On Tue, Apr 15, 2008 at 10:55:02AM -0400, George Nychis wrote: > Hi all, > > What I need is the output of GNU Radio's FIR filter (gr.fir_filter_ccc) to > be synchronized with the raw samples from the USRP into the input of a new > block. > > Like this, where the input to the new block ensures that input[0][N] is > related to input[1][N] ... such that input[M][N] is always valid for both > input streams: > http://skrbl.com/72178738 > > Then, the output streams need to be synchronized also... but I can ensure > this in work() as long as my input streams are synchronized. > > I re-went through the how to write a block guide, and I'm still a little > iffy on whether or not this is possible. Forecast() specifies the > relationship between input and output of the streams, but I'm wondering if > it can force the block to wait for an equal number of input items on both > streams? > > I'd greatly appreciate any feedback. > > Thanks! > George
They'll be synchronized. There's nothing special that you need to do assuming that "new block" derives from gr_sync_{block,interpolator, decimator} However, because of the group delay in the FIR, there'll be a constant offset between the two streams. The easiest way to fix that is to use gr.delay in the path that is currently straight through. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio