Re: [Discuss-gnuradio] Doppler simulator

[Marcus Müller]

Yes and no: the shifting is done right; however, you should make sure to use a consistent sampling rate throughout the block.
The USRP sink interprets the samples that come into it as having a sample rate of 5MS/s, whereas the nominal sampling rate in the signal sources is set to 2MS/s.

On 12/22/2014 10:45 AM, Saul E. wrote:

First of all, I want to thank you for your answer.

Then, It is correct? (for a simple simulation of 1k, 2k and 3k Hz of doppler shift)

​

Thank you.

Saul E.

2014-12-22 10:26 GMT+01:00 Marcus Müller <address@hidden>:

Hi Saul,

a doppler shift is, mathematically speaking, nothing more than a multiplication with a complex sine, so use a multiply block and a signal source per simulated sattelite.

Now, you might want to update your doppler shift according to a simulated sattelite's position. I recommend having a look at PyEphem[1], which offers you calculational routines for such things, and writing your own python block[2] to generate the complex sine.

Greetings,
Marcus

[1] http://rhodesmill.org/pyephem/
[2] http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials ; go through tutorials 1, 2, 3

On 12/22/2014 10:14 AM, Saul E. wrote:

Hi all!!

I am developing a SDR receiver and want to simulate the doppler of signal from several satellites.
Any suggestions?

Signal1, signal2 and signal3 are BPSK signals and I use a USRP N200.

​

Thank you very much in advance.

Saul E.

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio