Patent ID: 8711957

Claim:
An apparatus for transmitting data, the apparatus comprising: a first symbol mapper configured to generate a plurality of key symbols by performing symbol mapping on information about an optimum key index that instructs a modified Walsh-Hadamard matrix that causes a minimum peak-to-average power ratio (PAPR); a first modified Walsh-Hadamard transformer configured to generate a plurality of modified Walsh-Hadamard-transformed data symbols by performing modified Walsh-Hadamard transform on a plurality of data symbols according to a modified Walsh-Hadamard matrix that the optimum key index instructs; an inverse Fourier transformer configured to generate a plurality of inverse Fourier-transformed symbols by performing inverse Fourier transform on the plurality of key symbols and the plurality of modified Walsh-Hadamard-transformed data symbols; and a transmitter configured to transmit the plurality of inverse Fourier-transformed symbols to a channel through at least one antenna.