blob: 5120d352f9f89b1115f7f499744c9e8ee79e4d01 (
plain)
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
|
CIR scripts
===========
This is a set of script to do correlation measurement measurements
of a DAB signal. These scripts can be used to do channel impulse
response measurements using a RTLSDR receiver.
Right now there are three scripts:
* correlate_with_ref.py: Finds the NULL symbol of an IQ file, and runs
correlations against the known phase reference to find the components.
* simulate_channel.py: Reads an I/Q file generated by ODR-DabMod and
adds some additional components, somehow equivalent to signal reflexions.
Each reflexion has a delay and an amplitude factor.
* cir_measure.py: Runs a small webserver that does the correlation
all the time and updates a webpage
Example image: 
The image shows the received CIR of a real DAB signal captured with the RTLSDR.
Webserver
---------
To run the webserver on all network interfaces, receiving on 202.928MHz:
./cir_measure.py --host 0.0.0.0 --port 8080 --freq 202928000
More options are available (gain, number of samples), see the help with
./cir_measure.py -h
Offline processing
------------------
To read in a recording using a RTL-SDR receiver, use:
rtl_sdr -f 188928000 -s 2048000 -g 20 -S - | \
dd of=DAB_9A_10_u8_G20.iq bs=2 count=1966080
replace 1966080 (ten Mode 1 transmission frames) by a larger value if you want.
Then feed the data to the script
./correlate_with_ref.py u8 DAB_9A_10_u8_G20.iq
Requirements
============
librtlsdr and its tools.
Python with NumPy and matplotlib.
The iq files must be complex float or interleaved unsigned 8-bit.
Licence
=======
MIT. See LICENCE for details.
|
