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.
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 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.
In week 10 of GSoC I worked with two OFDM synchronization algorithms and implemented one of them in C++.
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.
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.
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.