COMPARISON OF PERFORMANCES BETWEEN SC-FDMA AND OFDMA SYSTEMS UNDER DIFFERENT SUBCARRIER MAPPING SCHEMES

Abstract

To improve the uplink performance of wireless network for long term evolution (LTE) single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA) are used. Two major concerns of these SC-FDMA and OFDMA are high peak-to-average power ratio (PAPR) and efficient subcarrier mapping scheme. This paper presents a performance comparison of SC-FDMA and OFDMA under different subcarrier mapping schemes which includes localized FDMA (LFDMA), distributed FDMA (DFDMA) and interleaved FDMA (IFDMA). Quadrature amplitude modulation (QAM) with different constellation sizes is used. The symbol error rate (SER) in SC-FDMA is minimized using appropriate mapping scheme. The PAPR is less in SC-FDMA compared to OFDMA. SC-FDMA with IFDMA shows better performance for the PAPR reduction compared to the OFDMA. Compared to OFDMA, using SC-FDMA with 8-QAM and IFDMA, PAPR is reduced by  78%, using SC-FDMA with 16-QAM and IFDMA, PAPR is reduced by  80%,  using SC-FDMA with 64-QAM and IFDMA, PAPR is reduced by  68%.