mirror of
https://gitlab.science.ru.nl/mthesis-edeboone/m-thesis-introduction.git
synced 2024-12-21 19:13:32 +01:00
Passband calculates power not amplitude
This commit is contained in:
parent
007bd7f963
commit
ee0f223423
2 changed files with 46 additions and 36 deletions
|
|
@ -1,4 +1,5 @@
|
|||
#!/usr/bin/env python3
|
||||
# vim: fdm=indent ts=4
|
||||
|
||||
__doc__ = \
|
||||
"""
|
||||
|
|
@ -45,31 +46,31 @@ def noisy_sine_realisation_snr(
|
|||
|
||||
|
||||
# determine signal to noise
|
||||
noise_level = bandlevel(noise, f_sample, noise_band)
|
||||
noise_power = bandpower(noise, f_sample, noise_band)
|
||||
if cut_signal_band_from_noise_band:
|
||||
lower_noise_band = passband(noise_band[0], signal_band[0])
|
||||
upper_noise_band = passband(signal_band[1], noise_band[1])
|
||||
|
||||
noise_level = bandlevel(noise, f_sample, lower_noise_band)
|
||||
noise_level += bandlevel(noise, f_sample, upper_noise_band)
|
||||
noise_power = bandpower(noise, f_sample, lower_noise_band)
|
||||
noise_power += bandpower(noise, f_sample, upper_noise_band)
|
||||
|
||||
signal_level = bandlevel(samples, f_sample, signal_band)
|
||||
signal_power = bandpower(samples, f_sample, signal_band)
|
||||
|
||||
snrs[j] = np.sqrt(signal_level/noise_level)
|
||||
snrs[j] = np.sqrt(signal_power/noise_power)
|
||||
|
||||
# make a nice plot showing what ranges were taken
|
||||
# and the bandlevels associated with them
|
||||
# and the bandpowers associated with them
|
||||
if return_ranges_plot and j == 0:
|
||||
combined_fft, freqs = ft_spectrum(samples+noise, f_sample)
|
||||
freq_scaler=1
|
||||
|
||||
# plot the original signal
|
||||
if False:
|
||||
_, ax = plt.subplots()
|
||||
ax = plot_signal(samples+noise, sample_rate=f_sample/1e6, time_unit='us', ax=ax)
|
||||
ax = plot_signal(samples+noise, sample_rate=f_sample/freq_scaler, time_unit='us', ax=ax)
|
||||
|
||||
# plot the spectrum
|
||||
if True:
|
||||
freq_scaler=1e6
|
||||
_, axs = plot_combined_spectrum(combined_fft, freqs, freq_scaler=freq_scaler, freq_unit='MHz')
|
||||
|
||||
# indicate band ranges and frequency
|
||||
|
|
@ -81,17 +82,22 @@ def noisy_sine_realisation_snr(
|
|||
# indicate initial phase
|
||||
axs[1].axhline(init_params[2], color='r', alpha=0.4)
|
||||
|
||||
# plot the band levels
|
||||
levelax = axs[0].twinx()
|
||||
levelax.set_ylabel("Bandlevel")
|
||||
levelax.hlines(signal_level, noise_band[0]/freq_scaler, signal_band[1]/freq_scaler, colors=['orange'])
|
||||
levelax.hlines(noise_level, noise_band[0]/freq_scaler, noise_band[1]/freq_scaler, colors=['purple'])
|
||||
levelax.set_ylim(bottom=0)
|
||||
# plot the band powers
|
||||
if False:
|
||||
powerax = axs[0].twinx()
|
||||
powerax.set_ylabel("Bandpower")
|
||||
else:
|
||||
powerax = axs[0]
|
||||
|
||||
powerax.hlines(np.sqrt(signal_power), noise_band[0]/freq_scaler, noise_band[1]/freq_scaler, colors=['orange'], zorder=5)
|
||||
