Forum: GNU Radio Block to keep streams in sync

Hi,

Is there a block in gnuradio that would watch stream tags and pad
zeros into the stream when a USRP drops packets. This would allow
other processing blocks to assume that outgoing and incoming IQ
streams are always in sync, which would help in many of the
applications that I'm working with.

juha

On Thu, Jan 10, 2013 at 6:32 PM, Juha Vierinen <jvierine@gmail.com> 
wrote:

> Hi,
>
> Is there a block in gnuradio that would watch stream tags and pad
> zeros into the stream when a USRP drops packets. This would allow
> other processing blocks to assume that outgoing and incoming IQ
> streams are always in sync, which would help in many of the
> applications that I'm working with.
>
> juha
>

Juha,

No, there isn't. Keep us posted if you come up with something.

Tom

On 01/10/2013 05:32 PM, Juha Vierinen wrote:
> Hi,
>
> Is there a block in gnuradio that would watch stream tags and pad
> zeros into the stream when a USRP drops packets. This would allow
> other processing blocks to assume that outgoing and incoming IQ
> streams are always in sync, which would help in many of the
> applications that I'm working with.
>

Is there some upstream logic that makes some assumptions from the sample
count -- rather than using the time stamp?

It should be possible to fill in missing samples using the timestamp
information, so the upstream logic sees zeros rather than gaps. But, I
worry that if something isnt keeping up, inserting more host samples
into the pipeline isnt the answer. That could just make the overflows
worse. Its better to make whatever that upstream logic is, to recover
from the gap.

-josh