Questions about ofdm_mapper_bcv

Dear All,

I'm working on OFDM things now and trying to achieve OFDMA in

gnuradio 3.7, the system is Ubuntu 12.07.

Right now, for the ofdm_mapper, it's function is to convert a stream

of byte into complex number. However, when I check the folder in
gr-digital, I found two ofdm_mapper_bcv files, one is ofdm_mapper_bcv.h
in gr-digital/include/gnuradio/digital/ofdm_mapper_bcv.h and the other
one is in gr-digital/lib/ofdm_mapper_bcv_imp.h

Now I'm confusing about this:

1. Are these two used in the ofdm simulation? Or I just need the

ofdm_mapper_bcv.h

2. What're the meaning of suffix of bcv and imp. actually I know c

and v means complex input and vector output, but not sure of the ‘b’ and
imp.

Thanks in advance!