I think we need to takes bets on the even/odd vs high/low division of channels between out1 and out2... :)
> On Feb 21, 2018, at 23:33, Jack Hickish <jackhick...@gmail.com> wrote: > > Well, if Dave, Glenn and Aaron all agree, then I'm sold. > > Thanks. > >> On Wed, Feb 21, 2018, 10:50 PM David MacMahon <dav...@berkeley.edu> wrote: >> Hi, Jack, >> >> I haven’t used the biplex_core block in a while, but I believe the inputs, >> pol1 and pol2, are two independent complex input signals. The outputs, out1 >> and out2, first output the frequency channels for input pol1, with the low >> half of the band being output in bit reversed order on out1 and the high >> half of the band being output on out2 in bit reversed order. After >> outputting the channels for pol1, out1 and out2 output the channels for pol2 >> in a similar order. >> >> For a 16 channel fft, I think out1 will have channels: pol1[0 4 2 6 1 5 3 7] >> followed by pol2[0 4 2 6 1 5 3 7]. Out2 will have the same output order but >> 8 (ie N/2) channels higher. I hope that makes sense, but if not I can make >> a better diagram for you tomorrow. >> >> Of course this should be verified with simulation, but I think it’s a good >> starting point. BTW, this assumes the inputs are presented in natural tone >> order at both inputs with the t=0 samples of pol1 and pol2 being presented >> at the respective inputs simultaneously. >> >> Dave >> >>> On Feb 21, 2018, at 18:04, Jack Hickish <jackhick...@gmail.com> wrote: >>> >> >>> Howdy, >>> >>> Partly motivated by a search for RAM savings, and partly for fun, I'm >>> looking through the innards of the fft_biplex_real_4x block. Can someone >>> tell me, using short words and/or pictures, what the the relationship >>> between the inputs (pol1, pol2) and the outputs (out1, out2) on the >>> biplex_core block is. >>> >>> I'm in the midst of reverse engineering the block by simulation / staring >>> at the unscrambler / reading about fft biplex implementations, but surely >>> someone must(!) know what this block actually does (or claims to do)? >>> >>> Yours, optimistically, >>> >>> Jack >> >>> -- >> >>> You received this message because you are subscribed to the Google Groups >>> "casper@lists.berkeley.edu" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to casper+unsubscr...@lists.berkeley.edu. >>> To post to this group, send email to casper@lists.berkeley.edu. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "casper@lists.berkeley.edu" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to casper+unsubscr...@lists.berkeley.edu. >> To post to this group, send email to casper@lists.berkeley.edu. > > -- > You received this message because you are subscribed to the Google Groups > "casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To post to this group, send email to casper@lists.berkeley.edu. -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu. To post to this group, send email to casper@lists.berkeley.edu.
