12-03-2009 04:23 AM
Hello
i have been working with viterbi encoding/decoding example given in Rf communication library for FPGA's . As per specifications is a 1/2 decoder with constrain length 7. Can I modify it for other decoders e.g. 2/3, 5/6 etc
Regards
12-04-2009 01:09 PM
Hi COMSIS,
You should be able to modify the example. There are a few recommendations/things to note:
1. I recommend saving the VIs to another directory, otherwise you'll have to reinstall the example if you want to revert back.
2. Most of the SubVIs appear to be re-entrant, so you'll need to make sure you open the actual SubVI file in order to modify it.
Unfortunately, I'm not too familiar with RF communications, so I won't be much help in what needs to be recoded the VI.
12-05-2009 03:23 AM
Hello
Tnx i have taken the precautionary measures mentioned in reply.
1- Actually I am interested in decoding part only. I already have a 2/3 or 5/6 encoded file. But I am confused how to tell the viterbi decoder vi that given input is a 2/3 or 5/6 encoded . As u See usually we need a generator matrix for decoding (and encoding as well). But here the vi for viterbi decoding residing in FPGA vi is not having such generator matrix as input it only has a trellis information input.
2- How does a trellis information specify the encoder type (ie either it is 1/2, 3/2 or 5/6). I am not getting it.
3- How should I modify the trellis information vi for my 2/3 or 5/6 decoder Also the given example has a sub vi
calculating trellis info which takes 1D array input and for 2/3 and 5/6 I have to have more than 2D array.
4- It seems that configurable Generator matrix means(as given in decoder vi specs) that it can work on 1/2, 1/3,
1/4.... Isn't it so.....
Regards
12-10-2009 12:29 PM
Hi COMSIS,
I'm sorry I couldn't much more help, but there's a chance the developers of this library may be able to answer your question if you post here:
http://forums.ni.com/ni/board/message?board.id=nilabs&thread.id=150&view=by_date_ascending&page=1
Since the library is under NI Labs, it's not officially supported by NI, but hopefully someone can answer your question here. Thanks!