Open AccessImproving performance of mobile fronthaul architecture employing high order delta-sigma modulator with PAM-4 format
Author(s) -
Haibo Li,
Rong Hu,
Qi Yang,
Ming Luo,
Zhixue He,
Peng Jiang,
Yongpiao Liu,
Xiang Li,
Shaohua Yu
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.000001
Subject(s) - delta sigma modulation , electronic engineering , quantization (signal processing) , modulation (music) , computer science , carrier to noise ratio , delta modulation , transmission (telecommunications) , noise shaping , sigma , bit error rate , channel (broadcasting) , bandwidth (computing) , physics , engineering , telecommunications , pulse amplitude modulation , algorithm , quantum mechanics , detector , acoustics , pulse (music)
An improved high-order delta-sigma modulator with multi-level quantizer is proposed to enable carrier aggregation of 4G-LTE signals in mobile fronthaul. Different from conventional delta-sigma modulation-based digital mobile fronthaul, a 2-bit quantizer is employed to reduce the quantization noise, which enabling the transmission via PAM-4 based IM-DD channel. Moreover, we employ the 4th-order high-pass filter (HPF) to replace the 1st-order HPF in the conventional delta-sigma modulator, resulting in a much better noise shaping performance. In the experiment, a PAM-4 based mobile fronthaul transmission of 32 aggregated 4G-LTE signals with a CPRI equivalent data rate of 39.32-Gb/s is demonstrated in a single-λ 10-Gb/s IM-DD channel. Significant improvement of 68% is achieved in the average EVM performance compared to the previous delta-sigma modulation-based digital mobile fronthaul.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom