Recursive decoder for switching between normalized and non-normalized probability estimates

A decoder for decoding encoded data, the decoder comprising:

• a processor having an input which receives probability estimates for a block of symbols, and which is arranged to calculate probability estimates for said symbols in a next iterative state;
• normalizing means coupled to the processor for normalizing said calculated probability estimates to provide normalized probability estimates;
• pipelining means between the processor and the normalizing means for providing non-normalized probability estimates;
• and
• switching means for receiving both said calculated probability estimates and said normalized probability estimates, an output of the switching means being coupled to the input of the processor;
• wherein the switching means is arranged to switch between the calculated probability estimates and the normalized probability estimates depending on the iterative state.