Over the past 13 weeks I worked on gr-inspector, a signal analysis toolbox for GNU Radio. GSoC now comes to an end, and it’s time to look back and evaluate the results. I can gladly say to have achieved all planned milestones, even one optional milestone (FM demodulation) was reached.
Week 12 – Solving the small issues
In the second last week of GSoC I dealt with all the small issues that accumulated over time and that I marked with “I’ll do this when the big issues are finished”.
Week 11 – Let the music play
Week 11 of GSoC was mainly dominated by two tasks: finishing all necessary parts for the sync block of last week and develop a solution for demodulating FM signals. Read here about the details.
Week 10 – Sync
In week 10 of GSoC I worked with two OFDM synchronization algorithms and implemented one of them in C++.
Week 9 – OFDM finale
In week 9 of GSoC I prototyped a new OFDM algorithm since the old one had too high CPU usage. I did some tests and managed to implement a C++ version this week.
Week 8 – Performance Issues
This week I dealt with the OFDM estimation algorithm and it’s C++ implementation. Although the algorithm did show nice recognition ability, it’s performance could not be increased to a usable level. Therefore the algorithm will now be replaced.
Week 7 – OFDM Prototype
This week of GSoC I dealt with a first approach to perform a OFDM parameter estimation. As mentioned in the last blog post, my milestones where altered to develop a OFDM estimation block. The parameters that should be estimated are
- Subcarrier spacing
- FFT length
- Symbol time
- Timing offset
- Frequency offset
The offsets should also be compensated. This week I developed a prototype for a OFDM estimator.
Week 6 – Tweaking
This week of GSoC, I dealt with the final GUI issues and improvements. Also, I improved the error handling of the Signal Separator block and implemented a JSON logic to load precalculated filter taps. Finally, my final milestones where changed in discussion with my mentors.
Week 5 – Midterms
After 5 weeks of coding it’s time for the midterms and to have a look back and see what I have accomplished. Let’s have again a look at the milestones:
- Prototype signal detection algorithms in python and evaluate best approach to implement
- Implement signal detection algorithm in C++ and wrapping it in a new block
- Create first GUI with QWT and QT with graphical feedback of signal detection block
- Verification with over-the-air signals
- Documentation for the mentioned components
All of the mentioned milestones could be accomplished thanks to the great help of my mentors. Read here about the details. If you want to check out the inspector, feel free to use the master branch of the official repo.
Week 4 – GUI
During the fourth week of GSoC, I mainly dealt with building the GUI. Read here more about it.
The Inspector 