Novel Scheme of Oversampling Spread Spectrum Roll-Off OFDM for PAPR Reduction

It is noted that OFDM has a good spectral efficiency. However, it has a high peak to average power ratio. In this paper, we propose a novel technique called Oversampling Spread Spectrum Roll-off OFDM (OSSR-OFDM) to reduce PAPR of OFDM signal. In OSSR-OFDM, each subcarrier forms nyquist pulse by spreading in frequency domain. The results of computer simulation show that our proposal with a lager roll-off factor can reduce the PAPR more effectively compared with conventional OFDM and CI/OFDM. There is no degradation in BER performance and no increasing in the out-of-band radiations in our proposal with alpha=0.2.