Patent ID: 7693179

Claim:
A transmission apparatus for transmitting data comprising: a table that stores four mappings for a 16 QAM modulation scheme, a selection section that selects a first mapping and a second mapping of said four mappings, a modulation section that modulates data using said selected first mapping and said selected second mapping, a transmission section that transmits the data modulated using said selected first mapping in a first transmission, and retransmits the data modulated using said selected second mapping of the mappings in a retransmission, wherein: one of said four mappings is represented as a bit sequence (i 1 q 1 i 2 q 2 ), and the other three mappings are produced, with respect to the bit sequence (i 1 q 1 i 2 q 2 ), by: (1) swapping i 1 and q 1 with i 2 and inverting logical values of i 1 and q 1 , (2) swapping i 1 and q 1 with i 2 and q 2 and (3) inverting logical values of i 2 and q 2 .