FE-OCDMA applied to C-RAN fronthaul in future mobile networks

An optical access link, based on Frequency Encoding Orthogonal Code Division Multiple Access (FE-OCDMA) for mitigation of Rayleigh backscattering crosstalk, is presented and analyzed. The proposed system supports up to 7 users, all sharing the same optical wavelength through a bidirectional fiber, allowing for full-duplex transmission. Results show that FE-OCDMA coding shows higher resilience to optical crosstalk compared to uncoded NRZ-OOK, allowing a data rate per user of 1 Gbps with BER lower than $10^{-3}$ at 7 dB signal-to-crosstalk ratio.