Disclosed are a radio communication terminal device, a radio communication base station device, and a radio communication method which can prevent input of an interference wave peak into a detection window of a cyclic shift sequence allocated to a local cell and improve the channel estimation accuracy in a base station. A frequency serving as a reference is set for a transmission band width of all the cells and respective terminals in which frame synchronization is established. By using the frequency as a reference point, a phase rotation addition unit (110) of a reference signal generation unit (108) adds a phase rotation corresponding to a frequency difference δ; between the transmission band of the reference point and that of the reference signal to a ZC sequence as a reference signal in the frequency region. The ZC sequence to which the phase rotation is added is multiplexed with transmission data in a multiplexing unit (114) and a multiplexed signal is transmitted from a transmission RF unit (115).