Experimental Demonstration and Performance Enhancement of 5G NR Multiband Radio over Fiber System Using Optimized Digital Predistortion

Applied Sciences

Jian Song¹  Mohsin Raza²  Muhammad Awais²  Muhammad Ikram Ashraf³  Muhammad Usman Hadi⁴ 

[1] Department of Electronic Systems, Aalborg University, 9220 Aalborg, Denmark;Faculty of Computer Engineering, Edge Hill University, Ormskirk L39 4QP, UK;Nokia Bell Labs, FI-02610 Espoo, Finland;School of Engineering, Ulster University, Newtownabbey BT37 0QB, UK;

关键词: digital predistortion;    magnitude selective affine;    radio over fiber;    neural network;    error vector magnitude;    adjacent channel power ratio;   

DOI  :  10.3390/app112411624

来源: DOAJ

【 摘 要 】

This paper presents an experimental realization of multiband 5G new radio (NR) optical front haul (OFH) based radio over fiber (RoF) system using digital predistortion (DPD). A novel magnitude-selective affine (MSA) based DPD method is proposed for the complexity reduction and performance enhancement of RoF link followed by its comparison with the canonical piece wise linearization (CPWL), decomposed vector rotation method (DVR) and generalized memory polynomial (GMP) methods. Similarly, a detailed study is shown followed by the implementation proposal of novel neural network (NN) for DPD followed by its comparison with MSA, CPWL, DVR and GMP methods. In the experimental testbed, 5G NR standard at 20 GHz with 50 MHz bandwidth and flexible-waveform signal at 3 GHz with 20 MHz bandwidth is used to cover enhanced mobile broad band and small cells scenarios. A dual drive Mach Zehnder Modulator having two distinct radio frequency signals modulates a 1310 nm optical carrier using distributed feedback laser for 22 km of standard single mode fiber. The experimental results are presented in terms of adjacent channel power ratio (ACPR), error vector magnitude (EVM), number of estimated coefficients and multiplications. The study aims to identify those novel methods such as MSA DPD are a good candidate to deploy in real time scenarios for DPD in comparison to NN based DPD which have a slightly better performance as compared to the proposed MSA method but has a higher complexity levels. Both, proposed methods, MSA and NN are meeting the 3GPP Release 17 requirements.

【 授权许可】

Unknown