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osqzss / gps-sdr-sim

Software-Defined GPS Signal Simulator
MIT License
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Which parameters should be used for user motion on a Lime SDR? #266

Closed dennisn00 closed 3 years ago

dennisn00 commented 3 years ago

Hi, I'm trying to simulate a moving user with a Lime SDR without success so far. When generating the nmea file, I use GPS frequency = 1 Hz Multi-point line with distance between points = 0.5 m

I create the GPS signal file with ./gps-sdr-sim -e brdc2830.20n -b 1 -s 1000000 -d 300 user_motion.csv

and play the signal with ./player/limeplayer -s 1000000 -b 1 -d 2047 -g 0.1 < ../gpssim.bin

The phone I use for testing cannot get a fix. I used the same parameters with a static location and it worked. Do I need different parameters for user motion?

dennisn00 commented 3 years ago

I found a mistake in my code so ./gps-sdr-sim is not called with the file user_motion.csv but with the file output.nmea instead which apparently is causing this error. I also found out that while the parameters in my original post work, it works even better with s = 2500000 and g = 0.04