Iterative decoder

A method of decoding a code block by iteration, comprising:

• performing forward and backward recursions over the code block or a code sub-block in each decoding iteration using a computation unit, comprising:
• using a first forward/backward decoding scheme in a first iteration;
• and
• using a second forward/backward decoding scheme in a second iteration,
• wherein the first and second decoding schemes are different in view of forward and backward processing and the second iteration is later than the first iteration.

A method of decoding a code block by iteration, comprising:

• performing forward and backward recursions over the code block or a code sub-block in a first decoding iteration according to a first forward/backward decoding scheme using a computation unit;
• calculating state metric values in the first iteration using the computation unit;
• storing the state metric values in a memory using the computation unit;
• reading the stored state metric values using the computation unit;
• initializing a forward or backward recursion in the second iteration by using the state metric values read from the memory using the computation unit;
• performing forward and backward recursions over the code block or a code sub-block in the second decoding iteration according to a second forward/backward decoding scheme which is different in schedule to the first decoding scheme using the computation unit;
• performing the forward and backward recursions over the code block or code sub-block according to a first decoding scheme in the first iteration;
• deriving a second decoding scheme from the first decoding scheme by interchanging backward and forward recursions;
• and
• performing the forward and backward recursions over the code block according to the second decoding scheme in the second iteration.