In an intensity-modulation direct-detection (IMDD) orthogonal frequency division multiplexing (OFDM) signal format, radio frequency (RF) power fading produces non-uniform receiving performance among the subcarriers due to chromatic dispersion. Hence each subscriber experiences distinct quality of service (QoS) in conventional frequency division multiple access (FDMA). In this paper, a multicarrier code division multiple access (MC-CDMA) signal along with multicode interference (MCI) cancellation process is proposed and experimentally demonstrated to enhance the receiving performance in an IMDD long reach passive optical network (LR-PON). With the proposed scheme, the receiving performance of each subcarrier can be equalized so that a universal transmitter design at central office (CO) can support all the subscribers with their locations ranging from back-to-back to 100 km. Our experimental results also reveal that, even under 20 dB RF power fading, the proposed scheme can still provide over 21.7 dB power budget and only approximately 2 dB sensitivity deviation is observed in an IMDD LR-PON system.

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