xi = rdsBand[::2] * c57
xq = rdsBand[1::2] * (-c57)
# low-pass filter
filtLP = signal.remez(400, [0, 2400, 3000, sampleRate / 4], [1, 0], Hz=sampleRate / 2)
xfi = signal.convolve(xi, filtLP)
xfq = signal.convolve(xq, filtLP)
# shape filter
shapeFilt = shaping_filter.rrcosfilter(300, 1, 1 / (2 * 1187.5), sampleRate / 2)[1]
xsfi = signal.convolve(xfi, shapeFilt)
xsfq = signal.convolve(xfq, shapeFilt)
if len(xsfi) % 2 == 1:
xsfi = xsfi[:-1]
xsfq = xsfq[:-1]
# downsample
xdi = (xsfi[::2] + xsfi[1::2]) / 2
xdq = xsfq[::2]
c57 = numpy.tile([1., -1.], len(rdsBand) / 4)
xi = rdsBand[::2] * c57
xq = rdsBand[1::2] * (-c57)
# low-pass filter
filtLP = signal.remez(400, [0, 2400, 3000, sampleRate / 4], [1, 0],
Hz=sampleRate / 2)
xfi = signal.convolve(xi, filtLP)
xfq = signal.convolve(xq, filtLP)
# shape filter
shapeFilt = shaping_filter.rrcosfilter(300, 1, 1 / (2 * 1187.5),
sampleRate / 2)[1]
xsfi = signal.convolve(xfi, shapeFilt)
xsfq = signal.convolve(xfq, shapeFilt)
if len(xsfi) % 2 == 1:
xsfi = xsfi[:-1]
xsfq = xsfq[:-1]
# downsample
xdi = (xsfi[::2] + xsfi[1::2]) / 2
xdq = xsfq[::2]
# remove phase drift using a moving average
def pulse_shaping_filter(length, sample_rate):
return shaping.rrcosfilter(length, 1, 1 / (2 * 1187.5), sample_rate + 1)[1]
def pulse_shaping_filter(length, sample_rate):
return shaping.rrcosfilter(length, 1, 1/(2*1187.5), sample_rate+1) [1]