diff options
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py | 2 | ||||
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_pnac.py | 80 |
2 files changed, 32 insertions, 50 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py b/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py index 0170c92d7..d315fd005 100644 --- a/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py +++ b/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py @@ -92,7 +92,7 @@ class ofdm_receiver(gr.hier_block2): self.ofdm_sync = ofdm_sync_pn(fft_length, cp_length, logging) elif SYNC == "pnac": nco_sensitivity = -2.0/fft_length # correct for fine frequency - self.ofdm_sync = ofdm_sync_pnac(fft_length, cp_length, ks0time) + self.ofdm_sync = ofdm_sync_pnac(fft_length, cp_length, ks0time, logging) elif SYNC == "fixed": nco_sensitivity = -2.0/fft_length # correct for fine frequency self.ofdm_sync = ofdm_sync_fixed(fft_length, cp_length, logging) diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_pnac.py b/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_pnac.py index 5c16a5703..89f70ed2b 100644 --- a/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_pnac.py +++ b/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_pnac.py @@ -25,28 +25,23 @@ from numpy import fft from gnuradio import gr class ofdm_sync_pnac(gr.hier_block2): - def __init__(self, fft_length, cp_length, ks): + def __init__(self, fft_length, cp_length, kstime, logging=False): - # FIXME: change the output signature - # should be the output of the divider (the normalized peaks) and - # the angle value out of the sample and hold block - # move sampler out of this block - gr.hier_block2.__init__(self, "ofdm_sync_pnac", gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature - gr.io_signature(1, 1, gr.sizeof_gr_complex*fft_length)) # Output signature + gr.io_signature2(2, 2, gr.sizeof_float, gr.sizeof_char)) # Output signature self.input = gr.add_const_cc(0) symbol_length = fft_length + cp_length - # PN Sync + # PN Sync with cross-correlation input - # autocorrelate with the known symbol - ks = ks[0:fft_length//2] - ks.reverse() - self.crosscorr_filter = gr.fir_filter_ccc(1, ks) + # cross-correlate with the known symbol + kstime = [k.conjugate() for k in kstime[0:fft_length//2]] + kstime.reverse() + self.crosscorr_filter = gr.fir_filter_ccc(1, kstime) self.connect(self.crosscorr_filter, gr.file_sink(gr.sizeof_gr_complex, "crosscorr.dat")) # Create a delay line @@ -62,7 +57,7 @@ class ofdm_sync_pnac(gr.hier_block2): # Create a moving sum filter for the input self.inputmag2 = gr.complex_to_mag_squared() - movingsum2_taps = [1.0 for i in range(fft_length/2)] + movingsum2_taps = [1.0 for i in range(fft_length//2)] self.inputmovingsum = gr.fir_filter_fff(1,movingsum2_taps) self.square = gr.multiply_ff() self.normalize = gr.divide_ff() @@ -73,19 +68,16 @@ class ofdm_sync_pnac(gr.hier_block2): self.sample_and_hold = gr.sample_and_hold_ff() - # Mix the signal with an NCO controlled by the sync loop - nco_sensitivity = -1.0/fft_length - self.nco = gr.frequency_modulator_fc(nco_sensitivity) - self.sigmix = gr.multiply_cc() - #ML measurements input to sampler block and detect self.sub1 = gr.add_const_ff(-1) - self.pk_detect = gr.peak_detector_fb(0.2, 0.25, 30, 0.0005) - - self.sampler = gr.ofdm_sampler(fft_length,symbol_length) + self.pk_detect = gr.peak_detector_fb(0.20, 0.20, 30, 0.001) self.connect(self, self.input) + + # Cross-correlate input signal with known preamble self.connect(self.input, self.crosscorr_filter) + + # use the output of the cross-correlation as input to Schmidl&Cox self.connect(self.crosscorr_filter, self.delay) self.connect(self.crosscorr_filter, (self.corr,0)) self.connect(self.delay, self.conjg) @@ -94,38 +86,28 @@ class ofdm_sync_pnac(gr.hier_block2): self.connect(self.moving_sum_filter, self.c2mag) self.connect(self.moving_sum_filter, self.angle) self.connect(self.angle, (self.sample_and_hold,0)) - self.connect(self.sample_and_hold, self.nco) - self.connect(self.input, (self.sigmix,0)) - self.connect(self.nco, (self.sigmix,1)) - self.connect(self.sigmix, (self.sampler,0)) - - self.connect(self.input, self.inputmag2, self.inputmovingsum) + # Get the power of the input signal to normalize the output of the correlation + self.connect(self.crosscorr_filter, self.inputmag2, self.inputmovingsum) self.connect(self.inputmovingsum, (self.square,0)) self.connect(self.inputmovingsum, (self.square,1)) self.connect(self.square, (self.normalize,1)) self.connect(self.c2mag, (self.normalize,0)) - self.connect(self.normalize, self.sub1, self.pk_detect) - self.connect(self.pk_detect, (self.sampler,1)) + self.connect(self.normalize, self.sub1, self.pk_detect) self.connect(self.pk_detect, (self.sample_and_hold,1)) - - self.connect(self.sampler, self) - - if 1: - self.connect(self.normalize, gr.file_sink(gr.sizeof_float, - "ofdm_sync_pnac-theta_f.dat")) - self.connect(self.angle, gr.file_sink(gr.sizeof_float, - "ofdm_sync_pnac-epsilon_f.dat")) - self.connect(self.pk_detect, gr.file_sink(gr.sizeof_char, - "ofdm_sync_pnac-peaks_b.dat")) - self.connect(self.sigmix, gr.file_sink(gr.sizeof_gr_complex, - "ofdm_sync_pnac-sigmix_c.dat")) - self.connect(self.sampler, gr.file_sink(gr.sizeof_gr_complex*fft_length, - "ofdm_sync_pnac-sampler_c.dat")) - self.connect(self.sample_and_hold, gr.file_sink(gr.sizeof_float, - "ofdm_sync_pnac-sample_and_hold_f.dat")) - self.connect(self.nco, gr.file_sink(gr.sizeof_gr_complex, - "ofdm_sync_pnac-nco_c.dat")) - self.connect(self.input, gr.file_sink(gr.sizeof_gr_complex, - "ofdm_sync_pnac-input_c.dat")) + + # Set output signals + # Output 0: fine frequency correction value + # Output 1: timing signal + self.connect(self.sample_and_hold, (self,0)) + self.connect(self.pk_detect, (self,1)) + + if logging: + self.connect(self.c2mag, gr.file_sink(gr.sizeof_float, "ofdm_sync_pnac-theta_f.dat")) + self.connect(self.normalize, gr.file_sink(gr.sizeof_float, "ofdm_sync_pnac-normalized_f.dat")) + self.connect(self.sub1, gr.file_sink(gr.sizeof_float, "ofdm_sync_pnac-sub1_f.dat")) + self.connect(self.angle, gr.file_sink(gr.sizeof_float, "ofdm_sync_pnac-epsilon_f.dat")) + self.connect(self.pk_detect, gr.file_sink(gr.sizeof_char, "ofdm_sync_pnac-peaks_b.dat")) + self.connect(self.sample_and_hold, gr.file_sink(gr.sizeof_float, "ofdm_sync_pnac-sample_and_hold_f.dat")) + self.connect(self.input, gr.file_sink(gr.sizeof_gr_complex, "ofdm_sync_pnac-input_c.dat")) |