A Novel Scheme of Polar-Coded SCMA OFDM Analogue Radio-over-Fiber for C-RAN Optical Fronthaul

A novel scheme of joint polar-code (PC) and sparse-code-multiple access (SCMA) over analogue radio-over-fiber (ROF) system is proposed. Some digital signal processing algorithms are designed to improve the tolerance of fiber chromatic dispersion (CD) and nonlinearity. The SCMA with non-ortho-overlapped code words provides better spectral efficiency for more users. A least square (LS) algorithm based on training sequence is designed to reduce the dispersion of optical fiber during long distance optical fiber transmission. In addition, the performance of various PC structures in the downlink is compared. Simulation results show that the proposed PC-SCMA analogue ROF system is feasible. The spectrum efficiency (SE) of the system with a 100km single fiber has been achieved 2.4bps/Hz with quadrature phase-shift keying (QPSK) signal in a single channel.