12-08-2012 04:34 PM
Hi,
I have a problem with the PSK demodulation: symbols after demodulation are different than symbols before modulation. What am I doing wrong? Please, help me 🙂
12-14-2012 03:38 AM
Hi man,
I think the problem is related to synchronization. You have to assemble your message (i.e. the bits that modulate the IQ signal) in the following scheme:
{<Guarding bits> <Synchronization bits> <Message bits>}
The purpose of the Guarding bits is to compensate for the transient effect of the filter in the "MT Demodulate PSK.vi".
I attached an example that I created. I assembled the sync and message sequence in a way so I'm sure that the sync senquence can not be found anywhere in the message:
- Guardian bits: 00000000
- Synchronization bits: 11100111
- Message bits: 01010101010... (128 bits).
I recommend studying the example "MT PSK Transceiver (One Shot).vi" which you can find in the Example Finder.
Regards,
Norbert
12-14-2012 05:44 AM
Thanks for the tips 🙂
Could you save your program in version 2009? Thank you in advance 🙂
12-14-2012 06:43 AM
No problem, 2009 version attached. Enjoy! 🙂
08-15-2014 01:04 AM
there is still a problem,do you notice that the last_5_bits missing?