[SOLVED] Encoding Recursive Systematic code

[emma2]

Hello,
In terms of encoding RSC .. Can we use coven function to encode it? I have Matlab book that implemented RSC function to encode it ..and that confused me :?:
any:idea:?

 

[kalyanasv]

Hi,
coven function? I don't have that on mine ..even get any function in my matlab...so you could also check if the book has written that function.
btw: which book ?

There is convenc i.e. convolutional encoder: Oh yeah first you have to ensure you have the matlab toolbox for communication toolbox.

 

[emma2]

Oops! I misspell it , exactly "convenc function"
Oh , yes I have that tool box. The book is A practical guide to error control coding using Matlab.
Actually he used convenc function in convolutional code but when it comes to turbo code he used the rsc function btw -I already have the rsc code but i didn't understand why not "convenc" because in both cases you will walk the trellis-
kalyanasv ..thanks alot..

 

[kalyanasv]

The good part is you have the comm toolbox. A recursive convolutional coder has a feedback path which a traditional convolutional coder doesn't have. So you could use the convolutional encoder (essentially xor'ing ) the inputs and feed it back to encoder to create a recursive one. Turbo codes could require interleavers..so it is a little different besides just the recursion.

 

[emma2]

Do you mean even if I built the trellis using the feedback coeffecient exactly : trellis=poly2trellis(4,[13 15],13); is not enough for the command "convenc" to the rest ifof the job , ?

 

[kalyanasv]

To start with :
If your just building a RSC code then you don't need an interleaver. All you need to do is feed that along with the input message to convenc.

If your building a turbo code then you have to consider an interleaver.