I’m trying to replicate a GNSS (Galileo) signal, I have the PRN code which is a 1.023 mega bit per second, and a navigation message which is a 50 bps. How can I force the Vector Source block to the frequency that I want, the frequency seems to be very high! a peak to peak is like 0.4 ms.
To replicate a GNSS signal, you can use the Vector Source block in your signal processing software. The Vector Source block can generate a digital signal with the specified frequency and modulation parameters, such as the PRN code and navigation message.
To force the Vector Source block to the desired frequency, you can adjust the sample rate and interpolation factor of the block. The sample rate determines the number of samples per second, while the interpolation factor determines the number of output samples per input sample.
To calculate the required sample rate, you can use the formula:
Sample Rate = PRN Code Rate * Interpolation Factor
For example, if the PRN code rate is 1.023 MHz and the desired output frequency is 10 kHz, you would need an interpolation factor of:
Interpolation Factor = Output Frequency / PRN Code Rate = 10 kHz / 1.023 MHz = 0.00977
Then, you can set the sample rate of the Vector Source block to:
Sample Rate = PRN Code Rate * Interpolation Factor = 1.023 MHz * 0.00977 = 10 kHz
This will generate a digital signal with the specified frequency and modulation parameters that can be used to replicate the GNSS signal.