From 00cf03a40f5ddee09aadec5a45d6bb311d170bbd Mon Sep 17 00:00:00 2001 From: Piotr Krysik Date: Mon, 20 Apr 2009 19:49:01 +0200 Subject: Corrected precision of FCCH search function --- src/lib/gsm_receiver_cf.cc | 257 ++++++++++++++++++++++++++++++---------- src/lib/gsm_receiver_cf.h | 32 +++-- src/python/cfile | Bin 0 -> 640000 bytes src/python/gsm_findfcch.py | 108 +++++++++++++++++ src/python/gsm_findfcch_usrp.py | 122 +++++++++++++++++++ 5 files changed, 450 insertions(+), 69 deletions(-) create mode 100644 src/python/cfile create mode 100755 src/python/gsm_findfcch.py create mode 100755 src/python/gsm_findfcch_usrp.py diff --git a/src/lib/gsm_receiver_cf.cc b/src/lib/gsm_receiver_cf.cc index 206bd5e..4f43f2b 100644 --- a/src/lib/gsm_receiver_cf.cc +++ b/src/lib/gsm_receiver_cf.cc @@ -27,14 +27,18 @@ #include #include #include +#include #include #include +#include +#define SAFETY_MARGIN 50 +#define BUFFER_SIZE (FCCH_HITS_NEEDED) gsm_receiver_cf_sptr -gsm_make_receiver_cf(int osr) +gsm_make_receiver_cf(gr_feval_dd *tuner, int osr) { - return gsm_receiver_cf_sptr(new gsm_receiver_cf(osr)); + return gsm_receiver_cf_sptr(new gsm_receiver_cf(tuner, osr)); } static const int MIN_IN = 1; // mininum number of input streams @@ -45,11 +49,19 @@ static const int MAX_OUT = 1; // maximum number of output streams /* * The private constructor */ -gsm_receiver_cf::gsm_receiver_cf(int osr) +gsm_receiver_cf::gsm_receiver_cf(gr_feval_dd *tuner, int osr) : gr_block("gsm_receiver", gr_make_io_signature(MIN_IN, MAX_IN, sizeof(gr_complex)), gr_make_io_signature(MIN_OUT, MAX_OUT, 142 * sizeof(float))), - d_counter(0) + d_osr(osr), + d_tuner(tuner), + d_prev_freq_offset(0), + d_phase_diff_buffer(BUFFER_SIZE), + d_counter(0), + d_x_temp(0), + d_x2_temp(0), + d_fcch_count(0), + d_state(fcch_search) { } @@ -73,76 +85,199 @@ gsm_receiver_cf::general_work(int noutput_items, { const gr_complex *in = (const gr_complex *) input_items[0]; float *out = (float *) output_items[0]; + int produced_out; -// DCOUT(ninput_items[0]); -// DCOUT(noutput_items); + switch (d_state) { + case fcch_search: - d_return = 0; //! - int start_pos = find_fcch_burst(in, ninput_items[0]); - for (int i = 0; i < TS_BITS; i++) { - out[i] = d_phase_diff_buffer[i+start_pos-USEFUL_BITS]; + if (find_fcch_burst(in, ninput_items[0])) { + produced_out = 1; + d_state = fcch_search; + } else { + produced_out = 0; + d_state = fcch_search; + } + + break; + + case sch_search: + break; } - consume_each(start_pos); - d_counter += start_pos; - return d_return; + +// for (int i = 0; i < TS_BITS; i++) { +// out[i] = d_phase_diff_buffer[i+start_pos-USEFUL_BITS]; +// } + + return produced_out; } -int gsm_receiver_cf::find_fcch_burst(const gr_complex *in, const int nitems) +bool gsm_receiver_cf::find_fcch_burst(const gr_complex *in, const int nitems) { - for (int i = 0; (i < nitems - 1) && (i < BUFFER_SIZE); i++) { - gr_complex conjprod = in[i+1] * conj(in[i]); - float diff_angle = gr_fast_atan2f(imag(conjprod), real(conjprod)); - d_phase_diff_buffer[i] = diff_angle; - } + float phase_diff = 0; + gr_complex conjprod; + int hit_count, miss_count, start_pos; + float min_phase_diff, max_phase_diff, lowest_max_min_diff; + float sum, best_sum; - int hit_count = 0; - int miss_count = 0; - int start_pos = -1; + int to_consume = 0; + int i = 0; + bool end = false; + bool result; - d_return = 0;//! - - for (int i = 0; ; i++) { - if (i > nitems - USEFUL_BITS - 1) { - start_pos = nitems - USEFUL_BITS - 1; - break; - } + circular_buffer_float::iterator buffer_iter; - if (d_phase_diff_buffer[i] > 0) { - if (! hit_count) { - start_pos = i+USEFUL_BITS; - } - hit_count++; - } else if (hit_count >= FCCH_HITS_NEEDED) { - DCOUT("znalezione fcch na pozycji" << d_counter+start_pos-USEFUL_BITS); - d_return = 1;//! - break; - } else if (++miss_count > FCCH_MAX_MISSES) { - start_pos = -1; - hit_count = miss_count = 0; + enum states { + init, search, found_something, fcch_found, search_fail + } fcch_search_state; + + fcch_search_state = init; + + while ((!end) && (i < nitems)) { + switch (fcch_search_state) { + + case init: + hit_count = 0; + miss_count = 0; + start_pos = -1; + lowest_max_min_diff = 99999; + d_phase_diff_buffer.clear(); + fcch_search_state = search; + + break; + + case search: + i++; + + if (i > nitems - BUFFER_SIZE) { + to_consume = i; + fcch_search_state = search_fail; + } + + conjprod = in[i] * conj(in[i-1]); + + phase_diff = gr_fast_atan2f(imag(conjprod), real(conjprod)); + + if (phase_diff > 0) { +// start_pos = i - 1; + to_consume = i; + fcch_search_state = found_something; + } else { + fcch_search_state = search; + } + + break; + + case found_something: + + if (phase_diff > 0) { + hit_count++; + } else { + miss_count++; + } + + //DCOUT("d_phase_diff_buffer.size(): " << d_phase_diff_buffer.size() << " hit_count: " << hit_count); + + if ((miss_count >= FCCH_MAX_MISSES) && (hit_count <= FCCH_HITS_NEEDED)) { + fcch_search_state = init; + continue; + } else if ((miss_count >= FCCH_MAX_MISSES) && (hit_count > FCCH_HITS_NEEDED)) { + fcch_search_state = fcch_found; + continue; + } else if ((miss_count < FCCH_MAX_MISSES) && (hit_count > FCCH_HITS_NEEDED)) { + //find difference between minimal and maximal element in the buffer + //for FCCH this value should be low + //this part is searching for a region where this value is lowest + min_phase_diff = *(min_element(d_phase_diff_buffer.begin(), d_phase_diff_buffer.end())); + max_phase_diff = *(max_element(d_phase_diff_buffer.begin(), d_phase_diff_buffer.end())); + + if(lowest_max_min_diff > max_phase_diff - min_phase_diff){ + lowest_max_min_diff = max_phase_diff - min_phase_diff; + start_pos = i - FCCH_HITS_NEEDED; + d_best_sum = 0; + for (buffer_iter = (d_phase_diff_buffer.begin()); + buffer_iter != (d_phase_diff_buffer.end()); + buffer_iter++) { + d_best_sum += *buffer_iter; + } + DCOUT(d_best_sum); + } + } + + i++; + + if (i >= nitems) { + fcch_search_state = search_fail; + continue; + } + + conjprod = in[i] * conj(in[i-1]); + phase_diff = gr_fast_atan2f(imag(conjprod), real(conjprod)); + d_phase_diff_buffer.push_back(phase_diff); + + fcch_search_state = found_something; + + break; + + case fcch_found: + DCOUT("znalezione fcch na pozycji" << d_counter + start_pos); + to_consume = start_pos + FCCH_HITS_NEEDED + 1; + /* mean = d_best_sum / FCCH_HITS_NEEDED; + phase_offset = mean - (M_PI / 2); + freq_offset = phase_offset * 1625000.0 / (12.0 * M_PI);*/ + compute_freq_offset(); + end = true; + result = true; + break; + + case search_fail: + end = true; + result = false; + break; } } - /* - //Do we have a match? - if (start_pos >= 0) { - //Is it within range? (we know it's long enough then too) - if (start_pos < 2*MAX_CORR_DIST) { - d_burst_start = start_pos; - d_bbuf_pos = 0; //load buffer from start - return FCCH; - } else { - //TODO: don't shift a tiny amount - shift_burst(start_pos - MAX_CORR_DIST); - } - } else { - //Didn't find anything - d_burst_start = MAX_CORR_DIST; - d_bbuf_pos = 0; //load buffer from start - } - */ - //DCOUT("start_pos: " << start_pos); + d_counter += to_consume; + consume_each(to_consume); + + return result; +} + +bool find_sch_burst( const gr_complex *in, const int nitems , gr_complex *out); + + +double gsm_receiver_cf::compute_freq_offset() +{ + float mean, phase_offset, freq_offset; + + DCOUT(" d_phase_diff_buffer.size(): " << d_phase_diff_buffer.size()); + + mean = d_best_sum / FCCH_HITS_NEEDED; + phase_offset = mean - (M_PI / 2); + freq_offset = phase_offset * 1625000.0 / (12.0 * M_PI); + DCOUT("freq_offset: " << freq_offset); + d_fcch_count++; + d_x_temp += freq_offset; + d_x2_temp += freq_offset * freq_offset; + d_mean = d_x_temp / d_fcch_count; + //d_mean = 0.9 * freq_offset + 0.1 * d_mean; + + + //d_tuner->calleval(freq_offset); + + d_prev_freq_offset -= freq_offset; + + DCOUT("wariancja: " << sqrt((d_x2_temp / d_fcch_count - d_mean * d_mean)) << " fcch_count:" << d_fcch_count << " d_mean: " << d_mean); - return start_pos; + return freq_offset; } +void gsm_receiver_cf::set_frequency() +{ + +} + +bool gsm_receiver_cf::find_sch_burst( const gr_complex *in, const int nitems , gr_complex *out) +{ + +} diff --git a/src/lib/gsm_receiver_cf.h b/src/lib/gsm_receiver_cf.h index 5bc7617..2012325 100644 --- a/src/lib/gsm_receiver_cf.h +++ b/src/lib/gsm_receiver_cf.h @@ -24,8 +24,8 @@ #include #include - -#define BUFFER_SIZE 4096 +#include +#include class gsm_receiver_cf; @@ -42,6 +42,8 @@ class gsm_receiver_cf; */ typedef boost::shared_ptr gsm_receiver_cf_sptr; +typedef boost::circular_buffer circular_buffer_float; + /*! * \brief Return a shared_ptr to a new instance of gsm_receiver_cf. * @@ -49,7 +51,7 @@ typedef boost::shared_ptr gsm_receiver_cf_sptr; * constructor is private. howto_make_square_ff is the public * interface for creating new instances. */ -gsm_receiver_cf_sptr gsm_make_receiver_cf( int osr ); +gsm_receiver_cf_sptr gsm_make_receiver_cf( gr_feval_dd *tuner, int osr ); /*! * \brief Receives fcch @@ -61,13 +63,27 @@ class gsm_receiver_cf : public gr_block { private: + gr_feval_dd *d_tuner; + const int d_osr; int d_counter; - int d_return; - float d_phase_diff_buffer[BUFFER_SIZE]; + float d_prev_freq_offset; + circular_buffer_float d_phase_diff_buffer; + double d_x_temp, d_x2_temp, d_mean; + int d_fcch_count; + double d_best_sum; - friend gsm_receiver_cf_sptr gsm_make_receiver_cf( int osr ); - gsm_receiver_cf( int osr ); - int find_fcch_burst( const gr_complex *in, const int items ); + enum states + { + fcch_search, sch_search + } d_state; + + friend gsm_receiver_cf_sptr gsm_make_receiver_cf( gr_feval_dd *tuner, int osr ); + gsm_receiver_cf( gr_feval_dd *tuner, int osr ); + + bool find_fcch_burst( const gr_complex *in, const int nitems ); + bool find_sch_burst( const gr_complex *in, const int nitems , gr_complex *out); + double compute_freq_offset ( ); + void set_frequency ( ); public: ~gsm_receiver_cf(); diff --git a/src/python/cfile b/src/python/cfile new file mode 100644 index 0000000..943e35f Binary files /dev/null and b/src/python/cfile differ diff --git a/src/python/gsm_findfcch.py b/src/python/gsm_findfcch.py new file mode 100755 index 0000000..7ab9c18 --- /dev/null +++ b/src/python/gsm_findfcch.py @@ -0,0 +1,108 @@ +#!/usr/bin/env python +#!/usr/bin/env python + +from gnuradio import gr, gru, blks2 +#, 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 + +class tune(gr.feval_dd): + def __init__(self, top_block): + gr.feval_dd.__init__(self) + self.top_block = top_block + self.center_freq = 0 + def eval(self, freq_offet): + self.center_freq = self.center_freq - freq_offet + self.top_block.set_frequency(self.center_freq) + return self.center_freq + + +class gsm_receiver_first_blood(gr.top_block): + def __init__(self): + gr.top_block.__init__(self) + (options, args) = self._przetworz_opcje() + self.tune_callback = tune(self) + self.options = options + self.args = args + 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): + nazwa_pliku = self.options.inputfile + zrodlo = gr.file_source(gr.sizeof_gr_complex, nazwa_pliku, False) + return zrodlo + + 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(self.tune_callback, self.options.osr) + 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("-r", "--osr", type="int", default=1, + help="Oversampling ratio [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") + (options, args) = parser.parse_args () + return (options, args) + + def set_frequency(self, center_freq): + self.filtr.set_center_freq(center_freq) + +def main(): + try: + gsm_receiver_first_blood().run() + except KeyboardInterrupt: + pass + +if __name__ == '__main__': + main() + + diff --git a/src/python/gsm_findfcch_usrp.py b/src/python/gsm_findfcch_usrp.py new file mode 100755 index 0000000..7bf81f3 --- /dev/null +++ b/src/python/gsm_findfcch_usrp.py @@ -0,0 +1,122 @@ +#!/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() + + -- cgit v1.2.3