add support for software IQ imbalance correction

this functionality depend on the gr-iqbal blocks developed by Sylvain
Munaut and is a compile time dependency:

http://cgit.osmocom.org/cgit/gr-iqbal

3 files changed, 129 insertions, 22 deletions

diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 494d498..4f9d7d3 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -47,6 +47,13 @@ GR_OSMOSDR_APPEND_LIBS(
     ${GNURADIO_CORE_LIBRARIES}
 )
 
+if(GNURADIO_IQBALANCE_FOUND)
+    message(STATUS "Will build with gnuradio iqbalance support.")
+    add_definitions(-DHAVE_IQBALANCE=1)
+    include_directories(APPEND ${GNURADIO_IQBALANCE_INCLUDE_DIRS})
+    GR_OSMOSDR_APPEND_LIBS(${GNURADIO_IQBALANCE_LIBRARIES})
+endif()
+
 ########################################################################
 # Setup OsmoSDR component
 ########################################################################
diff --git a/lib/osmosdr_source_c_impl.cc b/lib/osmosdr_source_c_impl.cc
index ba17a83..708831c 100644
--- a/lib/osmosdr_source_c_impl.cc
+++ b/lib/osmosdr_source_c_impl.cc
@@ -173,70 +173,81 @@ osmosdr_source_c_impl::osmosdr_source_c_impl (const std::string &args)
 //    BOOST_FOREACH( dict_t::value_type &entry, dict )
 //      std::cerr << "'" << entry.first << "' = '" << entry.second << "'" << std::endl;
 
+    osmosdr_src_iface *iface = NULL;
+    gr_basic_block_sptr block;
+
 #ifdef ENABLE_OSMOSDR
     if ( dict.count("osmosdr") ) {
       osmosdr_src_c_sptr src = osmosdr_make_src_c( arg );
-
-      for (size_t i = 0; i < src->get_num_channels(); i++)
-        connect(src, i, self(), channel++);
-
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_FCD
     if ( dict.count("fcd") ) {
       fcd_source_sptr src = make_fcd_source( arg );
-      connect(src, 0, self(), channel++);
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_FILE
     if ( dict.count("file") ) {
       file_source_c_sptr src = make_file_source_c( arg );
-      connect(src, 0, self(), channel++);
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_RTL
     if ( dict.count("rtl") ) {
       rtl_source_c_sptr src = make_rtl_source_c( arg );
-      connect(src, 0, self(), channel++);
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_RTL_TCP
     if ( dict.count("rtl_tcp") ) {
       rtl_tcp_source_c_sptr src = make_rtl_tcp_source_c( arg );
-      connect(src, 0, self(), channel++);
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_UHD
     if ( dict.count("uhd") ) {
       uhd_source_c_sptr src = make_uhd_source_c( arg );
-
-      for (size_t i = 0; i < src->get_num_channels(); i++)
-        connect(src, i, self(), channel++);
-
-      _devs.push_back( src.get() );
+      block = src; iface = src.get();
     }
 #endif
 
 #ifdef ENABLE_MIRI
     if ( dict.count("miri") ) {
       miri_source_c_sptr src = make_miri_source_c( arg );
+      block = src; iface = src.get();
+    }
+#endif
 
-      for (size_t i = 0; i < src->get_num_channels(); i++)
-        connect(src, i, self(), channel++);
+    if ( iface != NULL && long(block.get()) != 0 ) {
+      _devs.push_back( iface );
 
-      _devs.push_back( src.get() );
-    }
+      for (size_t i = 0; i < iface->get_num_channels(); i++) {
+#ifdef HAVE_IQBALANCE
+        iqbalance_optimize_c_sptr iq_opt = iqbalance_make_optimize_c( 0 );
+        iqbalance_fix_cc_sptr iq_fix = iqbalance_make_fix_cc();
+
+        connect(block, i, iq_fix, 0);
+        connect(iq_fix, 0, self(), channel++);
+
+        connect(block, i, iq_opt, 0);
+        msg_connect(iq_opt, "iqbal_corr", iq_fix, "iqbal_corr");
+
+        _iq_opt.push_back( iq_opt.get() );
+        _iq_fix.push_back( iq_fix.get() );
+#else
+        connect(block, i, self(), channel++);
 #endif
+      }
+    } else if ( (iface != NULL) || (long(block.get()) != 0) )
+      throw std::runtime_error("Eitner iface or block are NULL.");
+
   }
 
   if (!_devs.size())
@@ -305,6 +316,24 @@ double osmosdr_source_c_impl::set_sample_rate(double rate)
     BOOST_FOREACH( osmosdr_src_iface *dev, _devs )
       sample_rate = dev->set_sample_rate(rate);
 
