Wireless communications apparatus and wireless communications method

A wireless communication apparatus for a base station that transmits a modulation signal based on an orthogonal frequency division multiplexing scheme to a plurality of terminals, the apparatus comprising:

• a subcarrier allocation section that determines, for each individual terminal of the plurality of terminals, which subcarrier group or how many symbols along a time axis are to be allocated in a transmission frame, the transmission frame including a first part in which first transmission symbols for the each individual terminal served with the determined allocation are contained and a second part in which second transmission symbols for the each individual terminal served with the determined allocation are contained;
• a frame formation section that forms the transmission frame according to the determined allocation,
• wherein a transmission scheme for the second transmission symbols is different from a transmission scheme for the first transmission symbols,
• wherein a first modulated symbol including N bits information (N is a natural number) is arranged within M subcarriers (M is an integer equal to or greater than 2) or M symbols and N bits information is transmitted, in the transmission scheme for the first transmission symbols, and
• wherein a second modulated symbol including P bits (P is a natural number) information is arranged within one subcarrier or one symbol, and P×M bits information is transmitted by using M subcarriers or M symbols, in the transmission scheme for the second transmission symbols;
• and
• a transmitting section that transmits the modulation signal using the transmission frame.

A reception signal demodulation method for receiving and demodulating a modulation signal based on an orthogonal frequency division multiplexing scheme transmitted from a base station, the method comprising:

• specifying a position of a subcarrier group or symbols to which transmission data for a subject terminal is allocated, based on control information included in a transmission frame of the modulation signal,
• wherein transmission data for a plurality of terminals being allocated to the modulation signal, the transmission frame including a first part in which first transmission symbols addressed to the plurality of terminals are contained arranged and a second part in which second transmission symbols addressed to the plurality of terminals are contained,
• wherein a transmission scheme for the second transmission symbols is different from a transmission scheme for the first transmission symbols,
• wherein a first modulated symbol including N bits information (N is a natural number) is arranged within M subcarriers (M is an integer equal to or greater than 2) or M symbols, and N bits information is transmitted, in the transmission scheme for the first transmission symbols, and
• wherein a second modulated symbol including P bits (P is a natural number) information is arranged within one subcarrier or one symbol, and P×M bits information is transmitted by using M subcarriers or M symbols, in the transmission scheme for the second transmission symbols;
• and
• demodulating the modulation signal to generate reception data corresponding to the specified position of subcarrier group or symbols.

A reception signal demodulation apparatus for receiving and demodulating an orthogonal frequency division multiplexing signal transmitted from a base station, the apparatus comprising:

• a control information demodulating section that specifies a position of a subcarrier group or symbols to which transmission data for a subject terminal is allocated, based on control information included in a transmission frame of the modulation signal,
• wherein transmission data for a plurality of terminals being allocated to the modulation signal, the transmission frame including a first part in which first transmission symbols addressed to the plurality of terminals are contained and a second part in which second transmission symbols addressed to the plurality of terminals are contained,
• wherein a transmission scheme for the second transmission symbols is different from a transmission scheme for the first transmission symbols,
• wherein a first modulated symbol including N bits information (N is a natural number) is arranged within M subcarriers (M is an integer equal to or greater than 2) or M symbols, and N bits information is transmitted, in the transmission scheme for the first transmission symbols, and
• wherein a second modulated symbol including P bits (P is a natural number) information is arranged within one subcarrier or one symbol, and P×M bits information is transmitted by using M subcarriers or M symbols, in the transmission scheme for the second transmission symbols;
• and
• a data generation section that demodulates a modulation signal to generate reception data corresponding to the specified position of subcarrier group or symbols.