method of decoding is provided comprising processing iterations in each processing iteration there is a first max log map decoding operation giving rise to a systematic error due to the max log approximation and a first weighting operation to weight extrinsic information from the first decoding operation to be applied as a priori information to the second max log map decoding operation this is followed by a second max log map decoding operation also giving rise to a systematic error due to the max log approximation and a second weighting operation to weight extrinsic information from the second decoding to be applied as a priori information to the first max log map decoding of the next iteration the weights are applied to compensate for the systematic error due to the max log approximation made in the last max log map decoding operation application_number US 63778803 A description as background turbo coding will first be explained generally before focussing in on log map decoding and then max log map decoding an improvement to max log map decoding will then be presented fig1 shows a known turbo decoder 2 for a parallel concatenated code of rate u2153 i e where one information bit has two associated parity bits as presented for example in the book by b vucetic and j yuan entitled u201c turbo codes u201d published by kluwer academic publishers 2000 the code is termed parallel concatenated because two known recursive systematic convolutional encoders not shown within a turbo encoder not shown have operated on the same set of input bits rather than one encoding the output of the other given systematic i e information bit x t 0 and parity i e check sequence bits x t 1 and x t 2 generated at the turbo encoder not shown.