Low complexity PTS scheme for PAPR reduction of OFDM signals

A low complexity partial transmit sequence (PTS) scheme is proposed to improve the performance of the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. By analyzing the characteristic of candidate signals, the number of phase factor vectors is reduced from 64 to 16 without the loss of PAPR performance and the search time of the phase factor is reduced. The hardware cost of the IFFT unit can be reduced by adopting the group concept, rescheduling the time of the multiplication with twiddle factors, and using path-based constant multipliers instead of complex multipliers. In the IFFT unit, the hardware costs of complex multipliers, complex adders, and registers are respectively reduced by 58.8%, 28.6%, and 75.6% compared with four independent IFFT processors with radix 23 and single-path delay feedback. In addition, there is no need for ROM to store the twiddle factor. Moreover, because of the characteristic of the needed phase factor vectors, the hardware overhead of the optimization unit can be lessened.