Waveform Design of DFT-Spread WR-OFDM System for the OOB and PAPR Reduction

Abstract

Peak-to-average power ratio (PAPR) and out-of-band (OOB) spectrum power reduction have become challenging tasks in proper designing of power and spectrally efficient for the beyond 5th generation cellular communication systems. Power consumption in associated active devices of the power amplifier (PA) increases with large PAPR and reduction of OOB is very important for the improvement of spectrum efficiency. In this paper, a DFT (discrete Fourier transform) - Spread WR-OFDM (windowing and restructuring orthogonal frequency division multiplexing) communication system is proposed in consideration of developing reasonably acceptable future generation mobile and wireless system based on the significant reduction of both peak-to-average power ratio (PAPR) and out-of-band (OOB) power spectrum components. In our proposed system, Tukey (tapered cosine) time-domain windowing and localized subcarrier mapping have been implemented. In AWGN and multipath Rayleigh fading channels, the system performances are compared with the WR (window and restructuring) - OFDM and conventional CP (cyclic prefix) - OFDM system. Numerical results show that up to 3 dB more PAPR reduction as compared to the WR-OFDM system and out-of-band attenuation of 110 dB can be achieved at the window length of 62.