Patent ID: 7315578

Claim:
A method of computing bit soft values from Gray-coded modulation symbols in a received communication signal comprising: providing a set of unified equations, each unified equation corresponding to a bit position of the bit soft values to be computed irrespective of which region of a nominal modulation constellation the corresponding symbol lies within and yielding the exact solution as an applicable regional equation selected from a set of regional equations associated with a nominal modulation constellation for that bit position; generating symbol samples of the Gray-coded modulation symbols in the received communication signal, each symbol sample comprising real and imaginary components; scaling either the symbol samples or the nominal modulation constellation to compensate for a received amplitude of the modulation symbols; and determining bit soft values for each symbol sample based on, for each bit position to be determined, calculating the bit soft value by solving the corresponding unified equation using either the real or the imaginary component of the symbol sample depending on the bit position.