Comparison of the Link Level Performance between OFDMA and SC-FDMA

Since 3G long term evolution (LTE) is launched by 3GPP recently, many multiple access (MA) schemes have been proposed for 3G LTE, such as multi-carrier (MC) - WCDMA, MC-time duplex-synchronized CDMA (MC-TD-SCDMA), orthogonal frequency division multiple access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), which includes IFDMA (interleaved FDMA) and DFT-S OFDM (DFT-spreading OFDM). Among those schemes, OFDMA and DFT-S OFDM are both promising for their special advantages for uplink. In this paper, the link level performance of MA schemes are compared. The simulation results show that without coding, OFDMA has 1 dB performance gain than DFT-S OFDM when BER is equal to 10^-2. When turbo coding is adopted, OFDMA has near 3 dB performance gain than DFT-S OFDM when BLER is equal to 10^-2. The performance difference between OFDMA and DFT-S OFDM is increased for MIMO system. Since the PAPR can be reduced to lower than 6 dB as required by 3GPP, OFDMA has the performance gain than DFT-S OFDM in link level simulation.