By assigning a plurality of subcarriers 31 to a data channel 33 and
assigning fewer subcarriers 32 than the plurality of subcarriers 31 to a
control channel 34, and in addition locating the control channel 34 at
the center frequency fc of a frequency band used to transmit the data
channel 33, on the radio receiving apparatus side, the frequencies of a
local signal by which the received signal is multiplied share the same
value, thereby speeding up the switching between the control channel and
the data channel.