+#ifdef HAVE_IQBALANCE
+    size_t channel = 0;
+    BOOST_FOREACH( osmosdr_src_iface *dev, _devs ) {
+      for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++) {
+        if ( channel < _iq_opt.size() ) {
+          iqbalance_optimize_c *opt = _iq_opt[channel];
+
+          if ( opt->period() > 0 ) { /* optimize is enabled */
+            opt->set_period( dev->get_sample_rate() / 5 );
+            opt->reset();
+          }
+        }
+
+        channel++;
+      }
+    }
+#endif
+
     _sample_rate = sample_rate;
   }
 
@@ -542,3 +571,61 @@ std::string osmosdr_source_c_impl::get_antenna( size_t chan )
 
   return "";
 }
+
+void osmosdr_source_c_impl::set_iq_balance_mode( int mode, size_t chan )
+{
+#ifdef HAVE_IQBALANCE
+  size_t channel = 0;
+  BOOST_FOREACH( osmosdr_src_iface *dev, _devs ) {
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++) {
+      if ( chan == channel++ ) {
+        if ( chan < _iq_opt.size() && chan < _iq_fix.size() ) {
+          iqbalance_optimize_c *opt = _iq_opt[chan];
+          iqbalance_fix_cc *fix = _iq_fix[chan];
+
+          if ( IQBalanceOff == mode  ) {
+            opt->set_period( 0 );
+            /* store current values in order to be able to restore them later */
+            _vals[ chan ] = std::pair< float, float >( fix->mag(), fix->phase() );
+            fix->set_mag( 0.0f );
+            fix->set_phase( 0.0f );
+          } else if ( IQBalanceManual == mode ) {
+            if ( opt->period() == 0 ) { /* transition from Off to Manual */
+              /* restore previous values */
+              std::pair< float, float > val = _vals[ chan ];
+              fix->set_mag( val.first );
+              fix->set_phase( val.second );
+            }
+            opt->set_period( 0 );
+          } else if ( IQBalanceAutomatic == mode ) {
+            opt->set_period( dev->get_sample_rate() / 5 );
+            opt->reset();
+          }
+        }
+      }
+    }
+  }
+#endif
+}
+
+void osmosdr_source_c_impl::set_iq_balance( const std::complex<double> &correction, size_t chan )
+{
+#ifdef HAVE_IQBALANCE
+  size_t channel = 0;
+  BOOST_FOREACH( osmosdr_src_iface *dev, _devs ) {
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++) {
+      if ( chan == channel++ ) {
+        if ( chan < _iq_opt.size() && chan < _iq_fix.size() ) {
+          iqbalance_optimize_c *opt = _iq_opt[chan];
+          iqbalance_fix_cc *fix = _iq_fix[chan];
+
+          if ( opt->period() == 0 ) { /* automatic optimization desabled */
+            fix->set_mag( correction.real() );
+            fix->set_phase( correction.imag() );
+          }
+        }
+      }
+    }
+  }
+#endif
+}
diff --git a/lib/osmosdr_source_c_impl.h b/lib/osmosdr_source_c_impl.h
index a34bf3b..47d6695 100644
--- a/lib/osmosdr_source_c_impl.h
+++ b/lib/osmosdr_source_c_impl.h
@@ -22,6 +22,11 @@
 
 #include <osmosdr_source_c.h>
 
+#ifdef HAVE_IQBALANCE
+#include <iqbalance_optimize_c.h>
+#include <iqbalance_fix_cc.h>
+#endif
+
 #include <osmosdr_src_iface.h>
 
 #include <map>
@@ -57,6 +62,9 @@ public:
   std::string set_antenna( const std::string & antenna, size_t chan = 0 );
   std::string get_antenna( size_t chan = 0 );
 
+  void set_iq_balance_mode( int mode, size_t chan = 0 );
+  void set_iq_balance( const std::complex<double> &correction, size_t chan = 0 );
+
 private:
   osmosdr_source_c_impl (const std::string & args);  	// private constructor
 
@@ -72,6 +80,11 @@ private:
   std::map< size_t, double > _if_gain;
   std::map< size_t, std::string > _antenna;
   std::vector< osmosdr_src_iface * > _devs;
+#ifdef HAVE_IQBALANCE
+  std::vector< iqbalance_fix_cc * > _iq_fix;
+  std::vector< iqbalance_optimize_c * > _iq_opt;
+  std::map< size_t, std::pair<float, float> > _vals;
+#endif
 };
 
 #endif /* INCLUDED_OSMOSDR_SOURCE_C_IMPL_H */