def generate_test_sync_samples(M, K, L, alpha, cp_len, ramp_len, snr_dB, test_cfo, init_phase=0.0, ref_data=False):
block_len = M * K
data = get_random_qpsk(block_len, seed=generate_seed('awesomepayloadblabla'))
print 'QPSK source energy: ', calculate_average_signal_energy(data)
x = get_gfdm_frame(data, alpha, M, K, L, cp_len, ramp_len)
pn_symbols = get_random_qpsk(K, seed=generate_seed('awesome'))
preamble, x_preamble = generate_sync_symbol(pn_symbols, 'rrc', alpha, K, L, cp_len, ramp_len)
print 'frame energy:', calculate_average_signal_energy(x), 'preamble energy:', calculate_average_signal_energy(preamble)
frame = np.concatenate((preamble, x))
print 'tx frame len', len(frame), 'len(preamble)', len(preamble)
# simulate Noise and frequency offset!
phase_inc = cfo_to_phase_increment(test_cfo, K)
print 'phase_increment: ', phase_inc
wave = complex_sine(phase_inc, len(frame), init_phase)
# phase_shift = np.repeat(np.exp(1j * init_phase), len(frame))
# wave *= phase_shift
frame *= wave
noise_variance = calculate_awgn_noise_variance(frame, snr_dB)
s = get_complex_noise_vector(2 * block_len + len(frame), noise_variance)
s[block_len:block_len + len(frame)] += frame
if ref_data:
return s, x_preamble, pn_symbols, data
return s, x_preamble, pn_symbols
def main():
np.set_printoptions(precision=4, suppress=True)
# preamble_auto_corr_test()
sync_test()
return
# cfo = 1.024e-5
samp_rate = 12.5e6
freq = 20.
fft_len = 256
sc_bw = samp_rate / fft_len
cfo = freq_to_cfo(freq, fft_len, samp_rate)
ph_i = cfo_to_phase_increment(cfo, fft_len)
phase_inc = phase_increment(freq, samp_rate)
print 'samp_rate: {}, frequency: {}, fft_len: {}'.format(
samp_rate, freq, fft_len)
print 'subcarrier bandwidth: {}, cfo: {}, phase increment: {}/{}'.format(
sc_bw, cfo, ph_i, phase_inc)
# wave = get_complex_sine(freq, samp_rate, 129)
# s = np.ones(129)
# s = correct_frequency_offset(s, cfo, fft_len)
# # print wave
# print np.abs(wave - s)
preamble, x_preamble = generate_sync_symbol(
get_random_qpsk(fft_len, seed=generate_seed('awesome')), 'rrc', .5,
fft_len, 2, fft_len // 2, fft_len // 8)
init_phase = 0.8
wave = complex_sine(cfo_to_phase_increment(cfo, fft_len), len(preamble))
# phase_shift = np.repeat(, len(preamble))
wave *= np.exp(1j * init_phase)
preamble *= wave
print phase_inc
ac = auto_correlate_halfs(preamble[64:64 + 2 * fft_len])
fp = np.angle(ac)
ac_phase_inc = fp / fft_len
print 'auto corr phase: {}, AC phase {}, phase_inc: {}'.format(
phase_inc, fp, ac_phase_inc)
xc = cross_correlate_signal(preamble, x_preamble)
ap = np.angle(xc[64])
# print ap, (ap - init_phase) / (cfo * 2 * np.pi)
residual = ap - init_phase
res_phase = residual / (2 * fft_len)
print residual, res_phase, phase_inc / res_phase
# print fp, fp / (2 * np.pi)
# print (ap - init_phase) - fp
plt.plot(np.abs(xc) / 10000.)
plt.plot(np.angle(xc))
plt.show()
def main():
import matplotlib.pyplot as plt
np.set_printoptions(precision=4, suppress=True)
# preamble_auto_corr_test()
sync_test()
return
# cfo = 1.024e-5
samp_rate = 12.5e6
freq = 20.
