Abstract
Orthogonal frequency division multiplexing (OFDM) passive optical network (PONs) implementing with double-side band intensity modulation and direct detection (IMDD) is considered as a cost-effective design. However, radio frequency (RF) power fading induced by chromatic dispersion causes non-uniform receiving performance among users. Generally speaking, user who suffered from the most serious fading cannot reach the specific forward error correction (FEC) threshold. To solve above dilemma, most of researchers adaptively design signal level in optical line terminal (OLT) depending on different transmission distance. However, such adaptive approach hugely enhances the system complexity and hardware costs. Therefore, we employ multicarrier code division multiple access (MC-CDMA) technique to equalize users’ received performance via spreading subcarriers’ data with orthogonal code. After frequency spreading, all users would suffer from the same RF power fading response and thus have the same performance. In this thesis, we simulatively and experimentally proof that the proposed MC-CDMA PON could achieve a universal transmitter design for users ranging from back-to-back to 100 km. Meanwhile, we apply minimum mean square error (MMSE) equalizer, combining with multi-code interference (MCI) cancellation digital signal process (DSP) to further enhanced system performance in a long reach PON. Our experimental results reveal that even under about 20 dB RF power fading, the proposed scheme can still provide 21.7 dB power budget and only about 2 dB sensitivity deviation is observed.