Wireless communications apparatus and wireless communication method

Abstract

A communication method of a base station transmits a modulation signal based on an OFDM (orthogonal frequency division multiplexing) scheme to a plurality of communication terminals. The method includes using a transmission frame on which a first subcarrier group and a second subcarrier group are arranged, the first subcarrier group on which a signal using a first transmission scheme is arranged, and the second subcarrier group on which a signal using a second transmission scheme different from the signal using the first transmission scheme in transmission quality is arranged. The method also includes determining, on a per frame basis, which subcarrier group is allocated to each of the plurality of communication terminals and how many subcarriers are allocated to said each of the plurality of communication terminals, and forming the transmission frame based on the determined information. The method further includes transmitting the modulation signal using the transmission frame.

1 . A communication method of a base station which transmits a modulation signal based on an OFDM (orthogonal frequency division multiplexing) scheme to a plurality of communication terminals, the method comprising:
 using a transmission frame on which a first subcarrier group and a second subcarrier group are arranged, the first subcarrier group on which a signal using a first transmission scheme is arranged and the second subcarrier group on which a signal using a second transmission scheme different from the signal using the first transmission scheme in transmission quality is arranged;   determining on a per frame basis, which subcarrier group is allocated to each of the plurality of communication terminals and how many subcarriers are allocated to said each of the plurality of communication terminals and forming the transmission frame based on the determined information; and   transmitting the modulation signal using the transmission frame.   
   
   
       2 . A communication method according to  claim 1 ,
 wherein receiving of feedback information including radio propagation condition estimation information from said each of the plurality of communication terminals is performed and the determining of how many subcarriers are allocated to said each of the plurality of communication terminals is performed on the per frame basis, based on the feedback information.   
   
   
       3 . A communication method according to  claim 1 ,
 wherein in the 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 the forming of the transmission frame, a control information symbol is arranged on a fixed time unit in advance.   
   
   
       5 . A communication method according to  claim 3 ,
 wherein the control information symbol includes information on a frame configuration for the transmission frame.   
   
   
       6 . A communication method according to  claim 4 ,
 wherein the control information symbol includes information on a frame configuration for the transmission frame.   
   
   
       7 . A communication apparatus for a base station which transmits a modulation signal based on an OFDM (orthogonal frequency division multiplexing) scheme to a plurality of communication terminals, the apparatus comprising:
 a transmission frame forming section that uses a transmission frame on which a first subcarrier group and a second subcarrier group are arranged, the first subcarrier group on which a signal using a first transmission scheme is arranged and the second subcarrier group on which a signal using a second transmission scheme different from the signal using the first transmission scheme in transmission quality is arranged, that determines on a per frame basis, which subcarrier group is allocated to each of the plurality of communication terminals and how many subcarriers are allocated to said each of the plurality of communication terminals and that forms the transmission frame based on the determined information; and   a transmitting section that transmits the modulation signal using the transmission frame.   
   
   
       8 . A communication apparatus according to  claim 7 , further comprising:
 a receiving section which receives feedback information including radio propagation condition estimation information from said each of the plurality of communication terminals,   wherein the transmission frame forming section determines on the per frame basis, how many subcarriers are allocated to said each of the plurality of communication terminals based on the feedback information.   
   
   
       9 . A communication apparatus according to  claim 7 ,
 wherein the transmission frame forming section arranges a control information symbol on a fixed subcarrier.   
   
   
       10 . A communication apparatus according to  claim 7 ,
 wherein the transmission frame forming section arranges a control information symbol on a fixed time unit in advance.   
   
   
       11 . A communication apparatus according to  claim 9 ,
 wherein the control information symbol includes information on a frame configuration for the transmission frame.   
   
   
       12 . A communication apparatus according to  claim 10 ,
 wherein the control information symbol includes information on a frame configuration for the transmission frame.