In one aspect, the present invention greatly simplifies soft modulation calculations, in part by exploiting certain properties of Gray-mapped QAM constellations used in modulating symbols of interest. In at least one embodiment, the simplified processing includes performing the soft modulation separately for the real and imaginary parts of each symbol of interest, by using the Gray mapping to decompose each of the real and imaginary parts into binary soft modulations for each bit, and then using a computationally-efficient table lookup to calculate the binary soft modulation. Here, the look-up table comprises pre-computed bit contributions to the complex soft symbol value to be formed for the symbol of interest.