Low-PAPR Layered/Enhanced ACO-SCFDM for Optical-Wireless Communications

In this letter, we propose layered/enhanced asymmetrically clipped optical single-carrier frequency-division multiplexing (L/E-ACO-SCFDM) for optical-wireless communications. L/E-ACO-SCFDM has a lower computational complexity and peak-to-average power ratio (PAPR) than L/E-ACO orthogonal frequency-division multiplexing (L/E-ACO-OFDM). The computational complexity of the simplified transmitter in L/E-ACO-SCFDM with <inline-formula> <tex-math notation="LaTeX">$R$ </tex-math></inline-formula> layers is <inline-formula> <tex-math notation="LaTeX">$(2-2/2^{R})O(N)$ </tex-math></inline-formula>, which is lower than the computational complexity of <inline-formula> <tex-math notation="LaTeX">$(2-2/2^{R})O(N\text {log}_{2}N)$ </tex-math></inline-formula> in L/E-ACO-OFDM. At a complementary cumulative distribution function of <inline-formula> <tex-math notation="LaTeX">$10^{-3}$ </tex-math></inline-formula>, the PAPR of L/E-ACO-SCFDM is approximately 4.2, 3.4, and 2.7 dB lower than that of L/E-ACO-OFDM for 2, 3, and 4 layers, respectively. The simulation results indicate that L/E-ACO-SCFDM has better performance than L/E-ACO-OFDM under the transmitter nonlinearity and multipath fading.