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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 <uhd/usrp/tune_helper.hpp>
#include <uhd/usrp/subdev_props.hpp>
#include <uhd/usrp/dsp_props.hpp>
#include <uhd/usrp/dboard_iface.hpp> //unit_t
#include <uhd/utils/algorithm.hpp>
#include <boost/math/special_functions/sign.hpp>
#include <cmath>
using namespace uhd;
using namespace uhd::usrp;
/***********************************************************************
* Tune Helper Functions
**********************************************************************/
static tune_result_t tune_xx_subdev_and_dsp(
dboard_iface::unit_t unit,
wax::obj subdev, wax::obj dsp, size_t chan,
const tune_request_t &tune_request
){
wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ];
std::string freq_name = dsp[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
wax::obj dsp_freq_proxy = dsp[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)];
double dsp_sample_rate = dsp[DSP_PROP_CODEC_RATE].as<double>();
//------------------------------------------------------------------
//-- calculate the LO offset, only used with automatic policy
//------------------------------------------------------------------
double lo_offset = 0.0;
if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){
//If the local oscillator will be in the passband, use an offset.
//But constrain the LO offset by the width of the filter bandwidth.
double rate = dsp[DSP_PROP_HOST_RATE].as<double>();
double bw = subdev[SUBDEV_PROP_BANDWIDTH].as<double>();
if (bw > rate) lo_offset = std::min((bw - rate)/2, rate/2);
}
//------------------------------------------------------------------
//-- set the intermediate frequency depending upon the IF policy
//------------------------------------------------------------------
double target_inter_freq = 0.0;
switch (tune_request.inter_freq_policy){
case tune_request_t::POLICY_AUTO:
target_inter_freq = tune_request.target_freq + lo_offset;
subdev_freq_proxy = target_inter_freq;
break;
case tune_request_t::POLICY_MANUAL:
target_inter_freq = tune_request.inter_freq;
subdev_freq_proxy = target_inter_freq;
break;
case tune_request_t::POLICY_NONE: break; //does not set
}
double actual_inter_freq = subdev_freq_proxy.as<double>();
//------------------------------------------------------------------
//-- calculate the dsp freq, only used with automatic policy
//------------------------------------------------------------------
double delta_freq = std::fmod(tune_request.target_freq - actual_inter_freq, dsp_sample_rate);
bool outside_of_nyquist = std::abs(delta_freq) > dsp_sample_rate/2.0;
double target_dsp_freq = (outside_of_nyquist)?
boost::math::sign(delta_freq)*dsp_sample_rate - delta_freq : -delta_freq;
//invert the sign on the dsp freq given the following conditions
if (unit == dboard_iface::UNIT_TX) target_dsp_freq *= -1.0;
//------------------------------------------------------------------
//-- set the dsp frequency depending upon the dsp frequency policy
//------------------------------------------------------------------
switch (tune_request.dsp_freq_policy){
case tune_request_t::POLICY_AUTO:
dsp_freq_proxy = target_dsp_freq;
break;
case tune_request_t::POLICY_MANUAL:
target_dsp_freq = tune_request.dsp_freq;
dsp_freq_proxy = target_dsp_freq;
break;
case tune_request_t::POLICY_NONE: break; //does not set
}
double actual_dsp_freq = dsp_freq_proxy.as<double>();
//------------------------------------------------------------------
//-- load and return the tune result
//------------------------------------------------------------------
tune_result_t tune_result;
tune_result.target_inter_freq = target_inter_freq;
tune_result.actual_inter_freq = actual_inter_freq;
tune_result.target_dsp_freq = target_dsp_freq;
tune_result.actual_dsp_freq = actual_dsp_freq;
return tune_result;
}
static double derive_freq_from_xx_subdev_and_dsp(
dboard_iface::unit_t unit,
wax::obj subdev, wax::obj dsp, size_t chan
){
//extract actual dsp and IF frequencies
double actual_inter_freq = subdev[SUBDEV_PROP_FREQ].as<double>();
std::string freq_name = dsp[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
double actual_dsp_freq = dsp[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)].as<double>();
//invert the sign on the dsp freq given the following conditions
if (unit == dboard_iface::UNIT_TX) actual_dsp_freq *= -1.0;
return actual_inter_freq - actual_dsp_freq;
}
/***********************************************************************
* RX Tune
**********************************************************************/
tune_result_t usrp::tune_rx_subdev_and_dsp(
wax::obj subdev, wax::obj ddc, size_t chan,
const tune_request_t &tune_request
){
return tune_xx_subdev_and_dsp(dboard_iface::UNIT_RX, subdev, ddc, chan, tune_request);
}
double usrp::derive_freq_from_rx_subdev_and_dsp(
wax::obj subdev, wax::obj ddc, size_t chan
){
return derive_freq_from_xx_subdev_and_dsp(dboard_iface::UNIT_RX, subdev, ddc, chan);
}
/***********************************************************************
* TX Tune
**********************************************************************/
tune_result_t usrp::tune_tx_subdev_and_dsp(
wax::obj subdev, wax::obj duc, size_t chan,
const tune_request_t &tune_request
){
return tune_xx_subdev_and_dsp(dboard_iface::UNIT_TX, subdev, duc, chan, tune_request);
}
double usrp::derive_freq_from_tx_subdev_and_dsp(
wax::obj subdev, wax::obj duc, size_t chan
){
return derive_freq_from_xx_subdev_and_dsp(dboard_iface::UNIT_TX, subdev, duc, chan);
}
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