[Discuss-gnuradio] Strange OFDM behavior with CCSDS encoding

[Trevor Bosaw]

Right now I'm messing around with OFDM in grc, and I made an extremely  
simple system, where I have an input text file to an OFDM modulation  
to an OFDM demodulation to a file sink.  Obviously this setup works  
fine, outputting a text file pretty much the same as the input text  
file.

However, when trying to add error correction code, the ODFM  
demodulation never outputs any values.  Right after the input file  
source, I add an 'Encode CCSDS 27' block, which then is connected to  
an OFDM mod block, and a 'Decode CCSDS 27' block is added after an  
OFDM Demod block.  What could be the cause of this?  To my knowledge,  
the OFDM modulation and demodulation code does not care about what  
'kind' of input bytes there are, as long as there isn't something  
weird happening between the OFDM mod and OFDM demod.  The problem  
isn't with the error correction code either, as (according to a number  
sink) no values are ever being passed to the decode ccsds block.

Also, all of my options for the OFDM mod and demod is the defaults.

Again, here is my setup:

File Source(bytes) -> Encode CCSDS 27 (bytes to bytes) -> OFDM Mod  
(bytes to complex) -> OFDM Demod (complex to float) -> Decode CCSDS 27  
(float to bytes) -> file sink (bytes)

-Trevor