From 77d695f2efaa5b7b14dc02870a42746056b55295 Mon Sep 17 00:00:00 2001
From: Nick Foster <nick@ettus.com>
Date: Tue, 16 Apr 2013 19:23:53 -0700
Subject: [PATCH] First stab at interrogation uplink processing. Getting bits,
 inefficiently.

---
 apps/modes_rx                       |  2 +-
 include/gr_air_modes/CMakeLists.txt |  1 +
 lib/CMakeLists.txt                  |  1 +
 python/__init__.py                  |  2 +-
 python/rx_path.py                   | 43 +++++++++++++++++++++++++++++
 swig/air_modes.i                    |  2 ++
 6 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/apps/modes_rx b/apps/modes_rx
index 24de121..994fc8b 100755
--- a/apps/modes_rx
+++ b/apps/modes_rx
@@ -93,7 +93,7 @@ def main():
 
   if options.kml is not None:
     kmlgen.close()
-    
+
 
 if __name__ == '__main__':
   main()
diff --git a/include/gr_air_modes/CMakeLists.txt b/include/gr_air_modes/CMakeLists.txt
index 09254ca..6e70907 100644
--- a/include/gr_air_modes/CMakeLists.txt
+++ b/include/gr_air_modes/CMakeLists.txt
@@ -25,5 +25,6 @@ install(FILES
     slicer.h
     types.h
     api.h
+    uplink.h
     DESTINATION include/gr_air_modes
 )
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index e3bd53a..c2b5b5e 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -26,6 +26,7 @@ add_library(air_modes SHARED
     preamble_impl.cc
     slicer_impl.cc
     modes_crc.cc
+    uplink_impl.cc
 )
 target_link_libraries(air_modes ${Boost_LIBRARIES} ${GNURADIO_RUNTIME_LIBRARIES})
 set_target_properties(air_modes PROPERTIES DEFINE_SYMBOL "AIR_MODES_EXPORTS")
diff --git a/python/__init__.py b/python/__init__.py
index 29e0475..d46e95c 100644
--- a/python/__init__.py
+++ b/python/__init__.py
@@ -51,7 +51,7 @@ from air_modes_swig import *
 
 # import any pure python here
 #
-from rx_path import rx_path
+from rx_path import rx_path, uplink_rx_path
 from zmq_socket import zmq_pubsub_iface
 from parse import *
 from msprint import output_print
diff --git a/python/rx_path.py b/python/rx_path.py
index 36350c2..b62f67c 100644
--- a/python/rx_path.py
+++ b/python/rx_path.py
@@ -86,3 +86,46 @@ class rx_path(gr.hier_block2):
     def get_threshold(self, threshold):
         return self._sync.get_threshold()
 
+class uplink_rx_path(gr.hier_block2):
+    def __init__(self, rate, threshold, queue, use_pmf=False, use_dcblock=False):
+        gr.hier_block2.__init__(self, "modes_uplink_rx_path",
+                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
+                                gr.io_signature(0,0,0))
+
+        self._rate = int(rate)
+        self._threshold = threshold
+        self._queue = queue
+        self._spc = int(rate/4e6)
+
+        #demodulate DPSK via delay
+        self._delay = gr.delay(gr.sizeof_gr_complex, self._spc)
+        self._mult = gr.multiply_cc()
+        self._conj = gr.conjugate_cc()
+        self._c2r = gr.complex_to_real()
+        #self._bb = self._demod
+
+        self.filesink = gr.file_sink(gr.sizeof_float, "wat.dat")
+
+        # Pulse matched filter for 0.25us pulses
+#        if use_pmf:
+#            self._pmf = gr.moving_average_ff(self._spc, 1.0/self._spc, self._rate)
+#            self.connect(self._demod, self._pmf)
+#            self._bb = self._pmf
+
+        # Establish baseline amplitude (noise, interference)
+        self._avg = gr.moving_average_ff(48*self._spc, 1.0/(48*self._spc), self._rate) # 3 preambles
+
+        # Synchronize to uplink preamble
+        self._sync = air_modes_swig.modes_uplink(self._rate, self._threshold)
+
+        # Slice Mode-S bits and send to message queue
+#        self._slicer = air_modes_swig.modes_slicer(self._rate, self._queue)
+
+        # Wire up the flowgraph
+        self.connect(self, (self._mult, 0))
+        self.connect(self, self._delay, self._conj, (self._mult, 1))
+        self.connect(self._mult, self._c2r)
+        self.connect(self._c2r, (self._sync, 0))
+        self.connect(self._c2r, self._avg, (self._sync, 1))
+#        self.connect(self._sync, self._slicer)
+        self.connect(self._sync, self.filesink)
diff --git a/swig/air_modes.i b/swig/air_modes.i
index 6f5a42b..4ae26f3 100644
--- a/swig/air_modes.i
+++ b/swig/air_modes.i
@@ -11,7 +11,9 @@
 
 %include "gr_air_modes/preamble.h"
 %include "gr_air_modes/slicer.h"
+%include "gr_air_modes/uplink.h"
 
 GR_SWIG_BLOCK_MAGIC2(air_modes,preamble);
 GR_SWIG_BLOCK_MAGIC2(air_modes,slicer);
+GR_SWIG_BLOCK_MAGIC2(air_modes,uplink);