From 502eeffa9f5ebeec092be1954efeab4992ef9796 Mon Sep 17 00:00:00 2001
From: Tom Rondeau
Date: Mon, 22 Oct 2012 20:33:05 -0400
Subject: analog: adding dpll_bb to gr-analog.

---
 gr-analog/lib/dpll_bb_impl.cc | 98 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 gr-analog/lib/dpll_bb_impl.cc

(limited to 'gr-analog/lib/dpll_bb_impl.cc')

diff --git a/gr-analog/lib/dpll_bb_impl.cc b/gr-analog/lib/dpll_bb_impl.cc
new file mode 100644
index 000000000..a199b66b4
--- /dev/null
+++ b/gr-analog/lib/dpll_bb_impl.cc
@@ -0,0 +1,98 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007,2009,2010 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 "dpll_bb_impl.h"
+#include <gr_io_signature.h>
+#include <cstdio>
+
+namespace gr {
+  namespace analog {
+
+    dpll_bb::sptr
+    dpll_bb::make(float period, float gain)
+    {
+      return gnuradio::get_initial_sptr
+	(new dpll_bb_impl(period, gain));
+    }
+
+    dpll_bb_impl::dpll_bb_impl(float period, float gain)
+      : gr_sync_block("dpll_bb",
+		      gr_make_io_signature(1, 1, sizeof(char)),
+		      gr_make_io_signature(1, 1, sizeof(char))),
+	d_restart(0), d_pulse_phase(0)
+    {
+      d_pulse_frequency = 1.0/period;
+      d_gain = gain;
+      d_decision_threshold = 1.0 - 0.5*d_pulse_frequency;
+#if 0
+      fprintf(stderr,"frequency = %f period = %f gain = %f threshold = %f\n",
+	      d_pulse_frequency,
+	      period,
+	      d_gain,
+	      d_decision_threshold);
+#endif
+    }
+
+    dpll_bb_impl::~dpll_bb_impl()
+    {
+    }
+
+    int
+    dpll_bb_impl::work(int noutput_items,
+		       gr_vector_const_void_star &input_items,
+		       gr_vector_void_star &output_items)
+    {
+      const char *iptr = (const char*)input_items[0];
+      char *optr = (char*)output_items[0];
+
+      for(int i = 0; i < noutput_items; i++) {
+	optr[i]= 0;
+	if(iptr[i] == 1) {
+	  if(d_restart == 0) {
+	    d_pulse_phase = 1;
+	  }
+	  else {
+	    if(d_pulse_phase > 0.5)
+	      d_pulse_phase += d_gain*(1.0-d_pulse_phase);
+	    else
+	      d_pulse_phase -= d_gain*d_pulse_phase;
+	  }
+	  d_restart = 3;
+	}
+	if(d_pulse_phase > d_decision_threshold) {
+	  d_pulse_phase -= 1.0;
+	  if(d_restart > 0) {
+	    d_restart -= 1;
+	    optr[i] = 1;
+	  }
+	}
+	d_pulse_phase += d_pulse_frequency;
+      }
+      return noutput_items;
+    }
+
+  } /* namespace analog */
+} /* namespace gr */
-- 
cgit