Psk mod and channel model

GNU Radio
1

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.

2

Hi Marco,

Could you please attach your GRC file?

Thanks,
Aditya

3

Yes sure!

Marco.

From: Aditya D. [mailto:[email protected]]
Sent: sabato 8 febbraio 2014 17.24
To: Marco B.
Cc: [email protected]
Subject: Re: [Discuss-gnuradio] psk mod and channel model

Hi Marco,

Could you please attach your GRC file?

Thanks,
Aditya

On Sat, Feb 8, 2014 at 6:32 AM, Marco B.
<[email protected]mailto:[email protected]> 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.

4

On Sat, Feb 8, 2014 at 11:32 AM, Marco B. [email protected]
wrote:

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