powerax.hlines(np.sqrt(noise_power), noise_band[0]/freq_scaler, noise_band[1]/freq_scaler, colors=['purple'], zorder=5)
|
||||
|
||||
powerax.set_ylim(bottom=0)
|
||||
|
||||
axs[0].legend()
|
||||
|
||||
# plot signal_band pass signal
|
||||
if False:
|
||||
if True:
|
||||
freqs = np.fft.fftfreq(len(samples), 1/f_sample)
|
||||
bandmask = bandpass_mask(freqs, band=signal_band)
|
||||
fft = np.fft.fft(samples)
|
||||
|
|
@ -99,7 +105,7 @@ def noisy_sine_realisation_snr(
|
|||
bandpassed_samples = np.fft.ifft(fft)
|
||||
|
||||
_, ax3 = plt.subplots()
|
||||
ax3 = plot_signal(bandpassed_samples, sample_rate=f_sample/1e6, time_unit='us', ax=ax3)
|
||||
ax3 = plot_signal(bandpassed_samples, sample_rate=f_sample/freq_scaler, time_unit='us', ax=ax3)
|
||||
ax3.set_title("Bandpassed Signal")
|
||||
|
||||
|
||||
|
|
@ -122,10 +128,10 @@ if __name__ == "__main__":
|
|||
args.fname = None
|
||||
|
||||
###
|
||||
t_lengths = np.linspace(1e3, 5e4, 5)* 1e-9 # s
|
||||
N = 10e1
|
||||
fs_sine = [33.3e6, 50e6, 73.3e6] # Hz
|
||||
fs_sample = [250e6, 500e6] # Hz
|
||||
t_lengths = np.linspace(1, 50, 50) # us
|
||||
N = 50e0
|
||||
fs_sine = [33.3, 50, 73.3] # MHz
|
||||
fs_sample = [250, 500] # MHz
|
||||
if False:
|
||||
# show t_length and fs_sample really don't care
|
||||
fs_iter = [ (fs_sample[0], f_sine, t_lengths) for f_sine in fs_sine ]
|
||||
|
|
@ -146,7 +152,7 @@ if __name__ == "__main__":
|
|||
for i in range(int(N)):
|
||||
delta_f = 1/t_length
|
||||
signal_band = passband(f_sine- 3*delta_f, f_sine + 3*delta_f)
|
||||
noise_band = passband(30e6, 80e6)
|
||||
noise_band = passband(30, 80) # MHz
|
||||
|
||||
snrs[i], axs = noisy_sine_realisation_snr(
|
||||
N=1,
|
||||
|
|
@ -161,7 +167,7 @@ if __name__ == "__main__":
|
|||
noise_band = noise_band,
|
||||
signal_band = signal_band,
|
||||
|
||||
return_ranges_plot=True,
|
||||
return_ranges_plot=False,
|
||||
rng=rng,
|
||||
)
|
||||
|
||||
|
|
@ -176,14 +182,17 @@ if __name__ == "__main__":
|
|||
plt.show(block=False)
|
||||
else:
|
||||
#original code
|
||||
sine_amp = 1
|
||||
noise_sigma = 4
|
||||
|
||||
my_snrs = np.zeros( (len(fs_iter), len(t_lengths), int(N)) )
|
||||
for i, (f_sample, f_sine, t_lengths) in enumerate( fs_iter ):
|
||||
for k, t_length in enumerate(t_lengths):
|
||||
return_ranges_plot = ((k==0) and True) or ( (k==(len(t_lengths)-1)) and True) and i < 1
|
||||
return_ranges_plot = ((k==0) and not True) or ( (k==(len(t_lengths)-1)) and True) and i < 1
|
||||
|
||||
delta_f = 1/t_length
|
||||
signal_band = passband(f_sine- 3*delta_f, f_sine + 3*delta_f)
|
||||
noise_band=passband(30e6, 80e6)
|
||||
signal_band = passband( *(f_sine + 2*delta_f*np.array([-1,1])) )
|
||||
noise_band=passband(30, 80) # MHz
|
||||
|
||||
my_snrs[i,k], axs = noisy_sine_realisation_snr(
|
||||
N=N,
|
||||
|
|
@ -192,8 +201,8 @@ if __name__ == "__main__":
|
|||
|
||||
# signal properties
|
||||
f_sine = f_sine,
|
||||
sine_amp = 1,
|
||||
noise_sigma = 1,
|
||||
