amplitude
+    for (size_t i = 0; i < wave_table_len; i++){
+        const size_t q = (i+(3*wave_table_len)/4)%wave_table_len;
+        wave_table[i] = std::complex<float>(ampl*real_wave_table[i], ampl*real_wave_table[q]);
+    }
+
+    return wave_table;
+}
+
+static std::complex<float> wave_table_lookup(size_t &index){
+    static const std::vector<std::complex<float> > wave_table = gen_table();
+    index %= wave_table_len;
+    return wave_table[index];
+}
+
+/***********************************************************************
+ * Compute power of a tone
+ **********************************************************************/
+static double compute_tone_dbrms(
+    const std::vector<std::complex<float> > &samples,
+    const double freq //freq is fractional
+){
+    //shift the samples so the tone at freq is down at DC
+    std::vector<std::complex<double> > shifted(samples.size());
+    for (size_t i = 0; i < shifted.size(); i++){
+        shifted[i] = std::complex<double>(samples[i]) * std::pow(e, std::complex<double>(0, -freq*tau*i));
+    }
+
+    std::vector<std::complex<float> > buff(shifted.size());
+    for (size_t i = 0; i < buff.size(); i++) buff[i] = shifted[i];
+    std::ofstream outfile("/home/jblum/Desktop/gen.dat", std::ofstream::binary);
+    outfile.write((const char*)&buff.front(), buff.size() * 8);
+
+    //filter the samples with a narrow low pass
+    std::complex<double> iir_output = 0, iir_last = 0;
+    double output = 0;
+    for (size_t i = 0; i < shifted.size(); i++){
+        iir_output = alpha * shifted[i] + (1-alpha)*iir_last;
+        iir_last = iir_output;
+        output += std::abs(iir_output);
+    }
+
+    return 20*std::log10(output/shifted.size());
+}
+
+/***********************************************************************
+ * Transmit thread
+ **********************************************************************/
+static void tx_thread(uhd::usrp::multi_usrp::sptr usrp){
+    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] = wave_table_lookup(index);
+            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);
+}
+
+/***********************************************************************
+ * Main
+ **********************************************************************/
+int UHD_SAFE_MAIN(int argc, char *argv[]){
+    std::string args;
+    double rate;
+
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("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")
+    ;
+
+    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 Daughterboard 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 sample rates
+    usrp->set_rx_rate(rate);
+    usrp->set_tx_rate(rate);
+
+    //tune the transmitter with no cordic
+    uhd::tune_request_t tx_tune_req(2.155e9);
+    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);
+    {
+        boost::system_time start = boost::get_system_time();
+        while (not usrp->get_tx_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 LO to lock");
+            }
+        }
+    }
+
+    //tune the receiver
+    usrp->set_rx_freq(2.155e9 - .9344e6);
+    {
+        boost::system_time start = boost::get_system_time();
+        while (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 RX LO to lock");
+            }
+        }
+    }
+
+    //set max receiver gain
+    usrp->set_rx_gain(usrp->get_rx_gain_range().stop());
+
+    //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));
+
+    //receive some samples
+    std::vector<std::complex<float> > buff(100000);
+    usrp->set_time_now(uhd::time_spec_t(0.0));
+    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 = false;
+    stream_cmd.time_spec = uhd::time_spec_t(0.1);
+    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");
+    }
+
+    //stop the transmitter
+    threads.interrupt_all();
+    threads.join_all();
+
+    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 + tx_wave_freq - actual_rx_freq;
+    const double bb_imag_freq = actual_tx_freq - tx_wave_freq - actual_rx_freq;
+
+    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);
+
+    std::cout << "bb_tone_freq " << bb_tone_freq << std::endl;
+    std::cout << "bb_imag_freq " << bb_imag_freq << std::endl;
+    std::cout << "tone_dbrms " << tone_dbrms << std::endl;
+    std::cout << "imag_dbrms " << imag_dbrms << std::endl;
+    std::cout << "supression " << (tone_dbrms - imag_dbrms) << std::endl;
+
+    return 0;
+}