Patent ID: 7463698

Claim:
A transmitter comprising: a peak reducing part carrying out peak reduction processing; an OFDM signal generating part generating an OFDM signal from input information signal; a cyclic shifting part generating a signal obtained cyclically shifted from the OFDM signal; an adding part adding the OFDM signal and the cyclically shifted signal together; a shift amount determining part determining a shift amount based on at least one of the OFDM signal and an output signal of said adding part, wherein said cyclic shifting part generates the signal cyclically shifted from the OFDM signal based on the shift amount determined by said shift amount determining part; a weight generating part generating, based on the OFDM signal, weights for the OFDM signal and the cyclically shifted signal in such a manner that a peak power may be reduced; and a multiplying part multiplying the OFDM signal and the cyclically shifted signal with the weights generated by said weight generating part, wherein said adding part adds the output signals of said multiplying part together, and said weight generating part determines the weights w 1 and w 2 in such a manner that: phases of s(tp+t′) and s(tp−t′) may be opposite from a phase of s(tp), where s(tp) denotes a symbol causing the peak of the OFDM signal; and | s 1 ′|=|s 2 ′|, where: s 1 ′=w 1 ×s ( tp ) +w 2 ×s (mod( tp−t′+N FFT , N FFT )) s 2 ′=w 2 ×s (mod( tp+t′,N FFT )) +w 1 ×s ( tp ), where w 1 , W 2 denote the weights, mod denotes a remainder operator, N FFT (N FFT is an integer and N FFT >0) denotes an FFT point, and wherein t′ denotes the shift amount.