On Thu, 12 Apr 2012 13:33:01 -0400, Tom Rondeau wrote: > > Alick, > > Why are you using 1's and 0's? Is this just for some academic exercise > or are you trying to do something with this kind of a constellation? > I'm only asking out of curiosity. > > It also looks like you're heavily biasing the output to be all 1's and > very few 0's. That's going to be problematic for the recovery loops. > In particular, the FLL uses bandedge filters that rely on the excess > bandwidth. If you are never, or rarely, transitioning between symbols, > the excess bandwidth of the signal is going to be pretty much absent. > So I'd add the randomizer back in and see how that works. > > For simulation purposes, you can probably go in and remove the FLL > from the receiver chain in generic_mod_demod.py. > > Tom
Hi Tom, thank you for pointing out the issue of my set up. I want to embed channel estimation function into the receiver with training sequences (here all 1's). In a practical configuration, I think frame structure with preamble containing training sequences and (randomized) payload should work. (Is it so?) But now I haven't looked deep into the packet/frame related code, and I am not sure how to find frame header right on constellation. (Could you give some advice?) So I just begin with the set up above, which is problematic for the recovery loops. Besides, yes I will add the scrambler back in and do some tests. alick _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
