Soft Input Soft Output Viterbi Algorithm

Implementation of the SISO Viterbi algorithm.

Description

Implementation of the soft input soft output Viterbi algorithm (SOVA) decoder. The implementation assumes that a finite length trellis window is available for both forward and backward recursions. Thus, it resembles well a hardware implementation of the SOVA decoder. Note: best performance on MATLAB R13!

(check also: http://tvs019.et.tudelft.nl/notes/sova/notes.html)

• MATLAB release: MATLAB 6.5 (R13)
• Other requirements: Performed simulations on the same PCs using Matlab releases R12 and R13, indicate ~8 times speed difference in favour of R13.

[Owen Yang]

I will try it!

[mikel frago]

bug at line 63: oct2dec a decimal number if enc.nsym > 8

[Chakka Murali Mohan]

There is a bug in lines 62 and 63. No need of converting enc.ksym and enc.nsym form octal to decimal. They are all ready in decimals.

[Rathika Thiruvan]

best web site for all application

[Son Nguyen Viet]

I use the Viterbi algorithm for Speech reconigtion using Hidden Markov Model .

[kashif Zareef]

Good site helpful for biggners to Advance

[hakan hýzaar]

hakan

[raghunandan piplia]

good site

[ahmad takbir]

 

[Rustam Efendi Ahmad]

wonderful site and good m-files

[mohamed ahmed]

iam very intersting so we need more samples

[francesco pezzullo]

 

[RAVI CHANDRA REDDY]

good files of matlab Also look out for new variation of viterbi decoder by M.Satish kumar et all.

[Virupaxappa B G]

The implementation of Viterbo Decoder is really good and is giving clear view to the reader.

[meilana siswanto]

thanks a lot

[jalandhar reddy]

 

[ash y]

do u happen to have a similar code for matlab 5.3 R11?

[falcon falcon]

thanx

[gunadhar sareddy]

 

[baghdadi elamin]

i am a MSc student in telecom engineer at U. of K. in sudan

[Abuzar Ghalib]

 

[Mahdi Zamani]

 

[l x]

How can I modify it so that it can be used in TCM system? The input of SOVA decoder in TCM should be modulated constellation points.

[Yang Xiao]

I will refer the program to design some function block of our system STS-CDMA simulation programs.
However, I hope that the author can develop a program for calculating girth in LDPC parity check matrices.

[lkhagvaa l]

;l'm;

[Ahmed Hamed]

 How can I modify it so that it can be used in slow flat fading Rayleigh channel (y=ax+n).
kind regards

[samurai H]

 

[dedy efendi]

good

[arglues leon]

too many errors

[prashanth kumar]

good project

[Nguyen Ngoc Tien]

 

[Shahid Habib]

Very Good book

[Alex Fedorov]

Help Please!!!! It work on 8PSK Constellation?

[LEE WAN WOO]

Give me the good information

[mreza fasihi]

 

[Jerome Tang]

Good insight to implementation of the SISO Viterbi algorithm. Any chance if you have any m file on MIMO Viterbi algorith?

thanks

[Chintan P. Shah]

 

[Vaidehi Kulkarni]

Related to Information Theory

[Iman Hidayat]

Related to Information Theory

[Federico Ang]

@arglues leon - considering most ratings are 4 or 5 stars, are you sure you are using the code correctly?

anyway, the code is good and really, really helpful since I don't know any other site that offers this algorithm implementation. however, as the author says, it is not yet optimized. there are impractical lines of codes and some parts are still vague -- like the metric used in weighing the paths. by changing the metric to a euclidean distance metric, the code reverses the outputs. it's obvious since the original metric is maximized while eucledian distance must be minimized. just a thought.

[kim chul seung]

what ??!!

[omar youness]

nice work but can you sendme an exemple about the execution of that program ok plz i am waiting your reply thank you for your consideration ... omar youness lebanon
email:[e-mail]

[Bogdan Cristea]

Useful code, however I have some doubts about its correctness. When the transition metric in computed, the AWGN noise variance is not taken into account, while the code rate is used. This seems to me wrong.

[Ammar]

Hi. Any clues what kind of input codeword it expects. Real number, complex etc. I want encode and decode for the case of QPSK with a pi/4 phase shift.

Thanks in advance

[Arun Kumar Desiraju]

Does this decoder perform better than the original viterbi decoder in terms of BER?

[Ahmed alrekaby]

Hi, How can i modify this code to accept LLR's for coded symbols and produces LLR's for information and parity bits simultaneously. thanks alot.

[Ahmed alrekaby]

Hi, How can I modify this code to be useful in SCCC. thanks alot.

[FERSI Bilel]

Good work :)

Bilel telecommunications engineer