Hi, Could you tell me where is the part, ofdm_carrier_allocation be called ?
Thanks! tha 2016-05-27 0:52 GMT+09:00 Martin Braun <martin.br...@ettus.com>: > Also, that block is going away soon. > > I recommend looking at the carrier allocator block instead. > > M > > On 05/25/2016 10:20 PM, SangHyuk Kim wrote: > > Dear all, > > > > Sorry, my source code was wrong. > > > > There is only one /d_bit_offset += d_nbits; > > > > / > > /Thanks . > > / > > > > 2016-05-26 10:38 GMT+09:00 SangHyuk Kim <tkdgur7...@gmail.com > > <mailto:tkdgur7...@gmail.com>>: > > > > Hi all, > > > > I'm tracing how OFDM modulation is done by /ofdm/benchmark_tx.py. > > > > The file, ofdm.py indicates ofdm modulation is composed of like : > > > > modulation - mapper - preamble - IFFT - CP - scale > > |- mapper - preamble -| > > > > And I have a question at ofdm_mapper_bcv. > > > > In ofdm_mapper_bcv_impl::work, I can find making symbol part : > > > > /while(..){ > > / > > /if((8-d_bit_offset) >= d_nbits) { > > / > > /bits = ((1 << d_nbits)-1) & (d_msgbytes >> d_bit_offset); > > d_bit_offset += d_nbits; > > d_bit_offset += d_nbits; > > out[d_subcarrier_map[i]] = d_constellation[bits]; > > / > > /} > > / > > /} > > > > / > > For example, using BPSK : > > - d_nbits = 1 > > - d_msgbytes = 94 (0101 1110) > > > > 1st loop: > > - bits = (0000 0001) & (0101 1110) = 0 // takes right-most bit > > - d_bit_offset = 2 > > - out[..] = d_constellation[0] > > > > 2nd loop: > > - bits = (0000 0001) & (0001 0111) = 1 > > - d_bit_offset = 4 > > - out[..] = d_constellation[1] > > > > 3rd & 4th same like above. > > > > In this example, it just takes odd parts of byte (0, 1, 1, 1). > > > > How can receiver deduce even part (1, 1, 0, 0) ? > > > > I don't know why /d_bit_offset += d_nbits/ double times, not an one. > > > > Is this related with two mapping & preamble blocks ? (I/Q ch?) > > > > If right, these two mapping handle even or odd part of byte > > respectively ? > > > > Thanks. > > > > > > > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > >
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