Patent ID: 7570699

Claim:
A QAM (Quadrature Amplitude Modulation) symbol mapping method performed by a QAM symbol mapping apparatus, the method comprising the steps of: receiving a plurality of bits at an input of the QAM symbol mapping apparatus, the plurality of bits including a first set of bits and a second set of bits, the first set including two bits that represent set partitioning information and the second set including the other bits that represent amplitude information; determining phase information on the basis of predetermined relations between the first set of bits and two LSBs (Least Significant Bits) of the second set of bits; designating a half of the second set of bits as I signals of a first quadrant and the other half of the second set of bits as Q signals of the first quadrant according to a predetermined mapping of the first quadrant; and mapping the I and Q signals of the first quadrant to actual positions in a QAM constellation on the basis of the determined phase information.