turbo decoding

Is sova decoder and log-MAP decoder is same in turbo decoding?

[mohamed elganiny]

another question about this please, is SOVA decoder is the APP decoder in matlab simulink , and if yes how i can get soft output values from SOVA decoder in simulink

[Walter Roberson]

"APP" appears to mean "a-posteriori probability" in this context.

Answer 1

[Walter Roberson]

No, they are not.

[Walter Roberson]

They are completely different algorithms.

According to http://stats.stackexchange.com/questions/31119/posterior-probability-vs-viterbi-algorithm

"Viterbi gives most likely sequence, posterior (Forward-Backward) gives most likely state at each position. Which one you choose depends on what kind of errors you prefer -- if you care about the number of sequences you get correctly, then Viterbi algorithm is preferable, if it's the number of individual state errors, then, Forward-Backward is better."

You can find Sova implementations at:

https://www.mathworks.com/matlabcentral/fileexchange/3801-soft-input-soft-output-viterbi-algorithm

https://www.mathworks.com/matlabcentral/fileexchange/25293-matlab-for-digital-communication