Patent ID: 8265175

Claim:
A digital, communication system, comprising: a transmitter configured to transmit signals to a receiver via a communication channel; wherein the transmitter, comprises: a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate; a mapper configured to map said encoded bits to symbols in a symbol, constellation; a modulator configured to generate a signal, for transmission via the communication channel, using symbols generated by the mapper; wherein the receiver, comprises: a demodulator configured to demodulate the received signal, via the communication channel; a demapper configured to estimate likelihoods from the demodulated signal; a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper; and wherein the points of the symbol, constellation have non-uniform inter-point distances selected to achieve a gain in capacity for a predetermined signal, to noise ratio (SNR) relative to a symbol, constellation having uniform inter-point distances.