def test_estimate_channel_multiple_rx(self):
Nsc = 300 # 300 subcarriers
size = Nsc // 2
Nzc = 139
user1_seq = SrsUeSequence(
RootSequence(root_index=25, size=size, Nzc=Nzc), 1)
user2_seq = SrsUeSequence(
RootSequence(root_index=25, size=size, Nzc=Nzc), 4)
ue1_channel_estimator = CazacBasedChannelEstimator(user1_seq)
speed_terminal = 3/3.6 # Speed in m/s
fcDbl = 2.6e9 # Central carrier frequency (in Hz)
subcarrier_bandwidth = 15e3 # Subcarrier bandwidth (in Hz)
wave_length = 3e8/fcDbl # Carrier wave length
Fd = speed_terminal / wave_length # Doppler Frequency
Ts = 1./(Nsc * subcarrier_bandwidth) # Sampling interval
L = 16 # Number of jakes taps
# Create the fading generators and set multiple receive antennas
jakes1 = JakesSampleGenerator(Fd, Ts, L, shape=(3, 1))
jakes2 = JakesSampleGenerator(Fd, Ts, L, shape=(3, 1))
# Create a TDL channel object for each user
tdlchannel1 = TdlChannel(jakes1, channel_profile=COST259_TUx)
tdlchannel2 = TdlChannel(jakes2, channel_profile=COST259_TUx)
# Generate channel that would corrupt the transmit signal.
tdlchannel1._generate_impulse_response(1)
tdlchannel2._generate_impulse_response(1)
# Get the generated impulse response
impulse_response1 = tdlchannel1.get_last_impulse_response()
impulse_response2 = tdlchannel2.get_last_impulse_response()
# Get the corresponding frequency response
freq_resp_1 = impulse_response1.get_freq_response(Nsc)
H1 = freq_resp_1[:, :, 0, 0]
freq_resp_2 = impulse_response2.get_freq_response(Nsc)
H2 = freq_resp_2[:, :, 0, 0]
# Sequence of the users
r1 = user1_seq.seq_array()
r2 = user2_seq.seq_array()
# Received signal (in frequency domain) of user 1
comb_indexes = np.arange(0, Nsc, 2)
Y1 = H1[comb_indexes, :] * r1[:, np.newaxis]
Y2 = H2[comb_indexes, :] * r2[:, np.newaxis]
Y = Y1 + Y2
# Calculate expected estimated channel for user 1
y1 = np.fft.ifft(np.conj(r1[:, np.newaxis]) * Y, size, axis=0)
tilde_h1_espected = y1[0:16]
tilde_H1_espected = np.fft.fft(tilde_h1_espected, Nsc, axis=0)
# Test the CazacBasedChannelEstimator estimation
H1_estimated = ue1_channel_estimator.estimate_channel_freq_domain(Y.T, 15)
np.testing.assert_array_almost_equal(
H1_estimated, tilde_H1_espected.T)
# Test if true channel and estimated channel are similar. Since the
# channel estimation error is higher at the first and last
# subcarriers we will test only the inner 200 subcarriers
error = np.abs(H1[50:-50, :] - tilde_H1_espected[50:-50, :])
np.testing.assert_almost_equal(error/2., np.zeros(error.shape), decimal=2)
def test_estimate_channel_multiple_rx(self):
user1_seq = srs.SrsUeSequence(
1,
srs.SrsRootSequence(root_index=25, Nzc=139, extend_to=150))
user2_seq = srs.SrsUeSequence(
4,
srs.SrsRootSequence(root_index=25, Nzc=139, extend_to=150))
ue1_channel_estimator = srs.SrsChannelEstimator(user1_seq)
Nsc = 300 # 300 subcarriers
speed_terminal = 3/3.6 # Speed in m/s
fcDbl = 2.6e9 # Central carrier frequency (in Hz)
subcarrier_bandwidth = 15e3 # Subcarrier bandwidth (in Hz)
wave_length = 3e8/fcDbl # Carrier wave length
Fd = speed_terminal / wave_length # Doppler Frequency
Ts = 1./(Nsc * subcarrier_bandwidth) # Sampling interval
L = 16 # Number of jakes taps
# Create the fading generators and set multiple receive antennas
jakes1 = JakesSampleGenerator(Fd, Ts, L, shape=(3, 1))
jakes2 = JakesSampleGenerator(Fd, Ts, L, shape=(3, 1))
# Create a TDL channel object for each user
tdlchannel1 = TdlChannel(jakes1, channel_profile=COST259_TUx)
tdlchannel2 = TdlChannel(jakes2, channel_profile=COST259_TUx)
