Wide Dynamic Range Reception of TDM-Based DCO-OFDM Signals Using Optical Domain Power Equalization and Symmetrical Clipping Techniques

This paper proposes the burst-mode reception of dc-biased optical orthogonal frequency division multiplexing (DCO-OFDM) signals by introducing symmetrically clipped OFDM and an optical domain power equalizer (OD-PE) consisting of an optical amplifier with feed forward control. Both the clipping ratio optimization in suppressing the peak-to-average ratio of the OFDM signals and the output power equalization function of the OD-PE regardless of input power level reduce the impact of quantization errors in analogue-to-digital conversion (ADC) needed for digital signal processing (DSP)-based OFDM signal demodulation, which greatly improves the receiver´s dynamic range. Successful reception of 10-Gb/s time division multiplexing-based DCO-OFDM signals with wide dynamic range of 13.5 dB is experimentally demonstrated even for a 5-bit resolution ADC, which is typically used for real-time DSPs. Numerical calculations also support the measured results.