diff options
| -rwxr-xr-x | correlate_with_ref.py | 31 | ||||
| -rw-r--r-- | example_corr.png | bin | 25850 -> 253736 bytes |
2 files changed, 23 insertions, 8 deletions
diff --git a/correlate_with_ref.py b/correlate_with_ref.py index c086567..44e5a16 100755 --- a/correlate_with_ref.py +++ b/correlate_with_ref.py @@ -1,8 +1,14 @@ #!/usr/bin/env python # -# Correlate with the phase reference symbol +# Find NULL symbols in file, then correlate with the phase reference symbol and +# plot the resulting correlation result. # -# Licence: see LICENCE file +# This will display the Channel Impulse Reference +# +# Copyright (C) 2016 +# Matthias P. Braendli, matthias.braendli@mpb.li +# http://www.opendigitalradio.org +# Licence: The MIT License, see LICENCE file import numpy as np import matplotlib.pyplot as pp @@ -21,10 +27,13 @@ class CIR_Correlate: self.phase_ref = np.fromfile("phasereference.2048000.fc64.iq", np.complex64) if iq_format == "u8": - channel_out1 = np.fromfile(iq_filename, np.uint8) - channel_out2 = channel_out1.reshape(2, int(len(channel_out1)/2)) - channel_out3 = channel_out2[0,...] + 1j * channel_out2[1,...] - self.channel_out = channel_out3.astype(np.complex64) / 256.0 - (0.5+0.5j) + channel_u8_interleaved = np.fromfile(iq_filename, np.uint8) + channel_u8_iq = channel_u8_interleaved.reshape(int(len(channel_u8_interleaved)/2), 2) + # This directly converts to fc64 + channel_fc64_unscaled = channel_u8_iq[...,0] + np.complex64(1j) * channel_u8_iq[...,1] + channel_fc64_scaled = (channel_fc64_unscaled - 127.0) / 128.0 + channel_fc64_dc_comp = channel_fc64_scaled - np.average(channel_fc64_scaled) + self.channel_out = channel_fc64_dc_comp elif iq_format == "fc64": self.channel_out = np.fromfile(iq_filename, np.complex64) else: @@ -99,7 +108,7 @@ class CIR_Correlate: pp.subplot(211) pp.plot(cirs.sum(axis=0)) pp.subplot(212) - pp.imshow(cirs) + pp.imshow(cirs, aspect='auto') if plot_file: pp.savefig(plot_file) @@ -112,7 +121,7 @@ if __name__ == "__main__": print("Usage") print(" script [fc64|u8] <filename> [<figure filename>]") print(" fc64: file is 32-bit float I + 32-bit float Q") - print(" u8: file is 8-bit unsigned I + 8-bit unsigned Q") + print(" u8: file is 8-bit signed I + 8-bit signed Q") print(" if <figure filename> is given, save the figure instead of showing it") sys.exit(1) @@ -125,7 +134,13 @@ if __name__ == "__main__": file_figure = sys.argv[3] cir_corr = CIR_Correlate(file_in, file_format) + cir_corr.plot(file_figure) + + print("Null symbols at:") + print(" " + " ".join("{}".format(t_null) + for t_null in cir_corr.null_symbol_ixs)) + print("Done") diff --git a/example_corr.png b/example_corr.png Binary files differindex 810bb26..187d5f6 100644 --- a/example_corr.png +++ b/example_corr.png |
