Re: [Discuss-gnuradio] psk mod and channel model

[Tom Rondeau]

On Sat, Feb 8, 2014 at 11:32 AM, Marco Bosco <address@hidden> wrote:
> Hi!
>
> I am trying to do a simple simulation in GRC:
>
> Signal source --> Packet encoder --> PSK mod --> Channel model --> PSK demod 
> --> Packet decoder --> Scope sink
>
> The problem is that it works only if I enable differential encoding. How can 
> I make it works without using a differential encoding? (I don't want to 
> remove the channel model)
>
> Thanks,
>
> Marco.


Non-differential PSK has phase ambiguities, so you need to properly
rotate the constellation so that the receiver can properly decode the
symbols to the correct bits. Differential allows us to avoid dealing
with this ambiguity. You'll need something in the receiver that can
detect the rotation after the receiver locks and correct that.

Tom