1. A method of producing soft decisions for a signal, wherein a model provides an expression for an LLR for the signal, the LLR expression is dependent on noise power in the signal and can be rendered in a form independent of the noise power, wherein the method comprises evaluating the noise power independent expression using values from the signal to produce soft decisions, calculating a weight expressing the noise power affecting a soft decision relative to the noise power affecting at least one other soft decision and applying the weight to its respective soft decision.