def compare_subcarrier_location(alpha, M, K, overlap, oversampling_factor):
import matplotlib.pyplot as plt
import matplotlib.cm as cm
goofy_ordering = False
taps = gfdm_filter_taps('rrc', alpha, M, K, oversampling_factor)
A0 = gfdm_modulation_matrix(taps, M, K, oversampling_factor, group_by_subcarrier=goofy_ordering)
n = np.arange(M * K * oversampling_factor, dtype=np.complex)
colors = iter(cm.rainbow(np.linspace(0, 1, K)))
for k in range(K):
color = next(colors)
f = np.exp(1j * 2 * np.pi * (float(k) / (K * oversampling_factor)) * n)
F = abs(np.fft.fft(f))
fm = np.argmax(F) / M
plt.plot(F, '-.', label=k, color=color)
data = get_zero_f_data(k, K, M)
x0 = gfdm_gr_modulator(data, 'rrc', alpha, M, K, overlap, compat_mode=goofy_ordering) * (2. / K)
f0 = 1. * np.argmax(abs(np.fft.fft(x0))) / M
plt.plot(abs(np.fft.fft(x0)), label='FFT' + str(k), color=color)
xA = A0.dot(get_data_matrix(data, K, group_by_subcarrier=goofy_ordering).flatten()) * (1. / K)
fA = np.argmax(abs(np.fft.fft(xA))) / M
plt.plot(abs(np.fft.fft(xA)), '-', label='matrix' + str(k), color=color)
print fm, fA, f0
plt.legend()
plt.show()
def validate_subcarrier_location(alpha, M, K, overlap, oversampling_factor):
goofy_ordering = False
taps = gfdm_filter_taps('rrc', alpha, M, K, oversampling_factor)
A0 = gfdm_modulation_matrix(taps,
M,
K,
oversampling_factor,
group_by_subcarrier=goofy_ordering)
n = np.arange(M * K * oversampling_factor, dtype=np.complex)
for k in range(K):
f = np.exp(1j * 2 * np.pi * (float(k) / (K * oversampling_factor)) * n)
F = abs(np.fft.fft(f))
fm = 1. * np.argmax(F) / M
data = get_zero_f_data(k, K, M)
x0 = gfdm_gr_modulator(
data, 'rrc', alpha, M, K, overlap,
compat_mode=goofy_ordering) * (2. / K)
f0 = 1. * np.argmax(abs(np.fft.fft(x0))) / M
xA = A0.dot(
get_data_matrix(
data, K,
group_by_subcarrier=goofy_ordering).flatten()) * (1. / K)
fA = 1. * np.argmax(abs(np.fft.fft(xA))) / M
if not fm == fA == f0:
raise RuntimeError(
'ERROR: subcarriers are not located at the same bins!')
def compare_subcarrier_combination():
M = 8
K = 4
overlap = 2
data = get_zero_f_data(0, K, M)
data += 2 * get_zero_f_data(3, K, M)
print data
F = get_data_matrix(data, K, False)
print F
F = np.reshape(np.tile(F.flatten(), overlap), (-1, K))
X0 = np.real(gfdm_combine_subcarriers_in_fd(F, M, K, overlap))
print X0
X = np.zeros(M * K, dtype=np.complex)
for k in range(K):
s = np.zeros(M * K, dtype=np.complex)
s[0:M * overlap] = F[:, k]
s = np.roll(s, k * M - M / 2)
X += s
print np.real(np.roll(X, -M / 2))
print np.all(np.roll(X, -M / 2) == X0)
print np.all(X == X0)
print np.real(X)
def validate_subcarrier_location(alpha, M, K, overlap, oversampling_factor):
goofy_ordering = False
taps = gfdm_filter_taps('rrc', alpha, M, K, oversampling_factor)
A0 = gfdm_modulation_matrix(taps, M, K, oversampling_factor, group_by_subcarrier=goofy_ordering)
n = np.arange(M * K * oversampling_factor, dtype=np.complex)
for k in range(K):
f = np.exp(1j * 2 * np.pi * (float(k) / (K * oversampling_factor)) * n)
F = abs(np.fft.fft(f))
fm = 1. * np.argmax(F) / M
data = get_zero_f_data(k, K, M)
x0 = gfdm_gr_modulator(data, 'rrc', alpha, M, K, overlap, compat_mode=goofy_ordering) * (2. / K)
f0 = 1. * np.argmax(abs(np.fft.fft(x0))) / M
xA = A0.dot(get_data_matrix(data, K, group_by_subcarrier=goofy_ordering).flatten()) * (1. / K)
fA = 1. * np.argmax(abs(np.fft.fft(xA))) / M
if not fm == fA == f0:
raise RuntimeError('ERROR: subcarriers are not located at the same bins!')