Patent ID: 8526517

Claim:
A blind selective mapping (BSLM) method of generating U independent alternative symbol sequences by changing a phase of symbol sequences by phase sequences and transmitting the alternative symbol sequences with a minimum peak to average power ratio (PAPR) in an orthogonal frequency division multiplexing (OFDM) system, in which a transmitter uses m-sequences as the phase sequence and a receiver uses a maximum likelihood (ML) decoder to distinguish the phase sequence used by the transmitter, where U is a number predetermined by the OFDM system, the BSLM method comprising: partitioning U alternative symbol sequences into U/2 blocks in the transmitter; rotating phases in each block for each alternative symbol sequence that is an input symbol sequence multiplied by the m-sequence; selecting a signal sequence with a minimum PAPR among U alternative signal sequences generated by the m-sequences in the transmitter, wherein, after the selecting, an ML decoder in each sub-block calculates a value by two different metrics, the two different metrics being given as D v , w v u = ∑ n = 2 ⁢ N ⁡ ( v - 1 ) U 2 ⁢ Nv U - 1 ⁢ min X ^ n ∈ S 0 ⁢  R n ⁢ ⅇ - jθ ⁢ ⁢ w v u - G n ⁢ X ^ n  2 where w v u ∈ { 0 , 1 } , v ∈ { 1 , 2 , … ⁢ , U 2 } , R n is a received symbol after fast Fourier transform (FFT) demodulation at the receiver, G n is a frequency response of a fading channel at an n-th subcarrier, and {circumflex over (X)} n is a constellation point of S 0 , where D v , w v u is a metric value obtained by an ML decoding process for each sub-block, w v u represents each element of W u , W u being the u-th phase rotation vector for sub-blocks, and v represents a position of each element within W u .