The feasibility of a time-domain technique, proposed for uplink synchronization of the bandwidth scalable orthogonal frequency division multiple access passive optical network (BS-OFDMA PON), is experimentally demonstrated. The results show that a delay variation of less than 50% of the cyclic prefix is tolerable, relaxing the thin time synchronization required in the uplink of the evaluated architecture. Moreover, we enhance the spectral efficiency of the BS-OFDMA PON by reducing the guard band (${B_g}$B g ) between the optical carrier and the signal bandwidth, as well as by eliminating the frequency gap (${\Delta_{{f_G}}}$Δ f G ) between the optical network units. The downlink results demonstrate that ${\Delta_{{f_G}}}$Δ f G can be eliminated with negligible performance penalties, and B g can be reduced to almost half the signal bandwidth. Error-free transmissions were achieved after uplink propagation over 45 km of single-mode fibers with received power of ≈−16.8dBm and ${B_g}$B g =450MHz, with a signal bandwidth of 1 GHz.

中文翻译：

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基于频谱高效OFDMA的PON的时域上行链路同步方法

实验证明了为带宽可伸缩正交频分多址无源光网络 (BS-OFDMA PON) 的上行链路同步提出的时域技术的可行性。结果表明，小于循环前缀 50% 的延迟变化是可以容忍的，放松了评估架构的上行链路所需的细时间同步。此外，我们通过减少保护带（${B_g}$B G ) 光载波和信号带宽之间，以及通过消除频率间隙 (${\Delta _ {{f_G}}} $ Δ F G) 之间的光网络单元。下行结果表明${\Delta _ {{f_G}}} $Δ F G 可以通过可以忽略不计的性能损失来消除，并且 B. G可以减少到几乎一半的信号带宽。在单模光纤上行链路传播超过 45 公里后实现了无差错传输，接收功率为 ≈ − 16.8dBm 和 ${B_g} $B G = 450MHz，信号带宽为 1GHz。