Communication unit for soft-decision demodulation and method therefor

A communication unit for performing soft-decision demodulation comprising a receiver, wherein the receiver is arranged to receive a transmitted signal conveying a first set of bits comprising k bits that has been selected from a set of 2k possible signals, wherein the receiver comprises:

• a demodulator comprising a bank of 2k correlators and configured to:
• detect a transmission of each possible transmitted signal, and
• output 2k magnitudes of correlator outputs, based on the detected possible transmitted signals, by the bank of 2k correlators as a first set of inputs;
• and
• a de-mapper circuit coupled to the demodulator and configured to receive the first set of inputs and:
• determine statistics derived from a plurality of aggregated correlator output magnitude distributions of the first set of inputs, wherein the plurality of aggregated correlator output magnitude distributions is fewer than 22k;
• and
• calculate a first set of aposteriori soft bits comprising k soft bits from the determined statistics and output the first set of aposteriori soft bits comprising k soft bits.