Added phase tracker and alignment block for QAM

gr-hamnet70/grc/CMakeLists.txt

@@ -27,5 +27,6 @@ install(FILES
     hamnet70_async_scrambler.block.yml
     hamnet70_insert_pilot_symbols.block.yml
     hamnet70_correct_frequency_from_pilot_syms.block.yml
-    hamnet70_symbol_interleaver.block.yml DESTINATION share/gnuradio/grc/blocks
+    hamnet70_symbol_interleaver.block.yml
+    hamnet70_qam_phase_tracker.block.yml DESTINATION share/gnuradio/grc/blocks
 )

gr-hamnet70/grc/hamnet70_qam_phase_tracker.block.yml

@@ -0,0 +1,28 @@
+id: hamnet70_qam_phase_tracker
+label: QAM Phase Tracker
+category: '[hamnet70]'
+
+templates:
+  imports: import hamnet70
+  make: hamnet70.qam_phase_tracker(${symbols}, ${alpha}, ${start_tag})
+
+parameters:
+-   id: symbols
+    label: Constellation Symbols
+    dtype: complex_vector
+-   id: alpha
+    label: Alpha
+    dtype: float
+-   id: start_tag
+    label: Start Tag
+    dtype: string
+
+inputs:
+-   domain: stream
+    dtype: complex
+
+outputs:
+-   domain: stream
+    dtype: complex
+
+file_format: 1

gr-hamnet70/include/hamnet70/CMakeLists.txt

@@ -32,5 +32,6 @@ install(FILES
     async_scrambler.h
     insert_pilot_symbols.h
     correct_frequency_from_pilot_syms.h
-    symbol_interleaver.h DESTINATION include/hamnet70
+    symbol_interleaver.h
+    qam_phase_tracker.h DESTINATION include/hamnet70
 )

gr-hamnet70/include/hamnet70/qam_phase_tracker.h

@@ -0,0 +1,55 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2019 Thomas Kolb.
+ *
+ * This 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.
+ *
+ * This software 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 software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_HAMNET70_QAM_PHASE_TRACKER_H
+#define INCLUDED_HAMNET70_QAM_PHASE_TRACKER_H
+
+#include <hamnet70/api.h>
+#include <gnuradio/sync_block.h>
+
+namespace gr {
+  namespace hamnet70 {
+
+    /*!
+     * \brief <+description of block+>
+     * \ingroup hamnet70
+     *
+     */
+    class HAMNET70_API qam_phase_tracker : virtual public gr::sync_block
+    {
+     public:
+      typedef boost::shared_ptr<qam_phase_tracker> sptr;
+
+      /*!
+       * \brief Return a shared_ptr to a new instance of hamnet70::qam_phase_tracker.
+       *
+       * To avoid accidental use of raw pointers, hamnet70::qam_phase_tracker's
+       * constructor is in a private implementation
+       * class. hamnet70::qam_phase_tracker::make is the public interface for
+       * creating new instances.
+       */
+      static sptr make(const std::vector<gr_complex> &symbols, float alpha, const std::string &start_tag);
+    };
+
+  } // namespace hamnet70
+} // namespace gr
+
+#endif /* INCLUDED_HAMNET70_QAM_PHASE_TRACKER_H */
+

gr-hamnet70/lib/CMakeLists.txt

@@ -34,6 +34,7 @@ list(APPEND hamnet70_sources
     insert_pilot_symbols_impl.cc
     correct_frequency_from_pilot_syms_impl.cc
     symbol_interleaver_impl.cc
+    qam_phase_tracker_impl.cc
 )
 
 set(hamnet70_sources "${hamnet70_sources}" PARENT_SCOPE)

