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