Re: [Discuss-gnuradio] Synchronizing N210 TX and RX channels

[Martin Braun]

On 07/23/2014 10:43 AM, Stefan Wunsch wrote:
> If you use the Echotimer you can use the same IP vor TX and RX, this
> should work.
> 
> Probably you can do your own USRP Sink/Source with UHD. You dont need
> much code to implement this (Echotimer ~300 lines in the *impl.cc). Main
> change should be an other stream command (most likely
> STREAM_MODE_START_CONTINUOUS [0]). Good code examples are UHD
> Sink/Source in gr-uhd and especially the examples from UHD itself (<uhd
> repo>/host/examples). And the Echotimer of course!
> 
> My approach: Read the system time on the USRP, set the stream command on
> actual_time+some_offset and spawn two threads with a tx_streamer and a
> rx_streamer. You can use both of them on the sampe USRP without any
> problems (just dont use two of the same type on one USRP). This should
> also work with streaming if you can push your data in the work function
> continuously.

You could also do this inside your app, without having to write new
sources and sinks. If your N210s are connected via MIMO cable,
synchronizing them in time and frequency is pretty straightforward.

M