diff options
Diffstat (limited to 'host/lib/usrp/tune_helper.cpp')
| -rw-r--r-- | host/lib/usrp/tune_helper.cpp | 81 |
1 files changed, 42 insertions, 39 deletions
diff --git a/host/lib/usrp/tune_helper.cpp b/host/lib/usrp/tune_helper.cpp index 082c39f6d..c5cce3ecf 100644 --- a/host/lib/usrp/tune_helper.cpp +++ b/host/lib/usrp/tune_helper.cpp @@ -19,22 +19,21 @@ #include <uhd/utils/algorithm.hpp> #include <uhd/usrp/subdev_props.hpp> #include <uhd/usrp/dsp_props.hpp> +#include <uhd/usrp/dboard_iface.hpp> //unit_t #include <cmath> using namespace uhd; using namespace uhd::usrp; /*********************************************************************** - * Tune Helper Function + * Tune Helper Functions **********************************************************************/ static tune_result_t tune_xx_subdev_and_dxc( - bool is_tx, + dboard_iface::unit_t unit, wax::obj subdev, wax::obj dxc, double target_freq, double lo_offset ){ wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ]; - bool subdev_quadrature = subdev[SUBDEV_PROP_QUADRATURE].as<bool>(); - bool subdev_spectrum_inverted = subdev[SUBDEV_PROP_SPECTRUM_INVERTED].as<bool>(); wax::obj dxc_freq_proxy = dxc[DSP_PROP_FREQ_SHIFT]; double dxc_sample_rate = dxc[DSP_PROP_CODEC_RATE].as<double>(); @@ -43,55 +42,52 @@ static tune_result_t tune_xx_subdev_and_dxc( subdev_freq_proxy = target_inter_freq; double actual_inter_freq = subdev_freq_proxy.as<double>(); - // Calculate the DDC setting that will downconvert the baseband from the - // daughterboard to our target frequency. - double delta_freq = target_freq - actual_inter_freq; - int delta_sign = std::signum(delta_freq); - delta_freq *= delta_sign; - delta_freq = std::fmod(delta_freq, dxc_sample_rate); - bool inverted = delta_freq > dxc_sample_rate/2.0; - double target_dxc_freq = inverted? (delta_freq - dxc_sample_rate) : (-delta_freq); - target_dxc_freq *= delta_sign; - - // If the spectrum is inverted, and the daughterboard doesn't do - // quadrature downconversion, we can fix the inversion by flipping the - // sign of the dxc_freq... (This only happens using the basic_rx board) - if (subdev_spectrum_inverted){ - inverted = not inverted; - } - if (inverted and not subdev_quadrature){ - target_dxc_freq *= -1.0; - inverted = not inverted; - } - // down conversion versus up conversion, fight! - // your mother is ugly and your going down... - target_dxc_freq *= (is_tx)? -1.0 : +1.0; + //perform the correction correction for dxc rates outside of nyquist + double delta_freq = std::fmod(target_freq - actual_inter_freq, dxc_sample_rate); + bool outside_of_nyquist = std::abs(delta_freq) > dxc_sample_rate/2.0; + double target_dxc_freq = (outside_of_nyquist)? + std::signum(delta_freq)*dxc_sample_rate - delta_freq : -delta_freq; + + //invert the sign on the dxc freq given the following conditions + if (unit == dboard_iface::UNIT_TX) target_dxc_freq *= -1.0; dxc_freq_proxy = target_dxc_freq; double actual_dxc_freq = dxc_freq_proxy.as<double>(); - //return some kind of tune result tuple/struct + //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_dxc_freq; tune_result.actual_dsp_freq = actual_dxc_freq; - tune_result.spectrum_inverted = inverted; return tune_result; } +static double derive_freq_from_xx_subdev_and_dxc( + dboard_iface::unit_t unit, + wax::obj subdev, wax::obj dxc +){ + //extract actual dsp and IF frequencies + double actual_inter_freq = subdev[SUBDEV_PROP_FREQ].as<double>(); + double actual_dxc_freq = dxc[DSP_PROP_FREQ_SHIFT].as<double>(); + + //invert the sign on the dxc freq given the following conditions + if (unit == dboard_iface::UNIT_TX) actual_dxc_freq *= -1.0; + + return actual_inter_freq - actual_dxc_freq; +} + /*********************************************************************** * RX Tune **********************************************************************/ -tune_result_t uhd::usrp::tune_rx_subdev_and_ddc( +tune_result_t usrp::tune_rx_subdev_and_dsp( wax::obj subdev, wax::obj ddc, double target_freq, double lo_offset ){ - bool is_tx = false; - return tune_xx_subdev_and_dxc(is_tx, subdev, ddc, target_freq, lo_offset); + return tune_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc, target_freq, lo_offset); } -tune_result_t uhd::usrp::tune_rx_subdev_and_ddc( +tune_result_t usrp::tune_rx_subdev_and_dsp( wax::obj subdev, wax::obj ddc, double target_freq ){ @@ -100,21 +96,24 @@ tune_result_t uhd::usrp::tune_rx_subdev_and_ddc( if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){ lo_offset = 2.0*ddc[DSP_PROP_HOST_RATE].as<double>(); } - return tune_rx_subdev_and_ddc(subdev, ddc, target_freq, lo_offset); + return tune_rx_subdev_and_dsp(subdev, ddc, target_freq, lo_offset); +} + +double usrp::derive_freq_from_rx_subdev_and_dsp(wax::obj subdev, wax::obj ddc){ + return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc); } /*********************************************************************** * TX Tune **********************************************************************/ -tune_result_t uhd::usrp::tune_tx_subdev_and_duc( +tune_result_t usrp::tune_tx_subdev_and_dsp( wax::obj subdev, wax::obj duc, double target_freq, double lo_offset ){ - bool is_tx = true; - return tune_xx_subdev_and_dxc(is_tx, subdev, duc, target_freq, lo_offset); + return tune_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc, target_freq, lo_offset); } -tune_result_t uhd::usrp::tune_tx_subdev_and_duc( +tune_result_t usrp::tune_tx_subdev_and_dsp( wax::obj subdev, wax::obj duc, double target_freq ){ @@ -123,5 +122,9 @@ tune_result_t uhd::usrp::tune_tx_subdev_and_duc( if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){ lo_offset = 2.0*duc[DSP_PROP_HOST_RATE].as<double>(); } - return tune_tx_subdev_and_duc(subdev, duc, target_freq, lo_offset); + return tune_tx_subdev_and_dsp(subdev, duc, target_freq, lo_offset); +} + +double usrp::derive_freq_from_tx_subdev_and_dsp(wax::obj subdev, wax::obj duc){ + return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc); } |