Patent ID: 8406321

Claim:
A digital signal transmission method for modulating a codeword obtained by coding information bits to be transmitted, and transmitting modulation symbols obtained by the modulation with dividing into two or more blocks, comprising the step of: transmitting a plurality of said modulation symbols on a plurality of subcarriers using rotation code multiplexing, wherein the angle of a rotation code within a range from 0° to 45° applied to modulation symbols contained in the block early in the transmission sequence is greater than the angle of a rotation code within a range from 0° to 45° applied to the block later in the transmission sequence, where a rotation angle of 0° achieves a signal point arrangement identical to that of a non-multiplexed signal, a rotation angle of 45° achieves a signal point arrangement equivalent to that of a signal multiplexed with a Walsh-Hadamard code.