Morsy-Osman Mohamed, Zhuge Qunbi, Chen Lawrence R, Plant David V
Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7, Canada.
Opt Express. 2011 Dec 12;19(26):B329-36. doi: 10.1364/OE.19.00B329.
We propose the use of pilot-aided (PA) transmission, enabled by single-sideband-subcarrier modulation of both quadratures in the DSP-domain, in single-carrier systems to mitigate jointly laser phase noise and fiber nonlinearity. In addition to tolerance against laser phase noise, we show that the proposed scheme also improves the nonlinear tolerance of both polarization-division-multiplexed (PDM) QPSK and 16-QAM coherent transmission systems by increasing the maximum allowable launch power by 1 dB and 1.5 dB, respectively. The improved nonlinear performance of both systems also manifests itself as an increase in the maximum reach by 720 km and 480 km, respectively. Finally, when digital-to-analog converters (DACs) with lower bit resolutions are used at the transmitter, PA transmission is shown to preserve the same performance improvement over the non-PA case.
我们提议在单载波系统中使用导频辅助（PA）传输，该传输通过在数字信号处理（DSP）域中对两个正交分量进行单边带副载波调制来实现，以共同减轻激光相位噪声和光纤非线性。除了对激光相位噪声具有耐受性外，我们还表明，所提出的方案通过分别将最大允许发射功率提高1 dB和1.5 dB，还提高了偏振分复用（PDM）QPSK和16-QAM相干传输系统的非线性耐受性。两个系统改善后的非线性性能还分别表现为最大传输距离增加了720 km和480 km。最后，当在发射机处使用具有较低比特分辨率的数模转换器（DAC）时，PA传输在性能提升方面相对于非PA情况保持相同的优势。