# Generate channel that would corrupt the transmit signal.
tdlchannel1._generate_impulse_response(1)
tdlchannel2._generate_impulse_response(1)
# Get the generated impulse response
impulse_response1 = tdlchannel1.get_last_impulse_response()
impulse_response2 = tdlchannel2.get_last_impulse_response()
# Get the corresponding frequency response
freq_resp_1 = impulse_response1.get_freq_response(Nsc)
H1 = freq_resp_1[:, :, 0, 0]
freq_resp_2 = impulse_response2.get_freq_response(Nsc)
H2 = freq_resp_2[:, :, 0, 0]
# Sequence of the users
r1 = user1_seq.seq_array()
r2 = user2_seq.seq_array()
# Received signal (in frequency domain) of user 1
comb_indexes = np.arange(0, Nsc, 2)
Y1 = H1[comb_indexes, :] * r1[:, np.newaxis]
Y2 = H2[comb_indexes, :] * r2[:, np.newaxis]
Y = Y1 + Y2
# Calculate expected estimated channel for user 1
y1 = np.fft.ifft(np.conj(r1[:, np.newaxis]) * Y, 150, axis=0)
tilde_h1_espected = y1[0:16]
tilde_H1_espected = np.fft.fft(tilde_h1_espected, Nsc, axis=0)
# Test the SrsChannelEstimator estimation
H1_estimated = ue1_channel_estimator.estimate_channel_freq_domain(Y.T, 16)
np.testing.assert_array_almost_equal(
H1_estimated, tilde_H1_espected.T)
# Test if true channel and estimated channel are similar. Since the
# channel estimation error is higher at the first and last
# subcarriers we will test only the inner 200 subcarriers
error = np.abs(H1[50:-50, :] - tilde_H1_espected[50:-50, :])
np.testing.assert_almost_equal(error/2., np.zeros(error.shape), decimal=2)
def test_estimate_channel_with_dmrs(self):
Nsc = 24
size = Nsc
user1_seq = DmrsUeSequence(
RootSequence(root_index=17, size=size), 1)
user2_seq = DmrsUeSequence(
RootSequence(root_index=13, size=size), 4)
ue1_channel_estimator = CazacBasedChannelEstimator(user1_seq,
size_multiplier=1)
speed_terminal = 3/3.6 # Speed in m/s
fcDbl = 2.6e9 # Central carrier frequency (in Hz)
subcarrier_bandwidth = 15e3 # Subcarrier bandwidth (in Hz)
wave_length = 3e8/fcDbl # Carrier wave length
Fd = speed_terminal / wave_length # Doppler Frequency
Ts = 1./(Nsc * subcarrier_bandwidth) # Sampling interval
L = 16 # Number of jakes taps
jakes1 = JakesSampleGenerator(Fd, Ts, L)
jakes2 = JakesSampleGenerator(Fd, Ts, L)
# Create a TDL channel object for each user
tdlchannel1 = TdlChannel(jakes1, channel_profile=COST259_TUx)
tdlchannel2 = TdlChannel(jakes2, channel_profile=COST259_TUx)
# Generate channel that would corrupt the transmit signal.
tdlchannel1._generate_impulse_response(1)
tdlchannel2._generate_impulse_response(1)
# Get the generated impulse response
impulse_response1 = tdlchannel1.get_last_impulse_response()
impulse_response2 = tdlchannel2.get_last_impulse_response()
# Get the corresponding frequency response
freq_resp_1 = impulse_response1.get_freq_response(Nsc)
H1 = freq_resp_1[:, 0]
freq_resp_2 = impulse_response2.get_freq_response(Nsc)
H2 = freq_resp_2[:, 0]
# Sequence of the users
r1 = user1_seq.seq_array()
r2 = user2_seq.seq_array()
# Received signal (in frequency domain) of user 1
Y1 = H1 * r1
Y2 = H2 * r2
Y = Y1 + Y2
# Calculate expected estimated channel for user 1
y1 = np.fft.ifft(np.conj(r1) * Y, size)
tilde_h1 = y1[0:4]
tilde_H1 = np.fft.fft(tilde_h1, Nsc)
# xxxxxx DEBUG xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
a = y1[0:4]
A = np.fft.fft(a, Nsc)
import matplotlib.pyplot as plt
# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
# Test the CazacBasedChannelEstimator estimation
np.testing.assert_array_almost_equal(
ue1_channel_estimator.estimate_channel_freq_domain(Y, 3),
tilde_H1)
# Test if true channel and estimated channel are similar. Since the
# channel estimation error is higher at the first and last
# subcarriers we will test only the inner 200 subcarriers
error = np.abs(H1[5:-5] - tilde_H1[5:-5])
np.testing.assert_almost_equal(
error/2., np.zeros(error.size), decimal=2)