PROBLEM TO BE SOLVED: To provide a radio receiver that can be reduced in performance degradation of signals and for which a soft decision value can be calculated.SOLUTION: A radio receiver receives a transmission signal in which a bit sequence is subjected to bit conversion processing, scramble processing and M-phase PSK (Phase Shift Keying) modulation processing (M represents a positive integer), and contains a phase rotator and a demodulator. The phase rotator multiplies a first symbol obtained from a reception signal by a phase rotation amount of a signal determined by the scramble sequence used in the scramble processing, thereby obtaining a second symbol. The demodulator refers to a data rate and a signal point of a replica signal of N-phase PSK (N represents an integer from 1 to M) created on the basis of the bit conversion processing to demodulate the second symbol, and calculates the likelihood obtained through the demodulation as a soft decision value.