1 files changed, 78 insertions, 0 deletions
diff --git a/gnuradio-examples/python/hier/sounder/sounder_rx.py b/gnuradio-examples/python/hier/sounder/sounder_rx.py
new file mode 100644
index 000000000..6c8154baf
--- /dev/null
+++ b/gnuradio-examples/python/hier/sounder/sounder_rx.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+#
+# Copyright 2007 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 2, 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.
+# 
+
+from gnuradio import gr, usrp, eng_notation
+from usrp_source import usrp_source_c
+import math
+
+n2s = eng_notation.num_to_str
+
+class sounder_rx(gr.hier_block2):
+    """
+    Creates a top-level channel sounder block with the given parameters.
+    """
+
+    def __init__(self, subdev_spec, freq, cal, verbose, max_delay, chip_rate, gain):
+
+        # Call hierarchical block constructor
+        # Top-level blocks have no inputs or outputs
+        gr.hier_block2.__init__(self,
+                                "sounder_rx",           # Block typename
+                                gr.io_signature(0,0,0), # Input signature
+                                gr.io_signature(0,0,0)) # Output signature
+        self._freq = freq
+        self._cal = cal
+        self._verbose = verbose
+        self._max_delay = max_delay
+
+        self._u = usrp_source_c(0, subdev_spec, gain, chip_rate, self._freq, self._cal, verbose)
+        self.define_component("usrp", self._u)
+
+        self._chip_rate = self._u._if_rate
+        self._resolution = 1.0/self._chip_rate
+
+        min_chips = int(math.ceil(2.0*self._max_delay * self._chip_rate))
+        degree = int(math.ceil(math.log(min_chips)/math.log(2)))
+        self._length = 2**degree-1
+        self._seq_per_sec = self._chip_rate/self._length
+        self._tap = 0.0001
+
+        if self._verbose:
+            print "Actual chip rate is", n2s(self._chip_rate), "chips/sec"
+            print "Resolution is", n2s(self._resolution), "sec"
+            print "Using specified maximum delay spread of", self._max_delay, "sec"
+            print "Mininum sequence length needed is", n2s(min_chips), "chips"
+            print "Using PN sequence of degree", degree, "length", self._length
+            print "Sequences per second is", self._seq_per_sec
+            print "IIR tap is", self._tap
+        
+        self.define_component("s2v", gr.stream_to_vector(gr.sizeof_gr_complex, self._length))
+        self.define_component("fft", gr.fft_vcc(self._length, True, ())) # No window needed
+        self.define_component("avg", gr.single_pole_iir_filter_cc(self._tap, self._length))
+        self.define_component("keep", gr.keep_one_in_n(gr.sizeof_gr_complex*self._length, int(self._seq_per_sec)))
+        self.define_component("sink", gr.file_sink(gr.sizeof_gr_complex*self._length, "FFT.dat"))
+
+        self.connect("usrp", 0, "s2v", 0)
+        self.connect("s2v", 0, "fft", 0)
+        self.connect("fft", 0, "avg", 0)
+        self.connect("avg", 0, "keep", 0)
+        self.connect("keep", 0, "sink", 0)