CHIN-YA HUANG wrote:
Does anyone have clear idea about how gunradio implements serial to parallel mapping since 802.11 has 52 channels?
I check the gr_ofdm_mapper_bcv.cc , but still have no idea about it.
In further, I want to apply an array mapping to implement that different channels use different constellation. Does anyone have another comments if I apply an array in the gr_ofdm_mapper_bcv.cc file?
The OFDM system uses fft_length number of subcarriers and occupied_tones
number of used subcarriers. The used subcarriers are mapped to the
middle of the fft_length subcarriers leaving the same number of
guardband subcarriers on either side. The middle two subcarriers are
also nulled to avoid DC affects.
The mapping is done in gr_ofdm_mapper_bcv.cc. If you want to play with
this, I’d make a copy of this one as a different version of the mapping.