--- /dev/null
+#
+# Copyright 2002 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING. If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+## transform low pass coefficients into bandpass coefficients
+
+function bp_taps = lp_to_bp (lp_taps, center_freq, sampling_freq)
+ arg = 2 * pi * center_freq / sampling_freq;
+ bp_taps = lp_taps .* exp (j*arg*(0:length(lp_taps)-1)');
+endfunction