A radio communication method in a radio communication system in which data signals for a first and second user are respectively transmitted using first and second subcarrier groups, and pilot signals for the first and second users are multiplexed using time-division multiplexing with the data signals for those users, including arranging a pilot signal of the first user at frequencies different from frequencies of a pilot signal of the second user and mapping subcarrier components of the pilot signals so that one of subcarrier components of higher frequencies corresponds to one of subcarrier components of lower frequencies, wherein the pilot signals are generated using a Zadoff-Chu sequence.