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A Novel Bidirectional Multiband OFDM based RoF Architecture for Simultaneous Transmission of Downlink and Uplink Signals over a Single Fiber with Mitigation of Nonlinear Effects

A bidirectional radio over fiber (RoF) system for multi-band signal generation and transmission is proposed. Simultaneous bidirectional transmission of 5Gbps orthogonal frequency division multiplexing (OFDM) based multi-band 16-QAM downlink signal and 5Gbps OFDM based 4-QAM uplink signal over a single fiber is demonstrated. The simultaneous copropagation over a single fiber reduces the infrastructure requirement by 50%, which also reduces the installation and maintenance cost. The multi-band signals for multi-serve applications are obtained at the user end by heterodyne beating of the downlink signal based on the requirement. The blank carrier for uplink transmission is extracted from the downlink signal with the tunable fiber Bragg grating (FBG) and modulated by the uplink signal. After 24km of bidirectional transmission, the error vector magnitude (EVM) has been estimated as 15.9% and 21.03% for downlink and uplink, respectively, below the FEC limit for transmission. The power penalty after transmission of 24km is 4.5dB and 2.3dB for downlink and uplink transmission, respectively.