Transmit time tagging with GNU radio

[adim]

Hi,

Sorry if this question was answered elsewhere but: does the Lime SoapySDR/Osmocom API support transmit burst time tagging UHD-style?
So basically for TDMA I want to tag a stream of samples to specify the exact time it should be transmitted. I already do this in GNU radio for the USRP.

Thanks,
Adrian

[caipiblack]

Hi

I’m looking for the same thing,

Did you find a solution ?

Thanks

[andrewback]

Not sure if this is what you mean:

How to transmit bursts with Soapy SDR

Thanks Josh Here is what I found empirically to answer my questions. This may help others as there doesn’t seem to be any thorough code example to send and receive: You can send the entire buffer straight, but it seems smaller buffer get transmitted faster (eg a 275000 samples buffer seems to start being transmitted around 200µs later than a 10 times smaller buffer) The transmission indeed stops once the whole buffer is sent (there used to be a bug in a previous version that required you …

http://pothosware.github.io/SoapySDR/doxygen/0.7.1/classSoapySDR_1_1Device.html#aff08c2bfc323cd8d6d56b5f5d4432a97

http://pothosware.github.io/SoapySDR/doxygen/0.7.1/Constants_8h.html#a67027b65f63dffe851594c2df4a9d034

[adim]

gr-osmosdr doesn’t have support for tagging burst with the time, however gr-limesdr does have tx_time tags. Didn’t get to play with this feature yet, however since osmo-trx does it, I assume gr-limesdr does not necessarily need to be used directly.

[andrewback]

It’s in LMS API, which SoapySDR and gr-limesdr both sit on top of.