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Published 20 hours ago • verified publisher icon osqzss

Why "Carrier" IF Frequency

Open jonas229 opened this issue 4 years ago • 3 comments

After reviewing the old tickets, i realized that the generated file generally contains baseband signals. Nevertheless the Nav+C/A data is multiplied with cosine/sine, and you mentioned that this the IF frequency centered at 0 Hz. I don't understand why this is necessary and why it depends on the Carrier Phase. Could you give me a source hint or a short explanation why the values are multiplied with the waveforms?

Greetings Jonas

jonas229 avatar Apr 05 '20 19:04 jonas229

The satellite motion creates a small frequency shift due to the Doppler effect.

osqzss avatar Apr 05 '20 23:04 osqzss

Okay. So the Doppler frequency is taken into account at the code frequency when the next data Bit is computed and also at the carrier frequency? And the frequency shift of the Carrier is simulated with the multiplication with sine/cosine?

jonas229 avatar Apr 06 '20 09:04 jonas229

Yes.

osqzss avatar Apr 06 '20 10:04 osqzss