Patent ID: 7770092
Filing Date: 2010-08-03
Classification: H03M

Abstract:
1. A method for performing iterative decoding in accordance with a Log-MAP algorithm in a system using a turbo code, the method comprising: generating a look-up table stored in a memory comprising a plurality of values corresponding to a transcendent function representative of a correcting factor of a max* algorithm; performing a first calculation to obtain a forward metric; performing a second calculation to obtain a backward metric; performing a third calculation to obtain a log-likelihood ratio for every information bit to be decoded, wherein among said performed calculations at least one and no more than two calculations are performed by the use of said look-up table for implementing the Log-MAP decoding algorithm and the remaining calculations are performed implementing a Max Log-MAP decoding algorithm, wherein said step of generating the look-up table comprises the further step of generating each value according to the following equation: where p is a factor corresponding to a number of bits dedicated to the precision of the value LUT(Δ) and Δ is indicative of an argument varying within a range having a maximum limit Δ