Added new blocks for clock freqeuncy correction
diff --git a/python/clock_offset_corrector.py b/python/clock_offset_corrector.py
new file mode 100644
index 0000000..df97cca
--- /dev/null
+++ b/python/clock_offset_corrector.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+##################################################
+# Gnuradio Python Flow Graph
+# Title: Clock offset corrector
+# Author: Piotr Krysik
+# Generated: Wed Aug  6 13:47:38 2014
+##################################################
+
+from gnuradio import blocks
+from gnuradio import filter
+from gnuradio import gr
+from gnuradio.filter import firdes
+import gsm
+import math
+
+class clock_offset_corrector(gr.hier_block2):
+
+    def __init__(self, ppm=0, samp_rate=1625000.0/6.0*4.0, fc=936.6e6):
+        gr.hier_block2.__init__(
+            self, "Clock offset corrector",
+            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.samp_rate = samp_rate
+        self.fc = fc
+
+        ##################################################
+        # Blocks
+        ##################################################
+        self.ppm_msg = None;self.message_port_register_hier_out("ppm_msg")
+        self.gsm_controlled_rotator_cc_0 = gsm.controlled_rotator_cc(0,samp_rate)
+        self.gsm_controlled_const_source_f_0 = gsm.controlled_const_source_f(ppm)
+        self.fractional_resampler_xx_0 = filter.fractional_resampler_cc(0, 1)
+        self.blocks_multiply_const_vxx_0_0 = blocks.multiply_const_vff((1.0/1.0e6, ))
+        self.blocks_multiply_const_vxx_0 = blocks.multiply_const_vff((fc/samp_rate*(2*math.pi), ))
+        self.blocks_add_const_vxx_0 = blocks.add_const_vff((1, ))
+
+        ##################################################
+        # Connections
+        ##################################################
+        self.connect((self.gsm_controlled_const_source_f_0, 0), (self.blocks_multiply_const_vxx_0_0, 0))
+        self.connect((self, 0), (self.gsm_controlled_rotator_cc_0, 0))
+        self.connect((self.blocks_multiply_const_vxx_0_0, 0), (self.blocks_multiply_const_vxx_0, 0))
+        self.connect((self.blocks_add_const_vxx_0, 0), (self.fractional_resampler_xx_0, 1))
+        self.connect((self.gsm_controlled_rotator_cc_0, 0), (self.fractional_resampler_xx_0, 0))
+        self.connect((self.blocks_multiply_const_vxx_0, 0), (self.gsm_controlled_rotator_cc_0, 1))
+        self.connect((self.blocks_multiply_const_vxx_0_0, 0), (self.blocks_add_const_vxx_0, 0))
+        self.connect((self.fractional_resampler_xx_0, 0), (self, 0))
+
+        ##################################################
+        # Asynch Message Connections
+        ##################################################
+        self.msg_connect(self, "ppm_msg", self.gsm_controlled_const_source_f_0, "constant_msg")
+
+
+    def get_ppm(self):
+        return self.ppm
+
+    def set_ppm(self, ppm):
+        self.ppm = ppm
+        self.gsm_controlled_const_source_f_0.set_constant(self.ppm)
+
+    def get_samp_rate(self):
+        return self.samp_rate
+
+    def set_samp_rate(self, samp_rate):
+        self.samp_rate = samp_rate
+        self.blocks_multiply_const_vxx_0.set_k((self.fc/self.samp_rate*(2*math.pi), ))
+        self.gsm_controlled_rotator_cc_0.set_samp_rate(self.samp_rate)
+
+    def get_fc(self):
+        return self.fc
+
+    def set_fc(self, fc):
+        self.fc = fc
+        self.blocks_multiply_const_vxx_0.set_k((self.fc/self.samp_rate*(2*math.pi), ))
+