Ni Zhuqing, Fu Songnian, Li Haibo, Yang Zheng, Xie Chenhui, Li Xiang, Deng Lei, Tang Ming, Cheng Jingchi, Liu Deming
Opt Express. 2018 Aug 20;26(17):21585-21593. doi: 10.1364/OE.26.021585.
A code reservation technique is proposed to reduce the peak-to-average power ratio (PAPR) of digital code-division multiplexing (CDM) based channel aggregation for mobile fronthaul. We numerically investigate the relationship between the PAPR and the number of aggregated channels during the CDM based channel aggregation, and experimentally verify the transmission performance with the code reservation technique. The PAPR of aggregated signal, which is composed of 48x20MHz Long Term Evolution (LTE) signal mapped with 64 quadrature amplitude modulation (QAM), is reduced with the help of code reservation technique. The PAPR reduction enables larger optical modulation index (OMI) per channel at the linear operation region of a directly modulated laser (DML), leading to the optical signal-to-noise ratio (OSNR) improvement. After the transmission over 10km standard single mode fiber (SSMF), the receiver sensitivity can be improved by 4dB owing to the PAPR reduction.
