Effect of channel impairments on the performance of burst-mode receivers in gigabit PON

We experimentally study the effect of channel impairments on the performance of a burst-mode receiver (BMRx) in a 622 Mb/s 20-km Gigabit-capable passive optical network (GPON) uplink. Specifically, we study the impact of mode-partition noise in the GPON uplink in terms of the bit-error rate (BER) and the packet loss ratio (PLR) performance of the system. Our receiver features automatic phase acquisition using a clock phase aligner (CPA), and forward-error correction using (255, 239) Reed-Solomon codes. The BMRx provides instantaneous (0 preamble bit) phase acquisition and a PLR < 10^-6 for any phase step (plusmn2pi rads) between consecutive packets. The receiver also accomplishes a 3 dB coding gain at a BER = 10^-10. The CPA makes use of a phase picking algorithm and an oversampling clock and data recovery circuit operated at twice the bit rate.