Blind SLM and PTS method with low decoding complexity of OFDM signals

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
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• Rn is a received symbol after fast Fourier transform (FFT) demodulation at the receiver,
• Gn is a frequency response of a fading channel at an n-th subcarrier, and
• {circumflex over (X)}n is a constellation point of S0, where
• Dv, wvu is a metric value obtained by an ML decoding process for each sub-block,
• wvu represents each element of Wu, Wu being the u-th phase rotation vector for sub-blocks, and
• v represents a position of each element within Wu.