On Wed, Mar 03, 2010 at 11:25:56AM +0100, Mattias Kjellsson wrote: > Hi list, > > I have been trying to send and receive higher order constellations than > bpsk (qpsk, qam16, ...). The way I'm currently implementing this (in > c++) is that I have a custom "pack_k_bits_bb(int bits_per_symbol)"- > block and then feed the result into a "gr_chunks_to_symbols_bc"- block, > and then onward in the transmitting chain. > > On the receiving side, I use a "constellation_decoder_cb"- block > followed by a "gr_unpack_k_bits_bb"- block to get the bits back. > > This approach assumes that there are less than 8 bits per symbol, and > that the input to the transmitting chain is unpacked bytes, which is > also produced by the receiver. > > The question is now, how do you produce constellations with more than 1 > bit per symbol? Is there a better way to do this? Sure if one want to, > for instance, read from a file/device the input should be packed bytes, > but if the input to the transmitting chain is a "gr_scrambler_bb"- > block... This is one way of doing it.
I assume that you mean 1 byte per symbol. I suggest that you create *_ci and *_ii versions that handle 32-bits. Eric > > Comments and suggestions on how to do this in other ways are most > appreciated. > > BR > //Mattias _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
