Abstract—In this paper, a bidirectional Dense Wavelength Division Multiplexing Radio-over Fibre (DWDM-RoF) transmission system has been designed. In this system, four Orthogonal Frequency Division Multiplexing (OFDM) signals have been modulated using 16-Quadrature Amplitude Modulation (16-QAM) scheme with 20 Gbps and transmitted over a Standard Single Mode Fiber (SSMF). For upstream transmission, an optical band pass filter has been used at the Base Station (BS) side to reuse the same transmitted wavelength for the upstream transmission after being externally modulated with 20 Gbps On-Off Keying (OOK) baseband signal. The dispersion effect has been investigated and counteracted by employing a Dispersion Compensation Fiber (DCF). Simulation results showed an approximately negligible power penalty between Back to Back (B2B) and 120 km transmission. System Performance has been evaluated by measuring Symbol Error Rate (SER) and constellation diagram. Finally, the upstream signal performance has been evaluated by measuring its Bit Error Rate (BER) and eye diagram. As a result, error-free transmissions of 20 Gbps for both upstream and downstream signals over 30 km and up to 120 km (SMF-DCF) are demonstrated to verify the suitability of the proposed scheme in RoF systems.

Index Terms—DWDM, Radio-over-Fiber, dispersion compensation fiber, OFDM, dispersion power penalty


Cite: AbdulNasser A. Abbood and Hamed S. Al-Raweshidy  " Bidirectional DWDM-RoF System Employing 16QAM-OFDM Downstream Signal and Optical Carrier Reuse for Upstream Transmission," Journal of Communications, vol. 13, no. 5, pp. 247-252, 2018. Doi: 10.12720/jcm.13.5.247-252.