def test_equalize_data(self):
num_of_subcarriers = 24
ofdm_obj = OFDM(num_of_subcarriers, cp_size=8)
onetap_equalizer = ofdm.OfdmOneTapEqualizer(ofdm_obj)
qam_obj = fundamental.QAM(4)
# Input data
data = np.random.randint(0, 4, size=2 * num_of_subcarriers)
# Modulate with QAM
symbols = qam_obj.modulate(data)
# Modulate with OFDM
transmit_data = ofdm_obj.modulate(symbols)
# xxxxxxxxxx Channel Parameters xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# Calculate the actual bandwidth that we will use
bandwidth = 55e3 * num_of_subcarriers
Fd = 50 # Doppler frequency (in Hz)
Ts = 1. / bandwidth # Sampling interval (in seconds)
NRays = 16 # Number of rays for the Jakes model
jakes = fading_generators.JakesSampleGenerator(Fd,
Ts,
NRays,
shape=None)
tdlchannel = fading.TdlChannel(
jakes,
tap_powers_dB=fading.COST259_TUx.tap_powers_dB,
tap_delays=fading.COST259_TUx.tap_delays)
channel_memory = tdlchannel.num_taps_with_padding - 1
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx Pass the signal through the channel xxxxxxxxxxxxxxxxxx
received_signal = tdlchannel.corrupt_data(transmit_data)
# Impulse response used to transmit the signal
last_impulse_response = tdlchannel.get_last_impulse_response()
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx OFDM Reception xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# Demodulate with OFDM
received_demodulated_data = ofdm_obj.demodulate(
received_signal[:-channel_memory])
received_equalized_data = onetap_equalizer.equalize_data(
received_demodulated_data, last_impulse_response)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx Demodulation and testing xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
demodulated_received_data = qam_obj.demodulate(received_equalized_data)
np.testing.assert_array_equal(data, demodulated_received_data)
# Jakes sample generator parameters
Fd = 5
Ts = 2.0e-7
L = 20
# Channel Profile
channel_profile = COST259_TUx.get_discretize_profile(Ts)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx Input generation (not part of OFDM) xxxxxxxxxxxxxxxxxxxxxx
# generate input data
input_data = np.random.random_integers(0, 4 - 1, num_symbols)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx QPSK and OFDM Modulators xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
qpsk_obj = QPSK()
ofdm_obj = OFDM(fft_size=fft_size, cp_size=cp_size,
num_used_subcarriers=num_used_subcarriers)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx Modulate data xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
modulated_data = qpsk_obj.modulate(input_data)
transmit_data = ofdm_obj.modulate(modulated_data)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx Transmit data through the channel xxxxxxxxxxxxxxxxxxxxxxxx
jakes = JakesSampleGenerator(Fd, Ts, L)
channel = SuChannel(jakes, channel_profile)
channel_memory = channel.num_taps_with_padding - 1
received_data = channel.corrupt_data(transmit_data)
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# xxxxxxxxxx OFDM Demodulate data xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
def setUp(self):
"""Called before each test."""
self.ofdm_object = OFDM(64, 16, 52)
