A New Single Carrier Frequency Division Multiple Access Based on Discrete Cosine Transform Spread OFDMA.

Abstract

A single carrier frequency division multiple access (SC-FDMA), is a technique that has a similar performance and essentially the same overall complexity as those of orthogonal frequency division multiple access (OFDMA).In this paper, a strong "energy compaction" property of discrete cosine transform (DCT) is exploiting to enhance the performance of SC-FDMA system. A new SC-FDMA system for uplink wireless transmissions is proposed. The proposed system is based on DCT prior to the OFDMA modulation at the transmitter and reverse operation performed at the receiver. The proposed discrete cosine fourier transform (DCFT) SC-FDMA signal is compared with that of the DFT SC-FDMA and OFDMA signals in terms of bit error rate (BER) and peak-to average power ratio (PAPR). Moreover, the proposed system is compared to a recently introduced DCT SC-FDMA system. Simulation results show that the proposed DCFT SC-FDMA provides a significant improvement in BER performance than the DFT SC-FDMA, OFDMA and DCT SC-FDMA. There is a BER improvement of a gain up to 7 dB compared to OFDMA, 5 dB when compared to DFT SC-FDMA and 3 dB when compared to DCT SC-FDMA. In addition, it is found that the PAPR of the DCFT SC-FDMA signals is lower than that of OFDMA signals. Moreover, the proposed system complexity is comparable with the traditional DCT SC-FDMA.