Patent ID: 7792223

Claim:
A system for demodulating received data signals comprising: a communication interface being configured for receiving modulated data from a data source over a medium, the modulated data representing a plurality of bits, the plurality of bits including at least a first bit, the first bit being modulated by the data source using a predetermined first plurality of modulation symbols, the first plurality of modulation symbols being a subset of a second plurality of modulation symbols; and a processor coupled with the communication interface, the processor being configured to: determine a number of modulation symbols used for modulating the first bit; provide a set of permutations of possible modulation symbols based on the number of modulation symbols; provide a noise value, the noise value being associated with the medium; provide an attenuation value, the attenuation value being associated with the medium; determine a first minimum value for a first plurality of probability values for first bit being zero, each of the probability values being associated with a permutation, each of the probability values further being a function of the noise value, the attenuation value, and the modulated data; determine a second minimum value for second plurality of probability values for first bit being nonzero, each of the probability values being associated with a permutation, each of the probability values further being a function of the noise value, the attenuation value, and the modulated data; and determine a ratio between the first minimum value and the second minimum value.