added new file for usrp realtime receive - caution - this doesn't work well yet

4 files changed, 15 insertions, 127 deletions

diff --git a/src/lib/gsm_constants.h b/src/lib/gsm_constants.h
index 3f7ef04..1ebce1c 100644
--- a/src/lib/gsm_constants.h
+++ b/src/lib/gsm_constants.h
@@ -33,6 +33,8 @@
 
 #define CHAN_IMP_RESP_LENGTH  5
 
+#define MAX_SCH_ERRORS    2  //maximum number of subsequent sch errors after which gsm receiver goes to find_next_fcch state
+
 typedef enum {empty, fcch_burst, sch_burst, normal_burst, rach_burst, dummy} burst_type;
 typedef enum {unknown, multiframe_26, multiframe_51} multiframe_type;
 
diff --git a/src/lib/gsm_receiver_cf.cc b/src/lib/gsm_receiver_cf.cc
index 7f91fa8..0fde642 100644
--- a/src/lib/gsm_receiver_cf.cc
+++ b/src/lib/gsm_receiver_cf.cc
@@ -55,10 +55,10 @@ void gsm_receiver_cf::process_normal_burst(burst_counter burst_nr, const unsigne
 void gsm_receiver_cf::configure_receiver()
 {
   d_channel_conf.set_multiframe_type(TSC0, multiframe_51);
-  
+
   d_channel_conf.set_burst_types(TSC0, TEST_CCH_FRAMES, sizeof(TEST_CCH_FRAMES) / sizeof(unsigned), normal_burst);
   d_channel_conf.set_burst_types(TSC0, FCCH_FRAMES, sizeof(FCCH_FRAMES) / sizeof(unsigned), fcch_burst);
-  
+
 //   d_channel_conf.set_multiframe_type(TIMESLOT6, multiframe_26);
 //   d_channel_conf.set_burst_types(TIMESLOT6, TRAFFIC_CHANNEL_F, sizeof(TRAFFIC_CHANNEL_F) / sizeof(unsigned), normal_burst);
 }
@@ -94,7 +94,8 @@ gsm_receiver_cf::gsm_receiver_cf(gr_feval_dd *tuner, int osr)
     d_fcch_start_pos(0),
     d_freq_offset(0),
     d_state(first_fcch_search),
-    d_burst_nr(osr)
+    d_burst_nr(osr),
+    d_failed_sch(0)
 {
   int i;
   gmsk_mapper(SYNC_BITS, N_SYNC_BITS, d_sch_training_seq, gr_complex(0.0, -1.0));
@@ -102,7 +103,7 @@ gsm_receiver_cf::gsm_receiver_cf(gr_feval_dd *tuner, int osr)
   for (i = 0; i < TRAIN_SEQ_NUM; i++) {
     gmsk_mapper(train_seq[i], N_TRAIN_BITS, d_norm_training_seq[i], gr_complex(1.0, 0.0));
   }
-  
+
   /* Initialize GSM Stack */
   GS_new(&d_gs_ctx); //TODO: remove it! it'a not right place for a decoder
 }
@@ -218,10 +219,16 @@ gsm_receiver_cf::general_work(int noutput_items,
               detect_burst(input, &channel_imp_resp[0], burst_start, output_binary);           //MLSE detection of bits
               if (decode_sch(&output_binary[3], &t1, &t2, &t3, &d_ncc, &d_bcc) == 0) {         //and decode SCH data
                 // d_burst_nr.set(t1, t2, t3, 0);                                              //but only to check if burst_start value is correct
+                d_failed_sch = 0;
                 DCOUT("bcc: " << d_bcc << " ncc: " << d_ncc << " t1: " << t1 << " t2: " << t2 << " t3: " << t3);
                 offset =  burst_start - floor((GUARD_PERIOD) * d_OSR);                         //compute offset from burst_start - burst should start after a guard period
                 DCOUT(offset);
                 to_consume += offset;                                                          //adjust with offset number of samples to be consumed
+              } else {
+                d_failed_sch++;
+                if(d_failed_sch >= MAX_SCH_ERRORS){
+                  d_state = next_fcch_search;
+                }
               }
             }
             break;
@@ -680,6 +687,5 @@ int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex
   //std::cout << " burst_start: " << burst_start << " center: " << ((float)(search_start_pos + strongest_window_nr + chan_imp_resp_center)) / d_OSR << " stronegest window nr: " <<  strongest_window_nr << "\n";
 
   return burst_start;
-
 }
 
diff --git a/src/lib/gsm_receiver_cf.h b/src/lib/gsm_receiver_cf.h
index af13618..c37813a 100644
--- a/src/lib/gsm_receiver_cf.h
+++ b/src/lib/gsm_receiver_cf.h
@@ -96,6 +96,8 @@ class gsm_receiver_cf : public gr_block
     channel_configuration d_channel_conf; ///< mapping of burst_counter to burst_type
     //@}
     
