Patent ID: 7848464

Claim:
A method for receiving data in a communication system, the method comprising: receiving a first signal from a transmitter, canceling from the first signal a second signal desired to be received from the transmitter; and detecting and canceling an interference signal from the second signal-canceled first signal, calculating a Log Likelihood Ratio (LLR) of the interference signal-canceled first signal, and decoding the LLR, wherein the second signal is calculated in each constellation point determined according to a modulation scheme of the transmitter, wherein the LLR calculation comprises calculating a power ratio of the interference signal-canceled first signal to a noise included in the first signal, calculating a maximum value of the calculated power ratio, and calculating an LLR of the calculated maximum value, and wherein the power ratio calculation comprises calculating power ratios in constellation points determined according to the modulation scheme of the transmitter, and calculating a power ratio at a point in a first constellation quadrant, a power ratio at a point in a second constellation quadrant, a power ratio at a point in a third constellation quadrant, and a power ratio at a point in a fourth constellation quadrant.