Patent ID: 8270531

Claim:
A method for transmitting a data bit stream using a first 16-QAM constellation and a second 16-QAM constellation, the method comprising the steps of: forming a sequence of data words from the bit stream, each data word comprising four bits, mapping each data word to a modulation symbol using the first 16-QAM constellation to generate a first arrangement pattern of modulation symbols, mapping each data word to a modulation symbol using the second 16-QAM constellation to generate a second arrangement pattern of modulation symbols, and transmitting the first arrangement pattern of modulation symbols and the second arrangement pattern of modulation symbols according to a transmit diversity scheme, wherein the second arrangement pattern of modulation symbols is obtained by rearranging the first arrangement pattern of modulation symbols according to the rearrangement rules of FIG. 24 : wherein the differently dashed arrows indicate the rearrangement of a data word corresponding to a modulation symbol in the first 16-QAM constellation and the same data word corresponding to a modulation symbol in the second, rearranged 16-QAM constellation, wherein the modulation symbol in the first 16-QAM constellation is indicated by the start of an arrow line and the modulation symbol in the second, rearranged 16-QAM constellation is indicated by the end of the arrowhead of the same arrow, and wherein each of the first 16-QAM constellation and the second 16-QAM constellation has 16 modulation symbols representable in four rows and four columns in a complex coordinate plane, and each modulation symbol of the first and second 16-QAM constellations represents a combination of four bits, wherein each of the first 16-QAM constellation and the second 16-QAM constellation obeys the following mapping rules: a first one of the four bits representing the modulation symbol selects one of two contiguous symbol regions of the 16-QAM constellation based on its logical value, each of the two contiguous symbol regions comprising two columns adjacent to each other, a second one of the four bits representing the respective modulation symbol selects one of two contiguous symbol regions of the 16-QAM constellation based on its logical value, each of the two contiguous symbol regions comprising two rows adjacent to each other, a third one of the four bits representing the respective modulation symbol selects one of two non-contiguous symbol regions of the 16-QAM constellation based on its logical value, each of the two non-contiguous symbol regions comprising two columns not adjacent to each other, and a fourth one of the four bits representing the respective modulation symbol selects one of two non-contiguous symbol regions of the 16-QAM constellation based on its logical value, each of the two non-contiguous symbol regions comprising two rows not adjacent to each other.