PRN and GPS signal analysis: time and frequency transfert using software defined radio (EFTS 2023)

2023 European Frequency and Time Symposium laboratory session.

Apologies for the poor sound quality. All GNU Radio 3.10 flowcharts available at http://jmfriedt.free.fr/efts2023/

00:00:00: Introduction, outline of the presentation
00:05:43: Spectrum spreading for time transfer, theory and correlation in the Fourier domain
00:09:50: Correlation of a known random signal with GNU Radio for time of flight measurement
00:19:18: Pulse compression ratio as indicator of signal to noise ratio improvement
00:22:26: Pseudo-random sequences generated for Galois Linear Feedback Shift Register (GLFSR)
00:26:23: GLFSR orthogonality demonstration using GNU Radio
00:29:43: Binary phase shift keying and the Costas loop for frequency offset correction
00:32:38: Costas loop demonstration using GNU Radio
00:35:44: Analyzing real data fetched from iqengine.org, link budget and signal below thermal noise
00:42:55: Spectrum de-spreading using the signal squared (codeless decoding)
00:45:00: Correlation for decoding the GPS signal, Doppler-code "maps" using GNU Radio
01:01:35: PRN generation using an FPGA, Two Way Satellite Time and Frequency Transfer (TWSTFT) simulator, frequency difference measurement using the code