FRFT-SCFDMA scheme for uplink in 5G radio access networks

Single Carrier Frequency Division Multiple Access (SC-FDMA) is a promising technique compared to Orthogonal Frequency Division Multiple Access (OFDMA) for uplink transmission in 3rd Generation Partnership Project(3GPP) Long Term Evolution(LTE) because of its low peak to average power ratio (PAPR). However SC-FDMA is very sensitive to carrier frequency offset(CFO), which affects the error rate performance of the system adversely. This paper proposes an efficient signal processing technique known as fractional Fourier transform(FRFT) for Single Carrier Frequency Division Multiplexing(SCFDM) over Nakagami-m fading channel in the presence of CFO. A clear improvement has been shown in symbol error rate(SER) by using FRFT block in place of FFT block. Simulation results confirm that FRFT-SCFDM outperforms FFT-SCFDM as its probability of error can be controlled by varying FRFT angle(α) without significant increase in the complexity. Further, we have compared the FRFT implementations of SCFDM and OFDM and observed a gain of 7 dB for FRFT-SCFDM over FRFT-OFDM at CFO(ε) equals 0.1. Further, no change in PAPR, no significant increase in complexity with improved SER performance or quality of service(QoS) motivates FRFT-SCFDMA to be one of the potential candidates for uplink transmission for 5G radio access networks(RAN).