Digital Loopback

I was wondering if some one can tell me the correct blocks or sequence
to do
a digital loopback with no USRP where I can take a text file and
transmit to
another file at the distance end. I’ve done this with a packet encoder
and
decoder but would like to build it out of more basic blocks. The
following
is the chain I have now. Any Suggestions?

File Source (text
file)->simpleFramer->charToFloat->simpleCorrelator->UnpackedtoPack->PackedotUnpacked->charToFloat->SimpleCorrelator->SimpleFramer->FileSink(textfile)