Design and performance analysis of bidirectional TWDM-PON employing QAM-OFDM for downstream and re-modulation for upstream

The work in this paper carried using Optisystem v. 13 demonstrates TWDM- OFDM- PON with re-modulation scheme at the user side. OFDM modulation is used for four channels for downstream at 25 Gbps and re-modulation is done for 10 Gbps NRZ upstream channels using an Electroabsorption modulator (EAM).Utilization of wavelength reuse scheme with NRZ modulation to carry upstream traffic helps in reducing the cost of ONU. Performance analysis in terms of BER, received power and constellation diagram optimized the largest reach for 60 km corresponding to the reference BER of 10−12.