5 files changed, 2245 insertions, 8 deletions
diff --git a/gr-digital/examples/ofdm/benchmark_add_channel.py b/gr-digital/examples/ofdm/benchmark_add_channel.py
index 0d17efd052..f97214f78d 100755
--- a/gr-digital/examples/ofdm/benchmark_add_channel.py
+++ b/gr-digital/examples/ofdm/benchmark_add_channel.py
@@ -44,14 +44,14 @@ class my_top_block(gr.top_block):
 
         frequency_offset = options.frequency_offset / options.fft_length
 
-        self.src = gr.file_source(gr.sizeof_gr_complex, ifile)
+        self.src = blocks.file_source(gr.sizeof_gr_complex, ifile)
         #self.throttle = blocks.throttle(gr.sizeof_gr_complex, options.sample_rate)
 
         self.channel = filter.channel_model(noise_voltage, frequency_offset,
                                         time_offset, noise_seed=-random.randint(0,100000))
         self.phase = blocks.multiply_const_cc(complex(math.cos(phase_offset),
                                                   math.sin(phase_offset)))
-        self.snk = gr.file_sink(gr.sizeof_gr_complex, ofile)
+        self.snk = blocks.file_sink(gr.sizeof_gr_complex, ofile)
 
         self.connect(self.src, self.channel, self.phase, self.snk)
         
diff --git a/gr-digital/examples/ofdm/benchmark_rx.py b/gr-digital/examples/ofdm/benchmark_rx.py
index f1b65276d0..dbcd866ad2 100755
--- a/gr-digital/examples/ofdm/benchmark_rx.py
+++ b/gr-digital/examples/ofdm/benchmark_rx.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright 2006,2007,2011 Free Software Foundation, Inc.
+# Copyright 2006,2007,2011,2013 Free Software Foundation, Inc.
 # 
 # This file is part of GNU Radio
 # 
@@ -25,6 +25,7 @@ from gnuradio import eng_notation
 from gnuradio.eng_option import eng_option
 from optparse import OptionParser
 
+from gnuradio import blocks
 from gnuradio import digital
 
 # from current dir
@@ -44,9 +45,9 @@ class my_top_block(gr.top_block):
                                        options.spec, options.antenna,
                                        options.verbose)
         elif(options.from_file is not None):
-            self.source = gr.file_source(gr.sizeof_gr_complex, options.from_file)
+            self.source = blocks.file_source(gr.sizeof_gr_complex, options.from_file)
         else:
-            self.source = gr.null_source(gr.sizeof_gr_complex)
+            self.source = blocks.null_source(gr.sizeof_gr_complex)
 
         # Set up receive path
         # do this after for any adjustments to the options that may
diff --git a/gr-digital/examples/ofdm/benchmark_tx.py b/gr-digital/examples/ofdm/benchmark_tx.py
index 5962fe7ecb..2942178ccf 100755
--- a/gr-digital/examples/ofdm/benchmark_tx.py
+++ b/gr-digital/examples/ofdm/benchmark_tx.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright 2005,2006,2011 Free Software Foundation, Inc.
+# Copyright 2005,2006,2011,2013 Free Software Foundation, Inc.
 # 
 # This file is part of GNU Radio
 # 
@@ -27,6 +27,7 @@ from optparse import OptionParser
 import time, struct, sys
 
 from gnuradio import digital
+from gnuradio import blocks
 
 # from current dir
 from transmit_path import transmit_path
@@ -43,9 +44,9 @@ class my_top_block(gr.top_block):
                                         options.spec, options.antenna,
                                         options.verbose)
         elif(options.to_file is not None):
-            self.sink = gr.file_sink(gr.sizeof_gr_complex, options.to_file)
+            self.sink = blocks.file_sink(gr.sizeof_gr_complex, options.to_file)
         else:
-            self.sink = gr.null_sink(gr.sizeof_gr_complex)
+            self.sink = blocks.null_sink(gr.sizeof_gr_complex)
 