gr-hamnet70/lib/qam_phase_tracker_impl.cc

@@ -0,0 +1,132 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2019 Thomas Kolb.
+ *
+ * This 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.
+ *
+ * This software 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 software; 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 <gnuradio/io_signature.h>
+#include <gnuradio/expj.h>
+#include <gnuradio/math.h>
+#include "qam_phase_tracker_impl.h"
+
+namespace gr {
+	namespace hamnet70 {
+
+		qam_phase_tracker::sptr
+		qam_phase_tracker::make(const std::vector<gr_complex> &symbols, float alpha, const std::string &start_tag)
+		{
+			return gnuradio::get_initial_sptr
+				(new qam_phase_tracker_impl(symbols, alpha, start_tag));
+		}
+
+
+		/*
+		 * The private constructor
+		 */
+		qam_phase_tracker_impl::qam_phase_tracker_impl(const std::vector<gr_complex> &symbols, float alpha, const std::string &start_tag)
+			: gr::sync_block("qam_phase_tracker",
+					gr::io_signature::make(1, 1, sizeof(gr_complex)),
+					gr::io_signature::make(1, 1, sizeof(gr_complex))),
+				d_alpha(alpha),
+				d_startTag(pmt::intern(start_tag)),
+				d_avgPhaseOffset(0.0f)
+		{
+			// use only symbols in the upper right quadrant
+			for(auto s : symbols) {
+				if(s.real() >= 0 && s.imag() >= 0) {
+					d_refSymbols.push_back(s);
+					d_refPhase.push_back(gr::fast_atan2f(s));
+				}
+			}
+		}
+
+		/*
+		 * Our virtual destructor.
+		 */
+		qam_phase_tracker_impl::~qam_phase_tracker_impl()
+		{
+		}
+
+		int
+		qam_phase_tracker_impl::work(int noutput_items,
+				gr_vector_const_void_star &input_items,
+				gr_vector_void_star &output_items)
+		{
+			const gr_complex *in = (const gr_complex *) input_items[0];
+			gr_complex *out = (gr_complex *) output_items[0];
+
+			for(int i = 0; i < noutput_items; i++) {
+				out[i] = in[i] * gr_expj(-d_avgPhaseOffset);
+
+				std::vector<tag_t> tags;
+				get_tags_in_window(tags, 0, i, i+1, d_startTag);
+
+				if(tags.size() > 0) {
+					// start tag found on this item -> reset average
+					d_avgPhaseOffset = 0;
+				}
+
+				// update average phase offset from current symbol
+
+				gr_complex rotated = out[i];
+
+				float re = rotated.real();
+				float im = rotated.imag();
+
+				// normalize to positive quadrant
+				if(re < 0 && im > 0) {
+					rotated *= gr_expj(-M_PI/2);
+				} else if(re < 0 && im < 0) {
+					rotated *= -1;
+				} else if(im < 0) { // && re > 0
+					rotated *= gr_expj(M_PI/2);
+				} // else already ok
+
+				// find closest reference symbol
+				float min_dist = 1e9;
+				size_t closest_idx;
+
+				for(size_t r = 0; r < d_refSymbols.size(); r++) {
+					float d = std::norm(d_refSymbols[r] - rotated);
+
+					if(d < min_dist) {
+						closest_idx = r;
+						min_dist = d;
+					}
+				}
+
+				float phase = gr::fast_atan2f(rotated);
+				float delta_phase = phase - d_refPhase[closest_idx];
+
+				if(delta_phase > M_PI/4 || delta_phase < -M_PI/4) {
+					continue;
+				}
+
+				d_avgPhaseOffset += d_alpha * delta_phase;
+			}
+
+			// Tell runtime system how many output items we produced.
+			return noutput_items;
+		}
+
+	} /* namespace hamnet70 */
+} /* namespace gr */
+

gr-hamnet70/lib/qam_phase_tracker_impl.h

@@ -0,0 +1,54 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2019 Thomas Kolb.
+ *
+ * This 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.
+ *
+ * This software 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 software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_HAMNET70_QAM_PHASE_TRACKER_IMPL_H
+#define INCLUDED_HAMNET70_QAM_PHASE_TRACKER_IMPL_H
+
+#include <hamnet70/qam_phase_tracker.h>
+
+namespace gr {
+	namespace hamnet70 {
+
+		class qam_phase_tracker_impl : public qam_phase_tracker
+		{
+			private:
+				pmt::pmt_t              d_startTag;
+				float                   d_alpha;
+				float                   d_avgPhaseOffset;
+				std::vector<gr_complex> d_refSymbols;
+				std::vector<float>      d_refPhase;
+
+			public:
+				qam_phase_tracker_impl(const std::vector<gr_complex> &symbols, float alpha, const std::string &start_tag);
+				~qam_phase_tracker_impl();
+
+				// Where all the action really happens
+				int work(
+						int noutput_items,
+						gr_vector_const_void_star &input_items,
+						gr_vector_void_star &output_items
+						);
+		};
+
+	} // namespace hamnet70
+} // namespace gr
+
+#endif /* INCLUDED_HAMNET70_QAM_PHASE_TRACKER_IMPL_H */
+

gr-hamnet70/python/CMakeLists.txt

@@ -52,3 +52,4 @@ set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig)
 #GR_ADD_TEST(qa_insert_pilot_symbols ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_insert_pilot_symbols.py)
 #GR_ADD_TEST(qa_correct_frequency_from_pilot_syms ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_correct_frequency_from_pilot_syms.py)
 #GR_ADD_TEST(qa_symbol_interleaver ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_symbol_interleaver.py)
+GR_ADD_TEST(qa_qam_phase_tracker ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_qam_phase_tracker.py)

gr-hamnet70/python/qa_qam_phase_tracker.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2019 Thomas Kolb.
+#
+# This 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.
+#
+# This software 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 software; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+from gnuradio import gr, gr_unittest
+from gnuradio import blocks
+import hamnet70_swig as hamnet70
+
+class qa_qam_phase_tracker(gr_unittest.TestCase):
+
+    def setUp(self):
+        self.tb = gr.top_block()
+
+    def tearDown(self):
+        self.tb = None
+
+    def test_001_t(self):
+        # set up fg
+        self.tb.run()
+        # check data
+
+
+if __name__ == '__main__':
+    gr_unittest.run(qa_qam_phase_tracker)

gr-hamnet70/swig/hamnet70_swig.i

@@ -18,6 +18,7 @@
 #include "hamnet70/insert_pilot_symbols.h"
 #include "hamnet70/correct_frequency_from_pilot_syms.h"
 #include "hamnet70/symbol_interleaver.h"
+#include "hamnet70/qam_phase_tracker.h"
 %}
 
 
@@ -42,3 +43,5 @@ GR_SWIG_BLOCK_MAGIC2(hamnet70, insert_pilot_symbols);
 GR_SWIG_BLOCK_MAGIC2(hamnet70, correct_frequency_from_pilot_syms);
 %include "hamnet70/symbol_interleaver.h"
 GR_SWIG_BLOCK_MAGIC2(hamnet70, symbol_interleaver);
+%include "hamnet70/qam_phase_tracker.h"
+GR_SWIG_BLOCK_MAGIC2(hamnet70, qam_phase_tracker);