fft_len = 256
sc_bw = samp_rate / fft_len
cfo = freq_to_cfo(freq, fft_len, samp_rate)
ph_i = cfo_to_phase_increment(cfo, fft_len)
phase_inc = phase_increment(freq, samp_rate)
print 'samp_rate: {}, frequency: {}, fft_len: {}'.format(samp_rate, freq, fft_len)
print 'subcarrier bandwidth: {}, cfo: {}, phase increment: {}/{}'.format(sc_bw, cfo, ph_i, phase_inc)
# wave = get_complex_sine(freq, samp_rate, 129)
# s = np.ones(129)
# s = correct_frequency_offset(s, cfo, fft_len)
# # print wave
# print np.abs(wave - s)
preamble, x_preamble = generate_sync_symbol(get_random_qpsk(fft_len, seed=generate_seed('awesome')), 'rrc', .5, fft_len, 2, fft_len // 2, fft_len // 8)
init_phase = 0.8
wave = complex_sine(cfo_to_phase_increment(cfo, fft_len), len(preamble))
# phase_shift = np.repeat(, len(preamble))
wave *= np.exp(1j * init_phase)
preamble *= wave
print phase_inc
ac = auto_correlate_halfs(preamble[64:64 + 2 * fft_len])
fp = np.angle(ac)
ac_phase_inc = fp / fft_len
print 'auto corr phase: {}, AC phase {}, phase_inc: {}'.format(phase_inc, fp, ac_phase_inc)
xc = cross_correlate_signal(preamble, x_preamble)
ap = np.angle(xc[64])
# print ap, (ap - init_phase) / (cfo * 2 * np.pi)
residual = ap - init_phase
res_phase = residual / (2 * fft_len)
print residual, res_phase, phase_inc / res_phase
# print fp, fp / (2 * np.pi)
# print (ap - init_phase) - fp
plt.plot(np.abs(xc) / 10000.)
plt.plot(np.angle(xc))
plt.show()
def preamble_auto_corr_test():
K = 32
pn_seq = get_random_qpsk(K)
pn_symbols = np.tile(pn_seq, 2)
D = get_data_matrix(pn_symbols, K, True)
# print np.shape(D)
print 'subcarriers bear same symbols:', np.all(D[0] == D[1])
pl, p = generate_sync_symbol(pn_seq, 'rrc', .5, K, 2, K, K / 2)
# print np.shape(p)
acc = auto_correlate_halfs(p)
print acc, np.angle(acc)
taps = gfdm_filter_taps('rrc', .5, 2, K, 1)
A = gfdm_modulation_matrix(taps, 2, K)
x = A.dot(pn_symbols)
# print np.shape(x)
acc = auto_correlate_halfs(x)
print acc, np.angle(acc)
def preamble_auto_corr_test():
K = 32
pn_seq = get_random_qpsk(K)
pn_symbols = np.tile(pn_seq, 2)
D = get_data_matrix(pn_symbols, K, True)
# print np.shape(D)
print 'subcarriers bear same symbols:', np.all(D[0] == D[1])
pl, p = generate_sync_symbol(pn_seq, 'rrc', .5, K, 2, K, K / 2)
# print np.shape(p)
acc = auto_correlate_halfs(p)
print acc, np.angle(acc)
taps = gfdm_filter_taps('rrc', .5, 2, K, 1)
A = gfdm_modulation_matrix(taps, 2, K)
x = A.dot(pn_symbols)
# print np.shape(x)
acc = auto_correlate_halfs(x)
print acc, np.angle(acc)
def generate_test_sync_samples(M, K, L, alpha, cp_len, ramp_len, snr_dB,
test_cfo):
block_len = M * K
data = get_random_qpsk(block_len,
seed=generate_seed('awesomepayloadblabla'))
x = get_gfdm_frame(data, alpha, M, K, L, cp_len, ramp_len)
preamble, x_preamble = generate_sync_symbol(
get_random_qpsk(K, seed=generate_seed('awesome')), 'rrc', alpha, K, L,
cp_len, ramp_len)
print 'frame energy:', calculate_average_signal_energy(
x), 'preamble energy:', calculate_average_signal_energy(preamble)
preamble *= np.sqrt(
calculate_average_signal_energy(x) /
calculate_average_signal_energy(preamble))
frame = np.concatenate((preamble, x))
# simulate Noise and frequency offset!
frame = correct_frequency_offset(frame, test_cfo / (-2. * K))
noise_variance = calculate_awgn_noise_variance(frame, snr_dB)
s = get_complex_noise_vector(2 * block_len + len(frame), noise_variance)
s[block_len:block_len + len(frame)] += frame
return s, x_preamble
