Hello all,
I have a problem regarding using viterbi decoder in wifi PHY.
I try to use hmmviterbi in GNU Octave , for decoding soft data (which was
encoded with convolutional encoder with 3/4 rate) but met the following
problem:
How I can create the TRANSPROB (transition probability) and OUTPROB (output
probability) matrices.
Please help... Thanks in advance.
viterbi
Started by ●May 29, 2009
Reply by ●June 12, 20092009-06-12
Hello all,
>
>I have a problem regarding using viterbi decoder in wifi PHY.
>I try to use hmmviterbi in GNU Octave , for decoding soft data (which was encoded with convolutional encoder with 3/4 rate) but met the following problem:
>How I can create the TRANSPROB (transition probability) and OUTPROB (output probability) matrices.
>
>Please help... Thanks in advance.
I never tried this in octave. But i can tell you how in matlab its done.
Firstly you need to get the trellis structure of your encoder.
which is done by using command "poly2trellis".
poly2trellis yield a structure which has "TRANSPROB" , "OUTPROB" etc... This structure along with your encoded data is the input to viterbi decoder in matlab.
Hope something similar you can find in Octove too.
>
>I have a problem regarding using viterbi decoder in wifi PHY.
>I try to use hmmviterbi in GNU Octave , for decoding soft data (which was encoded with convolutional encoder with 3/4 rate) but met the following problem:
>How I can create the TRANSPROB (transition probability) and OUTPROB (output probability) matrices.
>
>Please help... Thanks in advance.
I never tried this in octave. But i can tell you how in matlab its done.
Firstly you need to get the trellis structure of your encoder.
which is done by using command "poly2trellis".
poly2trellis yield a structure which has "TRANSPROB" , "OUTPROB" etc... This structure along with your encoded data is the input to viterbi decoder in matlab.
Hope something similar you can find in Octove too.
