1 files changed, 93 insertions, 0 deletions
diff --git a/gr-analog/python/analog/nbfm_tx.py b/gr-analog/python/analog/nbfm_tx.py
new file mode 100644
index 0000000000..62b56bae52
--- /dev/null
+++ b/gr-analog/python/analog/nbfm_tx.py
@@ -0,0 +1,93 @@
+#
+# Copyright 2005,2012 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.
+#
+
+import math
+from gnuradio import gr, filter
+from fm_emph import fm_preemph
+
+try:
+    from gnuradio import analog
+except ImportError:
+    import analog_swig as analog
+
+class nbfm_tx(gr.hier_block2):
+    def __init__(self, audio_rate, quad_rate, tau=75e-6, max_dev=5e3):
+        """
+        Narrow Band FM Transmitter.
+
+        Takes a single float input stream of audio samples in the range [-1,+1]
+        and produces a single FM modulated complex baseband output.
+
+        Args:
+            audio_rate: sample rate of audio stream, >= 16k (integer)
+            quad_rate: sample rate of output stream (integer)
+            tau: preemphasis time constant (default 75e-6) (float)
+            max_dev: maximum deviation in Hz (default 5e3) (float)
+
+        quad_rate must be an integer multiple of audio_rate.
+        """
+
+	gr.hier_block2.__init__(self, "nbfm_tx",
+				gr.io_signature(1, 1, gr.sizeof_float),      # Input signature
+				gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
+
+        # FIXME audio_rate and quad_rate ought to be exact rationals
+        audio_rate = int(audio_rate)
+        quad_rate = int(quad_rate)
+
+        if quad_rate % audio_rate != 0:
+            raise ValueError, "quad_rate is not an integer multiple of audio_rate"
+
+
+        do_interp = audio_rate != quad_rate
+
+        if do_interp:
+            interp_factor = quad_rate / audio_rate
+            interp_taps = filter.optfir.low_pass(interp_factor,   # gain
+                                                 quad_rate,       # Fs
+                                                 4500,            # passband cutoff
+                                                 7000,            # stopband cutoff
+                                                 0.1,   	  # passband ripple dB
+                                                 40)              # stopband atten dB
+
+            #print "len(interp_taps) =", len(interp_taps)
+            self.interpolator = filter.interp_fir_filter_fff (interp_factor, interp_taps)
+
+        self.preemph = fm_preemph(quad_rate, tau=tau)
+
+        k = 2 * math.pi * max_dev / quad_rate
+        self.modulator = analog.frequency_modulator_fc(k)
+
+        if do_interp:
+            self.connect(self, self.interpolator, self.preemph, self.modulator, self)
+        else:
+            self.connect(self, self.preemph, self.modulator, self)
+
+
+class ctcss_gen_f(gr.hier_block2):
+    def __init__(self, sample_rate, tone_freq):
+	gr.hier_block2.__init__(self, "ctcss_gen_f",
+				gr.io_signature(0, 0, 0),               # Input signature
+				gr.io_signature(1, 1, gr.sizeof_float)) # Output signature
+
+        self.plgen = analog.sig_source_f(sample_rate, analog.GR_SIN_WAVE,
+                                         tone_freq, 0.1, 0.0)
+	self.connect(self.plgen, self)