         # do this after for any adjustments to the options that may
         # occur in the sinks (specifically the UHD sink)
diff --git a/gr-digital/examples/ofdm/rx_ofdm.grc b/gr-digital/examples/ofdm/rx_ofdm.grc
new file mode 100644
index 0000000000..47e165508c
--- /dev/null
+++ b/gr-digital/examples/ofdm/rx_ofdm.grc
@@ -0,0 +1,1092 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Feb 14 15:49:35 2013</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>rx_ofdm</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>OFDM Rx</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Example of an OFDM receiver</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(0, -1)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_symbols_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((100,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(762, 64)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_carriers</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((0,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(557, 64)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>header_formatter</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.packet_header_ofdm(occupied_carriers, 1, length_tag_name)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(876, 64)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_symbols</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((100,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(659, 64)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>(range(-26, -21) + range(-20, -7) + range(-6, 0) + range(1, 7) + range(8, 21) + range(22, 27),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(404, 64)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>analog_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>analog_noise_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>analog.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(-1, 185)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_sync_sc_cfb</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_sync_sc_cfb_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>cp_len</key>
+      <value>fft_len/4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 178)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>analog_frequency_modulator_fc</key>
+    <param>
+      <key>id</key>
+      <value>analog_frequency_modulator_fc_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>sensitivity</key>
+      <value>-2.0/fft_len</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(692, 175)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_xx</key>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(885, 223)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_delay</key>
+    <param>
+      <key>id</key>
+      <value>blocks_delay_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>delay</key>
+      <value>fft_len+fft_len/4</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 253)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3200000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(0, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>from gnuradio.digital.utils import tagged_streams</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(163, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>sync_word</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0, 0, 0, 0, 0, 0, 0, -1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, -1.0, 0, 1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, -1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 0, 0, 0, 0, 0]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(165, 46)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>header_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_bpsk()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(655, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>payload_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_qpsk()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(813, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>n_sync_symbols</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 108)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_throttle</key>
+    <param>
+      <key>id</key>
+      <value>blocks_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(181, 200)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_constellation_decoder_cb</key>
+    <param>
+      <key>id</key>
+      <value>digital_constellation_decoder_cb_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>constellation</key>
+      <value>header_mod.base()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(854, 343)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_frame_equalizer_vcvc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_frame_equalizer_vcvc_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>equalizer</key>
+      <value>digital.ofdm_equalizer_simpledfe(fft_len, header_mod.base(), occupied_carriers, pilot_carriers, pilot_symbols).base()</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>propagate_channel_state</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(421, 320)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_packet_headerparser_b</key>
+    <param>
+      <key>id</key>
+      <value>digital_packet_headerparser_b_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>header_formatter</key>
+      <value>header_formatter.formatter()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(651, 466)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>fft_vxx</key>
+    <param>
+      <key>id</key>
+      <value>fft_vxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>forward</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value></value>
+    </param>
+    <param>
+      <key>shift</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>nthreads</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(53, 429)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>64</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(301, -1)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"frame_len"</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(367, -1)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_constellation_decoder_cb</key>
+    <param>
+      <key>id</key>
+      <value>digital_constellation_decoder_cb_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>constellation</key>
+      <value>payload_mod.base()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(718, 635)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_null_sink</key>
+    <param>
+      <key>id</key>
+      <value>blocks_null_sink_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(938, 638)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_frame_equalizer_vcvc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_frame_equalizer_vcvc_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>equalizer</key>
+      <value>digital.ofdm_equalizer_simpledfe(fft_len, header_mod.base(), occupied_carriers, pilot_carriers, pilot_symbols, n_sync_symbols).base()</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_key</value>
+    </param>
+    <param>
+      <key>propagate_channel_state</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(265, 612)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>fft_vxx</key>
+    <param>
+      <key>id</key>
+      <value>fft_vxx_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>forward</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value></value>
+    </param>
+    <param>
+      <key>shift</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>nthreads</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(57, 605)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_serializer_vcc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_serializer_vcc_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>occupied_carriers</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>packet_len_tag_key</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>symbols_skipped</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>input_is_shifted</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(649, 305)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_serializer_vcc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_serializer_vcc_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>occupied_carriers</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_key</value>
+    </param>
+    <param>
+      <key>packet_len_tag_key</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>symbols_skipped</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>input_is_shifted</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 597)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_chanest_vcvc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_chanest_vcvc_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>sync_symbol1</key>
+      <value>sync_word</value>
+    </param>
+    <param>
+      <key>sync_symbol2</key>
+      <value>()</value>
+    </param>
+    <param>
+      <key>n_data_symbols</key>
+      <value>n_sync_symbols</value>
+    </param>
+    <param>
+      <key>eq_noise_red_len</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_carr_offset</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>force_one_symbol</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(52, 305)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_header_payload_demux</key>
+    <param>
+      <key>id</key>
+      <value>digital_header_payload_demux_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>header_len</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>items_per_symbol</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>guard_interval</key>
+      <value>fft_len/4</value>
+    </param>
+    <param>
+      <key>length_tag_key</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>trigger_tag_key</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>output_symbols</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(340, 461)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>fft_vxx_0</source_block_id>
+    <sink_block_id>digital_ofdm_chanest_vcvc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>analog_frequency_modulator_fc_0</source_block_id>
+    <sink_block_id>blocks_multiply_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_sync_sc_cfb_0</source_block_id>
+    <sink_block_id>analog_frequency_modulator_fc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>analog_noise_source_x_0</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>digital_ofdm_sync_sc_cfb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>blocks_delay_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_delay_0</source_block_id>
