Re: [Discuss-gnuradio] How to repeatedly & continously transmit a signal from a file ?

[Monahan-Mitchell, Tim]

> - How is it possible to transmit a file (as a signal source) repeatedly and 
> continously without interrupts (with gnuradio & uhd) ??
 
> Even without the USRP (i.e. just simulating with throttle & graphical sinks 
> and a file source) interrupts occurs (time-periods of no samples) for each 
> time the file repeats (i.e. starts over from the beginning). Same thing with 
> transmitting with USRP as uhd-source (then without throttling of course), 
> however no underruns are reported. 

> I want to continuously send a prepared signal from a file over and over again 
> but can't accept the interrupts each time the file ends & starts over. This 
> happens even at slow sample rates and I want to transmit really fast!

> I might have found a solution to this about year ago but now I can't remember 
> what I did... something simple...
> Somehow read in the whole file into cached memory so it doesn't need to be 
> re-read from disk for each repetition (in Linux)... but how?  

Maybe create a small ram-disk outside of GNU Radio, then copy your file to it, 
then use the new path for the file source block?

- Tim