1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
# -*- coding: utf-8 -*-
import numpy as np
import scipy
import matplotlib
matplotlib.use('agg')
import matplotlib.pyplot as plt
import datetime
import src.subsample_align as sa
from scipy import signal
import logging
class Dab_Util:
"""Collection of methods that can be applied to an array
complex IQ samples of a DAB signal
"""
def __init__(self, sample_rate):
"""
:param sample_rate: sample rate [sample/sec] to use for calculations
"""
self.sample_rate = sample_rate
self.dab_bandwidth = 1536000 #Bandwidth of a dab signal
self.frame_ms = 96 #Duration of a Dab frame
def lag(self, sig_orig, sig_rec):
"""
Find lag between two signals
Args:
sig_orig: The signal that has been sent
sig_rec: The signal that has been recored
"""
off = sig_rec.shape[0]
c = signal.correlate(sig_orig, sig_rec)
corr_path = ('/tmp/tx_rx_corr_' +
datetime.datetime.now().isoformat() +
'.pdf')
plt.plot(np.real(c[:10000]), label="corr")
plt.legend()
plt.savefig(corr_path)
plt.clf()
return np.argmax(c) - off + 1
def lag_upsampling(self, sig_orig, sig_rec, n_up):
if n_up != 1:
sig_orig_up = signal.resample(sig_orig, sig_orig.shape[0] * n_up)
sig_rec_up = signal.resample(sig_rec, sig_rec.shape[0] * n_up)
else:
sig_orig_up = sig_orig
sig_rec_up = sig_rec
l = self.lag(sig_orig_up, sig_rec_up)
l_orig = float(l) / n_up
return l_orig
def subsample_align_upsampling(self, sig1, sig2, n_up=32):
"""
Returns an aligned version of sig1 and sig2 by cropping and subsample alignment
Using upsampling
"""
assert(sig1.shape[0] == sig2.shape[0])
if sig1.shape[0] % 2 == 1:
sig1 = sig1[:-1]
sig2 = sig2[:-1]
sig1_up = signal.resample(sig1, sig1.shape[0] * n_up)
sig2_up = signal.resample(sig2, sig2.shape[0] * n_up)
off_meas = self.lag_upsampling(sig2_up, sig1_up, n_up=1)
off = int(abs(off_meas))
if off_meas > 0:
sig1_up = sig1_up[:-off]
sig2_up = sig2_up[off:]
elif off_meas < 0:
sig1_up = sig1_up[off:]
sig2_up = sig2_up[:-off]
sig1 = signal.resample(sig1_up, sig1_up.shape[0] / n_up).astype(np.complex64)
sig2 = signal.resample(sig2_up, sig2_up.shape[0] / n_up).astype(np.complex64)
return sig1, sig2
def subsample_align(self, sig1, sig2):
"""
Returns an aligned version of sig1 and sig2 by cropping and subsample alignment
"""
logging.debug("Sig1_orig: %d %s, Sig2_orig: %d %s" % (len(sig1), sig1.dtype, len(sig2), sig2.dtype))
off_meas = self.lag_upsampling(sig2, sig1, n_up=1)
off = int(abs(off_meas))
if off_meas > 0:
sig1 = sig1[:-off]
sig2 = sig2[off:]
elif off_meas < 0:
sig1 = sig1[off:]
sig2 = sig2[:-off]
if off % 2 == 1:
sig1 = sig1[:-1]
sig2 = sig2[:-1]
sig2 = sa.subsample_align(sig2, sig1)
logging.debug("Sig1_cut: %d %s, Sig2_cut: %d %s, off: %d" % (len(sig1), sig1.dtype, len(sig2), sig2.dtype, off))
return sig1, sig2
def fromfile(self, filename, offset=0, length=None):
if length is None:
return np.memmap(filename, dtype=np.complex64, mode='r', offset=64/8*offset)
else:
return np.memmap(filename, dtype=np.complex64, mode='r', offset=64/8*offset, shape=length)
# The MIT License (MIT)
#
# Copyright (c) 2017 Andreas Steger
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
|
