Abstract: A turbocode receiver system of a signal emitted by a turbo-coded modulated transmitter system, includes: a soft demapper (1) the output of which is connected to a turbodecoder (2), and an adaptive locked loop including: a measurement generator (3) the input of which is connected to the turbodecoder output to receive the reliability vector (LLRout) of the result and adapted to transform the vector into a reliability measurement (M(I)), equal to the average of the lowest reliability values of word bits, transmitted to a phase shift estimator (4) the output of which is connected to a phase compensator (5) positioned upstream of the soft demapper and adapted to correct the incoming signal of the phase value ?.

Abstract: The invention concerns a method for estimating the gain and/or the phase of observation data (yk) transmitted in QAM modulation. The method includes (A) iteratively estimating the phase and/or gain parameters based on a specific phase and/or gain law and (B) executing an adaptive procedure for estimating the phase and/or gain parameters, the adaptive procedure including at least one function for estimating the parameters based on the value of likelihood probability, expressed in terms of log-likelihood, of each observation data (yk) with respect to the set of bits constituting the symbols of the QAM modulation. The invention is applicable to single-carrier or multicarrier digital transmissions.

Abstract: Each received word is subjected to SISO turbodecoding consisting in generating decoded test words using an iterative algorithm, calculating the analog weight of the decoded test word, which weight is the half-sum of the products of the value of each bit mapped to ±1 of this decoded test word and the log-likelihood of this bit, classifying the analog weight values of the concurrent words according to a first analog weight vector and a second analog weight vector formed by the analog weight components of the decoded test words, the bit of rank j of which is at a first value, and a second analog weight vector formed by the analog weight components of the decoded test words, the bit of rank j of which is at a second value, and calculating the SISO decoding soft-decision output value as being the difference between the analog weight components of the first and second vectors.