analog: adding quadrature_demod_cf to gr-analog with QA and GRC.

1 files changed, 72 insertions, 0 deletions

diff --git a/gr-analog/lib/quadrature_demod_cf_impl.cc b/gr-analog/lib/quadrature_demod_cf_impl.cc
new file mode 100644
index 000000000..9490ba6be
--- /dev/null
+++ b/gr-analog/lib/quadrature_demod_cf_impl.cc
@@ -0,0 +1,72 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2004,2005,2010,2012 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio 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, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "quadrature_demod_cf_impl.h"
+#include <gr_io_signature.h>
+#include <gr_math.h>
+
+namespace gr {
+  namespace analog {
+    
+    quadrature_demod_cf::sptr
+    quadrature_demod_cf::make(float gain)
+    {
+      return gnuradio::get_initial_sptr
+	(new quadrature_demod_cf_impl(gain));
+    }
+
+    quadrature_demod_cf_impl::quadrature_demod_cf_impl(float gain)
+      : gr_sync_block("quadrature_demod_cf",
+		      gr_make_io_signature(1, 1, sizeof(gr_complex)),
+		      gr_make_io_signature(1, 1, sizeof(float))),
+	d_gain(gain)
+    {
+      set_history(2); // we need to look at the previous value
+    }
+
+    quadrature_demod_cf_impl::~quadrature_demod_cf_impl()
+    {
+    }
+
+    int
+    quadrature_demod_cf_impl::work(int noutput_items,
+				   gr_vector_const_void_star &input_items,
+				   gr_vector_void_star &output_items)
+    {
+      gr_complex *in = (gr_complex*)input_items[0];
+      float *out = (float*)output_items[0];
+      in++;	// ensure that in[-1] is valid
+
+      for(int i = 0; i < noutput_items; i++) {
+	gr_complex product = in[i] * conj(in[i-1]);
+	out[i] = d_gain * gr_fast_atan2f(imag(product), real(product));
+      }
+
+      return noutput_items;
+    }
+
+  } /* namespace analog */
+} /* namespace gr */