Patent ID: 7929414

Claim:
An apparatus for reducing a peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) system using a selected mapping (SLM) scheme, the apparatus comprising: a first generator for generating a plurality of OFDM signal sequences by performing an inverse fast Fourier transform (IFFT) operation on U input symbol sequences A 1 , A 2 , . . . , A u , which are probabilistically independent and have identical information; a combiner for linearly combining the plurality of OFDM signal sequences a i and a k , which are generated by the first generator, by using complex numbers c i and c k ; and a second generator for generating U 2 OFDM signal sequences through linear combination of the U OFDM signal sequences a u in a time domain transformed through IFFT by the linear combination of the combiner; wherein the first generator includes: a sampling unit for outputting an input symbol sequence A=[A 0 A 1 . . . A n-1 ] by sampling input data; a multiplying unit for outputting U input symbol sequences A 1 , A 2 , . . . , A u by multiplying the input symbol sequence A and U phase sequences P=[P u,0 P u,1 . . . P u,N-1 ] by a carrier located at the same position, where 1≦u≦U; and an IFFT unit for generating an OFDM signal sequence by performing an IFFT operation for each of the U input symbol sequences A 1 , A 2 , . . . , A u , wherein the OFDM signal sequence is generated according to an equation: a u =IFFT(A u )=IFFT(A P u ), wherein denotes multiplication of elements located at identical positions of each vector, and a phase sequence P u is a vector having complex numbers P u,n =e jφu,n (0≦n≦N−1) having a unit size when φ u,n has a value between 0 and 2π (φ u,n ∈[0,2π)) and when u is larger than 1 and smaller than U(1≦u≦U).