A question about dwrd

[vnikale]

Hello. I have another question. Why the array dwrd contains 60 elements instead of 50?

[osqzss]

The simulator needs to generate the signal transmitted earlier than the reception time. The first 10 dwrd elements contains the previous subframe 5 contents.

[vnikale]

Thank you for your answer! Theoretically, could it start the simulation from a previous subframe 4 or 3 (then dwrd would have 70 or 80 elements) instead of subframe 5?

[osqzss]

Yes, you can start simulation from any GPS signal reception time with -T option. Since the gps-sdr-sim updates the whole subframe contents every 30 seconds at the end of subframe 5, you only need a copy of the previous subframe 5.

[terrymarkovich]

Another question related to this. It appears that subframe 1 transmission starts with dwrd 9 bit 26 and ends with dwrd 59 bit 25. Does this mean that the first few bits of subframe 1 and the last few of subframe 5 are missed?

[terrymarkovich]

I got it. dwrd 9 and 59 are identical, so nothing is missed.