面向移动前传的大容量光接入网技术

Emerging Technologies of High Capacity Optical Access Network for Mobile Fronthaul

针对未来移动接入网大容量低成本的前传传输需求,提出并研究了可用于承载移动业务的高速无源光网络(PON)的新型数字均衡技术和新型调制编码方式,设计了针对光纤承载的增强型通用公共无线接口(eCPRI)的数据压缩方案。其中,基于强度分类的均衡器能够高能效地消除传输系统非线性;调制编码方案利用无线信号量化数据的权重差异,在光接口处采用非均匀4电平脉冲幅度调制(PAM4)信号及比特交织映射,提升传输鲁棒性;eCPRI上行压缩方案通过根据前传链路负载自适应调整接口的量化精度,降低前传接口量化精度,进而提升传输效率。

To meet the requirement of the high-capacity and low-cost fronthaul transmission for the future radio access network,a novel digital equalization technology and a new modulation coding scheme for the fronthaul-carrying passive optical network(PON)are proposed,and a data compression scheme for the fiber-based enhanced common public radio interface(eCPRI)is designed.The proposed intensity-directed feed forward equalizer can effectively remove the system nonlinearity at low computational cost.For the CPRI compression,given the significance diversity of quantized bits,the uneven 4-level pulse amplitude modulation(PAM4)is adopted to reinforce the transmission robustness.As for the uplink eCPRI,the load-adaptive flexible quantization scheme is proposed to reduce quantization resolution,thereby enhancing the transmission efficiency of eCPRI.