[srslte-users] Issue running examples

[Tom Tsou]

On Sun, Mar 29, 2015 at 8:54 PM, Eric Sollenberger <ericps1 at vt.edu> wrote:
> I think I read somewhere that you guys have been using USRP B210's for your
> development, have you run these examples on USRP N210's by any chance? If
> not do you have any expectation for whether or not it should run?

The N210 doesn't support reconfigurable clocking, so you can't set the
clock to a 'nice' LTE rate that is some multiple or fraction of 30.72
MHz. You can get around that by performing sample rate conversion on
the host, but that does add a fair amount of overhead and complexity
to the application. In summary, running LTE on the N210 is far less
convenient than the B200.

> I ran uhd_fft on one of the USRPs to verify that a signal was being
> transmitted by the USRP running pdsch_enodeb, and I saw periodic bursts
> towards the center of the FFT. I'm assuming this is the PSS/SSS and PBCH,
> but since there isn't a UE connected, no actual data is being sent and so
> the spectrum does not look like a typical OFDM waveform.

On an idle downlink, you should still see reference signals and
periodic SIB data on the shared channel in addition to the MIB and
synchronization symbols in the center. The spectrum should still look
very much like an OFDM signal.

 -TT