Re: newbie question about synchronization

On Jul 20, 6:10 am, "rifo" <rtur...@xxxxxxxx> wrote:

I am using two motorola 56303 development kits hence I will have
independent crystals on board for Tx and Rx. I don't know about the
clock mismatch, I will check the datasheets and report back about this but
frankly I don't also have any plans for synchronization of Tx and Rx
operations.

Please do.

Assuming you might be having independent crystals on Tx board and Rx
board generating the
RF carrier and the sampling clocks, you may need to do:
(a) carrier frequency offset error estimation and compensation
(b) sampling clock offset estimation and compensation
(c) Symbol boundary estimation

Do I need to implement all three of these. I would also appreciate if
you
point out any resources about the implementation of these algorithms.

The dry treatment is available in most textbooks, like Proakis or
Sklar or Messerschmitt/Lee.

But if you want to truly optimize the parameters, I am a big fan of
d'Andrea and Mengali's text, and also the Meyr/Moeneclaey/Fechtel
text. If you do a google search for "digital receiver
synchronization"
you can find several tutorial articles, but they do not go in much
depth.

If your goal is to just send from point A to point B and your SNR is
very high, then there is much fewer things to optimize, so the
tutorials
may be enough.

Regardless, for sure you need some sort of method for synchronizing.

I was going through the book of Sklar, "Digital Communications" and in
the synchronization chapter it said that;

"Take an AM radio, if there is only a central carrier and many receivers,
then in this system synchronization can be avoided"

This led me to think that, since I only generate a single carrier with
a fixed frequency I may at least skip carrier synchronization (since I
would have coded the receiver DSP with the knowledge of this carrier
frequency) But now I see that I have a misinterpretation of the above
phrase.

No way :-). Are you actually implementing a digital communication
system or an analog one? If you are doing just AM transmission,
then Sklar is correct. I had always assumed that you were doing
digital stuff.

I would be happy to hear your further advices
Thanks a lot
Rifo

If your mixers are implemented in digital, you can simplify some parts
from the above list.

Julius

.