Added new block which adapts stream of samples to GSM receiver's input requirements (integer multiply of 1625000/6 symbol rate, LP filtering)

1 files changed, 84 insertions, 0 deletions

diff --git a/python/receiver/gsm_input.py b/python/receiver/gsm_input.py
new file mode 100644
index 0000000..e1a51b0
--- /dev/null
+++ b/python/receiver/gsm_input.py
@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+##################################################
+# Gnuradio Python Flow Graph
+# Title: GSM input adaptor
+# Author: Piotr Krysik
+# Description: Adaptor of input stream for the GSM receiver. Contains frequency ofset corrector doing also resampling to integer multiplies of GSM sample rate and LP filter filtering GSM channel.
+# Generated: Thu Nov  6 14:41:06 2014
+##################################################
+
+from gnuradio import filter
+from gnuradio import gr
+from gnuradio.filter import firdes
+import gsm
+
+class gsm_input(gr.hier_block2):
+
+    def __init__(self, ppm=0, osr=4, fc=940e6, samp_rate_in=1e6):
+        gr.hier_block2.__init__(
+            self, "GSM input adaptor",
+            gr.io_signature(1, 1, gr.sizeof_gr_complex*1),
+            gr.io_signature(1, 1, gr.sizeof_gr_complex*1),
+        )
+
+        ##################################################
+        # Parameters
+        ##################################################
+        self.ppm = ppm
+        self.osr = osr
+        self.fc = fc
+        self.samp_rate_in = samp_rate_in
+
+        ##################################################
+        # Blocks
+        ##################################################
+        self.ppm_in = None;self.message_port_register_hier_out("ppm_in")
+        self.low_pass_filter_0_0 = filter.fir_filter_ccf(1, firdes.low_pass(
+        	1, 1625000.0/6.0*osr, 125e3, 5e3, firdes.WIN_HAMMING, 6.76))
+        self.gsm_clock_offset_corrector_0 = gsm.clock_offset_corrector(
+            fc=fc,
+            ppm=0,
+            samp_rate_in=samp_rate_in,
+            samp_rate_out=1625000.0/6.0*4.0,
+        )
+
+        ##################################################
+        # Connections
+        ##################################################
+        self.connect((self.low_pass_filter_0_0, 0), (self, 0))
+        self.connect((self.gsm_clock_offset_corrector_0, 0), (self.low_pass_filter_0_0, 0))
+        self.connect((self, 0), (self.gsm_clock_offset_corrector_0, 0))
+
+        ##################################################
+        # Asynch Message Connections
+        ##################################################
+        self.msg_connect(self, "ppm_in", self.gsm_clock_offset_corrector_0, "ppm_in")
+
+
+    def get_ppm(self):
+        return self.ppm
+
+    def set_ppm(self, ppm):
+        self.ppm = ppm
+
+    def get_osr(self):
+        return self.osr
+
+    def set_osr(self, osr):
+        self.osr = osr
+        self.low_pass_filter_0_0.set_taps(firdes.low_pass(1, 1625000.0/6.0*self.osr, 125e3, 5e3, firdes.WIN_HAMMING, 6.76))
+
+    def get_fc(self):
+        return self.fc
+
+    def set_fc(self, fc):
+        self.fc = fc
+        self.gsm_clock_offset_corrector_0.set_fc(self.fc)
+
+    def get_samp_rate_in(self):
+        return self.samp_rate_in
+
+    def set_samp_rate_in(self, samp_rate_in):
+        self.samp_rate_in = samp_rate_in
+        self.gsm_clock_offset_corrector_0.set_samp_rate_in(self.samp_rate_in)
+