1 files changed, 59 insertions, 0 deletions
diff --git a/python/receiver_hier.py b/python/receiver_hier.py
new file mode 100755
index 0000000..1737d41
--- /dev/null
+++ b/python/receiver_hier.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+
+import gsm
+from gnuradio.eng_option import eng_option
+from gnuradio import gr, gru, blocks
+from gnuradio import filter
+
+
+class tuner(gr.feval_dd):
+    def __init__(self, top_block):
+        gr.feval_dd.__init__(self)
+        self.top_block = top_block
+    def eval(self, freq_offet):
+        self.top_block.set_center_frequency(freq_offet)
+        return freq_offet
+
+class receiver_hier(gr.hier_block2):
+    def __init__(self, input_rate, osr=4):
+        gr.hier_block2.__init__(self, 
+                                "receiver_hier",
+                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
+                                gr.io_signature(1, 1, 142*gr.sizeof_float))
+        #set rates
+        gsm_symb_rate = 1625000/6.0
+        self.input_rate = input_rate
+        self.osr = osr
+        self.sps = input_rate / gsm_symb_rate / osr
+
+        #create callbacks
+        self.tuner_callback = tuner(self)
+        #create accompaning blocks
+        self.filtr = self._set_filter()
+        self.interpolator = self._set_interpolator()
+        self.receiver = self._set_receiver()
+        self.connect(self, self.filtr,  self.interpolator, self.receiver,  self)
+
+    def _set_filter(self):
+        filter_cutoff   = 125e3	
+        filter_t_width  = 10e3
+        offset = 0
+
+        filter_taps    = filter.firdes.low_pass(1.0, self.input_rate, filter_cutoff, filter_t_width, filter.firdes.WIN_HAMMING)
+        filtr          = filter.freq_xlating_fir_filter_ccf(1, filter_taps, offset, self.input_rate)
+        return filtr
+    
+    def _set_interpolator(self):
+        interpolator = filter.fractional_resampler_cc(0, self.sps) 
+        return interpolator
+    
+    def _set_receiver(self):
+        receiver = gsm.receiver(self.tuner_callback, self.osr)
+        return receiver
+
+    def set_center_frequency(self, center_freq):
+        self.filtr.set_center_freq(center_freq)
+
+    def set_timing(self, timing_offset):
+        pass
+