Abstract: A method is disclosed for digital data transmission using higher order modulation schemes, wherein a plurality of bits is mapped to bit positions of a symbol and the transmission has different error probabilities for at least two out of said bit positions. A data bit is mapped to a bit position in a first modulation scheme and transmitted in a symbol on the mapped bit position of the first modulation scheme. When a request is received from a receiver, for retransmission of a data block containing this data bit, a decision is made about a re-transmission of said bit, based on a reliability of the bit position in the first transmission, and if it is decided to retransmit the bit, the data bit is mapped to a bit position of a second modulation scheme and retransmitted in a symbol on the mapped bit position of the second modulation scheme.

Abstract: A multicarrier communication apparatus capable of reducing an amount of information required for feedback, making a range of transmission power fluctuation small, and achieving rapid convergence on a target transmission power is disclosed. With this apparatus, subcarrier pair determination section (1142) puts a plurality of subcarriers contained in a multicarrier signal into pairs, notifies combining section (106) of information pertaining to the pairs of subcarriers, combines received power of each pair of subcarriers, and outputs combined received power obtained in this manner to command producing section (1146). Target power storage section (1144) stores target power for received power in such a manner that SIR at the subject apparatus becomes a desired SIR.