sinak / gr-ltetrigger

GNU Radio out-of-tree module for triggering on LTE signal

gr-ltetrigger

gr-ltetrigger is a set of utilities for sensing LTE. It is built using GNU Radio and srsLTE.

Screenshots

Building

1. Install SWIG, GNU Radio, GNU Radio Companion, fftw and gr-osmosdr (example assumes Ubuntu 16.04, adjust as needed)

   $ sudo apt install gnuradio-dev swig fftw-dev gr-osmosdr gnuradio-companion

2. Build and install srsLTE. There is a naming collision between srsLTE and a requirement of GNU Radio, which we must fix before building:

   $ git clone https://github.com/srslte/srslte
   $ cd srslte
   $ grep -R -l " DEBUG(" . |xargs sed -i 's/ DEBUG(/ SRSLTE_DEBUG(/g'
   $ find -name ue_cell_search.c |xargs sed -i 's/DEBUG/SRSLTE_DEBUG/g'
   $ mkdir build; cd build
   $ cmake ../
   $ make && make test
   $ sudo make install

3. Build and install gr-ltetrigger:

   $ git clone https://github.com/NTIA/gr-ltetrigger
   $ cd gr-ltetrigger
   $ mkdir build; cd build
   $ cmake ../
   $ make && make test
   $ sudo make install
   $ sudo ldconfig

Quick Start

$ cd gr-ltetrigger/examples
$ ./cell_search_file.py --help
linux; GNU C++ version 5.3.1 20160413; Boost_105800; UHD_003.010.git-202-g9e0861e1

usage: cell_search_file.py [-h] -s Hz [-f Hz] [--repeat] [-c N]
[--throttle Hz] [--time-out sec]
[--threshold THRESHOLD]
filename

positional arguments:
filename

optional arguments:
-h, --help            show this help message and exit
-s Hz, --sample-rate Hz
input data's sample rate [Required]
-f Hz, --frequency Hz
input data's center frequency
--repeat              loop file until cell found or cut-off reached
[default=False]
-c N, --cut-off N     stop looping after N samples [default=-1]
--throttle Hz         throttle file source to lower CPU load [default=None]
--time-out sec        max time in seconds to perform search [default=-1]
--threshold THRESHOLD
set peak to side-lobe ratio threshold [default=4]
$ ./cell_search_file.py --sample-rate 15.36M ../test_frames/lte_frame_50prb_cellid_125 --repeat --time-out 1
linux; GNU C++ version 5.3.1 20160413; Boost_105800; UHD_003.010.git-202-g9e0861e1

Using Volk machine: avx2_64_mmx
Starting cell search... done.
{'cell_id': 125L,
'cp_len': 'Normal  ',
'nof_phich_resources': '1',
'nof_prb': 50L,
'nof_tx_ports': 1L,
'phich_len': 'Normal',
'sfn_offset': 0L,
'tracking_start_time': 1464123775L}

Support

Douglas Anderson | NTIA/Institute for Telecommunication Sciences | [email protected]

Legal

Copyright NTIA/Institute for Telecommunication Sciences. Released under GPL 3 - see LICENSE.