Reduction of PAPR for SC-FDMA System based on DCT and Hyperbolic Tangent Companding

SC-FDMA suffers from high Peak-to-Average Power Ratio (PAPR) problem, which restricts its usage in some applications. In this paper, a joint Discrete Cosine Transform (DCT) and hyperbolic tangent companding (HTC) technique has been studied in order to minimize the effects of the peak-to-average power ratio of the SCFDMA System. The proposed scheme utilizes a DCT rather than the conventional discrete Fourier transform (DFT) as a basis function to implement the single-carrier system. Simulation results show that the new proposed scheme reduces PAPR by about 4.2 dB and 2.6 dB companding respectively with the DCT SC-FDMA without commanding and DFT SC-FDMA with HTC at the same companding parameter. Also, it can be observed that proposed scheme provides a significant BER performance improvement over the DFT SC-FDMA with HTC by about 1.1dB. Simulation results show that, proposed scheme with HTC has the lowest BER degradation, followed by μ-law companding and A law companding by about 1.1dB, 3.1dB and 3.8dB respectively when compared with the original DCT SC-FDMA system without PAPR reduction. Key-Words: OFDMA, PAPR, SC-FDMA, DCT, Companding, BER.