#!/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: Wed Nov 19 08:23:52 2014 ################################################## from gnuradio import filter from gnuradio import gr from gnuradio.filter import firdes import grgsm 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 ################################################## # Variables ################################################## self.samp_rate_out = samp_rate_out = 1625000.0/6.0*osr ################################################## # 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, samp_rate_out, 125e3, 5e3, firdes.WIN_HAMMING, 6.76)) self.gsm_clock_offset_corrector_0 = grgsm.clock_offset_corrector( fc=936.6e6, ppm=0, samp_rate_in=samp_rate_in, ) self.fractional_resampler_xx_0 = filter.fractional_resampler_cc(0, samp_rate_in/samp_rate_out) ################################################## # Connections ################################################## self.connect((self.low_pass_filter_0_0, 0), (self, 0)) self.connect((self.fractional_resampler_xx_0, 0), (self.low_pass_filter_0_0, 0)) self.connect((self.gsm_clock_offset_corrector_0, 0), (self.fractional_resampler_xx_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 self.gsm_clock_offset_corrector_0.set_ppm(self.ppm) def get_osr(self): return self.osr def set_osr(self, osr): self.osr = osr self.set_samp_rate_out(1625000.0/6.0*self.osr) 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.fractional_resampler_xx_0.set_resamp_ratio(self.samp_rate_in/self.samp_rate_out) self.gsm_clock_offset_corrector_0.set_samp_rate_in(self.samp_rate_in) def get_samp_rate_out(self): return self.samp_rate_out def set_samp_rate_out(self, samp_rate_out): self.samp_rate_out = samp_rate_out self.low_pass_filter_0_0.set_taps(firdes.low_pass(1, self.samp_rate_out, 125e3, 5e3, firdes.WIN_HAMMING, 6.76)) self.fractional_resampler_xx_0.set_resamp_ratio(self.samp_rate_in/self.samp_rate_out)