Patent ID: 8705665

Claim:
A method for computing soft-decision Log-Likelihood-Ratios (LLRs) in a detector of a wireless communication receiver, said LLRs being used by a channel decoder, the method comprising: receiving a signal from a telecom front end, said signal corresponding to data belonging to a finite set of constellation symbols, each constellation symbol being arranged in a lattice constellation impaired by additive noise and also by a multiplicative channel; computing a limited list of distances representative of Euclidian distances between the received signal and a finite set of predetermined constellation symbols; deriving a set of soft decision LLRs from said limited list of distances under the constraint of a limited length of the list of distances; and completing said derived LLRs by clipping values read from a look-up table which is addressed by the values of the SNR and a bit index of a modulation constellation mapping of the constellation symbols, so as to complete the LLR computation for distances not included within said limited list of distances.