Wireless communications apparatus and wireless communication method
View Patent ↗The invention performs orthogonal frequency division multiplex processing on a transmission signal to form an OFDM modulation signal (daubed in FIG.) and performs orthogonal frequency division multiplex processing and code division multiple access processing on a transmission signal to form an OFDM-CDM modulation signal (shaded in FIG.) to transmit the OFDM modulation signal and the OFDM-CDM modulation signal, which makes it possible to transmit data in a very high rate using the OFDM modulation signal while making it possible to transmit data in a higher quality using the OFDM-CDM modulation signal than using the OFDM-modulation signal, although it is slightly inferior to OFDM modulation in terms of high rate transmission.
1. A communication method of a base station which transmits an OFDM (orthogonal frequency division multiplexing) signal to a plurality of communication terminals, said method comprising:
determining on a frame basis, how many and which subcarriers are allocated to each of the plurality of communication terminals and forming a transmission frame based on the determined information; and
transmitting the transmission frame.
2. A communication method according to claim 1 ,
wherein said determining of how many subcarriers are allocated to each of the plurality of communication terminals is performed on a frame basis, based on a feedback information which is transmitted from each of the plurality of communication terminals.
3. A communication method according to claim 1 , wherein in said forming of the transmission frame, a control information symbol is arranged on a fixed subcarrier.
4. A communication method according to claim 1 , wherein in said forming of the transmission frame, a control information symbol is arranged on a fixed time unit.
5. A communication method according to claim 4 , wherein the control information symbol includes information on a frame configuration for the transmission frame.
6. A communication apparatus for a base station which transmits an OFDM (orthogonal frequency division multiplexing) signal to a plurality of communication terminals, said apparatus comprising:
a transmission frame forming section which determines on a frame basis, how many and which subcarriers are allocated to each of the plurality of communication terminals and forms a transmission frame based on the determined information; and
a transmitting section which transmits the transmission frame.
7. A communication apparatus according to claim 6 , further comprising:
a receiving section which receives a feedback information from each of the plurality of communication terminals,
wherein said transmission frame forming section determines on a frame basis, how many subcarriers are allocated to each of the plurality of communication terminals based on the feedback information.
8. A communication apparatus according to claim 6 , wherein said transmission frame forming section arranges a control information symbol on a fixed subcarrier.
9. A communication apparatus according to claim 6 , wherein said transmission frame forming section arranges a control information symbol on a fixed time unit.
10. A communication apparatus according to claim 9 , wherein the control information symbol includes information on a frame configuration for the transmission frame.