Survey on Signal Scrambling PAPR Reduction Techniques with Explicit Side Information in OFDM

An OFDM is an attractive modulation technique for transmitting large amounts of digital data over radio waves. One major disadvantage of OFDM is the time domain OFDM signal which is a sum of several sinusoids leads to high peak to average power ratio (PAPR).  Number of techniques have been proposed in the literature for reducing the PAPR in OFDM system, among which Signal Scrambling Techniques which provides PAPR reduction without data rate loss are discussed and compared in this paper. Here more emphasis is given on SLM and PTS techniques as they are considered to be more powerful techniques for reducing PAPR.  In SLM  different phase rotations are used and alternate OFDM signals are generated by multiplying same data block with different phase rotations and one with minimum PAPR is selected for transmission while in PTS different combinations of phase rotations are used and the  combinations of phase factors with minimum PAPR is selected.