Radio communication apparatus capable of switching modulation schemes

Abstract

A radio communication apparatus includes a QPSK modulator that modulates transmission data to produce a QPSK modulation signal and a 64QAM modulator that modulates transmission data to produce a 64QAM modulation signal. A radio transmitter receives the QPSK modulation signal and the 64QAM modulation signal and outputs a transmission signal. An average transmission power of the QPSK modulation signal and the 64QAM modulation signal are within a predetermined output power range.

1 . A radio communication apparatus, comprising:
 a QPSK modulator to modulate transmission data to produce a QPSK modulation signal;   a 64QAM modulator to modulate transmission data to produce a 64QAM modulation signal; and   a radio transmitter to receive the QPSK modulation signal and the 64QAM modulation signal and output a transmission signal,   wherein an average transmission power of the QPSK modulation signal and the 64QAM modulation signal are within a predetermined output power range.   
     
     
         2 . The radio communication apparatus according to  claim 1 , further comprising a receiver to receive information regarding a radio wave propagation environment transmitted by a communication party, wherein the QPSK modulator, the 64QAM modulator, and the average transmission powers are controlled based upon the received information. 
     
     
         3 . The radio communication apparatus according to  claim 2 , wherein the received information includes information regarding communications traffic. 
     
     
         4 . The radio communication apparatus according to  claim 2 , wherein the QPSK modulator is selectable using a control signal and the 64QAM modulator is selectable using a control signal. 
     
     
         5 . The radio communication apparatus according to  claim 1 , wherein the radio communication apparatus is configured to use orthogonal frequency division multiplexing (OFDM). 
     
     
         6 . The radio communication apparatus according to  claim 5 , wherein the transmission data includes a frame having one or more preambles, one or more pilots, and data. 
     
     
         7 . The radio communication apparatus according to  claim 6 , wherein the frame is an OFDM signal frame and a pilot is inserted in the OFDM signal frame. 
     
     
         8 . The radio communication apparatus according to  claim 1 , wherein a magnitude of a modulated pilot is greater than a magnitude of modulated data. 
     
     
         9 . The radio communication apparatus according to  claim 1 , wherein a maximum transmission output power of the QPSK modulation signal and the 64QAM modulation signal are the same. 
     
     
         10 . A radio communication method, comprising:
 a QPSK modulator modulating transmission data to produce a QPSK modulation signal;   a 64QAM modulator modulating transmission data to produce a 64QAM modulation signal; and   a radio transmitter receiving the QPSK modulation signal and the 64QAM modulation signal and outputing a transmission signal,   wherein an average transmission power of the QPSK modulation signal and the 64QAM modulation signal are within a predetermined output power range.   
     
     
         11 . The radio communication method according to  claim 10 , further comprising:
 receiving information regarding a radio wave propagation environment transmitted by a communication party,   wherein the QPSK modulator, the 64QAM modulator, and the average transmission powers are controlled based upon the received information.   
     
     
         12 . The radio communication method according to  claim 11 , wherein the received information includes information regarding communications traffic. 
     
     
         13 . The radio communication method according to  claim 11 , further comprising:
 selecting the QPSK modulator using a control signal, and   selecting the 64QAM modulator using a control signal.   
     
     
         14 . The radio communication method according to  claim 10 , further comprising:
 generating orthogonal frequency division multiplexing (OFDM) signal based on the QPSK modulation signal and the 64QAM modulation signal.   
     
     
         15 . The radio communication method according to  claim 14 , wherein the transmission data includes a frame having one or more preambles, one or more pilots, and data. 
     
     
         16 . The radio communication method according to  claim 15 , wherein the frame is an OFDM signal frame and a pilot is inserted in the OFDM signal frame. 
     
     
         17 . The radio communication method according to  claim 10 , wherein a magnitude of a modulated pilot is greater than a magnitude of modulated data. 
     
     
         18 . The radio communication method according to  claim 10 , wherein a maximum transmission output power of the QPSK modulation signal and the 64QAM modulation signal are the same.