+    <sink_block_id>blocks_multiply_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_constellation_decoder_cb_0_0</source_block_id>
+    <sink_block_id>digital_packet_headerparser_b_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_serializer_vcc_0</source_block_id>
+    <sink_block_id>digital_constellation_decoder_cb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_sync_sc_cfb_0</source_block_id>
+    <sink_block_id>digital_header_payload_demux_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_chanest_vcvc_0</source_block_id>
+    <sink_block_id>digital_ofdm_frame_equalizer_vcvc_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_frame_equalizer_vcvc_0_0</source_block_id>
+    <sink_block_id>digital_ofdm_serializer_vcc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_packet_headerparser_b_0</source_block_id>
+    <sink_block_id>digital_header_payload_demux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>2</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>fft_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>fft_vxx_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_xx_0</source_block_id>
+    <sink_block_id>digital_header_payload_demux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_constellation_decoder_cb_0</source_block_id>
+    <sink_block_id>blocks_null_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_frame_equalizer_vcvc_0</source_block_id>
+    <sink_block_id>digital_ofdm_serializer_vcc_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_serializer_vcc_1</source_block_id>
+    <sink_block_id>digital_constellation_decoder_cb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fft_vxx_0_0</source_block_id>
+    <sink_block_id>digital_ofdm_frame_equalizer_vcvc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/ofdm/tx_ofdm.grc b/gr-digital/examples/ofdm/tx_ofdm.grc
new file mode 100644
index 0000000000..a2deb05f9f
--- /dev/null
+++ b/gr-digital/examples/ofdm/tx_ofdm.grc
@@ -0,0 +1,1143 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Tue Feb  5 14:47:32 2013</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>tx_ofdm</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>OFDM Tx</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Example of an OFDM Transmitter</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>no_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>run</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(0, -1)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>from gnuradio.digital.utils import tagged_streams</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(164, 45)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"packet_len"</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(399, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_symbols_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((100,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(735, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>(range(-26, -21) + range(-20, -7) + range(-6, 0) + range(1, 7) + range(8, 21) + range(22, 27),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(377, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_symbols</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((100,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(632, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pilot_carriers</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>((0,),)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(530, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>64</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(311, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>header_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_bpsk()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(620, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>payload_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_qpsk()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(783, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_throttle</key>
+    <param>
+      <key>id</key>
+      <value>blocks_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>bit_rate/8</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(234, 167)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>import numpy</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(164, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>import random</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(-1, 90)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>sync_word</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0, 0, 0, 0, 0, 0, 0, -1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, -1.0, 0, 1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, -1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, 1.0, 0, -1.0, 0, 1.0, 0, -1.0, 0, 0, 0, 0, 0, 0]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(95, 90)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>rolloff</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(234, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>header_formatter</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.packet_header_ofdm(occupied_carriers, 1, length_tag_name)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(849, 63)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_vector_source_x</key>
+    <param>
+      <key>id</key>
+      <value>blocks_vector_source_x_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>range(packet_len)</value>
+    </param>
+    <param>
+      <key>tags</key>
+      <value>tagged_streams.make_lengthtags((packet_len,), (0,), length_tag_name)</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(-1, 152)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>96</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_packet_headergenerator_bb</key>
+    <param>
+      <key>id</key>
+      <value>digital_packet_headergenerator_bb_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>header_formatter</key>
+      <value>header_formatter.formatter()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(761, 167)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>bit_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3200000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(311, 0)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>payload_mod.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(516, 228)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>payload_mod.points()</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(279, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>header_mod.points()</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(319, 305)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(44, 254)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_carrier_allocator_cvc</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_carrier_allocator_cvc_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fft_len</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>occupied_carriers</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>pilot_carriers</key>
+      <value>pilot_carriers</value>
+    </param>
+    <param>
+      <key>pilot_symbols</key>
+      <value>pilot_symbols</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 453)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_vector_source_x</key>
+    <param>
+      <key>id</key>
+      <value>sync_word_source</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>numpy.array(sync_word) * numpy.sqrt(2)</value>
+    </param>
+    <param>
+      <key>tags</key>
+      <value>tagged_streams.make_lengthtags((len(sync_word)/fft_len,), (0,), length_tag_name)</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 356)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(374, 382)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>fft_vxx</key>
+    <param>
+      <key>id</key>
+      <value>fft_vxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>forward</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value></value>
+    </param>
+    <param>
+      <key>shift</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>nthreads</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(765, 498)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_ofdm_cyclic_prefixer</key>
+    <param>
+      <key>id</key>
+      <value>digital_ofdm_cyclic_prefixer_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>input_size</key>
+      <value>fft_len</value>
+    </param>
+    <param>
+      <key>output_size</key>
+      <value>fft_len+fft_len/4</value>
+    </param>
+    <param>
+      <key>rolloff</key>
+      <value>rolloff</value>
+    </param>
+    <param>
+      <key>tagname</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(488, 505)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>ref_scale</key>
+      <value>2.0</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>win</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>win_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>freqvar</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(291, 460)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_null_sink</key>
+    <param>
+      <key>id</key>
+      <value>blocks_null_sink_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(438, 633)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_bb</key>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_bb_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>length_tag_name</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(472, 159)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>tdb</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(819, 232)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_vector_source_x_1</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>digital_crc32_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_bb_0</source_block_id>
+    <sink_block_id>digital_packet_headergenerator_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>digital_ofdm_carrier_allocator_cvc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_carrier_allocator_cvc_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>sync_word_source</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_packet_headergenerator_bb_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_bb_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_1</source_block_id>
+    <sink_block_id>fft_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_cyclic_prefixer_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fft_vxx_0</source_block_id>
+    <sink_block_id>digital_ofdm_cyclic_prefixer_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_ofdm_cyclic_prefixer_0</source_block_id>
+    <sink_block_id>blocks_null_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_bb_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>