+    unsigned d_failed_sch; ///< number of subsequent erroneous SCH bursts
+    
     // GSM Stack
     GS_CTX d_gs_ctx;//TODO: remove it! it'a not right place for a decoder
 
diff --git a/src/python/gsm_findfcch_usrp.py b/src/python/gsm_findfcch_usrp.py
deleted file mode 100755
index 7bf81f3..0000000
--- a/src/python/gsm_findfcch_usrp.py
+++ /dev/null
@@ -1,122 +0,0 @@
-#!/usr/bin/env python
-#!/usr/bin/env python
-
-from gnuradio import gr, gru, blks2
-from gnuradio import usrp
-#from gnuradio import gsm
-from gnuradio.eng_option import eng_option
-from optparse import OptionParser
-from os import sys
-#"""
-for extdir in ['../../debug/src/lib','../../debug/src/lib/.libs']:
-    if extdir not in sys.path:
-        sys.path.append(extdir)
-import gsm                        
-#"""
-def pick_subdevice(u):
-    if u.db[0][0].dbid() >= 0:
-        return (0, 0)
-    if u.db[1][0].dbid() >= 0:
-        return (1, 0)
-    return (0, 0)
-
-class gsm_receiver_first_blood(gr.top_block):
-    def __init__(self):
-        gr.top_block.__init__(self)
-        ( self.options, self.args) = self._przetworz_opcje()
-        self._ustaw_taktowanie()
-        self.zrodlo = self._ustaw_zrodlo()
-        self.filtr = self._ustaw_filtr()
-        self.interpolator = self._ustaw_interpolator()
-        self.odbiornik = self._ustaw_odbiornik()
-        self.konwerter = self._ustaw_konwerter()
-        self.ujscie = self._ustaw_ujscie()
-    
-        self.connect(self.zrodlo, self.filtr,  self.interpolator, self.odbiornik, self.konwerter, self.ujscie)
-#       self.connect(self.zrodlo, self.ujscie)
-  
-    def _ustaw_ujscie(self):
-        nazwa_pliku_wy = self.options.outputfile
-        ujscie = gr.file_sink(gr.sizeof_float, nazwa_pliku_wy)
-        return ujscie
-    
-    def _ustaw_zrodlo(self):	
-        options = self.options
-        fusb_block_size = gr.prefs().get_long('fusb', 'block_size', 4096)
-        fusb_nblocks    = gr.prefs().get_long('fusb', 'nblocks', 16)
-        self.usrp = usrp.source_c(decim_rate=options.decim, fusb_block_size=fusb_block_size, fusb_nblocks=fusb_nblocks)
-        
-        if options.rx_subdev_spec is None:
-            options.rx_subdev_spec = pick_subdevice(self.usrp)
-        
-        self.usrp.set_mux(usrp.determine_rx_mux_value(self.usrp, options.rx_subdev_spec))
-        # determine the daughterboard subdevice
-        self.subdev = usrp.selected_subdev(self.usrp, options.rx_subdev_spec)
-        input_rate = self.usrp.adc_freq() / self.usrp.decim_rate()
-
-        # set initial values
-        if options.gain is None:
-            # if no gain was specified, use the mid-point in dB
-            g = self.subdev.gain_range()
-            options.gain = float(g[0]+g[1])/2
-
-        r = self.usrp.tune(0, self.subdev, options.freq)
-        self.subdev.set_gain(options.gain)
-        return self.usrp
-    
-    def _ustaw_taktowanie(self):
-        options = self.options
-        clock_rate = 64e6
-        self.clock_rate = clock_rate
-        self.input_rate = clock_rate / options.decim
-        self.gsm_symb_rate = 1625000.0 / 6.0
-        self.sps = self.input_rate / self.gsm_symb_rate
-
-    def _ustaw_filtr(self):
-        filter_cutoff   = 145e3	
-        filter_t_width  = 10e3
-        offset = 0
-        print "input_rate:", self.input_rate, "sample rate:", self.sps, " filter_cutoff:", filter_cutoff, " filter_t_width:", filter_t_width
-        filter_taps     = gr.firdes.low_pass(1.0, self.input_rate, filter_cutoff, filter_t_width, gr.firdes.WIN_HAMMING)
-        filtr          = gr.freq_xlating_fir_filter_ccf(1, filter_taps, offset, self.input_rate)
-        return filtr
-
-    def _ustaw_konwerter(self):
-        v2s = gr.vector_to_stream(gr.sizeof_float, 142)
-        return v2s
-    
-    def _ustaw_interpolator(self):
-        interpolator = gr.fractional_interpolator_cc(0, self.sps) 
-        return interpolator
-    
-    def _ustaw_odbiornik(self):
-        odbiornik = gsm.receiver_cf(1)
-        return odbiornik
-    
-    def _przetworz_opcje(self):
-        parser = OptionParser(option_class=eng_option)
-        parser.add_option("-d", "--decim", type="int", default=128,
-                                    help="Set USRP decimation rate to DECIM [default=%default]")
-        parser.add_option("-I", "--inputfile", type="string", default="cfile",
-                                    help="Input filename")
-        parser.add_option("-O", "--outputfile", type="string", default="cfile2.out",
-                                    help="Output filename")
-        parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
-                                    help="Select USRP Rx side A or B (default=first one with a daughterboard)")   
-        parser.add_option("-f", "--freq", type="eng_float", default="950.4M",
-                                    help="set frequency to FREQ", metavar="FREQ")
-        parser.add_option("-g", "--gain", type="eng_float", default=None,
-                                    help="Set gain in dB (default is midpoint)")
-        (options, args) = parser.parse_args ()
-        return (options, args)
-
-def main():
-    try:
-        gsm_receiver_first_blood().run()
-    except KeyboardInterrupt:
-        pass
-
-if __name__ == '__main__':
-    main()
-
-