A transmitter is capable of suppressing a PAPR to be low and efficiently amplifying transmit power. The transmitter generates a transmission signal by oversampling a modulated signal, and includes a modulation unit that performs a modulation process on an information sequence and that generates a constant envelope signal and a phase interpolation unit that inserts a predetermined number of signals identical in amplitude to signal points of the constant envelope signal between the signal points so that signal points including original signal points are located equidistantly.