sine_amp = sine_amp,
|
||||
noise_sigma = noise_sigma,
|
||||
|
||||
noise_band = noise_band,
|
||||
signal_band = signal_band,
|
||||
|
|
@ -207,12 +216,13 @@ if __name__ == "__main__":
|
|||
|
||||
# plot the snrs
|
||||
fig, axs2 = plt.subplots()
|
||||
fig.basefname="signal_to_noise"
|
||||
axs2.set_xlabel("$N = T*f_s$")
|
||||
axs2.set_ylabel("SNR")
|
||||
|
||||
for i, (f_sample, f_sine, t_lengths) in enumerate(fs_iter):
|
||||
# plot the means
|
||||
l = axs2.plot(t_lengths*f_sample, np.mean(my_snrs[i], axis=-1), marker='*', ls='none', label='f:{}MHz, fs:{}MHz'.format(f_sine/1e6, f_sample/1e6), markeredgecolor='black')
|
||||
l = axs2.plot(t_lengths*f_sample, np.mean(my_snrs[i], axis=-1), marker='*', ls='none', label='f:{}MHz, fs:{}MHz'.format(f_sine, f_sample), markeredgecolor='black')
|
||||
|
||||
color = l[0].get_color()
|
||||
|
||||
|
|
|
|||
|
|
@ -16,9 +16,9 @@ class passband(namedtuple("passband", ['low', 'high'], defaults=[0, np.inf])):
|
|||
def freq_mask(frequencies):
|
||||
return bandpass_mask(frequencies, self)
|
||||
|
||||
def signal_level(samples, samplerate, normalise_bandsize=True, **ft_kwargs):
|
||||
def signal_power(samples, samplerate, normalise_bandsize=True, **ft_kwargs):
|
||||
|
||||
return bandlevel(samples, samplerate, self, normalise_bandsize, **ft_kwargs)
|
||||
return bandpower(samples, samplerate, self, normalise_bandsize, **ft_kwargs)
|
||||
|
||||
def filter_samples(samples, samplerate, **ft_kwargs):
|
||||
"""
|
||||
|
|
@ -52,7 +52,7 @@ def bandpass_mask(freqs, band=passband()):
|
|||
def bandsize(band = passband()):
|
||||
return band[1] - band[0]
|
||||
|
||||
def bandlevel(samples, samplerate=1, band=passband(), normalise_bandsize=True, **ft_kwargs):
|
||||
def bandpower(samples, samplerate=1, band=passband(), normalise_bandsize=True, **ft_kwargs):
|
||||
fft, freqs = ft_spectrum(samples, samplerate, **ft_kwargs)
|
||||
|
||||
bandmask = bandpass_mask(freqs, band=band)
|
||||
|
|
@ -62,9 +62,9 @@ def bandlevel(samples, samplerate=1, band=passband(), normalise_bandsize=True, *
|
|||
else:
|
||||
bins = 1
|
||||
|
||||
level = np.sum(np.abs(fft[bandmask])**2)
|
||||
power = np.sum(np.abs(fft[bandmask])**2)
|
||||
|
||||
return level/bins
|
||||
return power/bins
|
||||
|
||||
def signal_to_noise( samplerate, samples, noise, signal_band, noise_band=None):
|
||||
if noise_band is None:
|
||||
|
|
@ -73,9 +73,9 @@ def signal_to_noise( samplerate, samples, noise, signal_band, noise_band=None):
|
|||
if noise is None:
|
||||
noise = samples
|
||||
|
||||
noise_level = bandlevel(noise, samplerate, noise_band)
|
||||
noise_power = bandpower(noise, samplerate, noise_band)
|
||||
|
||||
signal_level = bandlevel(samples, samplerate, signal_band)
|
||||
signal_power = bandpower(samples, samplerate, signal_band)
|
||||
|
||||
return (signal_level/noise_level)**0.5
|
||||
return (signal_power/noise_power)**0.5
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue