Patent ID: 7552379
Filing Date: 2009-06-23
Classification: H03M

Abstract:
1. A method for performing iterative decoding of information coded by an error correction code, the method comprising: defining a transcendent first function representing a quantity to be evaluated for the decoding method; defining a quantized second function approximating the first function; computing first values of the second function obtained based on first arguments; the first values being not null and the first arguments being variable in a limited range having a maximum limit; computing second values of the second function obtained based on second arguments, the second values being null and the second arguments being external to the range; generating a look-up table representing the first function and containing the first and second values associated with indexes correlated to said first arguments and to an expected maximum limit; retrieving tabled values from said look-up table based on corresponding indexes for computing said quantity; receiving first and second soft values produced by a turbo encoder representing information transmitted on a communication channel, the first soft value corresponding to a transmitted bit to be decoded; computing the log-likelihood ratio by an iterative processing in a first decoder based on the forward and backward metrics and on the first and a second soft values; and feeding an interleaver with the calculated log-likelihood ratio to obtain an interleaved log-likelihood ratio.