Single carrier FDMA technique for wireless communication system

Abstract

Third generation partnership project- long term evolution (3GPP-LTE) standard has recommended single carrier frequency division multiple accessing (SC-FDMA) technique in the future generation wireless communication system for its uplink transmission. SC-FDMA gives low peak to average power ratio (PAPR) than the orthogonal frequency division multiplexing (OFDM) technique. In addition to low PAPR, it also delivers high throughput, has high spectral efficiency with low bit error rate. Mathematical modeling and Matlab simulation has been carried out to obtain PAPR performance of SC-FDMA technique with different number of subcarriers. Two different approaches of assigning subcarriers have been assumed, distributed FDMA (DFDMA) and localized FDMA (LFDMA). Interleaved FDMA (IFDMA) is a special case of DFDMA where, distribution of DFT outputs have been done uniformly with equal distance. The PAPR performance of IFDMA obtained from mathematical analysis and Matlab simulation is better than the LFDMA technique. For the case of 1024 numbers of subcarriers with 4 QAM modulation format, IFDMA gives 12.4 dB lower PAPR value than that of OFDM. Similarly, LFDMA has 5.5 dB lower PAPR value than that of OFDM. Although reduction in PAPR with IFDMA is more than that of LFDMA but its implementation is comparatively difficult due to the subcarrier adjacency constraint.