An optical 32QAM-OFDM-PON system with different numbers of sub-carriers using discrete multitone (DMT) modulation and demodulation is designed and demonstrated by experiment. Electron-optic generation, directly photoelectric detection, and electrical self-mixing reception of 32QAM-OFDM downstream signals are achieved. 5Gb/s 32QAM-OFDM downlink signals with different numbers of sub-carriers are successfully transmitted over 42 km SMF-28. Peak-to average power ratio (PAPR) characteristic, computational complexity and bit error rate (BER) performance are analyzed. The results show that the sub-carriers numbers of 32QAM-OFDM downlink signals should be carefully selected according to the actual requirements, if spectral efficiency, PAPR characteristic, computational complexity and receiver sensitivity are considered.

中文翻译：

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DMT调制的不同子载波数的光32QAM-OFDM-PON光接入方案研究

通过实验设计和演示了采用离散多音（DMT）调制和解调技术的具有不同数量子载波的32QAM-OFDM-PON光系统。实现了32QAM-OFDM下行信号的电光生成，直接光电检测和电自混合接收。具有不同子载波数量的5Gb / s 32QAM-OFDM下行链路信号已通过42 km SMF-28成功传输。分析了峰均功率比（PAPR）特性，计算复杂性和误码率（BER）性能。结果表明，在考虑频谱效率，PAPR特性，计算复杂度和接收机灵敏度的前提下，应根据实际需求精心选择32QAM-OFDM下行信号的子载波数量。