In a radio communication system in which multiple bands or a plurality of
different radio frequencies are used, a different radio transmission
method is used in each band or at each radio frequency. For example, by
transmitting data using radio formats which are different in each band or
at each radio frequency, the radio transmission method is made different
in each band or at each radio frequency. In order to vary the radio
format, (1) the pilot length is varied at each radio frequency; or (2)
the pilot interval is varied at each radio frequency; or (3) the guard
interval length is varied in each band or at each radio frequency; or (4)
when multicarrier modulation is used for radio communication in each
band, the subcarrier interval for multicarrier transmission is varied in
each band.