turbo codes

How many type of decoding algorithms are used in turbo decoding?

Answer 1

[Walter Roberson]

According to http://en.wikipedia.org/wiki/Turbo_code, "many".

As Turbo codes are a class of codes, I suspect that the answer is that there are an infinite number of decoding algorithms that fall in to the class. The number that are used in practice is a different question and is probably unknowable.