Patent ID: 7142610

Claim:
A system for communicating channel symbols, the system comprising, a turbo encoder for turbo encoding input data into turbo encoded data, a mapper for mapping the turbo encoded data into mapped data defining symbols of a i bits, the mapping serving to define boundary lines within a symbol constellation space of the symbols, the constellation signal space is a quadrature signal constellation space having a horizontal inphase i-axis and a vertical quadrature q-axis, the boundary lines being defined by i-axis and q-axis values, the boundary lines being lines extending through the symbol constellation space for bitwise separating zero and one bit values into respective bit i-0 and bit i-1 groups, a modulator for modulating the mapped data into channel symbols within the symbol constellation space, the modulator serving to communicate the channel symbols across a communication channel, a demodulator for M-ary demodulating each of the channel symbols into respective received signals where M=2 L , the received signals have an inphase component r (i) and a quadrature component r (q) , where L is the number of bits in a channel symbol, a soft metrics generator for generating bitwise soft metrics Λ(i) for each bit a i from each of the received signals, each of the bitwise soft metrics being a shortest distance from the received signal to one of the bitwise bit i boundary lines, and a turbo decoder for decoding the bitwise soft metrics into an estimate of the input data.