FSK Demodulator and sync index found

[MariaStevens]

Hello.

I am very much confused regarding understanding the in depth function of this block. i have following questions.

1) what is the purpose of FIFO in this FSK demodulator.vi? what is the length of these FIFO?

2) if i have a complete packet and data like below then what will be the output of this FSK demodulator block?

random arbitray data (8bits)+ gaurd bits (2bits)+sync bits (16bits)+data (60bits)+random arbitrary data(8bits)

what will be extracted exactly from this provided data and how?

3) how much data is buffered/queued by this FSK demodulator out of which it try to find the peak of correlation?

4) where is the process of finding peak correlation takin place in this vi.

5) can this FSK demodulator.vi be used for receiving bursty communication? 

6) why is sync index found a decimal value? if it shows the start of sync SYMBOL then it should be some complete integer . i hope sync index found is related to extracting message bits (and is entirely a different process from max eye sub vi or symbol timing synchronization)

I would be thankfull if i get some detailed descriptive reply. thankyou so much.

i am working on FSK transceiver example present in labview 2012.

[Wan-L]

Hello Maria,

You can use the MT Generate Synchronization Parameters VI to tell the FSK Demodulator VI to look for a sequence of sync bits. You will have to embedded these sync bits in your bit stream yourself in the transmission side.

Beyond this, I don't think the demodulator VI does any "decoding" of your bit stream. It simply takes samples fetched IQ samples from the RFSA driver and converts them bits based on the FSK scheme. What you do with the demodulated bit stream is up to you.

The demodulator VI also doesn't detect bursts for you. You will either have to tell your VSA to aquire only bursts of data. Or detect the bursts in software. 

I can't reveal much detail about the demodulator algorithm itself because its proprietary. However, since you can open up the VI, you can always use LabVIEWs debugging tools to get a better understanding of what its doing.