1. A method of demapping in a receiver wherein the input signal is a) demodulated into I real and Q imaginary data which was mapped using a constellation having M data bits for each I and Q, b) demapped, c) deinterleaved and d) decoded, the method of demapping comprising: deriving M intermediate soft bit values y j for each of the I and Q data as a function of the spacing in the constellation; limiting the range of the M values y j ; deriving a look-up table index for each of the limited M values y j ; indexing a look-up table, having 2 N+1 entries for supporting up to N soft bits, for each M data bit using the derived indices; and outputting the K soft bits for each data bit of the I and Q data where K<=N.